Professor Patrick Regan
Professor of Radionuclide Metrology
DPhil FInstP
Biography
Paddy Regan joined the academic staff in the Physics Department at Surrey in 1994 after holding postdoctoral research positions in experimental nuclear structure physics at the University of Pennsylvania, USA and the Australian National University in Canberra. He was subsequently promoted to Senior Lecturer (2002), Reader (2005) and a Personal Chair in Experimental Nuclear Physics (2009).
Since 2013, he has held the NPL-Surrey Chair in Radionuclide Metrology and is part-based within the Nuclear Metrology Group at the National Physical Laboratory (NPL) in Teddington where he is the Science Area Leader.
He has co-authored over 300 peer-reviewed scientific papers on nuclear physics and radiation detection/instrumentation research and given more than 100 invited international conference and workshop presentations on his research.
Paddy was elected a Fellow of the Institute of Physics in 2000. From 2002-2013, he held Visiting Research positions in Experimental Nuclear Physics at the Wright Nuclear Structure Laboratory, Yale University and was also an Adjunct Professor in Physics at the University of Notre Dame (Indiana, USA) on their UK-London Programme providing pre-medical physics courses to their London-based students.
From 2001 until 2010, he was the Collaboration Spokesperson for the Stopped RISING Collaboration (https://doi.org/10.1016/j.nimb.2007.04.219 ). As part of this role, he led experimental studies on the internal structure of exotic forms of atomic nuclei using both metastable state spectroscopy for studies of the heaviest odd-odd N=Z nuclear systems ( https://doi.org/10.1016/j.physletb.2008.01.017 ) and beta-decay delayed, time correlated gamma-ray spectroscopy for nuclear shape evolution studies in the heaviest Osmium ( https://doi.org/10.1103/PhysRevC.85.034301 ) and Tungsten isotopes (https://doi.org/10.1103/PhysRevC.80.064308 ).
He was the Chair of the PreSPEC International Steering Committee, which oversaw the experimental programme for nuclear structure physics at GSI/FAIR and was an elected member of the NuSTAR Board for the FAIR project in Darmstadt, Germany (2008-2012); Chair of the GSI Users Executive Committee (2009) and the EURISOL User Executive Committee (2012-15). He was a member of the International Scientific Advisory Committee for the Radioactive Isotope Science Project in Daejeon, South Korea and also currently serves on the Programme Advisory Committee for the Institute of Nuclear Physics Laboratory, in Orsay, Paris, France (from 2013-present). He currently serves on the Science and Technology Facilities Council (STFC) Science Board as a non-core member (from 2016-present).
He has served a member of the UK Science and Technologies Facilities Council Education, Training and Careers Committee (2007-2011); Chaired of the South African National Research Foundation Review Committee on Nuclear Physics (2015); and Chaired the Portuguese Research Foundations Committee on Physical and Natural Sciences (2013 and 2016).
He has successfully supervised more than 40 doctoral research students in thesis topics in a range of pure and applied topics, including fundamental nuclear structure physics of the decays of exotic nuclei with equal proton and neutron numbers (https://doi.org/10.1016/S0370-2693(98)00994-0 ; https://doi.org/10.1103/PhysRevLett.81.3337 ; https://doi.org/10.1016/j.physletb.2008.01.017 ); signatures of evolution from vibrational to rotational collective modes in 'transitional nuclei' as a function of increasing angular momentum ( https://doi.org/10.1103/PhysRevLett.90.152502 ; https://doi.org/10.1103/PhysRevC.68.044313 ); the measurement and application of electromagnetic transition rates between nuclear excited states to probe single-particle/collective mode competition and the nature of nuclear deformation( https://doi.org/10.1103/PhysRevC.76.064302 ; https://doi.org/10.1103/PhysRevC.87.014323 ); the origin of high angular momentum states in odd-odd nuclei with limited valence space ( https://doi.org/10.1103/PhysRevC.87.044337 ); nuclear shape evolution ( https://doi.org/10.1103/PhysRevC.95.024328 ); Total absorption decay spectrometry and links to nuclear fission waste decay data ( https://doi.org/10.1103/PhysRevC.96.014320 ); radiation detection system design, modelling and commissioning (https://doi.org/10.1016/j.apradiso.2011.12.023 ; https://doi.org/10.1016/j.radphyschem.2017.02.007 ); radiation dosimetry and radiobiological effects (https://doi.org/10.1016/j.radphyschem.2016.02.030 ); environmental radioactivity measurements ( https://doi.org/10.1016/j.apradiso.2012.04.017); and the provision of radiological and radiopharmaceutical standards and reference materials for environmental source measurements (https://doi.org/10.1016/j.apradiso.2017.02.007 ).
He has also supervised more than 120 MSc research dissertation projects in nuclear and radiation physics.
Paddy was external examiner for MSc and Post-graduate courses at the Universities of Liverpool (2008-2013) and Manchester (2012-2016) and is currently external examiner for the MSc/PgDip course in Nuclear Decommissioning and Waste Management at the University of Birmingham (from 2017-). He has acted as external PhD examiner for 38 doctoral theses, including for universities in Spain (University of Santiago De Compostela); France (Universities of Paris Sud and Bordeaux); Finland (Jyvaskyla); Sweden (U. Stockholm); South Africa (U. of Cape Town); USA (Yale University); and Germany (University of Cologne); Italy (University of Padova); Canada (Simon Fraser University); and India (Andhra University).
Paddy has been regularly engaged by the TV, radio and written press media on issues related to radiation and nuclear physics. In this capacity he has made over 100 mainstream TV and radio appearances on issues related to radiation physics (see e.g., http://www.bbc.com/news/av/world-asia-pacific-12744973/japan-earthquake-nuclear-physicist-on-radiation-risk ). He has also served as a court-appointed expert witness on the effects of ionising radiation giving evidence on the nature and effects of ionizing radiation from British Nuclear Weapons tests in the 1950 and 1960s (see https://www.judiciary.gov.uk/wp-content/uploads/JCO/Documents/Judgments/ionising-radiation-appeals-20130507+.pdf ).
In his spare time Paddy plays a poor of game golf off an honest 16 handicap and likes to walk Luna, the family dog.
University roles and responsibilities
- BSc and MPhys Physics with Nuclear Astrophysics Course Coordinator
- Module Coordinator for Fundamentals of Physics
- Module Coordinator for Radionuclide Metrology
- Module Coordinator for Nuclear Reactor and Health Physics
Previous roles
2005 - 2015
MPhys Research Year Director with responsibility for MPhys research year placements and research dissertations (typically 15-20 placements per year).
2002 - 2015
Course Director for the MSc Radiation and Environmental Protection.
News
Research
Research interests
Paddy specialises in using gamma-ray and charged-particle spectroscopic techniques to study exotic forms of nuclear matter, with particular emphasis on unusual proton to neutron ratios; the behaviour of nuclei at large angular momentum and the determination of gamma ray transition strengths which can be used to test the best current models of the internal structure of the atomic nucleus.
This includes work at large scale international accelerator facilities such as GSI-FAIR (Germany) and RIBF-RIKEN (Japan) using secondary radioactive ion-beams produced following high-energy projectile fragmentation and projectile fission reactions to study decays of very exotic nuclear species. These studies focus on understanding the formation of heavy elements in explosive astrophysical scenarios (see e.g., https://doi.org/10.1103/PhysRevLett.118.072701 ) and the underlying reasons why some atomic nuclei have non-spherical, prolate deformed shape configurations (see e.g., https://doi.org/10.1016/j.physletb.2016.09.058 ; https://doi.org/10.1103/PhysRevLett.113.262502).
His expertise is in the design and operation of multi-detection gamma-ray detection spectrometers using both semiconductor (Germanium and Silicon) based and halide-scintillator (specifically Lanthanum-Tribromide) based materials (see https://doi.org/10.1016/j.nima.2014.02.037 ). Such spectrometers allow precision measurements of nuclear structure and their characteristic decay properties using gamma-ray coincidence techniques, with their associated digital counting systems routinely able to detect coincident events occurring with less than 1 billionth of a second (i.e. 1 nanosecond) time difference (see e.g., https://doi.org/10.1103/PhysRevC.91.027302 ; https://doi.org/10.1103/PhysRevC.87.014323 ). This work has additional potential applications in both medical (radiopharmaceutical) and long-term civilian nuclear waste management quantitative imaging.
Paddy's research has also overlaps into measurements of naturally occurring radioactive materials (NORM) in environmental samples using applications of the gamma-ray spectroscopic techniques he uses in his more fundamental research projects, including providing radiological maps of the states of Qatar (https://doi.org/10.1016/j.nima.2009.11.029 ), Kuwait (https://doi.org/10.1016/j.radphyschem.2015.01.041) and coastal regions of Thailand ( https://doi.org/10.1016/j.apradiso.2012.04.017 ; https://doi.org/10.1016/j.jenvrad.2014.07.017 ).
His NPL role includes overseeing the development of novel metrological techniques and instrumentation (https://doi.org/10.1016/j.radphyschem.2017.02.007 ) together with precision measurement of the underpinning nuclear decay data from which primary radiological standards can be produced (https://doi.org/10.1016/j.apradiso.2017.07.056 ). This includes studies related to radiopharmaceuticals and members of the naturally occurring radioactive decay chains (see e.g., https://doi.org/10.1016/j.apradiso.2015.04.008 ; https://doi.org/10.1016/j.apradiso.2015.02.003 ).
Research collaborations
Paddy has led experimental nuclear physics experiments at laboratories in the UK, Denmark, Australia, Canada, South Africa, France, Germany, Italy, Romania, Japan and the USA. He has been the spokesperson for a number of international programmes to produce and study the internal structure of new, radioactive isotopes, including investigations into the variation of nuclear shapes and internal structural competitions as a function of increasing angular momentum or 'spin'.
He is a current co-spokesperson for experiments of the HiSPEC/DESPEC part of the NuSTAR collaboration at the GSI/FAIR facility in Darmstadt and was also co-spokesperson for the NuBALL gamma-ray collaboration based at IPN-Orsay, Paris.
My teaching
Paddy currently teaches on the following courses within the Physics Department
1) 1st year Fundamentals of Physics (PHY1033) ; (2) MSc Radiation Physics (PHMY032);
(3) MSc Reactor and Health Physics (PHYM063); and (4) MSc Radionuclide Metrology (PHYM058)
In his time at Surrey, Paddy has also taught a wide range of undergraduate and postgraduate courses including:
(1) 1st year Atoms, Molecules and Quanta (1AMQ); (2) 1st year Introduction to Astronomy and Space Science 1IASS; (3) 2nd year Galaxies and Large Scale Structures (2GLSS); (5) 2nd year general laboratories; (2LAB) (6) 2nd year specialist nuclear astrophysics laboratories (2NALAB); (7) 2nd year Radiation Detection and Measurement (2RDM); (7) 2nd year Introduction to Astrophysics (2IA) (8) Honours year Nuclear Astrophysics (3NA); (9) PhD Nuclear Experimental Techniques (4NET); (10) MSc Radiation Laboratories; (11) MSc Nuclear Reactor Physics; (12) MSc Environmental Radioactivity; (13) MSc Radiation Dosimetry.
My publications
Publications
J Wu, S Nishimura, G Lorusso, P Moller, E Ideguchi, Patrick Regan, GS Simpson, P-A Soderstrom, Philip Walker, H Watanabe, ZY Xu, H Baba, F Browne, R Daido, P Doornenbal, YF Fang, G Gey, T Isobe, PS Lee, JJ Liu, Z Li, Z Korkulu, Z Patel, V Phong, S Rice, H Sakurai, L Sinclair, T Sumikama, M Tanaka, A Yagi, YL Ye, R Yokoyama, GX Zhang, T Alharbi, N Aoi, FL Bello Garrote, G Benzoni, AM Bruce, RJ Carroll, KY Chae, Z Dombradi, A Estrade, A Gottardo, CJ Griffin, H Kanaoka, I Kojouharov, FG Kondev, S Kubono, N Kurz, I Kuti, S Lalkovski, GJ Lane, EJ Lee, T Lokotko, Gavin Lotay, C-B Moon, H Nishibata, I Nishizuka, CR Nita, A Odahara, Zsolt Podolyak, OJ Roberts, H Schaffner, Callum Shand, J Taprogge, S Terashima, Z Vajta, S Yoshida (2017)94 -Decay Half-lives of Neutron-Rich 55Cs to 67Ho: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation, In: Physical Review Letters118(7)072701 American Physical Society
The -decay half-lives of 94 neutron-rich nuclei 144−151Cs, 146−154Ba, 148−156La, 150−158Ce, 153−160Pr, 156−162Nd, 159−163Pm, 160−166Sm, 161−168Eu, 165−170Gd, 166−172Tb, 169−173Dy, 172−175Ho and two isomeric states 174mEr, 172mDy were measured at Radioactive Isotope Beam Factory (RIBF), providing a new experimental basis to test theoretical models. Striking, large drops of -decay half-lives are observed at neutron-number N = 97 for 58Ce, 59Pr, 60Nd, 62Sm, and N = 105 for 63Eu, 64Gd, 65Tb, 66Dy. Features in the data mirror the interplay between pairing effects and microscopic structure. r-Process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.
RHIANN CANAVAN, M. Rudigier, PATRICK HENRY REGAN, D. Thisse, M. Lebois, J N Wilson, N. Jovancevic, P.-A. Söderström, SEAN MICHAEL COLLINS, Jaime Benito García, S. Bottoni, MATTHEW HENRY BRUNET, N. Cieplicka-Orynczak, S. Courtin, DANIEL THOMAS DOHERTY, Luis Mario Fraile Prieto, K. Hadynska-Klek, G. Hafner, M. Heine, V. Karayonchev, Ł.W. Iskra, ADAM RUSSELL KENNINGTON, P. Koseoglou, GAVIN JAMES LOTAY, G Lorusso, M Nakhostin, C.R. Nita, S. Oberstedt, ZSOLT PODOLYAK, L Qi, J.-M. Régis, V. Sánchez-Tembleque, R Shearman, María Victoria Vedia Fernández, W. Witt (2020)Half-life measurements in Dy-164,Dy-166 using γ−γ fast-timing spectroscopy with the ν-Ball spectrometer, In: Physical Review. C101(2) American Physical Society
We report on the measurement of lifetimes of excited states in the near-mid-shell nuclei Dy-164,Dy-166 using the gamma-ray coincidence fast-timing method. The nuclei of interest were populated using reactions between an O-18 beam and a gold-backed isotopically enriched Dy-164 target of thickness 6.3 mg/cm(2) at primary beam energies of 71, 76, and 80 MeV from the IPN-Orsay laboratory, France. Excited states were populated in Dy-164, Dy-166, and W-178,W-179 following Coulomb excitation, inelastic nuclear scattering, two-neutron transfer, and fusion-evaporation reaction channels respectively. Gamma rays from excited states were measured using the nu-Ball high-purity germanium (HPGe)-LaBr3 hybrid gamma-ray spectrometer with the excited state lifetimes extracted using the fast-timing coincidence method using HPGe-gated LaBr3-LaBr3 triple coincident events. The lifetime of the first I-pi = 2(+) excited state in Dy-166 was used to determine the transition quadrupole deformation of this neutron-rich nucleus for the first time. The experimental methodology was validated by showing consistency with previously determined excited state lifetimes in Dy-164. The half-lives of the yrast 2(+) states in Dy-164 and Dy-166 were 2.35(6) and 2.3(2) ns, respectively, corresponding to transition quadrupole moment values of Q(0) = 7.58(9) and 7.5(4) eb, respectively. The lifetime of the yrast 2(+) state in Dy-166 is consistent with a quenching of nuclear quadrupole deformation at beta approximate to 0.35 as the N = 104 mid-shell is approached.
M. Rudigier, P. M. Walker, R.L. Canavan, Zs. Podolyak, P. H. Regan, P.-A. Söderström, M. Lebois, J.N. Wilson, N. Jovancevic, A. Blazhev, J. Benito, S. Bottoni, M. Brunet, N. Cieplicka-Orynczak, S. Courtin, D. T. Doherty, L.M. Fraile, K. Hadynska-Klek, M. Heine, Ł.W. Iskra, J. Jolie, V. Karayonchev, A. R. Kennington, P. Koseoglou, G. Lotay, G. Lorusso, M. Nakhostin, C.R. Nita, S. Oberstedt, L. Qi, J.-M. Régis, V. Sánchez-Tembleque, R. Shearman, W. Witt, V. Vedia, K.O. Zell (2020)Multi-quasiparticle sub-nanosecond isomers in 178W, In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics801135140 Elsevier
We report on the first measurement of the half-lives of and four-quasiparticle states in the even-even nucleus 178W. The sub-nanosecond half-lives were measured by applying the centroid shift method to data taken with LaBr3(Ce) scintillator detectors of the NuBall array at the ALTO facility in Orsay, France. The half-lives of these states only became experimentally accessible by the combination of several experimental techniques - scintillator fast timing, isomer spectroscopy with a pulsed beam, and the event-by-event calorimetry information provided by the NuBall array. The measured half-lives are and for the and states, respectively. The decay transitions include weakly hindered E1 and E2 branches directly to the ground-state band, bypassing the two-quasiparticle states. This is the first such observation for an E1 transition. The interpretation of the small hindrance hinges on mixing between the ground-state band and the t-band.
J. J Liu, J Lee, H Watanabe, S Nishimura, G. X Zhang, J Wu, P. M Walker, P. H Regan, P. -A Söderström, H Kanaoka, Z Korkulu, P. S Lee, A Yagi, A. C Dai, F. R Xu, D. S Ahn, T Alharbi, H Baba, F Browne, A. M Bruce, R. J Carroll, K. Y Chae, Zs Dombradi, P Doornenbal, A Estrade, N Fukuda, C Griffin, E Ideguchi, N Inabe, T Isobe, S Kanaya, I Kojouharov, F. G Kondev, T Kubo, S Kubono, N Kurz, I Kuti, S Lalkovski, G. J Lane, C. S Lee, E. J Lee, G Lorusso, G Lotay, C. -B Moon, I Nishizuka, C. R Nita, A Odahara, Z Patel, V. H Phong, Zs Podolyák, O. J Roberts, H Sakurai, H Schaffner, C. M Shand, Y Shimizu, T Sumikama, H Suzuki, H Takeda, S Terashima, Zs Vajta, J. J Valiente-Dobón, Z. Y Xu (2020)Isomeric and beta-decay spectroscopy of 173,174Ho, In: Physical Review. C, Nuclear Physics102(2) American Physical Society (APS)
β-decay spectroscopy of 173,174Ho (Z = 67, N = 106,107) was conducted at Radioactive Isotope Beam Factory at RIKEN by using in-flight fission of a 345-MeV/u 238U primary beam. A previously unreported isomeric state at 405 keV with half-life of 3.7(12) μs and a spin and parity of (3/2+) is identified in 173Ho. Moreover, a new state with a spin and parity of 9- was discovered in 174Er. The experimental log ft values of 5.84(20) and 5.25(18) suggest an allowed-hindered β decay from the ground state of 174Ho to the Kπ = 8- isomeric state in 174Er. Configuration-constrained potential energy surface (PES) calculations were performed and the predictions are in reasonable agreement with the experimental results.
P-A Söderström, Philip Walker, J Wu, HL Liu, Patrick Regan, H Watanabe, P Doornenbal, Z Korkulu, P Lee, JJ Liu, G Lorusso, S Nishimura, VH Phong, T Sumikama, FR Xu, S Lalkovski, Gavin Lotay, Z Patel, Zsolt Podolyak, Callum Shand (2016)K-mixing in the doubly mid-shell nuclide 170Dy and the role of vibrational degeneracy, In: Physics Letters B762pp. 404-408 Elsevier
A detailed study of the structure of the doubly mid-shell nucleus View the MathML source has been carried out, following isomeric and β decay. We have measured the yrast band up to the spin-parity Jπ=6+ state, the K=2γ -vibration band up to the 5+ state, a low-lying negative-parity band based on a 2− state that could be a candidate for the lowest energy octupole vibration state within this nucleus, and a candidate for the Kπ=6+ two quasi-particle isomer. This state was determined to have an excitation energy of 1643.91(23) keV and a half life of 0.99(4) μs, with a reduced hindrance for its decay to the ground-state band an order of magnitude lower than predicted by NpNn systematics. This is interpreted as being due to γ -vibrational mixing from a near degeneracy of the isomer and the 6+ state of the γ band. Furthermore, the parent nucleus 170Tb has been determined to have a half-life of View the MathML source s with a possible spin-parity of 2−.
G.X. Zhang, H. Watanabe, G.D. Dracoulis, F.G. Kondev, G.J. Lane, P.H. Regan, P.-A. Söderström, P.M. Walker, K. Yoshida, H. Kanaoka, Z. Korkulu, P.S. Lee, J.J. Liu, S. Nishimura, J. Wu, A. Yagi, D.S. Ahn, T. Alharbi, H. Baba, F. Browne, A.M. Bruce, M.P. Carpenter, R.J. Carroll, K.Y. Chae, C.J. Chiara, Zs. Dombradi, P. Doornenbal, A. Estrade, N. Fukuda, C. Griffin, E. Ideguchi, N. Inabe, T. Isobe, S. Kanaya, I. Kojouharov, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, T. Lauritsen, C.S. Lee, E.J. Lee, C.J. Lister, G. Lorusso, G. Lotay, E.A. McCutchan, C.-B. Moon, I. Nishizuka, C.R. Nita, A. Odahara, Z. Patel, V.H. Phong, Zs. Podolyak, O.J. Roberts, H. Sakurai, H. Schaffner, D. Seweryniak, C.M. Shand, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda, S. Terashima, Zs. Vajta, J.J. Valiente-Dóbon, Z.Y. Xu, S. Zhu (2019)Interplay of quasiparticle and vibrational excitations: First observation of isomeric states in ¹⁶⁸Dy and ¹⁶⁹Dy, In: Physics Letters B799135036pp. 1-7 Elsevier
The neutron-rich dysprosium isotopes ¹⁶⁸Dy₁₀₂ and ¹⁶⁹Dy₁₀₃ have been investigated using the EURICA γ-ray spectrometer, following production via in-flight fission of a high-intensity uranium beam in conjunction with isotope separation through the BigRIPS separator at RIBF in RIKEN Nishina Center. For ¹⁶⁸Dy, a previously unreported isomer with a half-life of 0.57(7) μs has been identified at an excitation energy of 1378 keV, and its presence affirmed independently using γ-γ-γ coincidence data taken with Gammasphere via two-proton transfer from an enriched ¹⁷⁰Er target performed at Argonne National Laboratory. This isomer is assigned Jπ = Kπ = (4⁻) based on the measured transition strengths, decay patterns, and the energy systematics for two-quasiparticle states in N = 102 isotones. The underlying mechanism of two-quasiparticle excitations in the doubly midshell region is discussed in comparison with the deformed QRPA and multi-quasiparticle calculations. In ¹⁶⁹Dy, the B(E2) value for the transition de-exciting the previously unreported Kπ = (1/2⁻) isomeric state at 166 keV to the Kπ = (5/2⁻) ground state is approximately two orders of magnitude larger than the E2 strength for the corresponding isomeric-decay transition in the N = 103 isotone ¹⁷³Yb, suggesting the presence of a significant γ-vibrational admixture with a dominant neutron one-quasiparticle component in the isomeric state.
E. R. Gamba, A. M. Bruce, S. Lalkovski, M. Rudigier, S. Bottoni, M. P. Carpenter, S. Zhu, J. T. Anderson, A. D. Ayangeakaa, T. A. Berry, I. Burrows, M. Carmona Gallardo, R. J. Carroll, P. Copp, D. M. Cullen, T. Daniel, G. Fernández Martínez, J. P. Greene, L. A. Gurgi, D. J. Hartley, R. Ilieva, S. Ilieva, F. G. Kondev, T. Kröll, G. J. Lane, T. Lauritsen, I. Lazarus, G. Lotay, C. R. Niţă, Zs. Podolyak, V. Pucknell, M. Reed, P. H. Regan, J. Rohrer, J. Sethi, D. Seweryniak, C. M. Shand, J. Simpson, M. Smoleń, E. A. Stefanova, V. Vedia, O. Yordanov (2019)Fast-timing measurements in the ground-state band of ¹¹⁴Pd, In: Physical Review C100(4)044309 American Physical Society
Using a hybrid Gammasphere array coupled to 25 LaBr3(Ce) detectors, the lifetimes of the first three levels of the yrast band in ¹¹⁴Pd populated via ²⁵²Cf decay, have been measured. The measured lifetimes are τ₂+=103(10)ps, τ₄+=22(13)ps, and τ₆+≤10ps for the 2⁺₁, 4⁺₁, and 6⁺₁ levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities B(E2;J→J−2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio RB(E₂)=B(E2;4⁺₁→2⁺₁)/B(E2;2⁺₁→0⁺₁)=0.80(42) is measured for the first time in ¹¹⁴Pd and compared with the known values RB(E₂) in the palladium isotopic chain: the systematics suggest that, for N=68, a transition from γ-unstable to a more rigid γ-deformed nuclear shape occurs.
T Sumikama, N Fukuda, N Inabe, D Kameda, T Kubo, Y Shimizu, H Suzuki, H Takeda, K Yoshida, H Baba, F Browne, A.M Bruce, R Carroll, N Chiga, R Daido, F Didierjean, P Doornenbal, Y Fang, G Gey, E Ideguchi, T Isobe, S Lalkovski, Z Li, G Lorusso, R Lozeva, H Nishibata, S Nishimura, I Nishizuka, A Odahara, Z Patel, Zs Podolyák, P.H Regan, S Rice, O.J Roberts, H Sakurai, G.S Simpson, L Sinclair, P.A Söderström, M Tanaka, J Taprogge, H Watanabe, V Werner, O Wieland, J Wu, Z.Y Xu, ZSOLT PODOLYAK, A Yagi (2021)Observation of new neutron-rich isotopes in the vicinity of $^{110}$Zr, In: PHYSICAL REVIEW C103(1)014614
Neutron-rich radioactive isotope (RI) beams in the vicinity of Zr110 were produced using the in-flight fission of a 345-MeV/nucleon U238 beam at the RIKEN Radioactive Isotope Beam Factory. The RI beams were separated in flight by the large-acceptance two-stage fragment separator BigRIPS. Isotopes were clearly identified in a low-background particle-identification plot, which was obtained from the measurements of time of flight, magnetic rigidity, and energy loss using beam-line detectors placed in the BigRIPS separator and the ZeroDegree spectrometer. Nine new isotopes, Br101, Kr102, Rb105,106, Sr108, Y110,111, Zr114, and Nb117, are reported for the first time, with their measured production cross sections compared with the extrapolations of lighter isotopes down to the femtobarn regime.
G. Fruet, S. Courtin, M. Heine, D. G. Jenkins, P. Adsley, A. Brown, R. Canavan, W. N. Catford, E. Charon, D. Curien, S. Della Negra, J. Duprat, F. Hammache, J. Lesrel, G. Lotay, A. Meyer, D. Montanari, L. Morris, M. Moukaddam, J. Nippert, Zs. Podolyak, P. H. Regan, I. Ribaud, M. Richer, M. Rudigier, R. Shearman, N. de Séréville, C. Stodel (2020)Advances in the Direct Study of Carbon Burning in Massive Stars, In: Physical Review Letters124192701 American Physical Society
The 12C + 12C fusion reaction plays a critical role in the evolution of massive stars and also strongly impacts various explosive astrophysical scenarios. The presence of resonances in this reaction at energies around and below the Coulomb barrier makes it impossible to carry out a simple extrapolation down to the Gamow window—the energy regime relevant to carbon burning in massive stars. The 12C + 12C system forms a unique laboratory for challenging the contemporary picture of deep sub-barrier fusion (possible sub-barrier hindrance) and its interplay with nuclear structure (sub-barrier resonances). Here, we show that direct measurements of the 12C + 12C fusion cross section may be made into the Gamow window using an advanced particle-gamma coincidence technique. The sensitivity of this technique effectively removes ambiguities in existing measurements made with gamma ray or charged-particle detection alone. The present cross-section data span over 8 orders of magnitude and support the fusion-hindrance model at deep sub-barrier energies.
R.-B Gerst, A Blazhev, N Warr, J Wilson, M Lebois, N Jovančević, D Thisse, R Canavan, Matthias Rudigier, D Étasse, E Adamska, P Adsley, A Algora, M Babo, K Belvedere, J Benito, G Benzoni, A Boso, S Bottoni, N Cieplicka-Oryńczak, M Bunce, R Chakma, S Courtin, M Cortés, P Davies, C Delafosse, M Fallot, B Fornal, L Fraile, D Gjestvang, A Gottardo, V Guadilla, G Häfner, K Hauschild, M Heine, C Henrich, I Homm, F Ibrahim, S Jazrawi, A Korgul, Ł Iskra, P Ivanov, P Koseoglou, T Kröll, T Kurtukian-Nieto, L Le Meur, S Leoni, J Ljungvall, A Lopez-Martens, R Lozeva, I Matea, K Miernik, J Nemer, S Oberstedt, W Paulsen, M Piersa, Y Popovitch, C Porzio, L Qi, D Ralet, P Regan, D Reygadas-Tello, K Rezynkina, V Sánchez-Tembleque, C Schmitt, P.-A Söderström, C Sürder, G Tocabens, V Vedia, D Verney, B Wasilewska, J Wiederhold, M Yavachova, F Zeiser, S Ziliani (2020)Prompt and delayed $\gamma$ spectroscopy of neutron-rich $^{94}$Kr and observation of a new isomer, In: Physical review. C, Nuclear physics102(6)064323 American Physical Society
Prompt and delayed γ-ray spectroscopy of the neutron-rich 94Kr was performed, as part of the fission campaign at the ALTO facility of the IPN Orsay, using the fast-neutron-induced fission reaction 238U(n,f) in combination with the ν-Ball array, a novel hybrid γ spectrometer for energy and lifetime measurements. Several new yrast and nonyrast transitions were observed for the first time, extending the previously known level scheme. Additionally, we report on the observation of a new short-lived isomer at 3444 keV with a half-life of 32(3) ns. The analysis of the Nilsson orbitals obtained from Gogny cranked Hartree-Fock-Bogoliubov calculations suggests a (9−) spin and an oblate deformation for this isomer corresponding to a two-quasineutron state, indicating an isomeric structure very similar to that of the neighboring isotones 96Sr and 92Se
R. R Trinder, Tz Kokalova, D. J Parker, C Wheldon, B Phoenix, P Ivanov, B Russel, BENJAMIN LUKE WEBSTER, PATRICK HENRY REGAN, A Robinson, D Cullen, S Pells, R Allen, S Pirrie, A Turner, P Santa Rita (2020)Theragnostics - Alternative production of terbium isotopes at the University of Birmingham using an MC40 cyclotron, In: Journal of Physics. Conference Series1643(1) IOP Publishing
In this work alternative methods for the production of terbium isotopes, and in particular 152Tb and 155Tb, have been investigated. These isotopes, which could be used for theragnostics, have been produced using an alpha and a proton beam incident on europium and gadolinium targets, respectively. The experimental results have been compared with the predicted cross-sections, calculated using TALYS and PACE4 code.
G. Hafner, R. Lozeva, A Blazhev, RHIANN CANAVAN, D. Etasse, J. Jolie, N. Jovancevic, R.-B. Gerst, Th Kröll, M. Lebois, PATRICK HENRY REGAN, M. Rudigier, D. Thisse, N Warr, J N Wilson (2020)Lifetime measurement around 132Sn with the ν-Ball array, In: Journal of Physics: Conference Series1643 IOP Publishing
Neutron-rich nuclei were studied after fast neutron-induced fission of 238U and 232Th at the ALTO facility in Orsay, France. The neutrons were produced with the LICORNE directional neutron source using a pulsed 7Li beam provided by the Tandem accelerator. The actinide targets were surrounded by the ν-Ball array to measure the de-excitation of fission fragments. The ν-Ball array is a hybrid spectrometer which consists of HPGe detectors (equipped with BGO shielding) and LaBr3(Ce) scintillation detectors allowing for high-resolution γ-ray spectroscopy and lifetime measurements in the ns/sub-ns range. This contribution presents preliminary results on 134Te and 137I populated in the 238U(n,f) reaction.
R Shearman, G Lorusso, A Boso, PATRICK HENRY REGAN, S Nishimura, Z Y Xu, A Jungclaus, Y Shimizu, G S Simpson, P-A Söderström, H Watanabe, F Browne, P Doornenbal, G Gey, H S Jung, B Meyer, T Sumikama, J Taprogge, Zs Vajta, J Wu, H Baba, G Benzoni, K Y Chae, F C L Crespi, N Fukuda, R Gernhäuser, N Inabe, T Isobe, T Kajino, D Kameda, G D Kim, STACY YEONCHI KIM, I Kajouharov, F G Kondev, T Kubo, N Kurz, Y K Kwon, G J Lane, ZHONG LI, A Montaner-Pizá, K Moschner, F Naqvi, M Niikura, H Nishibata, A Odahara, R Orlandi, Z Patel, Zsolt Podolyak, H Sakurai, H Schaffner, P Schury, S Shibagaki, K Steiger, H Suzuki, H Takeda, A Wendt, A Yagi, K Yoshinaga (2020)Determination of beta-delayed neutron emission probability limits of rhodium isotopes by gamma-ray spectroscopy, In: Journal of physics. Conference series1643(1) IOP Publishing
The decay of five neutron-heavy rhodium isotopes were studied at the Radioactive Isotope Beam Factory (RIBF) Facility at the RIKEN Nishina Center after relativistic fission of 238U beam on a thick beryllium target. Previously unknown associated gamma-ray decay energies are reported for each nuclide, and through evaluating the intensity of the 2+ → 0+ E2 transition in the even-even palladium daughter nuclei, 120,122,124Pd, from the beta-tagged gamma-ray spectra an upper or lower limit of beta-delayed neutron emission is deduced for each nuclei. A general, expected trend of increasing Pn is observed in the direction of the neutron drip line.
MATTHEW ALAN GOODWIN, R Britton, ANNETTE DAVIES, PATRICK HENRY REGAN, S Bell (2020)High resolution β - γ coincidence spectrometry at the UK CTBT Radionuclide Laboratory, In: Journal of physics. Conference series1643(1) IOP Publishing
Detection of radioxenon is often considered the most probable indicator of an underground nuclear explosion. GBL15 is the UK's Comprehensive Nuclear-Test-Ban Treaty Certified Radionuclide Laboratory, operated at AWE Aldermaston and has a history of developing high fidelity coincidence detection systems for particulate radionuclides. The Laboratory also operates a SAUNA II system, using NaI(Tl) and plastic scintillator detectors to measure β - γ coincidences from the decay of the four radioxenon isotopes, namely 133Xe, 135Xe, 131mXe & 133mXe. Here the efforts to date in exploring new technologies for next generation laboratory-based β - γ coincidence spectrometry for radioxenon measurements are discussed. Results are presented from preliminary measurements using a PIPSBox detector with a high purity germanium γ detector and the output compared to that of lower resolution systems. This investigation will be used to scope future programmes on the technology used for the measurement of radioactive noble gas nuclides at GBL15.
SHAHEEN JAZRAWI, DANIEL THOMAS DOHERTY, J.M Allmond, PATRICK HENRY REGAN, R.V.F Janssens, W Korten, S Zhu, M Zielińska, D Radford, S Ansari, K Auranen, B Bucher, M.P Carpenter, WILTON NEIL CATFORD, K Hadyńska-Klek, JACK HENDERSON, M Hendricks, M Komorowska, F.G Kondev, T Lauritsen, JUERONG LI, GAVIN JAMES LOTAY, P.J Napiorkowski, E Padilla-Rodal, R.C Pardo, B.C Rasco, W Reviol, D.G Sarantites, D Seweryniak, D Santiago-Gonzalez, G Savard, P Singh, S.M Stolze, R Vondrasek, G Wilson, CHUAN-YU WU, J Wu (2020)A High-Resolution Study of the 110Tc → 110Ru → 110Rh → 110Pd Decay Chain with the GRETINA Array, In: Journal of Physics. Conference Series1643(1) IOP Publishing
Spectroscopic data, such as precise γ-ray branching and E2/M1 multipole-mixing ratios, provide vital constraints when performing multi-dimensional Coulomb-excitation analyses. Consequently, as part of our new Coulomb-excitation campaign aimed at investigating the role of exotic non-axial (triaxial) deformations in the unstable refractory Ru-Mo isotopes, additional beta-decay data was obtained. These measurements make use of ANL's CARIBU facility, which provides intense beams of radioactive refractory isotopes along with the excellent efficiency and angular resolution of the GRETINA γ-ray tracking array. In this article, we report on the analysis of the A = 110 decay chain, focussing on the identification of previously unreported states in 110Ru following the decay of 110Tc.
E Rapisarda, R Shearman, M Rudigier, M Huyse, M Piersa, T Alexander, P Van Duppen, D S Judson, R Marginean, T Stora, R Lică, P M Walker, R E Mihai, S Stegemann, M Madurga, A Gredley, R D Page, L J Harkness-Brennan, F Rotaru, R Wadsworth, M Brunet, P Rahkila, V Vedia, H O U Fynbo, M Lund, L M Fraile, J R Creswell, T Berry, S Lalkovski, S Ansari, F Wearing, N Warr, S M Judge, V Pucknell, E R Gamba, C Nita, C M Shand, P H Regan, Ch Sotty, A Perea, R J Carroll, Z Patel, A N Andreyev, N Marginean, I H Lazarus, I Marroquin, O Tengblad, M Górska, Zs Podolyák, C Mihai, H Grawe, R B Gerst, M J G Borge, C Fahlander, A Negret, P T Greenlees, J Phrompao, H De Witte, I Kuti, J Kurcewicz, E Nácher, J Konki, S Pascu, W Gelletly, ZSOLT PODOLYAK (2020)Competition between Allowed and First-Forbidden β Decay: The Case of 208Hg → 208Tl, In: Physical review letters125192501 American Physical Society
The β decay of 208Hg into the one-proton hole, one neutron-particle 20881Tl127 nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z<82 quadrant of neutron-rich nuclei. While both negative and positive parity states with spin 0 and 1 are expected within the Qβ window, only three negative parity states are populated directly in the β decay. The data provide a unique test of the competition between allowed Gamow-Teller and Fermi, and first-forbidden β decays, essential for the understanding of the nucleosynthesis of heavy nuclei in the rapid neutron capture process. Furthermore, the observation of the parity changing 0+→0−β decay where the daughter state is core excited is unique, and can provide information on mesonic corrections of effective operators.
AB Garnsworthy, PH Regan, L Caceres, Y Pietri, Y Sun, D Rudolph, M Gorska, Z Podolyak, SJ Steer, R Hoischen, A Heinz, F Becker, R Bednarczyk, P Doornenbal, H Geissel, J Gerl, H Grawe, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tachenov, E Werner-Malento, HJ Wollersheim, G Benzoni, BB Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dornbradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfutzner, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wieland, FR Xu (2008)Neutron-proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei (82)(41)Nb and (86)(43)TC (vol 660, pg 326, 2008), In: PHYSICS LETTERS B668(5)pp. 460-460 ELSEVIER SCIENCE BV
C Wheldon, JJ Valiente-Dobon, PH Regan, CJ Pearson, CY Wu, JF Smith, AO Macchiavelli, D Cline, RS Chakrawarthy, R Chapman, M Cromaz, P Fallon, SJ Freeman, W Gelletly, AG Goergen, AB Hayes, H Hua, SD Langdown, IY Lee, X Liang, Z Podolyak, G Sletten, R Teng, D Ward, DD Warner, AD Yamamoto (2006)Observation of an isomeric state in Au-197, In: PHYSICAL REVIEW C74(2)ARTN 0pp. ?-? AMERICAN PHYSICAL SOC
S Lalkovski, AM Bruce, A Jungclaus, M Gorska, M Pfuetzner, L Caceres, F Naqvi, S Pietri, Z Podolyak, GS Simpson, K Andgren, P Bednarczyk, T Beck, J Benlliure, G Benzoni, E Casarejos, B Cederwall, FCL Crespi, JJ Cuenca-Garcia, IJ Cullen, AMD Bacelar, P Detistov, P Doornenbal, GF Farrelly, AB Garnsworthy, H Geissel, W Gelletly, J Gerl, J Grebosz, B Hadinia, M Hellstrom, C Hinke, R Hoischen, G Ilie, G Jaworski, J Jolie, A Khaplanov, S Kisyov, M Kmiecik, I Kojouharov, R Kumar, N Kurz, A Maj, S Mandal, V Modamio, F Montes, S Myalski, M Palacz, W Prokopowicz, P Reiter, PH Regan, D Rudolph, H Schaffner, D Sohler, SJ Steer, S Tashenov, J Walker, PM Walker, H Weick, E Werner-Malento, O Wieland, HJ Wollersheim, M Zhekova (2013)Core-coupled states and split proton-neutron quasiparticle multiplets in Ag122-126, In: PHYSICAL REVIEW C87(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
G A Jones, P H Regan, Z Podolyak, N Yoshinaga, K Higashiyama, G de Angelis, Y H Zhang, A Gadea, C A Ur, M Axiotis, D Bazzacco, D Bucurescu, E Farnea, W Gelletly, M Ionescu-Bujor, A Lordachescu, T Kroll, S D Langdown, S Lenzi, S Lunardi, N Marginean, T Martinez, N H Medina, R Menegazzo, D R Napoli, B Quintana, B Rubio, C Rusu, R Schwenger, D Tonev, J J Doban, W van Oertzen (2007)Yrast Studies of Se-80,Se-82 Using Deep-Inelastic Reactions, In: Physical Review C76(5)
We report the results of an experiment in which we studied the near-yrast states in selenium isotopes approaching N=50 following their population in multinucleon transfer reactions between a Se-82 beam and a Os-192 target. The level schemes for Se-80,Se-82 derived from the current work are compared with restricted-basis shell-model calculations and pair-truncated shell-model calculations. These provide a good description of the yrast sequences in these nuclei using a basis space limited to excitations in the nu(p3/2, p1/2, p1/2) and pi(f5/2, p3/2, p1/2) orbitals.
YH Zhang, Z Podolyak, G de Angelis, A Gadea, C Ur, S Lunardi, N Marginean, C Rusu, R Schwengner, T Kroll, DR Napoli, R Menegazzo, D Bazzacco, E Farnea, S Lenzi, T Martinez, M Axiotis, D Tonev, W Gelletly, S Langdown, PH Regan, JJV Dobon, W von Oertzen, B Rubio, B Quintana, N Medina, R Broda, D Bucurescu, M Ionescu-Bujor, A Iordachescu (2004)Stability of the N=50 shell gap in the neutron-rich Rb, Br, Se, and Ge isotones, In: PHYSICAL REVIEW C70(2)ARTN 0pp. ?-? AMERICAN PHYSICAL SOC
S. F. Ashley, P. H. Regan, K. Andgren, E. A. McCutchan, N. V. Zamfir, L. Amon, R. B. Cakirli, R. F. Casten, R. M. Clark, W. Gelletly, G. Gürdal, K. L. Keyes, D. A. Meyer, M. N. Erduran, A. Papenberg, N. Pietralla, C. Plettner, G. Rainovski, R. V. Ribas, N. J. Thomas, J. Vinson, D. D. Warner, V. Werner, E. Williams, H. L. Liu, F. R. Xu (2007)Intrinsic state lifetimes in 103Pd and 106,107Cd, In: Physical Review C76(064302)
P-A Soderstrom, J Nyberg, PH Regan, A Algora, G de Angelis, SF Ashley, S Aydin, D Bazzacco, RJ Casperson, WN Catford, J Cederkall, R Chapman, L Corradi, C Fahlander, E Farnea, E Fioretto, SJ Freeman, A Gadea, W Gelletly, A Gottardo, E Grodner, CY He, GA Jones, K Keyes, M Labiche, X Liang, Z Liu, S Lunardi, N Marginean, P Mason, R Menegazzo, D Mengoni, G Montagnoli, D Napoli, J Ollier, S Pietri, Z Podolyak, G Pollarolo, F Recchia, E Sahin, F Scarlassara, R Silvestri, JF Smith, K-M Spohr, SJ Steer, AM Stefanini, S Szilner, NJ Thompson, GM Tveten, CA Ur, JJ Valiente-Dobon, V Werner, SJ Williams, FR Xu, JY Zhu (2010)Spectroscopy of neutron-rich Dy-168,Dy-170: Yrast band evolution close to the NpNn valence maximum, In: PHYSICAL REVIEW C81(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
A Gadea, DR Napoli, G de Angelis, R Menegazzo, AM Stefanini, L Corradi, M Axiotis, L Berti, E Fioretto, T Kroell, A Latina, N Marginean, G Maron, T Martinez, D Rosso, C Rusu, N Toniolo, S Szilner, M Trotta, D Bazzacco, S Beghini, M Bellato, F Brandolini, E Farnea, R Isocrate, SM Lenzi, S Lunardi, G Montagnoli, P Pavan, CR Alvarez, F Scarlassara, C Ur, N Blasi, A Bracco, F Camera, S Leoni, B Million, M Pignanelli, G Pollarolo, A DeRosa, C Inglima, M La Commara, G La Rana, D Pierroutsakou, M Romoli, M Sandoli, PG Bizzeti, AM Bizzeti-Sona, G Lo Bianco, CM Petrache, A Zucchiatti, P Cocconi, B Quintana, C Beck, D Curien, G Duchene, F Haas, P Medina, P Papka, J Durell, SJ Freeman, A Smith, B Varley, K Fayz, V Pucknell, J Simpson, W Gelletly, P Regan (2004)Coupling a CLOVER detector array with the PRISMA magnetic spectrometer - Investigation of moderately neutron-rich nuclei populated by multinucleon transfer and deep inelastic collisions, In: EUROPEAN PHYSICAL JOURNAL A20(1)pp. 193-197
GA Jones, Z Podolyak, N Schunck, PM Walker, G De Angelis, YH Zhang, M Axiotis, D Bazzacco, PG Bizzeti, F Brandolini, R Broda, D Bucurescu, E Farnea, W Gelletly, A Gadea, M Ionescu-Bujor, A Iordachescu, T Kroll, SD Langdown, S Lunardi, N Marginean, T Martinez, NH Medina, B Quintana, PH Regan, B Rubio, CA Ur, JJ Valiente-Dobon, SJ Williams (2005)Oblate collectivity in the yrast structure of Pt-194, In: ACTA PHYSICA POLONICA B36(4)pp. 1323-1327
N Alkhomashi, PH Regan, Z Podolyak, S Pietri, AB Garnsworthy, SJ Steer, J Benlliure, E Caserejos, RF Casten, J Gerl, HJ Wollersheim, J Grebosz, G Farrelly, M Gorska, I Kojouharov, H Schaffner, A Algora, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, AMD Bacelar, IJ Cullen, L Caceres, P Doornenbal, ME Estevez, Y Fujita, W Gelletly, R Hoischen, R Kumar, N Kurz, S Lalkovski, Z Liu, C Mihai, F Molina, AI Morales, D Muecher, W Prokopowicz, B Rubio, Y Shi, A Tamii, S Tashenov, JJ Valiente-Dobon, PM Walker, PJ Woods, FR Xu (2009)beta(-)-delayed spectroscopy of neutron-rich tantalum nuclei: Shape evolution in neutron-rich tungsten isotopes, In: PHYSICAL REVIEW C80(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
PM Regan, C Chandler, CJ Pearson, B Blank, R Grzywacz, M Lewitowicz, AM Bruce, WN Catford, N Curtis, S Czajkowski, P Dessagne, A Fleury, W Gelletly, J Giovinazzo, Z Janas, C Longour, C Marchand, C Miehe, NA Orr, RD Page, MS Pravikoff, AT Reed, MG Saint-Laurent, SM Vincent, R Wadsworth, DD Warner, JS Winfield (1997)Studies of isomeric states and limits of particle stability around N∼Z∼40 using fragmentation reactions, In: Acta Physica Polonica B28(1-2)pp. 431-442
Fragmentation products from a 92Mo beam on a natural nickel target have been used to study structural properties of the very neutron deficient nuclei around N∼Z∼40. We present the first observation of isomeric decays in the Tz=1 systems 3674Kr, 3980 Y and 4184Nb. The isomer in 74Kr is interpreted as the hindered decay from an excited 0+ state, confirming the prediction of prolate/oblate shape coexistence in this nucleus. Transitions from states below an isomer in the N=Z nucleus 4386Tc have also been tentatively identified, making this the heaviest N=Z system for which decays from excited states have been observed. In addition, we have obtained the first conclusive evidence for the existence of the Tz = -1/2 isotopes 3977Y, 4079Zr and 4283Mo. The data for 3977Y is of particular interest in light of the reported instability in the lighter odd-Z, Tz = -1/2 systems 69Br and 73Rb.
AM Baxter, AP Byrne, GD Dracoulis, PM Davidson, TR McGoram, PH Regan, C Chandler, W Gelletly, C Wheldon, R Julin, JFC Cocks, K Helariutta, P Jones, S Juutinen, H Kankaanpaa, H Kettunen, P Kuusiniemi, M Leino, M Muikku, A Savelius, RVF Janssens, T Brown, MP Carpenter, CN Davids, T Lauritsen, D Nisius, PT Greenlees (1998)Identification of yrast states in Pb-187, In: PHYSICAL REVIEW C58(5)pp. 2671-2676 AMERICAN PHYSICAL SOC
AM Denis Bacelar, AM Bruce, S Lalkovski, Z Podolyák, N Al-Dahan, N Alkhomashi, IJ Cullen, AY Deo, GF Farrelly, W Gelletly, PH Regan, SJ Steer, TPD Swan, PM Walker, M Górska, S Pietri, MV Ricciardi, P Boutachkov, C Domingo-Pardo, F Farinon, H Geissel, J Gerl, N Goel, J Grȩbosz, R Hoischen, I Kojouharov, N Kurz, C Nociforo, A Prochazka, W Prokopowicz, K-H Schmidt, H Schaffner, H Weick, HJ Wollersheim, P Detistov, A Algora, F Molina, B Rubio, Z Dombradi, J Benlliure, AI Morales, S Verma, A Bracco, S Leoni, D Montanari, R Nicolini, E Calore, DR Napoli, JJ Valiente-Dobón, E Casarejos, M Doncel, D Rudolph, A Musumarra, K Steiger, P Strmen, I Szarka (2013)The population of metastable states as a probe of relativistic-energy fragmentation reactions, In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics723(4-5)pp. 302-306 Elsevier
Isomeric ratios have been measured for high-spin states in Po84198,200,206,208, At85208,209,210,211, Rn86210,211,212,213,214, Fr87208,211,212,213,214, Ra88210,211,212,214,215, and Ac89215 following the projectile fragmentation of a 1 AGeV U beam by a Be target at GSI Helmholtzzentrum für Schwerionenforschung. The fragments were separated in the fragment separator (FRS) and identified by means of energy loss and time-of-flight techniques. They were brought to rest at the centre of the RISING gamma-ray detector array and intensities of gamma rays emitted in the decay of isomeric states with half-lives between 100 ns and 40 μs and spin values up to 55/2ℏ were used to obtain the corresponding isomeric ratios. The data are compared to theoretical isomeric ratios calculated in the framework of the abrasion-ablation model. Large experimental enhancements are obtained for high-spin isomers in comparison to expected values. © 2013 Elsevier B.V.
SM Vincent, PH Regan, DD Warner, RA Bark, D Blumenthal, MP Carpenter, CN Davids, W Gelletly, RVF Janssens, CD O'Leary, CJ Lister, J Simpson, D Seweryniak, T Saitoh, J Schwartz, S Tormanen, O Juillet, F Nowacki, P Van Isacker (1998)Competing T=0 and T=1 structures in the N=Z nucleus Ga-62(31), In: PHYSICS LETTERS B437(3-4)pp. 264-272 ELSEVIER SCIENCE BV
N Al-Dahan, Z Podolyak, PH Regan, SJ Steer, N Alkhomashi, AMD Bacelar, M Gorska, SB Pietri, W Gelletly, PM Walker, G Farrelly, AI Morales, AY Deo, IJ Cullen, J Gerl, C Domingo-Pardo, S Verma, T Swan, HJ Wollersheim, AM Bruce, S Lalkovski, J Benlliure, A Algora, P Boutachkov, A Bracco, E Calore, E Casarejos, P Detistov, Z Dombradi, M Doncel, F Farinon, H Geissel, N Goel, J Grebosz, R Hoischen, I Kojouharov, S Leoni, F Molina, D Montanari, A Musumarra, R Nicolini, DR Napoli, C Nociforo, B Rubio, A Prochazka, D Rudolph, P Strmen, I Szarka, JJ Valiente-Dobon, H Weick, A Blazhev, J Jolie, N Warr, A Zilges (2009)Structure of N >= 126 nuclei produced in fragmentation of (238)U, In: CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS1090pp. 145-148
PH Regan, N Alkhomashi, N Al-Dahan, Z Podolyak, EB Suckling, PD Stevenson, SB Pietri, SJ Steer, AB Garnsworthy, W Gelletly, J Benlliure, AI Morales, J Gerl, M Gorska, HJ Wollersheim, R Kumar, J Grebosz, A Algora, G Benzoni, P Boutachkov, AM Bruce, E Casarejos, IJ Cullen, AMD Bacelar, A Blazhev, ME Estevez, G Farrelly, Y Fujita, R Hoischen, S Lalkovski, Z Liu, I Kojouharov, N Kurz, C Mihai, F Molina, D Muecher, B Rubio, H Schaffner, S Tashenov, A Tamii, JJV Dobon, PM Walker, PJ Woods, A Blazhev, J Jolie, N Warr, A Zilges (2009)New Insights into the Structure of Exotic Nuclei Using the RISING Active Stopper, In: CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS1090pp. 122-129
S Myalski, M Kmiecik, A Maj, PH Regan, AB Garnsworthy, S Pietri, D Rudolph, Z Podolyak, SJ Steer, F Becker, P Bednarczyk, J Gerl, M Gorska, H Grawe, I Kojouharov, H Schaffner, HJ Wollersheim, W Prokopowicz, J Grebosz, G Benzoni, B Blank, C Brandau, AM Bruce, L Caceres, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbal, E Estevez, H Geissel, W Gelletly, A Heinz, R Hoischen, G Ilie, GA Jones, A Jungclaus, A Kelic, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkovski, Z Liu, F Montes, M Pfutzner, T Saito, T Shizuma, AJ Simons, S Schwertel, S Tachenov, PM Walker, E Werner-Malento, O Wieland (2007)Isomeric ratio for the I-pi=8(+) yrast state in Pd-96 produced in the relativistic fragmentation of Ag-107, In: ACTA PHYSICA POLONICA B38(4)pp. 1277-1282 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
We report on the preliminary results from a study of the decay of the I-pi = 8(+) T-1/2 = 2 mu s isomer in Pd-96 performed as part of the Stopped-Beam RISING campaign within the Rare Isotope Investigation at GSI (RISING). The Pd-96 ions were produced following the projectile fragmentation of a 750 MeV per nucleon Ag-107 primary beam. The reaction products were separated and identified by the in-flight method using the GSI Fragment Separator. The residues of interest were stopped in a perspex stopper surrounded by an array of 15, seven-element germanium Cluster detectors. One of the goals of the current work is to investigate the population of high-spin states produced projectile fragmentation reactions using isomeric ratio measurements to infer information on the angular momentum population distribution. In this short contribution the method and results of determining the isomeric ratio for the I-pi = 8(+) microsecond isomer in Pd-96 nucleus are presented.
T.A. Berry, Zs. Podolyak, R.J. Carroll, R. Lică, H. Grawe, N.K. Timofeyuk, T. Alexander, A.N. Andreyev, S. Ansari, M.J.G. Borge, J. Creswell, C. Fahlander, L.M. Fraile, H.O.U. Fynbo, W. Gelletly, R.-B. Gerst, M. Górska, A. Gredley, P. Greenlees, L.J. Harkness-Brennan, M. Huyse, S.M. Judge, D.S. Judson, J. Konki, J. Kurcewicz, I. Kuti, S. Lalkovski, I. Lazarus, M. Lund, M. Madurga, N. Mărginean, R. Mărginean, I. Marroquin, C. Mihai, R.E. Mihai, E. Nácher, S. Nae, A. Negret, C. Niţă, R.D. Page, S. Pascu, Z. Patel, A. Perea, V. Pucknell, P. Rahkila, E. Rapisarda, P.H. Regan, F. Rotaru, C.M. Shand, E.C. Simpson, Ch. Sotty, S. Stegemann, T. Stora, O. Tengblad, A. Turturica, P. Van Duppen, V. Vedia, R. Wadsworth, P.M. Walker, N. Warr, F. Wearing, H. De Witte (2019)Investigation of the Δn = 0 selection rule in Gamow-Teller transitions: The β-decay of 207Hg, In: Physics Letters B793pp. 271-275 Elsevier
Gamow-Teller β decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This Δn=0 requirement plays a major role in the β decay of heavy neutron-rich nuclei, affecting the nucleosynthesis through the increased half-lives of nuclei on the astrophysical r-process pathway below both Z=50 (for N ˃ 82) and Z = 82 (for N ˃ 126). The level of forbiddenness of the Δn=1v1g9/2 → π0g7/2 transition has been investigated from the β decay of the ground state of 207Hg into the single-proton-hole nucleus 207Tl in an experiment at the ISOLDE Decay Station. From statistical observational limits on possible γ-ray transitions depopulating the π0g-17/2 state in 207Tl, an upper limit of 3.9 x 10-3% was obtained for the probability of this decay, corresponding to log ft ˃ 8.8 within a 95% confidence limit. This is the most stringent test of the Δn=0 selection rule to date.
GF Farrelly, Z Podolyak, SJ Steer, S Pietri, FR Xu, E Werner-Malento, T Shizuma, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, T Kurtukian-Nieto, G Benzoni, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geisserl, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfuezner, A Jungclaus, DL Balabanski, C Brandau, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, HL Liu, Z Liu, A Maj, S Myalski, S Schwerrel, PM Walker, O Wieland (2009)REVISION OF THE K-ISOMER IN W-190(116), In: ACTA PHYSICA POLONICA B40(3)pp. 885-888
Z Podolyak, SJ Steer, S Pietri, E Werner-Malento, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, T Kurtukian-Nieto, G Benzoni, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfutzner, M Hellstrom, A Jungclaus, LL Andersson, L Atanasova, DL Balabanski, A Bentley, B Blank, A Blazhev, C Brandau, J Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland, BA Brown (2007)Isomeric decay studies around Pt-204 and Tb-148, In: EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 165-168 EDP SCIENCES S A
Relativistic energy projectile fragmentation of Pb-208 has been used to produce a range of exotic nuclei. The nuclei of interest were studied by detecting delayed gamma rays following the decay of isomeric states. Experimental information on the excited states of the neutron-rich N = 126 nucleus, Pt-204, following internal decay of two isomeric states, was obtained for the first time. In addition, decays from the previously reported isomeric I=27h and I=(49/2)h states in Tb-148 and Gd-147, respectively, have been observed. These isomeric decays represent the highest spin discrete states observed to date following a projectile fragmentation reaction, and opens further the possibility of doing 'high-spin physics' using this technique.
G. A. Jones, P. H. Regan, Zs. Podolyák, N. Yoshinaga, K. Higashiyama, G. de Angelis, Y. H. Zhang, A. Gadea, C. A. Ur, M. Axiotis, D. Bazzacco, D. Bucurescu, E. Farnea, W. Gelletly, M. Ionescu-Bujor, A. Iordachescu, Th. Kröll, S. D. Langdown, S. Lenzi, S. Lunardi, N. Marginean, T. Martinez, N. H. Medina, R. Menegazzo, D. R. Napoli, B. Quintana, B. Rubio, C. Rusu, R. Schwengner, D. Tonev, J. J. Valiente Dobón, W. von Oertzen (2007)Yrast studies of 80,82Se using deep-inelastic reactions, In: Physical Review C76(054317)
AI Morales, J Benlliure, J Agramunt, A Algora, N Alkhomashi, H Alvarez-Pol, P Boutachkov, AM Bruce, LS Caceres, E Casarejos, AMD Bacelar, P Doornenbal, D Dragosavac, G Farrelly, A Gadea, W Gelletly, J Gerl, M Gorska, J Grebosz, I Kojouharov, F Molina, D Perez-Loureiro, S Pietri, Z Podolyak, PH Regan, B Rubio, H Shaffner, SJ Steer, S Tashenov, S Verma, HJ Wollersheim (2011)Synthesis of N=127 isotones through (p,n) charge-exchange reactions induced by relativistic Pb-208 projectiles, In: PHYSICAL REVIEW C84(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
E Valencia, A Algora, JL Tain, S Rice, J Agramunt, AA Zakari-Issoufou, J Äystö, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V Eloma, T Eronen, E Estevez, GF Farrelly, M Fallot, A Garcia, W Gelletly, MB Gomez-Hornillos, V Gorlychev, J Hakala, A Jokinen, MD Jordan, A Kankainen, FG Kondev, T Martinez, E Mendoza, F Molina, I Moore, A Perez, Z Podolyak, H Penttilä, A Porta, PH Regan, J Rissanen, B Rubio, C Weber (2014)Gamma/neutron competition above the neutron separation energy in delayed neutron emitters, In: EPJ Web of Conferences66
To study the β-decay properties of some well known delayed neutron emitters an experiment was performed in 2009 at the IGISOL facility (University of Jyväskylä in Finland) using Total Absorption -ray Spectroscopy (TAGS) technique. The aim of these measurements is to obtain the full β-strength distribution below the neutron separation energy (Sn) and the γ/neutron competition above. This information is a key parameter in nuclear technology applications as well as in nuclear astrophysics and nuclear structure. Preliminary results of the analysis show a significant γ-branching ratio above Sn. © Owned by the authors, published by EDP Sciences, 2014.
AA Zakari-Issoufou, A Porta, M Fallot, A Algora, JL Tain, E Valencia, S Rice, J Agramunt, J Äystö, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V Eloma, E Estévez, GF Farrelly, A Garcia, W Gelletly, MB Gomez-Hornillos, V Gorlychev, J Hakala, A Jokinen, MD Jordan, A Kankainen, FG Kondev, T Martinez, E Mendoza, F Molina, I Moore, A Perez, Z Podolyak, H Penttilä, PH Regan, J Rissanen, B Rubio, C Weber (2014)Results of fission products β decay properties measurement performed with a total absorption spectrometer, In: EPJ Web of Conferences66
β-decay properties of fission products are very important for applied reactor physics, for instance to estimate the decay heat released immediately after the reactor shutdown and to estimate the ν flux emitted. An accurate estimation of the decay heat and the ν emitted flux from reactors, are necessary for purposes such as reactors operation safety and non-proliferation. In order to improve the precision in the prediction for these quantities, the bias due to the Pandemonium effect affecting some important fission product data has to be corrected. New measurements of fission products β-decay, not sensitive to this effect, have been performed with a Total Absorption Spectrometer (TAS) at the JYFL facility of Jyväskylä. An overview of the TAS technique and first results from the 2009 campaign will be presented. © Owned by the authors, published by EDP Sciences, 2014.
Z Podolyak, SJ Steer, S Pietri, FR Xu, HL Liu, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, T Kurtukian-Nieto, G Benzoni, T Shizuma, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfutzner, A Jungclaus, DL Balabanski, C Brandau, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, PM Walker, E Werner-Malento, O Wieland (2009)Weakly deformed oblate structures in Os-198(76)122, In: PHYSICAL REVIEW C79(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
AB Garnsworthy, PH Regan, S Pietri, Y Sun, FR Xu, D Rudolph, M Gorska, L Caceres, Z Podolyak, SJ Steer, R Hoischen, A Heinz, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, H Grawe, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopwicz, T Saito, H Schaffner, S Tachenov, E Werner-Malento, HJ Wollersheim, G Benzoni, B Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfuetzner, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wieland (2009)Isomeric states in neutron-deficient A similar to 80-90 nuclei populated in the fragmentation of Ag-107, In: PHYSICAL REVIEW C80(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
SM Vincent, PH Regan, D Blumenthal, M Carpenter, CN Davids, W Gelletly, RVF Janssens, CJ Lister, D Seweryniak, J Schwartz, J Simpson, DD Warner (1999)Discrete line spectroscopy of Ga-62(31) with AYEBALL, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 679-683
C Longour, JG Narro, B Blank, M Lewitowicz, C Miehe, PH Regan, D Applebe, L Axelsson, AM Bruce, WN Catford, C Chandler, RM Clark, DM Cullen, S Czajkowski, JM Daugas, P Dessagne, A Fleury, L Frankland, W Gelletly, J Giovinazzo, B Greenhalgh, R Grzywacz, M Harder, KL Jones, N Kelsall, T Kszczot, RD Page, CJ Pearson, AT Reed, O Sorlin, R Wadsworth (1999)Half-lives of the odd-odd N=Z nuclei Y-78, Nb-82, Tc-86, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 759-762
S Lalkovski, S Kisyov, M Zhekova, AM Bruce, AMD Bacelar, M Górska, S Pietri, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Gerl, J Grȩbosz, I Kojouharov, N Kurz, W Prokopowicz, H Schaffner, S Tashenov, HJ Wollersheim, Z Podolyák, IJ Cullen, GF Farrelly, AB Garnsworthy, W Gelletly, PH Regan, S Steer, PM Walker, E Casarejos, S Myalski, C Hinke, G Ilie, G Jaworski, M Palacz (2012)Single-particle isomeric states in Pd and Ru, In: Journal of Physics: Conference Series366(1)
Neutron-rich nuclei were populated in a relativistic fission of U. Gamma-rays with energies of 135 keV and 184 keV were associated with two isomeric states in Pd and Ru. Half-lives of 0.63(5) μs and 2.0(3) μs were deduced and the isomeric states were interpreted in terms of prolate deformed single-particle states.
S Lalkovski, AM Bruce, AMD Bacelar, M Gorska, S Pietri, Z Podolyak, P Bednarczyk, L Caceres, E Casarejos, IJ Cullen, P Doornenbal, GF Farrelly, AB Garnsworthy, H Geissel, W Gelletly, J Gerl, J Grebosz, C Hinke, G Ilie, D Ivanova, G Jaworski, S Kisyov, I Kojouharov, N Kurz, N Minkov, S Myalski, M Palacz, P Petkov, W Prokopowicz, PH Regan, H Schaffner, S Steer, S Tashenov, PM Walker, HJ Wollersheim (2013)Submicrosecond isomer in Rh-117(45)72 and the role of triaxiality in its electromagnetic decay rate, In: PHYSICAL REVIEW C88(2)ARTN 0pp. ?-? AMER PHYSICAL SOC
S Mohammadi, PH Regan, SM Vincent, D Blumenthal, M Carpenter, CN Davids, W Gelletly, RVF Janssens, CJ Lister, CJ Pearson, J Simpson, D Seweryniak, J Schwartz, DD Warner (1999)High spin states in Ni-58, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 909-912
SM Vincent, PH Regan, S Mohammadi, W Gelletly, D Blumenthal, MP Carpenter, CN Davids, RVF Janssens, CJ Lister, CJ Pearson, J Simpson, D Seweryniak, J Schwartz, DD Warner (1999)A yrast study of the A=61 isobars Cu-61(29) and Zn-61(30), In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 941-943
AI Morales, J Benlliure, T Kurtukian-Nieto, K-H Schmidt, S Verma, PH Regan, Z Podolyak, M Gorska, S Pietri, R Kumar, E Casarejos, N Al-Dahan, A Algora, N Alkhomashi, H Alvarez-Pol, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, LS Caceres, IJ Cullen, AMD Bacelar, P Doornenbal, ME Estevez-Aguado, G Farrelly, Y Fujita, AB Garnsworthy, W Gelletly, J Gerl, J Grebosz, R Hoischen, I Kojouharov, N Kurz, S Lalkovski, Z Liu, C Mihai, F Molina, D Muecher, B Rubio, H Shaffner, SJ Steer, A Tamii, S Tashenov, JJ Valiente-Dobon, PM Walker, HJ Wollersheim, PJ Woods (2014)Half-Life Systematics across the N=126 Shell Closure: Role of First-Forbidden Transitions in the beta Decay of Heavy Neutron-Rich Nuclei, In: PHYSICAL REVIEW LETTERS113(2)ARTN 0pp. ?-? AMER PHYSICAL SOC
S Rice, A Algora, JL Tain, E Valencia, J Agramunt, B Rubio, William Gelletly, Patrick Regan, A-A Zakari-Issoufou, M Fallot, A Porta, J Rissanen, T Eronen, J Äystö, L Batist, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V-V Elomaa, E Estevez, GF Farrelly, AR Garcia, B Gomez-Hornillos, V Gorlychev, J Hakala, MD Jordan, A Jokinen, VS Kolhinen, FG Kondev, T Martínez, P Mason, E Mendoza, I Moore, H Penttilä, Zsolt Podolyak, M Reponen, V Sonnenschein, AA Sonzogni, P Sarriguren (2017)Total absorption spectroscopy study of the β decay of 86Br and 91Rb, In: Physical Review C96(1)014320 American Physical Society
The beta decays of 86Br and 91Rb have been studied using the total absorption spectroscopy technique. The radioactive nuclei were produced at the Ion Guide Isotope Separator On-Line facility in Jyväskylä and further purified using the JYFLTRAP. 86Br and 91Rb are considered to be major contributors to the decay heat in reactors. In addition, 91Rb was used as a normalization point in direct measurements of mean gamma energies released in the beta decay of fission products by Rudstam et al. assuming that this decay was well known from high-resolution measurements. Our results show that both decays were suffering from the Pandemonium effect and that the results of Rudstam et al. should be renormalized. The relative impact of the studied decays in the prediction of the decay heat and antineutrino spectrum from reactors has been evaluated
Z Janas, C Chandler, B Blank, PH Regan, AM Bruce, WN Catford, N Curtis, S Czajkowski, P Dessagne, A Fleury, W Gelletly, J Giovinazzo, R Grzywacz, M Lewitowicz, C Longour, C Marchand, C Miehé, NA Orr, RD Page, CJ Pearson, MS Pravikoff, AT Reed, MG Saint-Laurent, JA Sheikh, SM Vincent, R Wadsworth, DD Warner, JS Winfield (1999)Observation of the Z = N + 1 Nuclei 7739Y, 7949Zr, and 8342Mo, In: Physical Review Letters82(2)pp. 295-298
The very neutron deficient Z = N + 1 nuelei 7739Y, 7940Zr, and 8342Mo have been observed for the first time following the fragmentation of a 92Mo beam. In contrast, no evidence was found for the existence of 8141Nb and 8543Tc. The observation of 7739Y is of particular interest in light of the instability of the odd-proton, Z = N + 1 systems, 6935Br, 7337Rb, 8141Nb, and 8543Tc, and may be explained as a consequence of the shape polarizing effect of the highly deformed, prolate Z = N = 38 core. The experimental results are discussed within the framework of the shell-correction model, which together with proton-decay calculations allow an estimate of the proton separation energies of these highly exotic systems to be calculated.
S Mohammadi, Z Podolyák, G De Angelis, M Axiotis, D Bazzacco, PG Bizzeti, F Brandolini, R Broda, D Bucurescu, E Farnea, W Gelletly, A Gadea, M Ionescu-Bujor, A Iordachescu, T Kröll, S Longdown, S Lunardi, N Marginean, T Martinez, NH Medina, B Quintana, PH Regan, B Rubio, CA Ur, JJ Valiente Dobón, PM Walker, YH Zhang (2004)High-spin states populated in deep-inelastic reactions, In: Brazilian Journal of Physics34(3 A)pp. 792-795
High spin states in the neutron rich 188Os and 190Os nuclei have been populated using the 82Se + 192Os deep-inelastic reaction. The level schemes are extended up to spin I ≈21. The observed new structures are tentatively interpreted as fragments of rotational bands built on multi-quasiparticle configurations.
PJR Mason, Z Podolyak, NM Arginean, PH Regan, T Alexander, A Algora, T Alharbi, M Bowry, R Britton, D Bucurescu, AM Bruce, M Bunce, G Cata-Danil, I Cata-Danil, N Cooper, D Deleanu, D Delion, D Filipescu, W Gelletly, T Glodariu, I Gheorghe, D Ghita, G Ilie, D Ivanova, S Kisyov, S Lalkovski, R Lica, SN Liddick, R Marginean, C Mihai, K Mulholland, A Negret, CR Nita, S Rice, OJ Roberts, T Sava, JF Smith, P-A Soederstroem, PD Stevenson, L Stroe, S Toma, C Townsley, V Werner, E Wilson, RT Wood, NV Zamfir, M Zhekova, T Niksic, M Milin, D Vretenar, S Szilner (2012)Li-7-Induced Reactions for Fast-Timing With LaBr3:Ce Detectors, In: NUCLEAR STRUCTURE AND DYNAMICS '121491pp. 93-96
PH Regan, AB Gamsworthy, SJ Steer, S Pletri, Z Podolyak, D Rudolph, M Gorska, L Caceres, E Wemer-Malento, J Gerl, HJ Wollersheim, F Becker, P Bednarczyk, PD Doornenbal, H Geissel, H Grawe, J Grebosz, R Hoischen, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, M Hellstroem, A Jungclaus, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, B Blank, A Blazhev, C Brandau, J Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, G Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wieland (2007)First results from the stopped RISING campaign at GSI: The mapping of isomeric decays in highly exotic nuclei, In: Six International Conference of the Balkan Physical Union899pp. 19-22
S Pietri, PH Regan, Z Podolyak, D Rudolph, S Steer, AB Garnsworthy, E Werner-Malento, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, I Kojouharov, H Schaffner, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, N Kurz, F Montes, W Prokopowicz, T Saito, S Tashenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, M Hellstrom, A Jungclaus, J Simpson, L-L Andersson, L Atanasova, D Balabanski, MA Bentley, B Blank, A Blazhev, C Brandau, JR Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)Recent results in fragmentation isomer spectroscopy with rising, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS261(1-2)pp. 1079-1083
MA Bentley, SJ Williams, DT Joss, CD O'Leary, AM Bruce, JA Cameron, MP Carpenter, P Fallon, L Frankland, W Gelletly, CJ Lister, G Martinez-Pinedo, A Poves, PH Regan, P Reiter, B Rubio, J Sanchez-Solano, D Seweryniak, CE Svensson, SM Vincent, DD Warner (2002)Mirror symmetry and Coulomb effects in light N approximate to Z nuclei, In: CZECHOSLOVAK JOURNAL OF PHYSICS52pp. C597-C606
CD O'Leary, MA Bentley, SM Lenzi, G Martinez-Pinedo, DD Warner, AM Bruce, JA Cameron, MP Carpenter, CN Davids, P Fallon, L Frankland, W Gelletly, RVF Janssens, DT Joss, CJ Lister, PH Regan, P Reiter, B Rubio, D Seweryniak, CE Svensson, SM Vincent, SJ Williams (2002)Isovector pairing in odd-odd N=Z Mn-50, In: PHYSICS LETTERS B525(1-2)pp. 49-55 ELSEVIER SCIENCE BV
D Rudolph, S Pietri, Z Podolyak, PH Regan, AB Garnsworthy, R Hoischen, SJ Steer, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Gerl, M Gorska, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, E Werner-Malento, HJ Wollersheim, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, G Benzoni, B Blank, A Blazhev, C Brandau, JR Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, A Heinz, M Hellstrom, G Ilie, EK Johansson, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfutzner, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)Exciting isomers from the first stopped-beam RISING campaign, In: EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 173-176
S Pietri, PH Regan, Z Podolyak, D Rudolph, M Gorska, A Jungclaus, M Pfuetzner, AB Garnsworthy, SJ Steer, L Caceres, E Werner-Malento, R Hoischen, J Gerl, I Kojouharov, H Schaffner, HJ Wollersheim, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Grebosz, A Kelic, N Kurz, F Montes, W Prokopowicz, T Saito, S Tashenov, A Heinz, T Kurtukian-Nieto, G Benzoni, M Hellstrom, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, B Blank, A Blazhev, C Brandau, JR Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)First results from the stopped beam isomer rising campaign at GSI, In: ACTA PHYSICA POLONICA B38(4)pp. 1255-1264
JJ Valiente-Dobón, PH Regan, C Wheldon, CY Wu, N Yoshinaga, K Higashiyama, JF Smith, D Cline, RS Chakrawarthy, R Chapman, M Cromaz, P Fallon, SJ Freeman, A Görgen, W Gelletly, A Hayes, H Hua, SD Langdown, IY Lee, X Liang, AO Macchiavelli, CJ Pearson, Z Podolyák, G Sletten, R Teng, D Ward, DD Warner, AD Yamamoto (2004)136Ba studied via deep-inelastic collisions: Identification of the (νh11/2)10+-2 isomer, In: Physical Review C - Nuclear Physics69(2)pp. 243161-2431613
A multinucleon transfer reaction between a thin self-supporting 78198Pt target and an 850 MeV 54136X6 beam has been used to populate and study the structure of the N=80 isotone 56136Ba. Making use of time-correlated γ-ray spectroscopy, evidence for an Iπ=(10+) isomeric state has been found with a measured half-life of 91±2 ns. Prompt-delayed correlations have also enabled the tentative measurement of the near-yrast states which lie above the isomer. Shell-model calculations suggest that the isomer has a structure which can be assigned predominantly as (vh 11/2)10+-2. The results are discussed in terms of standard and pair-truncated shell-model calculations, and compared to the even-Z N=80 isotones ranging from 50130Sn to 68148Er. A qualitative explanation of the observed dramatic decrease in the B(E2:10+→8+) value for the N=80 isotones at 136Ba is given in terms of the increasing single-hole energy of the h11/2 neutron configuration as the proton subshell is filled. The angular momentum transfer to the binary fragments in the reaction has also been investigated in terms of the average total γ-ray fold versus the scattering angle of the recoils.
T Alexander, Z Podolyak, ML Cortes, J Gerl, D Rudolph, LG Sarmiento, F Ameil, T Arici, D Bazzacco, C Bauer, MA Bentley, A Blazhev, M Bowry, P Boutachkov, R Carroll, C Fahlander, A Gadea, J Gellanki, W Gelletly, A Givechev, N Goel, P Golubev, M Gorska, A Gottardo, E Gregor, G Guastalla, T Habermann, M Hackstein, A Jungclaus, I Kojouharov, W Korten, S Kumar, N Kurz, N Lalovic, M Lettmann, C Lizarazo, C Louchart, S Mandal, E Merchan, C Michelagnoli, T Moeller, K Moschner, Z Patel, N Pietralla, S Pietri, D Ralet, M Reese, PH Regan, P Reiter, H Schaffner, P Singh, C Stahl, R Stegmann, O Stezowksi, J Taprogge, P Thoele, PM Walker, O Wieland, A Wendt, E Wilson, R Wood, H-J Wollersheim (2015)ISOMERIC RATIOS IN Hg-206, In: ACTA PHYSICA POLONICA B46(3)pp. 601-605 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
206Hg was populated in the fragmentation of an E∕A = 1 GeV 208Pb beam at GSI. It was part of a campaign to study nuclei around 208Pb via relativistic Coulomb excitation. The observation of the known isomeric states confirmed the identification of the fragmentation products. The isomeric decays were also used to prove that the correlations between beam identification detectors and the AGATA γ-ray tracking array worked properly and that the tracking efficiency was independent of the time relative to the prompt flash.
N Cieplicka, B Fornal, KH Maier, B Szpak, R Broda, W Krolas, T Pawlat, J Wrzesinski, RVF Janssens, MP Carpenter, CJ Chiara, CR Hoffman, FG Kondev, T Lauritsen, S Zhu, Z Podolyak, M Bowry, M Bunce, W Gelletly, R Kempley, M Reed, P Regan, P Walker, E Wilson, AY Deo, G Dracoulis, G Lane, C Rodriguez-Triguero (2014)ANGULAR DISTRIBUTIONS OF gamma RAYS FROM Bi-210 PRODUCED IN Pb-208+Pb-208 DEEP-INELASTIC REACTIONS, In: ACTA PHYSICA POLONICA B45(2)pp. 205-210
GA Jones, Z Podolyak, PM Walker, PH Regan, G de Angelis, M Axiotis, D Bazzacco, PG Bizzeti, F Brandolini, R Broda, D Bucurescu, E Farnea, W Gelletly, A Gadea, M Ionescu-Bujor, A Iordachescu, T Kroll, SD Langdown, S Lunardi, N Marginean, T Martinez, NH Medina, B Quintana, B Rubio, CA Ur, JJ Valiente-Dobon, SJ Williams, YH Zhang (2005)Population of yrast states in Os-191 using deep-inelastic reactions, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1891-S1894
WN Catford, S Mohammadi, PH Regan, CS Purry, W Gelletly, PM Walker, GJ Gyapong, J Simpson, DD Warner, T Davinson, R Neal, RD Page, AC Shotter, IM Hibbert, R Wadsworth, SA Forbes, AM Bruce, C Thwaites, P Thirolf, P VanDuppen, W Galster, A Ninane, J Vervier, P Decrock, M Huyse, J Szerypo, J Wauters (1997)High resolution gamma-ray spectroscopy with a radioactive beam, In: NUCLEAR PHYSICS A616(1-2)pp. C303-C310
Z Podolyak, S Mohammadi, G De Angelis, YH Zhang, M Axiotis, D Bazzacco, PG Bizzeti, F Brandolini, R Broda, D Bucurescu, E Farnea, W Gelletly, A Gadea, M Ionescu-Bujor, A Iordachescu, T Kroll, SD Langdown, S Lunardi, N Marginean, T Martinez, NH Medina, B Quintana, PH Regan, B Rubio, CA Ur, JJ Valiente-Dobon, PM Walker (2004)Structure of neutron-rich nuclei from deep-inelastic reactions, In: INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS13(1)pp. 123-126
AB Garnsworthy, PH Regan, S Pietri, D Rudolph, L Caceres, M Gorska, Z Podolyak, SJ Steer, A Heinz, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, H Grawe, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopwicz, T Saito, H Schaffner, S Tachenov, E Werner-Malento, HJ Wollersheim, G Benzoni, B Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, R Hoischen, G Ilie, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfutzner, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)Isomeric states in the light Tc isotopes, In: ACTA PHYSICA POLONICA B38(4)pp. 1265-1269
N Al-Dahan, Z Podolyak, PH Regan, M Gorska, H Grawe, KH Maier, J Gerl, SB Pietri, HJ Wollersheim, N Alkhomashi, AY Deo, AMD Bacelar, G Farrelly, SJ Steer, AM Bruce, P Boutachkov, C Domingo-Pardo, A Algora, J Benlliure, A Bracco, E Calore, E Casarejos, IJ Cullen, P Detistov, Z Dombradi, M Doncel, F Farinon, W Gelletly, H Geissel, N Goel, J Grebosz, R Hoischen, I Kojouharov, N Kurz, S Lalkovski, S Leoni, F Molina, D Montanari, AI Morales, A Musumarra, DR Napoli, R Nicolini, C Nociforo, A Prochazka, W Prokopowicz, B Rubio, D Rudolph, H Schaffner, P Strmen, I Szarka, T Swan, JS Thomas, JJ Valiente-Dobon, S Verma, PM Walker, H Weick (2009)Nuclear structure "southeast" of Pb-208: Isomeric states in Hg-208 and Tl-209, In: PHYSICAL REVIEW C80(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
A. M. Bruce, A. P. Byrne, G. D. Dracoulis, W. Gelletly, T. Kibedi, F. G. Kondev, C. S. Purry, P. H. Regan, C. Thwaites, P. M. Walker (1997)Systematics of Kπ = 8- isomers in N = 74 nuclei, In: Physical Review C55(620)pp. 620-624
C Chandler, PH Regan, CJ Pearson, B Blank, AM Bruce, WN Catford, N Curtis, S Czajkowski, W Gelletly, R Grzywacz, Z Janas, M Lewitowicz, C Marchand, NA Orr, RD Page, A Petrovici, AT Reed, MG Saint-Laurent, SM Vincent, R Wadsworth, DD Warner, JS Winfield (1997)Evidence for a highly deformed oblate 0(+) state in Kr-74(36), In: PHYSICAL REVIEW C56(6)pp. R2924-R2928 AMERICAN PHYSICAL SOC
AB Garnsworthy, PH Regan, L Caceres, S Pietri, Y Sun, D Rudolph, M Gorska, Z Podolyak, SJ Steer, R Hoischen, A Heinz, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, H Grawe, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tachenov, E Werner-Malento, HJ Wollersheim, G Benzoni, BB Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfutzner, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wielandi, FR Xu (2008)Neutron-proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei Nb-82(41) and Tc-86(43), In: PHYSICS LETTERS B660(4)pp. 326-330 ELSEVIER SCIENCE BV
S Mohammadi, G De Angelis, M Axiotis, D Bazzacco, PG Bizzeti, F Brandolini, R Broda, D Bucurescu, E Farnea, W Gelletly, A Gadea, M Ionescu-Bujor, A Iordachescu, T Kroll, S Longdown, S Lunardi, N Marginean, T Martinez, N Medina, Z Podolyak, B Quintana, PH Regan, B Rubio, CA Ur, J-JV Dobon, PM Walker, YH Zhang (2006)Yrast states in Os-188,Os-190 nuclei, In: INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS15(8)pp. 1797-1802
WN Catford, S Mohammadi, PH Regan, CS Purry, W Gelletly, PM Walker, GJ Gyapong, J Simpson, DD Warner, T Davinson, R Neal, RD Page, AC Shotter, IM Hibbert, R Wadsworth, SA Forbes, AM Bruce, C Thwaites, P Thirolf, P VanDuppen, W Galster, A Ninane, J Vervier, P Decrock, M Huyse, J Szerypo, J Wauters (1996)High resolution gamma-ray spectroscopy with a radioactive beam, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT371(3)pp. 449-459 ELSEVIER SCIENCE BV
T. A. Berry, Zs. Podolyak, R. J. Carroll, R. Lică, B. A. Brown, H. Grawe, Ch. Sotty, N. K. Timofeyuk, T. Alexander, A. N. Andreyev, S. Ansari, M. J. G. Borge, M. Brunet, J. R. Cresswell, C. Fahlander, L. M. Fraile, H. O. U. Fynbo, E. Gamba, W. Gelletly, R.-B. Gerst, M. Górska, A. Gredley, P. Greenlees, L. J. Harkness-Brennan, M. Huyse, S. M. Judge, D. S. Judson, J. Konki, M. Kowalska, J. Kurcewicz, I. Kuti, S. Lalkovski, I. Lazarus, M. Lund, M. Madurga, N. Mărginean, R. Mărginean, I. Marroquin, C. Mihai, R. E. Mihai, E. Nácher, A. Negret, S. Nae, C. Niţă, S. Pascu, R. D. Page, Z. Patel, A. Perea, J. Phrompao, M. Piersa, V. Pucknell, P. Rahkila, E. Rapisarda, P. H. Regan, F. Rotaru, M. Rudigier, C. M. Shand, R. Shearman, E. C. Simpson, S. Stegemann, T. Stora, O. Tengblad, A. Turturica, P. Van Duppen, V. Vedia, P. M. Walker, N. Warr, F. P. Wearing, H. De Witte (2020)Octupole states in 207Tl studied through β decay, In: Physical Review C101(5)054311 American Physical Society
The β decay of 207Hg into the single-proton-hole nucleus 207Tl has been studied through γ-ray spectroscopy at the ISOLDE Decay Station (IDS) with the aim of identifying states resulting from coupling of the πs−11/2, πd−13/2, and πh−111/2 shell model orbitals to the collective octupole vibration. Twenty-two states were observed lying between 2.6 and 4.0 MeV, eleven of which were observed for the first time, and 78 new transitions were placed. Two octupole states (s1/2-coupled) are identified and three more states (d3/2-coupled) are tentatively assigned using spin-parity inferences, while further h11/2-coupled states may also have been observed for the first time. Comparisons are made with state-of-the-art large-scale shell model calculations and previous observations made in this region, and systematic underestimation of the energy of the octupole vibrational states is noted. We suggest that in order to resolve the difference in predicted energies for collective and noncollective t=1 states (t is the number of nucleons breaking the 208Pb core), the effect of t=2 mixing may be reduced for octupole-coupled states. The inclusion of mixing with t=0,2,3 excitations is necessary to replicate all t=1 state energies accurately.
M Gorska, H Grawe, L Caceres, A Algora, M Boehmer, P Boutachkov, K Eppinger, T Faestermann, Y Fujita, A Gadea, A Garnsworthy, W Gelletly, J Gerl, R Gernhaeuser, C Hinke, A Jungclaus, I Kojouharov, R Kruecken, L Maier, P Molina, M Pfuetzner, S Pietri, Z Podolyak, PH Regan, B Rubio, D Rudolph, HJ Wollersheim (2009)NUCLEAR STRUCTURE ADDRESSED AT GSI/RISING, In: INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS18(4)pp. 759-766
N Alkhomashi, PH Regan, Z Podoyak, SB Pietri, AB Garnsworthy, SJ Steer, J Benlliure, E Caserejos, M Gorska, J Gerl, HJ Wollersheim, J Grebosz, N Kurz, I Kojouharov, H Schaffner, A Alcora, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, L Caceres, P Doornenbal, AMD Bacelar, IJ Cullen, ME Estevez, G Farrelly, Y Fujita, W Gelletly, R Hoischen, R Kumar, S Lalkovski, Z Liu, C Mihai, F Molina, D Muecher, B Rubio, A Tamii, S Tashenov, JJ Valiente-Dobon, PM Walker, PJ Woods (2009)beta(-)-DELAYED AND ISOMER SPECTROSCOPY OF NEUTRON-RICH Ta AND W ISOTOPES, In: ACTA PHYSICA POLONICA B40(3)pp. 875-878
S Myalski, A Maj, Z Podolyak, F Becker, P Bednarczyk, G Benzoni, B Blank, C Brandau, AM Bruce, L Caceres, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbal, E Estevez, AB Garnsworthy, H Geissel, W Gelletly, J Gerl, M Corska, H Grawe, J Grebosz, A Heinz, R Hoischen, G Ilie, GA Jones, A Jungclaus, A Kelic, M Kmiecik, I Kojouharov, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkovski, Z Liu, F Montes, M Pfuetzner, S Pietri, W Prokopowicz, PH Regan, D Rudolph, T Saito, H Schaffner, S Schwertel, T Shizuma, AJ Simon, SJ Steer, S Tashenov, PM Walker, E Werner-Malento, O Wieland, HJ Wollersheim (2009)ISOMERIC RATIOS FOR NUCLEI WITH Z=62-67 AND A=142-152 PRODUCED IN THE RELATIVISTIC FRAGMENTATION OF Pb-208, In: ACTA PHYSICA POLONICA B40(3)pp. 879-883
Z Podolyak, SJ Steer, S Pietri, M Gorska, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, J Gerl, HJ Wollersheim, H Grawe, KH Maier, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, T Kurtukian-Nieto, G Benzoni, M Pfuetzner, A Jungclaus, DL Balabanski, C Brandau, BA Brown, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, ME Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, PM Walker, E Werner-Malento, O Wieland (2009)Structure of neutron-rich nuclei around the N=126 closed shell; the yrast structure of Au-205(126) up to spin-parity I-pi = (19/2(+)), In: EUROPEAN PHYSICAL JOURNAL A42(3)pp. 489-493
PH Regan, JJ Valiente-Dobon, C Wheldon, CY Wu, JF Smith, AO Macchiavelli, D Cline, RS Chakrawarthy, R Chapman, M Cromaz, P Fallon, SJ Freeman, A Gorgen, W Gelletly, A Hayes, SD Langdown, IY Lee, X Liang, CJ Pearson, Z Podolyak, R Teng, D Ward, DD Warner, AD Yamamoto (2004)Production of exotic nuclear isomers in multi-nucleon transfer reactions, In: LASER PHYSICS LETTERS1(6)pp. 317-324 IOP PUBLISHING LTD
M Caamano, PM Walker, PH Regan, M Pfutzner, Z Podolyak, J Gerl, M Hellstrom, P Mayet, MN Mineva, A Aprahamian, J Benlliure, AM Bruce, PA Butler, DC Gil, DM Cullen, J Doring, T Enqvist, C Fox, JG Narro, H Geissel, W Gelletly, J Giovinazzo, M Gorska, H Grawe, R Grzywacz, A Kleinbohl, W Korten, M Lewitowicz, R Lucas, H Mach, CD O'Leary, F De Oliveira, CJ Pearson, F Rejmund, M Rejmund, M Sawicka, H Schaffner, C Schlegel, K Schmidt, KH Schmidt, PD Stevenson, C Theisen, F Vives, DD Warner, C Wheldon, HJ Wollersheim, S Wooding, F Xu, O Yordanov (2005)Isomers in neutron-rich A approximate to 190 nuclides from Pb-208 fragmentation, In: EUROPEAN PHYSICAL JOURNAL A23(2)pp. 201-215 SPRINGER
AMD Bacelar, AM Bruce, Z Podolyak, S Lalkovski, S Pietri, N Al-Dahan, M Gorska, A Algora, N Alkhomashi, J Benlliure, P Boutachkov, A Bracco, E Calore, E Casarejos, IJ Cullen, AY Deo, P Detistov, Z Dombradi, C Domingo-Pardo, M Doncel, F Farinon, GF Farrelly, H Geissel, W Gelletly, J Gerl, N Goel, J Grebosz, R Hoischen, I Kojouharov, N Kurz, S Leoni, F Molina, AI Morales, D Montanari, A Musumarra, R Nicolini, DR Napoli, C Nociforo, A Prochazka, W Prokopowicz, PH Regan, B Rubio, D Rudolph, S Verma, SJ Steer, P Strmen, TPD Swan, I Szarka, JJ Valiente-Dobon, PM Walker, H Weick, HJ Wollersheim (2009)ANGULAR MOMENTUM POPULATION IN FRAGMENTATION REACTIONS, In: ACTA PHYSICA POLONICA B40(3)pp. 889-892
Z Podolyak, PH Regan, M Pfutzner, J Gerl, M Hellstrom, M Caamano, P Mayet, C Schlegel, A Aprahamian, J Benlliure, AM Bruce, PA Butler, DC Gil, DM Cullen, J Doring, T Enqvist, F Rejmund, C Fox, JG Narro, H Geissel, W Gelletly, J Giovinazzo, M Gorska, H Grawe, R Grzywacz, A Kleinbohl, W Korten, M Lewitowicz, R Lucas, H Mach, M Mineva, CD O'Leary, F De Oliveira, CJ Pearson, M Rejmund, M Sawicka, H Schaffner, K Schmidt, C Theisen, PM Walker, DD Warner, C Wheldon, HJ Wollersheim, SC Wooding, FR Xu (2000)Isomer spectroscopy of neutron rich W-190(116), In: PHYSICS LETTERS B491(3-4)pp. 225-231 ELSEVIER SCIENCE BV
AI Morales, J Benlliure, PH Regan, Z Podolyak, M Gorska, N Alkhomashi, S Pietri, R Kumar, E Casarejos, J Agramunt, A Algora, H Alvarez-Pol, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, LS Caceres, IJ Cullen, AMD Bacelar, P Doornenbal, D Dragosavac, ME Estevez, G Farrelly, Y Fujita, AB Garnsworthy, W Gelletly, J Gerl, J Grebosz, R Hoischen, I Kojouharov, N Kurz, S Lalkovski, Z Liu, D Perez-Loureiro, W Prokopowicz, C Mihai, F Molina, D Muecher, B Rubio, H Schapffner, SJ Steer, A Tamii, S Tashenov, JJV Dobon, S Verma, PM Walker, HJ Wollersheim, PJ Woods (2009)beta-DELAYED gamma-RAY SPECTROSCOPY OF HEAVY NEUTRON RICH NUCLEI "SOUTH" OF LEAD, In: ACTA PHYSICA POLONICA B40(3)pp. 867-870
C Longour, JG Narro, B Blank, M Lewitowicz, C Miehe, PH Regan, D Applebe, L Axelsson, AM Bruce, WN Catford, C Chandler, RM Clark, DM Cullen, S Czajkowski, JM Daugas, P Dessagne, A Fleury, L Frankland, W Gelletly, J Giovinazzo, B Greenhalgh, R Grzywacz, M Harder, KL Jones, N Kelsall, T Kszczot, RD Page, CJ Pearson, AT Reed, O Sorlin, R Wadsworth (1998)Observation of Fermi superallowed beta(+) decays in heavy odd-odd, N = Z nuclei: Evidence for 0(+) ground states in Y-78, Nb-82, and Tc-86, In: PHYSICAL REVIEW LETTERS81(16)pp. 3337-3340 AMERICAN PHYSICAL SOC
PH Regan, AB Garnsworthy, S Pietri, L Caceres, M Gorska, D Rudolph, Z Podolyak, SJ Steer, R Hoischen, J Gerl, HJ Wollersheim, J Grebosz, H Schaffner, W Prokopwicz, I Kojouharov, F Becker, P Bednarczyk, P Doornenball, H Geissel, H Grawe, A Kelic, N Kurz, F Montes, T Saito, S Tashenov, E Werner-Malento, A Heinz, L Atanasova, D Balabanski, G Benzoni, B Blank, A Blazhev, C Brandau, AM Bruce, F Camera, IJ Cullen, ME Estevez, C Fahlander, W Gelletly, G Ilie, A Jungclaus, J Jolie, T Kurtukian-Nieto, Z Liu, M Kmiecik, A Maj, S Myalski, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wieland (2007)Isomer spectroscopy using relativistic projectile fragmentation at the N=Z line for A similar to 80 -> 90., In: NUCLEAR PHYSICS A787pp. 491C-498C ELSEVIER SCIENCE BV
The preliminary results from the RISING Stopped Beam Isomer Campaign are presented, with specific focus on results of the initial experiment to investigate isomeric decays along the N=Z line around A similar to 80-90 following the projectile fragmentation of a Ag-107 primary beam at an energy of 750 MeV per nucleon. A description of the technical aspects behind the design of the RISING array is presented, together with evidence for previously unreported isomeric decays in Tc-87,Tc-88 and the N=Z nuclei Nb-82(41) and Tc-86(43).
JL Tain, A Algora, J Agramunt, V Guadilla, MD Jordan, A Montaner-Piza, B Rubio, E Valencia, D Cano-Ott, W Gelletly, T Martinez, E Mendoza, Z Podolyak, P Regan, J Simpson, AJ Smith, J Strachan (2015)A decay total absorption spectrometer for DESPEC at FAIR, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT803pp. 36-46 ELSEVIER SCIENCE BV
JL Tain, E Valencia, A Algora, J Agramunt, B Rubio, S Rice, W Gelletly, P Regan, A-A Zakari-Issoufou, M Fallot, A Porta, J Rissanen, T Eronen, J Aysto, L Batist, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V-V Elomaa, E Estevez, GF Farrelly, AR Garcia, B Gomez-Hornillos, V Gorlychev, J Hakala, MD Jordan, A Jokinen, VS Kolhinen, FG Kondev, T Martinez, E Mendoza, I Moore, H Penttila, Z Podolyak, M Reponen, V Sonnenschein, AA Sonzogni (2015)Enhanced gamma-Ray Emission from Neutron Unbound States Populated in beta Decay, In: PHYSICAL REVIEW LETTERS115(6)ARTN 06250 AMER PHYSICAL SOC
T Alharbi, PH Regan, PJR Mason, N Marginean, Z Podolyak, AM Bruce, EC Simpson, A Algora, N Alazemi, R Britton, MR Bunce, D Bucurescu, N Cooper, D Deleanu, D Filipescu, W Gelletly, D Ghita, T Glodariu, G Ilie, S Kisyov, J Lintott, S Lalkovski, S Liddick, C Mihai, K Mulholland, R Marginean, A Negret, M Nakhostin, CR Nita, OJ Roberts, S Rice, JF Smith, L Stroe, T Sava, C Townsley, E Wilson, V Werner, M Zhekova, NV Zamfir (2013)Electromagnetic transition rates in the N=80 nucleus Ce-138(58), In: PHYSICAL REVIEW C87(1)ARTN 01432 AMER PHYSICAL SOC
Z Janas, C Chandler, B Blank, PH Regan, AM Bruce, WN Catford, N Curtis, S Czajkowski, P Dessagne, A Fleury, W Gelletly, J Giovinazzo, R Grzywacz, M Lewitowicz, C Longour, C Marchand, C Miehe, NA Orr, RD Page, CJ Pearson, MS Pravikoff, AT Reed, MG Saint-Laurent, JA Sheikh, SM Vincent, R Wadsworth, DD Warner, JS Winfield (1999)Observation of the Z=N+1 nuclei Y-77(39), Zr-79(40), and Mo-83(42), In: PHYSICAL REVIEW LETTERS82(2)pp. 295-298 AMERICAN PHYSICAL SOC
SJ Steer, Z Podolyak, S Pietri, PH Regan, D Rudolph, E Werner-Malento, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tachenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, A Jungclaus, DL Balabanski, C Brandau, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, S Schwertel, PM Walker, O Wieland (2007)Identification of isomeric states 'south' of Pb-208 via projectile fragmentation, In: ACTA PHYSICA POLONICA B38(4)pp. 1283-1286
PH Regan, GA Jones, Z Podolyak, N Yoshinaga, K Higashiyama, G de Angelis, YH Zhang, A Gadea, CA Ur, M Axiotis, D Bazzacco, R Broda, D Bucurescu, E Farnea, W Gelletly, M Ionescu-Bujor, A Iordachescu, T Kroll, SD Langdown, S Lenzi, S Lunardi, N Marginean, T Martinez, N Medina, R Menegazzo, DR Napoli, B Quintana, B Rubio, C Rusu, R Schwenger, D Tonev, JJ Valiente Dobon, W von Oertzen (2006)Multinucleon transfer reactions to study single-particle evolution in Se isotopes, In: Capture Gamma-Ray Spectroscopy and Related Topics819pp. 464-471
SM Vincent, PH Regan, DD Warner, W Gelletly, J Simpson, R Bark, D Blumenthal, MP Carpenter, CN Davids, DJ Henderson, RVF Janssens, CJ Lister, D Nisius, CD O'Leary, CJ Pearson, T Saitoh, J Schwartz, D Seweryniak, S Tormanen (1998)Probing the structure of the N=Z=31 nucleus Ga-62(31), In: ENAM 98: EXOTIC NUCLEI AND ATOMIC MASSES455pp. 450-455
A Algora, E Valencia, JL Tain, MD Jordan, J Agramunt, B Rubio, E Estevez, F Molina, A Montaner, V Guadilla, M Fallot, A Porta, A-A Zakari-Issoufou, VM Bui, S Rice, Z Podolyak, PH Regan, W Gelletly, M Bowry, P Mason, GF Farrelly, J Rissanen, T Eronen, I Moore, H Penttila, J Aysto, V Eloma, J Hakala, A Jokinen, V Kolkinen, M Reponen, V Sonnenschein, D Cano-Ott, T Martinez, E Mendoza, AR Garcia, MB Gomez-Hornillos, V Gorlychev, R Caballero-Folch, FG Kondev, AA Sonzogni (2014)Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure, In: NUCLEAR DATA SHEETS120pp. 12-15 ACADEMIC PRESS INC ELSEVIER SCIENCE
D Bucurescu, C Rusu, N Marginean, C A Ur, G de Angelis, L Corradi, D Bazzacco, S Beghini, F Della Vedova, G Duchene, E Farnea, T Faul, E Fioretto, A Gadea, W Gelletly, B Guiot, M Ionescu-Bujor, A Lordachescu, S D Landown, S M Lenzi, S Lunardi, P Mason, C Mihai, R Marginean, R Menegazzo, G Montagnoli, D Napoli, Z Podolyak, P H Regan, F Scarlassara, A M Stefanini, G Suliman, S Szilner, M Trotta, J J Valiente-Dobon, Y H Zhang (2007)Gamma-ray Spectroscopy of the Neutron-Rich Nuclei Rb-89, Y-92, and Y-93 with Multinucleon Transfer Reactions, In: Physical Review C76(6)
The positive-parity yrast states in the Rb-89, Y-92, and Y-93 nuclei were studied using gamma-ray spectroscopy with heavy-ion induced reactions. In the multinucleon transfer reactions Pb-208+Zr-90 (590 MeV) and U-238+Se-82 (505 MeV), several gamma-ray transitions were identified in these nuclei by means of coincidences between recoiling ions identified with the PRISMA spectrometer and gamma rays detected with the CLARA gamma-ray array in thin target experiments. Level schemes were subsequently determined from triple-gamma coincidences recorded with the GASP array in a thick target experiment, in the reactions produced by a 470 MeV Se-82 beam with a Os-192 target. The observed level schemes are compared to shell-model calculations.
D. Bucurescu, C. Rusu, N. Mărginean, C. A. Ur, G. de Angelis, L. Corradi, D. Bazzacco, S. Beghini, F. Della Vedova, G. Duchene, E. Farnea, T. Faul, E. Fioretto, A. Gadea, W. Gelletly, B. Guiot, M. Ionescu-Bujor, A. Iordăchescu, S. D. Landown, S. M. Lenzi, S. Lunardi, P. Mason, C. Mihai, R. Mărginean, R. Menegazzo, G. Montagnoli, D. Napoli, Zs. Podolyák, P. H. Regan, F. Scarlassara, A. M. Stefanini, G. Suliman, S. Szilner, M. Trotta, J. J. Valiente-Dobón, Y. H. Zhang (2007)gamma--ray spectroscopy of the neutron-rich nuclei 89Rb, 92Y, and 93Y with multinucleon transfer reactions, In: Physical Review C76(064301)
The positive-parity yrast states in the 89Rb, 92Y, and 93Y nuclei were studied using gamma-ray spectroscopy with heavy-ion induced reactions. In the multinucleon transfer reactions 208Pb+90Zr (590 MeV) and 238U+82Se (505 MeV), several gamma-ray transitions were identified in these nuclei by means of coincidences between recoiling ions identified with the PRISMA spectrometer and gamma rays detected with the CLARA gamma-ray array in thin target experiments. Level schemes were subsequently determined from triple gamma coincidences recorded with the GASP array in a thick target experiment, in the reactions produced by a 470 MeV 82Se beam with a 192Os target. The observed level schemes are compared to shell-model calculations.
S Rice, A Algora, JL Tain, E Valencia, J Agramunt, B Rubio, William Gelletly, Patrick Regan, A-A Zakari-Issoufou, M Fallot, A Porta, J Rissanen, T Eronen, J Aysto, L Batist, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V-V Elomaa, E Estevez, GF Farrelly, AR Garcia, B Gomez-Hornillos, V Gorlychev, J Hakala, MD Jordan, A Jokinen, VS Kolhinen, FG Kondev, T Martinez, E Mendoza, I Moore, H Penttila, Zsolt Podolyak, M Reponen, V Sonnenschein, AA Sonzogni, P Sarriguren (2017)Total Absorption Spectroscopy Study of the Beta Decay of 86Br and 91 1 Rb, In: Physical Review C96014320 American Physical Society
The beta decays of 86Br and 91Rb have been studied using the total absorption spectroscopy technique. The radioactive nuclei were produced at the IGISOL facility in Jyvaskyla and further purified using the JYFLTRAP. 86Br and 91Rb are considered high priority contributors to the decay heat in reactors. In addition 91Rb was used as a normalization point in direct measurements of mean gamma energies released in the beta decay of fission products by Rudstam et al. assuming that this decay was well known from high-resolution measurements. Our results shows that both decays were suffering from the Pandemonium effect and that the results of Rudstam et al. should be renormalized.
S Rice, E Valencia, A Algora, JL Tain, PH Regan, Z Podolyak, J Agramunt, W Gelletly, AL Nichols, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, B Wadsworth, D Watts (2012)Decay Heat Measurements Using Total Absorption Gamma-ray Spectroscopy, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS381ARTN 0pp. ?-? IOP PUBLISHING LTD
AM Bruce, S Lalkovski, AMD Bacelar, M Gorska, S Pietri, Z Podolyak, Y Shi, PM Walker, FR Xu, P Bednarczyk, L Caceres, E Casarejos, IJ Cullen, P Doornenbal, GF Farrelly, AB Garnsworthy, H Geissel, W Gelletly, J Gerl, J Grebosz, C Hinke, G Ilie, G Jaworski, I Kojouharov, N Kurz, S Myalski, M Palacz, W Prokopowicz, PH Regan, H Schaffner, S Steer, S Tashenov, HJ Wollersheim (2010)Shape coexistence and isomeric states in neutron-rich Tc-112 and Tc-113, In: PHYSICAL REVIEW C82(4)ARTN 0pp. ?-? AMER PHYSICAL SOC
MA Bentley, SJ Williams, DT Joss, CD O'Leary, AM Bruce, JA Cameron, MP Carpenter, P Fallon, L Frankland, W Gelletly, CJ Lister, G Martinez-Pinedo, A Poves, PH Regan, P Reiter, B Rubio, JS Solano, D Seweryniak, CE Svensson, SM Vincent, DD Warner (2000)Mirror symmetry at high spin in Fe-51 and Mn-51, In: PHYSICAL REVIEW C62(5)ARTN 05130 AMERICAN PHYSICAL SOC
PH Regan, C Chandler, CJ Pearson, B Blank, R Grzywacz, M Lewitowicz, AM Bruce, WN Catford, N Curtis, S Czajkowski, P Dessagne, A Fleury, W Gelletly, J Giovinazzo, Z Janas, C Longour, C Marchand, C Miehe, NA Orr, RD Page, MS Pravikoff, AT Reed, MG SaintLaurent, SM Vincent, R Wadsworth, DD Warner, JS Winfield (1997)Studies of isomeric states and limits of particle stability around N greater than or similar to Z greater than or similar to 40 using fragmentation reactions, In: ACTA PHYSICA POLONICA B28(1-2)pp. 431-442
AA Zakari-Issoufou, A Porta, M Fallot, A Algora, JL Tain, E Valencia, S Rice, J Agramunt, J Äystö, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V Eloma, E Estévez, GF Farrelly, A Garcia, W Gelletly, MB Gomez-Hornillos, V Gorlychev, J Hakala, A Jokinen, MD Jordan, A Kankainen, FG Kondev, T Martinez, E Mendoza, F Molina, I Moore, A Perez, Z Podolyak, H Penttilä, PH Regan, J Rissanen, B Rubio, C Weber (2013)Measurement of fission products β decay properties using a total absorption spectrometer, In: EPJ Web of Conferences62
In a nuclear reactor, the decay of fission fragments is at the origin of decay heat and antineutrino flux. These quantities are not well known while they are very important for reactor safety and for our understanding of neutrino physics. One reason for the discrepancies observed in the estimation of the decay heat and antineutrinos flux coming from reactors could be linked with the Pandemonium effect. New measurements have been performed at the JYFL facility of Jyväskylä with a Total Absorption Spectrometer (TAS) in order to circumvent this effect. An overview of the TAS technique and first results from the 2009 measurement campaign will be presented. © Owned by the authors, published by EDP Sciences, 2013.
PH Regan, C Wheldon, AD Yamamoto, CY Wu, S Ashley, P Mumby-Croft, D Seaborne, AO Macchiavelli, D Cline, JF Smith, RS Chakrawarthy, M Cromaz, P Fallon, SJ Freeman, W Gelletly, A Gorgen, A Hayes, H Hua, SD Langdown, IY Lee, CJ Pearson, Z Podolyak, R Teng, JJ Valiente-Dobon (2004)Structural evolution in the (N,Z,I-pi) coordinate frame for A-100, In: NUCLEAR PHYSICS, LARGE AND SMALL726pp. 157-162
LS Caceres, M Gorska, A Jungclaus, PH Regan, AB Garnsworthy, S Pietri, Z Podolyak, D Rudolph, SJ Steer, H Grawe, DL Balabanski, F Becker, P Bednarczyk, G Benzoni, B Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbalal, E Estevez, H Geissel, W Gelletly, J Gerl, J Grebosz, A Heinz, R Hoischen, G Ilie, J Jolie, GA Jones, M Kmiecik, I Kojouharov, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkowski, L Liu, A Maj, S Myalsk, F Montes, M Pfuetzner, W Prokopowicz, T Saito, H Schatfner, S Schwertel, T Shizuma, AJ Simons, S Tashenov, PM Walker, E Werner-Malento, O Wielandh, HJ Wollersheim (2007)Identification of excited states in the N = Z nucleus Nb-82, In: ACTA PHYSICA POLONICA B38(4)pp. 1271-1275
M Pfutzner, PH Regan, PM Walker, M Caamano, J Gerl, M Hellstrom, P Mayet, KH Schmidt, Z Podolyak, MN Mineva, A Aprahamian, J Benlliure, AM Bruce, PA Butler, DC Gil, DM Cullen, J Doring, T Enquist, C Fox, J Garces Narro, H Geissel, W Gelletly, J Giovinazzo, M Gorska, H Grawe, R Grzywacz, A Kleinbohl, W Korten, M Lewitowicz, R Lucas, H Mach, CD O'Leary, F De Oliveira, CJ Pearson, F Rejmund, M Rejmund, M Sawicka, H Schaffner, C Schlegel, K Schmidt, C Theisen, F Vives, DD Warner, C Wheldon, HJ Wollersheim, S Wooding (2002)Angular momentum population in the fragmentation of Pb-208 at 1 GeV/nucleon, In: PHYSICAL REVIEW C65(6)ARTN 0pp. ?-? AMERICAN PHYSICAL SOC
S Mohammadi, Z Podolyak, G de Angelis, M Axiotis, D Bazzacco, PG Bizzeti, F Brandolini, R Broda, D Bucurescu, E Farnea, W Gelletly, A Gadea, M Ionescu-Bujor, A Iordachescu, T Kroll, S Longdown, S Lunardi, N Marginean, T Martinez, NH Medina, B Quintana, PH Regan, B Rubio, CA Ur, JJV Dobon, PM Walker, YH Zhang (2004)High-spin states populated in deep-inelastic reactions, In: BRAZILIAN JOURNAL OF PHYSICS34(3A)pp. 792-795
D Bucurescu, Z Podolyak, C Rusu, G de Angelis, YH Zhang, G Cata-Danil, I Cata-Danil, M Ivascu, N Marginean, R Marginean, LC Mihailescu, GA Suliman, PH Regan, W Gelletly, SD Langdown, JJV Dobon, D Bazzacco, S Lunardi, CA Ur, M Axiotis, A Gadea, E Farnea, M Ionescu-Bujor, A Iordachescu, T Kroll, T Martinez, PG Bizzetti, R Broda, NH Medina, B Quintana, B Rubio (2005)High-spin states in the nuclei Y-91 and Nb-95, In: PHYSICAL REVIEW C71(3)ARTN 0pp. ?-? AMERICAN PHYSICAL SOC
PJR Mason, Zsolt Podolyak, N Marginean, Patrick Regan, Paul Stevenson, V Werner, T Alexander, A Algora, T Alharbi, M Bowry, R Britton, AM Bruce, D Bucurescu, M Bunce, G Cata-Danil, I Cata-Danil, N Cooper, D Deleanu, D Delion, D Filipescu, William Gelletly, D Ghita, I Gheorghe, T Glodariu, G Ilie, D Ivanova, S Kisyov, S Lalkovski, R Lica, SN Liddick, R Marginean, C Mihai, K Mulholland, CR Nita, A Negret, S Pascu, S Rice, OJ Roberts, T Sava, JF Smith, P-A Soederstroem, L Stroe, G Suliman, R Suvaila, S Toma, C Townsley, E Wilson, Rachael Wood, M Zhekova, C Zhou (2013)Half-life of the yrast 2(+) state in W-188: Evolution of deformation and collectivity in neutron-rich tungsten isotopes, In: PHYSICAL REVIEW C88(4)044301pp. ?-? AMER PHYSICAL SOC
The half-life of the yrast I π = 2+ state in the neutron-rich nucleus 188W has been measured using fast-timing techniques with the HPGe and LaBr3:Ce array at the National Institute of Physics and Nuclear Engineering, Bucharest. The resulting value of t1/2 = 0.87(12) ns is equivalent to a reduced transition probability of B(E2; 2+ 1 → 0+ 1 ) = 85(12) W.u. for this transition. The B(E2; 2+ 1 → 0+ 1 ) is compared to neighboring tungsten isotopes and nuclei in the Hf, Os, and Pt isotopic chains. Woods-Saxon potential energy surface (PES) calculations have been performed for nuclei in the tungsten isotopic chain and predict prolate deformed minima with rapidly increasing γ softness for 184–192W and an oblate minimum for 194W.
C Chandler, PH Regan, B Blank, CJ Pearson, AM Bruce, WN Catford, N Curtis, S Czajkowski, P Dessagne, A Fleury, W Gelletly, J Giovinazzo, R Grzywacz, Z Janas, M Lewitowicz, C Marchand, C Miehe, NA Orr, RD Page, MS Pravikoff, AT Reed, MG Saint-Laurent, SM Vincent, R Wadsworth, DD Warner, JS Winfield, F Xu (2000)Observation of isomeric states in neutron deficient A similar to 80 nuclei following the projectile fragmentation of Mo-92, In: PHYSICAL REVIEW C61(4)ARTN 04430 AMERICAN PHYSICAL SOC
SF Ashley, A Linnemann, J Jolie, PH Regan, K Andgren, A Dewald, EA McCutchan, B Melon, O Moeller, NV Zamfir, L Amon, N Boelaert, RB Cakirli, RF Casten, RM Clark, C Fransen, W Gelletly, G Gurdal, M Heidemann, KL Keyes, MN Erduran, DA Meyer, A Papenberg, C Plettner, G Rainovski, RV Ribas, NJ Thomas, J Vinson, DD Warner, V Werner, E Williams, KO Zell (2007)Lifetime determination of excited states in Cd-106, In: ACTA PHYSICA POLONICA B38(4)pp. 1385-1388
SF Ashley, PH Regan, K Andgren, EA McCutchan, NV Zamfir, L Amon, RB Cakirli, RF Casten, RM Clark, W Gelletly, G Guerdal, KL Keyes, DA Meyer, MN Erduran, A Papenberg, N Pietralla, C Plettner, G Rainovski, RV Ribas, NJ Thomas, J Vinson, DD Warner, V Werner, E Williams, HL Liu, FR Xu (2007)Intrinsic state lifetimes in (103)Pd and (106,107)Cd, In: PHYSICAL REVIEW C76(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
N Alkhomashi, PH Regan, Z Podolyák, S Pietri, AB Garnsworthy, SJ Steer, J Benlliure, E Caserejos, RF Casten, J Gerl, HJ Wollersheim, J Grebosz, G Farrelly, M Górska, I Kojouharov, H Schaffner, A Algora, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, AMD Bacelar, IJ Cullen, L Cáceres, P Doornenbal, ME Estevez, Y Fujita, W Gelletly, R Hoischen, R Kumar, N Kurz, S Lalkovski, Z Liu, C Mihai, F Molina, AI Morales, D Mücher, W Prokopowicz, B Rubio, Y Shi, A Tamii, S Tashenov, JJ Valiente-Dobón, PM Walker, PJ Woods, FR Xu (2009)β - Dcopy of neutron-rich tantalum nuclei: Shape evolution in neutron-rich tungsten isotopes, In: Physical Review C - Nuclear Physics80(6)064308pp. 1-12
RS Kempley, Z Podolyak, D Bazzacco, A Gadea, E Farnea, JJ Valiente-Dobon, D Mengoni, F Recchia, E Sahin, A Gottardo, L Corradi, E Fioretto, S Szilner, V Anagnostatou, N Al-Dahan, G De Angelis, M Bellato, B Berti, D Bortolato, M Bowry, M Bunce, P Cocconi, A Colombo, Z Dombradi, C Fanin, W Gelletly, R Isocrate, S Ketenci, N Kondratyev, I Kuti, PJR Mason, C Michelagnoli, T Mijatovic, P Molini, G Montagnioli, D Montanari, M Nakhostin, DR Napoli, D Pellegrini, PH Regan, G Rampazzo, P Reiter, D Rosso, F Scarlassara, A Stefanini, P Singh, N Toniolo, CA Ur (2011)CROSS-COINCIDENCES IN THE Xe-136+Pb-208 DEEP-INELASTIC REACTION, In: ACTA PHYSICA POLONICA B42(3-4)pp. 717-720
S Myalski, A Maj, Z Podolyak, M Kmiecik, P Bednarczyk, J Grebosz, PH Regan, AB Garnsworthy, S Pietri, D Rudolph, SJ Steer, F Becker, J Gerl, M Gorska, H Grawe, I Kojouharov, H Schaffner, HJ Wollersheim, W Prokopowicz, G Benzoni, B Blank, C Brandau, AM Bruce, L Caceres, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbal, E Estevez, H Geissel, W Gelletly, A Heinz, R Hoischen, G Ilie, GA Jones, A Jungclaus, A Kelic, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkovski, Z Liu, F Montes, M Pfuetzner, T Saito, T Shizuma, AJ Simons, S Schwertel, S Tachenov, PM Walker, E Werner-Malento, O Wieland (2012)STUDY OF ISOMER PRODUCTION RATES FOR A=142-152 AND Z=62-67 IN FRAGMENTATION OF A RELATIVISTIC Pb-208 BEAM, In: ACTA PHYSICA POLONICA B43(2)pp. 253-259 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
CS PURRY, PM WALKER, GD DRACOULIS, T KIBEDI, S BAYER, AM BRUCE, AP BYRNE, M DASGUPTA, W GELLETLY, F KONDEV, PH REGAN, C THWAITES (1995)ROTATION OF AN 8-QUASI-PARTICLE ISOMER, In: PHYSICAL REVIEW LETTERS75(3)pp. 406-409 AMERICAN PHYSICAL SOC
E Grodner, A Gadea, P Sarriguren, SM Lenzi, J Grebosz, JJ Valiente-Dobon, A Algora, M Gorska, PH Regan, D Rudolph, G de Angelis, J Agramunt, N Alkhomashi, LA Susam, D Bazzacco, J Benlliure, G Benzoni, P Boutachkov, A Bracco, L Caceres, RB Cakirli, FCL Crespi, C Domingo-Pardo, M Doncel, Z Dombradi, P Doornenbal, E Farnea, E Ganioglu, W Gelletly, J Gerl, A Gottardo, T Hueyuek, N Kurz, S Leoni, D Mengoni, F Molina, AI Morales, R Orlandi, Y Oktem, RD Page, D Perez, S Pietri, Z Podolyak, A Poves, B Quintana, S Rinta-Antila, B Rubio, BSN Singh, AN Steer, S Verma, R Wadsworth, O Wieland, HJ Wollersheim (2014)Hindered Gamow-Teller Decay to the Odd-Odd N = Z Ga-62: Absence of Proton-Neutron T=0 Condensate in A=62, In: PHYSICAL REVIEW LETTERS113(9)ARTN 09250 AMER PHYSICAL SOC
T Alharbi, PJR Mason, PH Regan, N Marginean, Z Podolyak, A Algora, N Alazemi, AM Bruce, R Britton, MR Bunce, D Bucurescu, N Cooper, D Deleanu, D Filipescu, W Gelletly, D Ghita, T Glodariu, G Ilie, S Kisyov, J Lintott, S Lalkovski, S Liddick, C Mihai, K Mulholland, R Marginean, A Negret, M Nakhostin, OJ Roberts, S Rice, JF Smith, L Stroe, T Sava, C Townsley, E Wilson, V Werner, M Zhekova, NV Zamfir, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, B Wadsworth, D Watts (2012)Electromagnetic Transition Rate Measurements in the N=80 Isotone, Ce-138, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS381ARTN 0pp. ?-? IOP PUBLISHING LTD
JG Narro, C Longour, PH Regan, B Blank, CJ Pearson, M Lewitowicz, C Miehe, W Gelletly, D Appelbe, L Axelsson, AM Bruce, WN Catford, C Chandler, RM Clark, DM Cullen, S Czajkowski, JM Daugas, P Dessagne, A Fleury, L Frankland, J Giovinazzo, B Greenhalg, R Grzywacz, M Harder, KL Jones, N Kelsall, T Kszczot, RD Page, AT Reed, O Sorlin, R Wadsworth (2001)Fermi superallowed beta(+) decays and T=1 ground states of heavy odd-odd N=Z nuclei, In: PHYSICAL REVIEW C63(4)ARTN 04430 AMERICAN PHYSICAL SOC
PH Regan, GA Jones, Z Podolyak, G de Angelis, YH Zhang, A Gadea, CA Ur, M Abdullah, M Axiotis, D Bazzacco, R Broda, D Bucurescu, E Farnea, W Gelletly, M Ionescu-Bujor, A Iordachescu, T Kroell, SD Langdown, S Lenzi, S Lunardi, N Marginean, T Martinez, N Medina, R Menegazzo, DR Napoli, B Quintana, B Rubio, C Rusu, R Schwenger, D Tonev, JJ Valiente-Dobon, W von Oertzen, G Wollel (2006)Nuclear structure and reaction mechanism studies with multinucleon reactions, In: FUSION06: Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier853pp. 271-276
JJ Valiente-Dobon, CJ Pearson, PH Regan, PJ Sellin, W Gelletly, E Morton, A Boston, M Descovich, PJ Nolan, J Simpson, I Lazarus, D Warner (2003)Performance of a 6x6 segmented germanium detector for gamma-ray tracking, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT505(1-2)pp. 174-177
SJ Williams, MA Bentley, DD Warner, AM Bruce, JA Cameron, MP Carpenter, P Fallon, L Frankland, W Gelletly, RVF Janssens, DT Joss, CD O'Leary, CJ Lister, A Poves, PH Regan, P Reiter, B Rubio, D Seweryniak, CE Svensson, SM Vincent (2003)Anomalous Coulomb matrix elements in the f(7/2) shell, In: PHYSICAL REVIEW C68(1)ARTN 01130 AMERICAN PHYSICAL SOC
A-A Zakari-Issoufou, M Fallot, A Porta, A Algora, JL Tain, E Valencia, S Rice, VM Bui, S Cormon, M Estienne, J Agramunt, J Aysto, M Bowry, JA Briz, R Caballero-Folch, D Cano-Ott, A Cucoanes, V-V Elomaa, T Eronen, E Estevez, GF Farrelly, AR Garcia, W Gelletly, MB Gomez-Hornillos, V Gorlychev, J Hakala, A Jokinen, MD Jordan, A Kankainen, P Karvonen, VS Kolhinen, FG Kondev, T Martinez, E Mendoza, F Molina, I Moore, AB Perez-Cerdan, Z Podolyak, H Penttila, PH Regan, M Reponen, J Rissanen, B Rubio, T Shiba, AA Sonzogni, C Weber (2015)Total Absorption Spectroscopy Study of Rb-92 Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape, In: PHYSICAL REVIEW LETTERS115(10)ARTN 10250 AMER PHYSICAL SOC
N Al-Dahan, PH Regan, Z Podolyák, PM Walker, N Alkhomashi, GD Dracoulis, G Farrelly, J Benlliure, SB Pietri, RF Casten, PD Stevenson, W Gelletly, SJ Steer, AB Garnsworthy, E Casarejos, J Gerl, HJ Wollersheim, J Grebosz, M Górska, I Kojouharov, H Schaffner, A Algora, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, IJ Cullen, AM Denis Bacelar, AY Deo, ME Estevez, Y Fujita, R Hoischen, R Kumar, S Lalkovski, Z Liu, PJ Mason, C Mihai, F Molina, D Mücher, B Rubio, A Tamii, S Tashenov, JJ Valiente-Dobón, PJ Woods (2012)Multiple β - Decaying states in 194Re: Shape evolution in neutron-rich osmium isotopes, In: Physical Review C - Nuclear Physics85(3)034301pp. ?-? American Physical Society
decays from heavy, neutron-rich nuclei with A∼190 have been investigated following their production via the relativistic projectile fragmentation of an E/A=1 GeV 208Pb primary beam on a ∼2.5 g/cm2 9Be target. The reaction products were separated and identified using the GSI FRagment Separator (FRS) and stopped in the RISING active stopper. γ decays were observed and correlated with these secondary ions on an event-by-event basis such that γ-ray transitions following from both internal (isomeric) and β decays were recorded. A number of discrete, β-delayed γ-ray transitions associated with β decays from 194Re to excited states in 194Os have been observed, including previously reported decays from the yrast Iπ=(6+) state. Three previously unreported γ-ray transitions with energies 194, 349, and 554 keV are also identified; these transitions are associated with decays from higher spin states in 194Os. The results of these investigations are compared with theoretical predictions from Nilsson multi-quasiparticle (MQP) calculations. Based on lifetime measurements and the observed feeding pattern to states in 194Os, it is concluded that there are three β−-decaying states in 194Re.
D Bucurescu, C Rusu, N Marginean, CA Ur, G de Angelis, L Corradi, D Bazzacco, S Beghini, F Della Vedova, G Duchene, E Farnea, T Faul, E Fioretto, A Gadea, W Gelletly, B Guiot, M Ionescu-Bujor, A Iordachescu, SD Landown, SM Lenzi, S Lunardi, P Mason, C Mihai, R Marginean, R Menegazzo, G Montagnoli, D Napoli, Z Podolyak, PH Regan, F Scarlassara, AM Stefanini, G Suliman, S Szilner, M Trotta, JJ Valiente-Dobon, YH Zhang (2007)gamma-ray spectroscopy of the neutron-rich nuclei (89)Rb, (92)Y, and (93)Y with multinucleon transfer reactions, In: PHYSICAL REVIEW C76(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
C Wheldon, JJ Valiente-Dobon, PH Regan, CJ Pearson, CY Wu, JF Smith, AO Macchiavelli, D Cline, RS Chakrawarthy, R Chapman, M Cromaz, P Fallon, SJ Freeman, A Gorgen, W Gelletly, A Hayes, H Hua, SD Langdown, IY Lee, X Liang, Z Podolyak, G Sletten, R Teng, D Ward, DD Warner, AD Yamamoto (2004)Multi-quasi particle states in W-184 via multi-nucleon transfer, In: EUROPEAN PHYSICAL JOURNAL A20(3)pp. 365-369 SPRINGER
P. H. Regan, T. M. Menezes, C. J. Pearson, W. Gelletly, C. S. Purry, P. M. Walker, S. Juutinen, R. Julin, K. Helariutta, A. Savelius, P. Jones, P. Jämsen, M. Muikku, P. A. Butler, G. Jones, P. Greenlees (1997)Observation of (h11/2)2 neutron alignments in 100Mo, 104Ru, and 108Pd using deep inelastic reactions, In: Physical Review C55(2305)pp. 2305-2313
MA Bentley, SJ Williams, DT Joss, CD O'Leary, AM Bruce, L Frankland, JA Cameron, CE Svensson, MP Carpenter, CJ Lister, R Reiter, D Seweryniak, P Fallon, W Gelletly, PH Regan, G Martinez-Pinedo, A Poves, JS Solano, B Rubio, DD Warner (2002)Mirror symmetry and coulomb energies at high angular momentum, In: REVISTA MEXICANA DE FISICA48pp. 123-128
E Valencia, A Algora, JL Tain, S Rice, J Agramunt, AA Zakari-Issoufou, A Porta, M Fallot, MD Jordan, F Molina, E Estevez, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V Eloma, T Eronen, A Garcia, MB Gomez-Hornillos, V Gorlychev, J Hakala, A Jokinen, FG Kondev, T Martinez, I Moore, J Rissanen, J Äystö, H Penttilä, A Kankainen, B Rubio, W Gelletly, A Perez, Z Podolyak, PH Regan, GF Farrelly, C Weber, E Mendoza (2013)Total absorption γ-ray spectroscopy of beta delayed neutron emitters, In: AIP Conference Proceedings1541pp. 161-162
Preliminary results of the data analysis of the beta decay of 94Rb using a novel - segmented- total absorption spectrometer are shown in this contribution. This result is part of a systematic study of important contributors to the decay heat problem in nuclear reactors. In this particular case the goal is to determine the beta intensity distribution below the neutron separation energy and the gamma/beta competition above. © 2013 AIP Publishing LLC.
SJ Steer, ZS PodolyÁk, S Pietri, M GÓrska, GF Farrelly, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, J Gerl, HJ Wollersheim, H Grawe, KH Maier, F Becker, P Bednarczyk, L CÁceres, P Doornenbal, H Geissel, J Grbosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, T Kurtukian-Nieto, G Benzoni, M PfÜtzner, A Jungclaus, DL Balabanski, C Brandau, A Brown, AM Bruce, WN Catford, IJ Cullen, Z DombrÁdi, ME Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R KrÜcken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, PM Walker, E Werner-Malento, O Wieland (2009)Isomeric decay studies in neutron-rich N ≈ 126 nuclei, In: International Journal of Modern Physics E18(4)pp. 1002-1007
Heavy neutron-rich nuclei were populated via relativistic energy fragmentation of a E/A=1 GeV 208Pb beam. The nuclei of interest were selected and identified by a fragment separator and then implanted in a passive plastic stopper. Delayed rays following internal isomeric decays were detected by the RISING array. Experimental information was obtained on a number of nuclei with Z=73-80 (Ta-Hg), providing new information both on the prolate-oblate transitional region as well as on the N=126 closed shell nuclei.
SJ Steer, Z Podolyak, S Pietri, M Gorska, PH Regan, D Rudolph, E Werner-Malento, AB Garnsworthy, R Hoischen, J Gerl, HJ Wollersheim, KH Maier, H Grawe, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Greabosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, A Jungclaus, DL Balabanski, C Brandau, BA Brown, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, ME Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, PM Walker, O Wieland (2008)Single-particle behavior at N=126: Isomeric decays in neutron-rich Pt-204, In: PHYSICAL REVIEW C78(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
SM Vincent, PH Regan, S Mohammadi, D Blumenthal, M Carpenter, CN Davids, W Gelletly, SS Ghugre, DJ Henderson, RVF Janssens, M Hjorth-Jensen, B Kharraja, CJ Lister, CJ Pearson, D Seweryniak, J Schwartz, J Simpson, DD Warner (1999)Near yrast study of the fpg shell nuclei Ni-58, Cu-61, and Zn-61, In: PHYSICAL REVIEW C60(6)ARTN 06430 AMER PHYSICAL SOC
E Valencia, JL Tain, A Algora, J Agramunt, E Estevez, MD Jordan, B Rubio, S Rice, Patrick Regan, William Gelletly, Zsolt Podolyak, M Bowry, P Mason, GF Farrelly, A Zakari-Issoufou, M Fallot, A Porta, VM Bui (2017)Total absorption γ -ray spectroscopy of the β-delayed neutron emitters 87Br, 88Br, and 94Rb, In: Physical Review C: Nuclear Physics024320 American Physical Society
We investigate the decay of 87,88Br and 94Rb using total absorption γ -ray spectroscopy. These important fission products are β-delayed neutron emitters. Our data show considerable βγ intensity, so far unobserved in high-resolution γ -ray spectroscopy, from states at high excitation energy. We also find significant differences with the β intensity that can be deduced from existing measurements of the β spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for 235U fission at cooling times in the range 1–100 s. We also use summation calculations to evaluate the impact of present data on reactor antineutrino spectra. We find a significant effect at antineutrino energies in the range of 5 to 9 MeV. In addition, we observe an unexpected strong probability for γ emission from neutron unbound states populated in the daughter nucleus. The γ branching is compared to Hauser-Feshbach calculations, which allow one to explain the large value for bromine isotopes as due to nuclear structure. However the branching for 94Rb, although much smaller, hints of the need to increase the radiative width γ by one order of magnitude. This increase in γ would lead to a similar increase in the calculated (n,γ ) cross section for this very neutron-rich nucleus with a potential impact on r process abundance calculations.
C Schlegel, PH Regan, M Pfutzner, J Gerl, M Hellstrom, Z Podolyak, M Caamano, P Mayet, A Aprahamian, J Benlliure, AM Bruce, PA Butler, DC Gil, DM Cullen, J Doring, T Enquist, E Farget, C Fox, JG Narro, W Gelletly, J Giovinazzo, M Gorska, H Grawe, R Grzywacz, A Kleinbohl, W Korten, M Lewitowicz, R Lucas, H Mach, M Mineva, C O'Leary, F De Oliveira, CJ Pearson, M Rejmund, M Sawicka, H Schaffner, K Schmidt, C Theisen, PM Walker, DD Warner, C Wheldon, HJ Wollersheim, S Wooding, F Xu (2000)K-isomers in very neutron-rich nuclei around mass 180, In: PHYSICA SCRIPTAT88pp. 72-76
AA Zakari-Issoufou, A Algora, J Agramunt, J Aysto, M Bowry, VM Bui, R Caballero-Folch, D Cano-Ott, V Eloma, E Estevez, M Fallot, GF Farrelly, A Garcia, W Gelletly, MB Gomez-Hornillos, V Gorlychev, J Hakala, A Jokinen, MD Jordan, A Kankainen, FG Kondev, T Martinez, E Mendoza, F Molina, I Moore, A Perez, A Porta, Z Podolyak, H Penttila, PH Regan, S Rice, J Rissanen, B Rubio, JL Tain, E Valencia, C Weber (2013)The total absorption spectroscopy technique for reactor technology and basic nuclear physics, In: IEEE Nuclear Science Symposium Conference Record
Understanding the β-decay properties of fission products is very important for nuclear reactor monitoring & safety. Indeed, the β-decay of fission products is a source of power during nuclear reactor operation and after, this activity is the main contributor to the decay-heat representing ∼7-8% of a reactor nominal power. β-decay is also at the origin of the antineutrinos coming from nuclear reactor. The study of antineutrinos is mandatory for nuclear safeguard policies based on antineutrino detection. But there are still some discrepancies in the calculation of the decay-heat and antineutrino spectra. One reason of the distortions observed seems to be linked to the Pandemonium effect. In order to improve the accuracy in the prediction of these quantities, new measurements of fission products β-decay properties, not sensitive to this effect, have been performed with a Total Absorption spectrometer (TAS). An overview of the TAS technique and first results from the latest experiment will be presented. © 2013 IEEE.
Z Podolyak, GF Farrelly, PH Regan, AB Garnsworthy, SJ Steer, M Gorska, J Benlliure, E Casarejos, S Pietri, J Gerl, HJ Wollersheim, R Kumar, F Molina, A Algora, N Alkhomashi, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, L Caceres, IJ Cullen, AMD Bacelar, P Doornenbal, ME Estevez, Y Fujita, W Gelletly, H Geissel, H Grawe, J Grebosz, R Hoischen, I Kojouharov, S Lalkovski, Z Liu, KH Maier, C Mihai, D Muecher, B Rubio, H Schaffner, A Tamii, S Tashenov, JJ Valiente-Dobon, PM Walker, PJ Woods (2009)Proton-hole excitation in the closed shell nucleus Au-205, In: PHYSICS LETTERS B672(2)pp. 116-119 ELSEVIER SCIENCE BV
AI Morales, J Benlliure, M Gorska, H Grawe, S Verma, PH Regan, Z Podolyak, S Pietri, R Kumar, E Casarejos, A Algora, N Alkhomashi, H Alvarez-Pol, G Benzoni, A Blazhev, P Boutachkov, AM Bruce, LS Caceres, IJ Cullen, AMD Bacelar, P Doornenbal, ME Estevez-Aguado, G Farrelly, Y Fujita, AB Garnsworthy, W Gelletly, J Gerl, J Grebosz, R Hoischen, I Kojouharov, N Kurz, S Lalkovski, Z Liu, C Mihai, F Molina, D Muecher, W Prokopowicz, B Rubio, H Schaffner, SJ Steer, A Tamii, S Tashenov, JJ Valiente-Dobon, PM Walker, HJ Wollersheim, PJ Woods (2013)beta-delayed gamma-ray spectroscopy of Au-203,Au-204 and Pt200-202, In: PHYSICAL REVIEW C88(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
PH Regan, AD Yamamoto, FR Xu, CY Wu, AO Macchiavelli, D Cline, JF Smith, SJ Freeman, JJ Valiente-Dobon, K Andgren, RS Chakrawarthy, M Cromaz, P Fallon, W Gelletly, A Gorgen, A Hayes, H Hua, SD Langdown, IY Lee, CJ Pearson, Z Podolyak, R Teng, C Wheldon (2003)Binary-reaction spectroscopy of Mo-99,Mo-100: Intruder alignment systematics in N=57 and N=58 isotones, In: PHYSICAL REVIEW C68(4)ARTN 0pp. ?-? AMERICAN PHYSICAL SOC
CS Purry, PM Walker, GD Dracoulis, T Kibedi, FG Kondev, S Bayer, AM Bruce, AP Byrne, W Gelletly, PH Regan, C Thwaites, O Burglin, N Rowley (1998)Multi-quasiparticle isomers and rotational bands in W-178, In: NUCLEAR PHYSICS A632(2)pp. 229-274 ELSEVIER SCIENCE BV
H Al-Sulaiti, T Nasir, PH Regan, D Bradley, K Al-Mugren, N Alkhomashi, N Al-Dahan, M Al-Dosari, SJ Bukhari, M Matthews, T Santawamaitre, D Malain, A Habib (2014)Effect of the grain size of the soil on the measured activity and variation in activity in surface and subsurface soil samples, In: Pakistan Journal of Scientific and Industrial Research Series A: Physical Sciences57(3)pp. 129-138
Correlation between grain size and activity concentrations of soils and concentrations of various radionuclides in surface and subsurface soils has been measured for samples taken in the State of Qatar by gamma-spectroscopy using a high purity germanium detector. From the obtained gamma-ray spectra, the activity concentrations of the 238U (226Ra) and 232Th (228Ac) natural decay series, the long-lived naturally occurring radionuclide 40K and the fission product radionuclide 137Cs have been determined. Gamma dose rate, radium equivalent, radiation hazard index and annual effective dose rates have also been estimated from these data. In order to observe the effect of grain size on the radioactivity of soil, three grain sizes were used i.e., smaller than 0.5 mm; smaller than 1 mm and greater than 0.5 mm; and smaller than 2 mm and greater than 1 mm. The weighted activity concentrations of the 238U series nuclides in 0.5-2 mm grain size of sample numbers was found to vary from 2.5±0.2 to 28.5±0.5 Bq/kg, whereas, the weighted activity concentration of 40 K varied from 21±4 to 188±10 Bq/kg. The weighted activity concentrations of 238U series and 40 K have been found to be higher in the finest grain size. However, for the 232Th series, the activity concentrations in the 1-2 mm grain size of one sample were found to be higher than in the 0.5-1 mm grain size. In the study of surface and subsurface soil samples, the activity concentration levels of 238 U series have been found to range from 15.9±0.3 to 24.1±0.9 Bq/kg, in the surface soil samples (0-5 cm) and 14.5±0.3 to 23.6±0.5 Bq/kg in the subsurface soil samples (5-25 cm). The activity concen- trations of 232Th series have been found to lie in the range 5.7±0.2 to 13.7±0.5 Bq/kg, in the surface soil samples (0-5 cm) and 4.1±0.2 to 15.6±0.3 Bq/kg in the subsurface soil samples (5-25 cm). The activity concentrations of 40K were in the range 150±8 to 290±17 Bq/kg, in the surface soil samples (0-5 cm) and 129±7 to 299±14 Bq/kg, in the subsurface soil samples (5-25 cm). The activity concentrations of 238U series, 232Th series and 40K in the surface and deep soil samples are approximately same. The 137Cs activity concentration levels in surface soil samples in four sites were found to be higher than those observed for the soil samples that been collected at a depth of 5-25 cm. They ranged from 1.65±0.22 to 19.0±0.9 Bq/kg, in the surface soil samples (0-5 cm) and 0.5±0.2 to 15.4±0.7 Bq/kg, in the subsurface soil samples (5-25 cm).
AS Habib, DA Bradley, PH Regan, AL Shutt (2010)The use of MCNP and gamma spectrometry in supporting the evaluation of NORM in Libyan oil pipeline scale, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 245-251
D Malain, PH Regan, DA Bradley, M Matthews, HA Al-Sulaiti, T Santawamaitre (2012)An evaluation of the natural radioactivity in Andaman beach sand samples of Thailand after the 2004 tsunami., In: Appl Radiat Isot70(8)pp. 1467-1474
Following the 2004 'Boxing day' tsunami, a determination has been made of the activity concentrations of (226)Ra, (232)Th and (40)K in beach sand samples which have been collected from various locations along the Andaman coast of the Thai peninsula. Use has been made of a HPGe detector-based, low-background gamma-ray counting system. The natural radioactivity levels of (226)Ra, (232)Th and (40)K measured from these samples was found to lie in the range 1.6-52.5, 0.3-73.9 and 2.8-1111.9Bq/kg respectively for the west coast and 3.5-83.1, 4.5-42.0, and 9.6-1376 Bq/kg respectively for the east coast. The radioactivity concentrations of (226)Ra, (232)Th and (40)K along the Andaman coast are comparable to that of the east coast, which was not exposed to the tsunami. The corresponding annual effective dose varies from 1.6-105.9 μSv/y with a mean value of 59.1 ± 0.3 μSv/y, significantly lower than the worldwide average as reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) (2000).
N Alazemi, AD Bajoga, DA Bradley, PH Regan, H Shams (2016)Soil radioactivity levels, radiological maps and risk assessment for the state of Kuwait., In: Chemosphere154pp. 55-62 Elsevier
An evaluation of the radioactivity levels associated with naturally occurring radioactive materials has been undertaken as part of a systematic study to provide a surface radiological map of the State of Kuwait. Soil samples from across Kuwait were collected, measured and analysed in the current work. These evaluations provided soil activity concentration levels for primordial radionuclides, specifically members of the (238)U and (232)Th decay chains and (40)K which. The (238)U and (232)Th chain radionuclides and (40)K activity concentration values ranged between 5.9 ↔ 32.3, 3.5 ↔ 27.3, and 74 ↔ 698 Bq/kg respectively. The evaluated average specific activity concentrations of (238)U, (232)Th and (40)K across all of the soil samples have mean values of 18, 15 and 385 Bq/kg respectively, all falling below the worldwide mean values of 35, 40 and 400 Bq/kg respectively. The radiological risk factors are associated with a mean of 33.16 ± 2.46 nG/h and 68.5 ± 5.09 Bq/kg for the external dose rate and Radium equivalent respectively. The measured annual dose rates for all samples gives rise to a mean value of 40.8 ± 3.0 μSv/y while the internal and internal hazard indices have been found to be 0.23 ± 0.02 and 0.19 ± 0.01 respectively.
FCA Da Silva, David Bradley, Patrick Regan, Z Siti Rozaila (2016)Measurement of the total activity concentrations of Libyan oil scale, In: Radiation Physics and Chemistry137pp. 198-202 Elsevier
Twenty-three oil scale samples obtained from the Libyan oil and gas industry production facilities onshore have been measured using high-resolution gamma-ray spectrometry with a shielded HPGe detector, the work being carried out within the Environmental Radioactivity Laboratory at the University of Surrey. The main objectives of this work were to determine the extent to which the predominant radionuclides associated with the uranium and thorium natural decay chains were in secular equilibrium with their decay progeny, also to compare differences between the total activity concentrations (TAC) in secular equilibrium and disequilibrium and to evaluate the measured activities for the predominant gamma-ray emitting decay radionuclides within the 232Th and 238U chains. The oil scale NORM samples did not exhibit radioactive equilibrium between the decay progeny and longer-lived parent radionuclides of the 238U and 232Th series.
D Malain, PH Regan, DA Bradley, M Matthews, T Santawamaitre, HA Al-Sulaiti (2010)Measurements of NORM in beach sand samples along the Andaman coast of Thailand after the 2004 tsunami, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 441-445
AD Bajoga, N Alazemi, PH Regan, DA Bradley (2015)Radioactive investigation of NORM samples from Southern Kuwait soil using high-resolution gamma-ray spectroscopy, In: RADIATION PHYSICS AND CHEMISTRY116pp. 305-311 PERGAMON-ELSEVIER SCIENCE LTD
AD Bajoga, N Alazemi, H Shams, Patrick Regan, David Bradley (2016)Evaluation of naturally occurring radioactivity across the State of Kuwait using high-resolution gamma-ray spectrometry, In: Radiation Physics and Chemistry137pp. 203-209 Elsevier
A study of natural radioactivity from 90 different soil samples from the state of Kuwait has been carried out to ascertain the NORM concentration values across the country. The calculated activity concentrations were determined from: (i) the decays of the 226Ra, 214Pb and 214Bi members of the 4n+2 decay chain headed by 238U and; (ii) the 228Ac, 212Pb and 208Tl members of the 4n chain headed by 232Th. The study also included evaluations for the 235U decay chain with the 186 keV doublet transition used together with the measured 4n+2 activity concentration values to determine the 235U/238U isotopic ratios for each sample. The values for the arithmetic mean activity concentrations for 90 separate locations across Kuwait as determined in the current work were 17.2, 14.1, and 368 Bq/kg, with standard deviations of 5.2, 3.7 and 90 Bq/kg for the 238U, 232Th and 40K activity concentrations respectively. Measured isotope ratios for 235U/238U give an arithmetic mean value for all of the samples of 0.045±0.003, consistent with that expected for natural uranium. These results indicate no evidence for a radiologically significant dispersion of additional depleted uranium across the entire State of Kuwait from the 1991 Gulf War.
Abdullah Shanar B Alsubaie (2020)Challenges to analysis of major, minor and trace elemental concentrations in two media of toxicological interest. University of Surrey
Since the industrial revolution pollution has typically been classified according to whether it concerns air, water or noise, the issue of light-pollution now joining these. Pollution, direct or otherwise, causes damage to the living environment. In the present study of moderate to high atomic number media, analysis of major, minor and trace elemental concentrations is shown to be effective via x-ray fluorescence and mass spectroscopy (MS) based methods. Particular choice has been made of two media of highly differing constitution, both of toxicological consequence and each with its own challenges. Metals are prevalent in the widespread environmental emissions that result from the use of motorised vehicles, not least in road dust. Conversely, the metals manifest in Kohl have been analysed as an example of how an absence of regulatory control can allow the unimpeded marketing of personal products of clear human health impact. In conducting such a study, comparison has been made of several sensitive yet convenient sample analysis techniques (XRF, SEM/EDX, ICP-MS and ICP-OES), their relative efficacy being examined. The ICP-based methods provide for quantitative sample analysis while XRF/EDX can provide quantitative and qualitative analysis. The XRF study of Kohl has involved analysis of Pb, Fe and Zn concentrations in 135 samples, obtained from nine randomly selected market outlets (15 aliquots of each brand being represented). Among the published physiological effects of exposure to Pb is replacement of Ca in bones and teeth, making them weak and fragile, other impacts including nephrotoxicity, linked with increased Pb blood levels. While in this study the work on Kohl formed an introduction to elemental analysis, one particular challenge, also one that quickly became apparent but yet notable in terms of its absence from discussion in the literature, was investigation of high concentrations of highly attenuating media. Sample dilution and account of it has been required in arriving at reliable quantification. One desire has been to draw regulator attention to the potentiality of convenient, compact instrumentation and associated methodology, allowing for product screening. For road dust, obtained from a total of 60 locations, analysis has been conducted on particle sizes ranging from < 45 m up to 125 m. Arid climate samples were collected from the campuses of King Saud University, the Kuwait Research Institute and Qatar University, while maritime climate samples were collected from the Surrey University campus. Ttropical climate samples were collected from the campus of the University of Malaya as well as surrounding roads to the Malaysian radiation consultancy company, Asia Lab (now Alypz Sdn. Bhd.). Roadside dirt has been sampled along busy campus roads of universities/research centres in Guildford, Riyadh, Kuwait City, Doha and Kuala Lumpur, satisfying interest in climatic influences as well as vehicle engine size (in the Gulf countries non-commercial vehicle engine capacities tend to be greater than those in the UK or Malaysia, a product of relatively cheap fuel prices). A total of 200 street dust samples have been analyzed, elemental concentrations being reported for Mg, Al, Ti, Mn, Fe, Co, Zr, Mo, Ba, Tl, V, Rd, Pb, Cu, Zn, Ni, Cr, Cd, As, Hg and Au. For all five urban centres, Al, Fe, Mg, and Si values were found to be well above background although concentrations of Ti, Cr and Ba were lower than values reported by others. The concentrations of Pb were relatively low, likely attributable to restrictions on lead in fuel. Au and Ag were detected in low quantities in both Arid and Maritime climates, use being made of the SEM/EDX, appearing at levels unlikely to make economic sense in terms of recovery. Note that elemental loadings are provided in terms of concentrations per unit mass of sample. In general, the elements found in elevated concentrations can all be linked to the wear and tear of motor parts as debris. For the Guildford samples, obtained at three different times of the year, the main SEM/EDX findings were for Mg, Al, Cr, Ti, Mn, Fe, Co, Cu, Zr, Mo, Ba, Tl, V, Rh, Au and Ag, values ranging from non-detectable (below detection limits), through to from as low as 34.7 E-6 mg/m2 up to as high as 6 E-2 mg/m2. Note that the output provides estimates of elemental loadings per unit area at the sampling site. Using ICP-MS, Guildford concentrations in mg/kg (ppm) have been found for Al, V, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Mo, Cd, Sb, Pb, and U, for samples of mean size < 45 micron. Respective values were 3081, 12.3, 40.2, 333, 14133, 3.5, 70.4, 288, 5.96, 0.400, 2.35, 0.567, 2.77, 78.0, 0.657, results showing particular elevations of Al, Fe, Cu, Zn and Pb. Other toxic metals found in the Guildford and Kuwait samples in different concentrations were V, Ti, Cr, and Ba. For Riyadh and Doha samples four elements have been observed to be particularly prominent: Al, Fe, Mg, and Si, notwithstanding that they all have natural abundance in desert sands. Elemental presence has been seen to be influenced by climatic conditions as well as vehicle engine size. In conclusion, the various techniques offer complementary information on vehicular emission elemental concentrations in urban environments.
AS Habib, AL Shutt, PH Regan, MC Matthews, H Alsulaiti, DA Bradley (2014)Characterization of naturally occurring radioactive materials in Libyan oil pipe scale using a germanium detector and Monte Carlo simulation, In: RADIATION PHYSICS AND CHEMISTRY95pp. 352-355 PERGAMON-ELSEVIER SCIENCE LTD
H Al-Sulaiti, N Alkhomashi, N Al-Dahan, M Al-Dosari, DA Bradley, S Bukhari, M Matthews, PH Regan, T Santawamaitre (2011)Determination of the natural radioactivity in Qatarian building materials using high-resolution gamma-ray spectrometry, In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment652(1)pp. 915-919 Elsevier
T Santawamaitre, D Malain, HA Al-Sulaiti, M Matthews, DA Bradley, PH Regan (2011)Study of natural radioactivity in riverbank soils along the Chao Phraya river basin in Thailand, In: SORMA XII 2010: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment652(1)pp. 920-924 Elsevier
H Al-Sulaiti, T Nasir, KS Al Mugren, N Alkhomashi, N Al-Dahan, M Al-Dosari, DA Bradley, S Bukhari, M Matthews, PH Regan, T Santawamaitre, D Malain, A Habib (2012)Determination of the natural radioactivity levels in north west of Dukhan, Qatar using high-resolution gamma-ray spectrometry., In: Appl Radiat Isot70(7)pp. 1344-1350
This study is aimed at the determination of the activity concentrations of naturally occuring and technologically enhanced levels of radiation in 34 representative soil samples that have been collected from an inshore oil field area which was found to have, in a previous study, the highest observed value of 226Ra concentration among 129 soil samples. The activity concentrations of 238U and 226Ra have been inferred from gamma-ray transitions associated with their decay progenies and measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the values of the activity concentrations associated with the naturally occuring radionuclide chains for all the samples collected from NW Dukhan. Discrete-line, gamma-ray energy transitions from spectral lines ranging in energy from ∼100 keV up to 2.6 MeV have been associated with characteristic decays of the various decay products within the 235.8U and 232Th radioactive decay chains. These data have been analyzed, under the assumption of secular equilibrium for the U and Th decay chains. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented. The weighted mean value of the activity concentrations of 226Ra in one of the samples was found to be around a factor of 2 higher than the values obtained in the previous study and approximately a factor of 10 higher than the accepted worldwide average value of 35 Bq/kg. The weighted mean values of the activity concentrations of 232Th and 40K were also deduced and found to be within the worldwide average values of 30 and 400 Bq/kg, respectively. Our previous study reported a value of 201.9±1.5Stat.±13Syst.Bq/kg for 226Ra in one sample and further investigation in the current work determined a measured value for 226Ra of 342.00±1.9Stat.±25Syst.Bq/kg in a sample taken from the same locality. This is significantly higher than all the other investigated soil samples in the current and previous works. Notably, the Th levels in the same sample are within the worldwide average expectations, implying that the increased 226Ra concentration arises from TENORM processes.
Hasan M. Shams (2020)Determination of levels of naturally occurring radioactive materials in lagoon samples containing water from oil fields in the State of Kuwait. University of Surrey
An evaluation of the specific activity concentrations associated with technologically enhanced naturally occurring radioactive materials (TENORM) and anthropogenic radionuclides has been undertaken, with particular focus on produced water from the Kuwait oil industry. This work is part of a systematic study to provide a radiological map of the outer boundary of the produced water lagoon located in the Minagish oil field in the south west region of the State of Kuwait. This particular lagoon contains material from the discharge of produced water which is a by-product of oil production in the region. The lagoon samples were prepared and placed into sealed, marinelli beakers for a full gamma-ray spectrometric analysis using a high-resolution, low-background, high-purity germanium detection systems at the University of Surrey Environmental Radioactivity Laboratory. Of particular interest are the calculation of the activity concentrations associated with members of the decay chains following decays of the primordial radionuclides of the 238U chain (226Ra, 214Pb, 214Bi) and the 232Th chain (228Ra, 228Ac, 212Pb, 212Bi, 208Tl), and the enhanced concentrations of radium isotopes. This thesis presents overview of the experimental samples which have been measured and the analysis techniques applied, including isotopic correlation plots across the sample region. The result shows the expected significant increase in 226Ra (and progeny) concentrations compared to the NORM values were taken from outside of the lagoon, with 226Ra activity concentrations ranging from approximately 10 Bq/kg to 2 kBq/kg from different samples. Radium equivalent and hazard indices are calculated for different regions of the pool boundary, with some regions have hardard indices greater than unity, and therefore constituting a potential radiological hazard. The analysis also investigates the correlations between members of the 232Th and 238U chain in these samples, and shows evidence for enhancement of radium isotopes (226Ra and 228Ra) in the lagoon produced water samples compared to the background levels.
T Santawamaitre, D Malain, HA Al-Sulaiti, DA Bradley, MC Matthews, PH Regan (2014)Determination of U-238, Th-232 and K-40 activity concentrations in riverbank soil along the Chao Phraya river basin in Thailand, In: JOURNAL OF ENVIRONMENTAL RADIOACTIVITY138pp. 80-86 ELSEVIER SCI LTD
Amal Alqahtani (2020)Versatile Passive Dosimetry at Radiotherapy and Greater Levels using Borosilicate Glass
In line with the rapid advances that are being made in medical and industrial applications of radiation at elevated doses, a need is seen for convenient detectors that also offer a favourable range of characteristics. Particular utilisations herein largely depend upon the sensitivity of the dosimetric medium and also upon spatial resolution. The work herein is novel, encompassing characterisation of defects and dosimetric studies of commercial low-cost borosilicate (Pyrex) microscope glass slides and glass-fibre filters, with a view to making use of these as thermoluminescent dosimeters (TLDs). The particular glass forms studied herein have a number of potentially favourable physical characteristics, including being small in thickness (from a few mm down to sub mm diameters), inexpensive, readily available, resistant to moisture/wetting and reusable. Having established the utility of both the glass slides and filter forms towards photon irradiations, the work makes a more detailed investigation of the microscope slide (coverslips), the high degree of optical performance of these being indicative of homogeneity. Dosimetric characterisation of borosilicate glass has been obtained by irradiating them in various radiotherapy and product-irradiator beams, including kilovoltage and megavoltage photons, and megavoltage electrons. The borosilicate glass is found to exhibit minimal fading, competitive with commercial LiF thermoluminescent (TLD-100) dosimeters, also demonstrating a large dynamic dose range over which they remain linear, from sub-Gy through to 250 kGy. Via computerised glow curve deconvolution, the broad overarching peak has been analysed, being best fit deconvolved at into five peaks, associated with silicon oxygen defect centres (Si-ODC), B-O centres and B structural defects. More definitively, the first, second and third peaks, with activation energies of less than 1.2 eV, can be related to the existence of O+ and O- in the silica network. Also shown is that the borosilicate glass is capable of neutron detection, arising predominantly from the order of 4 % boron content, use being made of linacs operating in the photon mode. In line with conventional wisdom, no evidence is found at 6 MV for photo-neutron contamination. Conversely, at 10 MV and in particular 15 MV, appreciable neutron contribution to the signal is seen. The evident dose-dependent non-linearity is suggested to arise from the 10B (n, ) 7Li reaction, the alpha particles delivering dose dependent damage to the glass insulating material, forming additional defects.
H Shams, AD Bajoga, N Alazemi, DA Bradley, PH Regan (2016)A preliminary evaluation of naturally occurring radioactivity concentration levels across the State of Kuwait, In: APPLIED RADIATION AND ISOTOPES109pp. 479-481 PERGAMON-ELSEVIER SCIENCE LTD
Terver Daniel (2017)Nuclear structure studies of low-lying states in 194Os using fast-timing coincidence gamma-ray spectroscopy.
The properties of excited states in the neutron-rich nucleus 194Os have been investigated using the 192Os(18O,16O)194Os 2 neutron transfer reaction using a 80 MeV 18O heavy-ion beam provided by the tandem van de Graaff accelerator at the IFIN-HH laboratory Bucharest. Discrete γ-ray decays from excited states have been measured using the hybrid HPGe-LaBr3(Ce) γ-ray spectroscopic array RoSPHERE. The timing and energy response of the RoSPHERE system have been evaluated using a number of point radioactive sources and through other nuclear reaction products formed from reactions on minor target contaminants as well as via unsafe Coulomb excitation on the 192Os target. The work identifies a number of previously unreported low lying non-yrast states in 194Os as well as the first B(E2;2+ → 0+) measurement for this nucleus. The experimental results are compared with HFB/IBM calculations and are consistent with a reduction in a quadrupole collectivity in Os isotopes with increasing N.
Amjad Alyahyawi (2020)Silica-based Passive Dosimeters for sub-Gy Patient-focused Dose Evaluations University of Surrey
In use of doped silica glass TL dosimeters, previous studies by others have focused on measurement of the radiation doses delivered during radiotherapy applications, with levels of dose typically in the fractions of a Gy to some several tens of Gy level. The present work is differentiated from such efforts, the thesis evaluating the utility of several types of enhanced-sensitivity doped silica glass TL dosimeter, novel forms that have been developed for measurement of low radiation doses. The range of interest is from several μGy to several tens of mGy level (ie doses some 0.1% and less of that of the therapy doses previously investigated), the focus being on medical applications within which such exposures arise. The stochastic effects of radiation are without threshold, the probability nevertheless increasing with dose. As such, the low radiation doses that can give rise to small but extant probability of inducing cancer need to be measured, allowing for dose mitigation measures that can be evaluated. Therefore, one of the main purposes of this research is to examine the development of new dosimeters that can measure such low radiation doses, either in diagnostic uses of x-rays or in regard to scattered radiation received to the lens of the eye during stereotactic radiosurgery (SRS) applications. The diagnostic applications of choice are those which find widespread use, from single exposure dental doses, through to chest radiography and mammographic imaging. As no dosimeter exists that can come close to approximating the ideal characteristics of an omni-utility sensor, a number of glass TL dosimeter forms have been investigated, differing in dopant concentration, size and fabrication, examined for use in the different dose regimes. The characterisation of GeB-PFc, Ge-PFc, GeB-FF, Ge-doped disc, Ge-SMF and LiF (all defined in detail in the thesis) have been performed, including the study of linearity, fading, energy response, dose response, and sensitivity. The outcome is one demonstrating successful accommodation of all of the dose ranges of interest. Additional sensitivity of between 20% to 30% has been shown to be available through thin (several tens of microns) high Z coatings to flat fibres (FF), the coatings acting as photoelectron and Auger electron conversion media. Being small in size, non toxic and devoid of any electrical contact, it is the intention that these TL forms take on the important role of safe and accurate dose evaluations as an aid in dose optimization measures.
A Gottardo, JJ Valiente-Dobón, G De Angelis, DR Napoli, E Sahin, A Gottardo, S Lunardi, SM Lenzi, E Maglione, G Benzoni, R Nicolini, A Bracco, F Camera, FCL Crespi, A Corsi, S Leoni, B Million, AI Morales, O Wieland, R Nicolini, A Bracco, F Camera, A Corsi, S Leoni, A Gadea, A Algora, S Lunardi, D Bazzacco, E Farnea, SM Lenzi, R Menegazzo, D Mengoni, F Recchia, CA Ur, E Maglione, P Boutachkov, M Górska, S Pietri, H Weick, ML Cortes, C Domingo-Pardo, T Engert, F Farinon, H Geissel, J Gerl, N Goel, E Gregor, T Habermann, R Hoischen, I Kojouharov, N Kurz, F Naqvi, C Nociforo, A Prochazka, W Prokopowicz, H Schaffner, A Sharma, H-J Wollersheim, AM Bruce, M Bunce, AM Denis Bacelar, J Grebosz, Z Podolyák, PH Regan, N Al-Dahan, M Bowry, AY Deo, GF Farrelly, MW Reed, TPD Swan, PM Walker, M Pfützner, J Alcántara Núñez, Y Ayyad, J Benlliure, N Alkhomashi, PRP Allegro, RV Ribas, E Casarejos, M Doncel, Z Dombradi, K Eppinger, S Klupp, K Steiger, R Hoischen, D Rudolph, R Janik, B Sitar, P Strmen, I Szarka, S Mandal, D Siwal, F Naqvi, PM Walker, F Nowacki, AP Zuker (2012)New isomers in the full seniority scheme of neutron-rich lead isotopes: The role of effective three-body forces, In: Physical Review Letters109(16) American Physical Society
The neutron-rich lead isotopes, up to Pb216, have been studied for the first time, exploiting the fragmentation of a primary uranium beam at the FRS-RISING setup at GSI. The observed isomeric states exhibit electromagnetic transition strengths which deviate from state-of-the-art shell-model calculations. It is shown that their complete description demands the introduction of effective three-body interactions and two-body transition operators in the conventional neutron valence space beyond Pb208. © 2012 American Physical Society.
AI Morales, G Benzoni, A Gottardo, JJ Valiente-Dobon, N Blasi, A Bracco, F Camera, FCL Crespi, A Corsi, S Leoni, B Million, R Nicolini, O Wieland, A Gadea, S Lunardi, M Gorska, PH Regan, Z Podolyak, M Pfuetzner, S Pietri, P Boutachkov, H Weick, J Grebosz, AM Bruce, J Alcantara Nunez, A Algora, N Al-Dahan, Y Ayyad, N Alkhomashi, PRP Allegro, D Bazzacco, J Benlliure, M Bowry, M Bunce, E Casarejos, ML Cortes, AMD Bacelar, AY Deo, G de Angelis, C Domingo-Pardo, M Doncel, Z Dombradi, T Engert, K Eppinger, GF Farrelly, F Farinon, E Farnea, H Geissel, J Gerl, N Goel, E Gregor, T Habermann, R Hoischen, R Janik, S Klupp, I Kojouharov, N Kurz, S Mandal, R Menegazzo, D Mengoni, DR Napoli, F Naqvi, C Nociforo, A Prochazka, W Prokopowicz, F Recchia, RV Ribas, MW Reed, D Rudolph, E Sahin, H Schaffner, A Sharma, B Sitar, D Siwal, K Steiger, P Strmen, TPD Swan, I Szarka, CA Ur, PM Walker, H-J Wollersheim (2014)beta-decay studies of neutron-rich Tl, Pb, and Bi isotopes, In: PHYSICAL REVIEW C89(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
S Akkoyun, A Algora, B Alikhani, F Ameil, G De Angelis, L Arnold, A Astier, A Ataç, Y Aubert, C Aufranc, A Austin, S Aydin, F Azaiez, S Badoer, DL Balabanski, D Barrientos, G Baulieu, R Baumann, D Bazzacco, FA Beck, T Beck, P Bednarczyk, M Bellato, MA Bentley, G Benzoni, R Berthier, L Berti, R Beunard, G Lo Bianco, B Birkenbach, PG Bizzeti, AM Bizzeti-Sona, F Le Blanc, JM Blasco, N Blasi, D Bloor, C Boiano, M Borsato, D Bortolato, AJ Boston, HC Boston, P Bourgault, P Boutachkov, A Bouty, A Bracco, S Brambilla, IP Brawn, A Brondi, S Broussard, B Bruyneel, D Bucurescu, I Burrows, A Bürger, S Cabaret, B Cahan, E Calore, F Camera, A Capsoni, F Carrió, G Casati, M Castoldi, B Cederwall, J-L Cercus, V Chambert, M El Chambit, R Chapman, L Charles, J Chavas, E Clément, P Cocconi, S Coelli, PJ Coleman-Smith, A Colombo, S Colosimo, C Commeaux, D Conventi, RJ Cooper, A Corsi, A Cortesi, L Costa, FCL Crespi, JR Cresswell, DM Cullen, D Curien, A Czermak, D Delbourg, R Depalo, T Descombes, P Désesquelles, P Detistov, C Diarra, F Didierjean, MR Dimmock, QT Doan, C Domingo-Pardo, M Doncel, F Dorangeville, N Dosme, Y Drouen, G Duchêne, B Dulny, J Eberth, P Edelbruck, J Egea, T Engert, MN Erduran, S Ertürk, C Fanin, S Fantinel, E Farnea, T Faul, M Filliger, F Filmer, C Finck, G De France, A Gadea, W Gast, A Geraci, J Gerl, R Gernhäuser, A Giannatiempo, A Giaz, L Gibelin, A Givechev, N Goel, V González, A Gottardo, X Grave, J Grȩbosz, R Griffiths, AN Grint, P Gros, L Guevara, M Gulmini, A Görgen, HTM Ha, T Habermann, LJ Harkness, H Harroch, K Hauschild, C He, A Hernández-Prieto, B Hervieu, H Hess, T Hüyük, E Ince, R Isocrate, G Jaworski, A Johnson, J Jolie, P Jones, B Jonson, P Joshi, DS Judson, A Jungclaus, M Kaci, N Karkour, M Karolak, A Kaşkaş, M Kebbiri, RS Kempley, A Khaplanov, S Klupp, M Kogimtzis, I Kojouharov, A Korichi, W Korten, T Kröll, R Krücken, N Kurz, BY Ky, M Labiche, X Lafay, L Lavergne, IH Lazarus, S Leboutelier, F Lefebvre, E Legay, L Legeard, F Lelli, SM Lenzi, S Leoni, A Lermitage, D Lersch, J Leske, SC Letts, S Lhenoret, RM Lieder, D Linget, J Ljungvall, A Lopez-Martens, A Lotodé, S Lunardi, A Maj, J Van Der Marel, Y Mariette, N Marginean, R Marginean, G Maron, AR Mather, W Mȩczyński, V Mendéz, P Medina, B Melon, R Menegazzo, D Mengoni, E Merchan, L Mihailescu, C Michelagnoli, J Mierzejewski, L Milechina, B Million, K Mitev, P Molini, D Montanari, S Moon, F Morbiducci, R Moro, PS Morrall, O Möller, A Nannini, DR Napoli, L Nelson, M Nespolo, VL Ngo, M Nicoletto, R Nicolini, Y Le Noa, PJ Nolan, M Norman, J Nyberg, A Obertelli, A Olariu, R Orlandi, DC Oxley, C Özben, M Ozille, C Oziol, E Pachoud, M Palacz, J Palin, J Pancin, C Parisel, P Pariset, G Pascovici, R Peghin, L Pellegri, A Perego, S Perrier, M Petcu, P Petkov, C Petrache, E Pierre, N Pietralla, S Pietri, M Pignanelli, I Piqueras, Z Podolyak, P Le Pouhalec, J Pouthas, D Pugnére, VFE Pucknell, A Pullia, B Quintana, R Raine, G Rainovski, L Ramina, G Rampazzo, G La Rana, M Rebeschini, F Recchia, N Redon, M Reese, P Reiter, PH Regan, S Riboldi, M Richer, M Rigato, S Rigby, G Ripamonti, AP Robinson, J Robin, J Roccaz, J-A Ropert, B Rossé, C Rossi Alvarez, D Rosso, B Rubio, D Rudolph, F Saillant, E Şahin, F Salomon, M-D Salsac, J Salt, G Salvato, J Sampson, E Sanchis, C Santos, H Schaffner, M Schlarb, DP Scraggs, D Seddon, M Şenyiǧit, M-H Sigward, G Simpson, J Simpson, M Slee, JF Smith, P Sona, B Sowicki, P Spolaore, C Stahl, T Stanios, E Stefanova, O Stézowski, J Strachan, G Suliman, P-A Söderström, JL Tain, S Tanguy, S Tashenov, C Theisen, J Thornhill, F Tomasi, N Toniolo, R Touzery, B Travers, A Triossi, M Tripon, KMM Tun-Lanoë, M Turcato, C Unsworth, CA Ur, JJ Valiente-Dobon, V Vandone, E Vardaci, R Venturelli, F Veronese, C Veyssiere, E Viscione, R Wadsworth, PM Walker, N Warr, C Weber, D Weisshaar, D Wells, O Wieland, A Wiens, G Wittwer, HJ Wollersheim, F Zocca, NV Zamfir, M Ziȩbliński, A Zucchiatti (2012)AGATA - Advanced GAmma Tracking Array, In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment668pp. 26-58 Elsevier
A. Gottardo, J. J. Valiente-Dobón, G. Benzoni, A. I. Morales, A. Gadea, S. Lunardi, P. Boutachkov, A. M. Bruce, M. Górska, J. Grebosz, S. Pietri, Zs. Podolyak, M. Pfützner, P. H. Regan, D. Rudolph, H. Weick, J. Alcántara Núñez, A. Algora, N. Al-Dahan, G. de Angelis, Y. Ayyad, N. Alkhomashi, P. R. P. Allegro, D. Bazzacco, J. Benlliure, M. Bowry, A. Bracco, M. Bunce, F. Camera, E. Casarejos, M. L. Cortes, F. C. L. Crespi, A. Corsi, A. M. Denis Bacelar, A. Y. Deo, C. Domingo-Pardo, M. Doncel, Zs. Dombradi, T. Engert, K. Eppinger, G. F. Farrelly, F. Farinon, H. Geissel, J. Gerl, N. Goel, E. Gregor, T. Habermann, R. Hoischen, R. Janik, S. Klupp, I. Kojouharov, N. Kurz, S. M. Lenzi, S. Leoni, S. Mandal, R. Menegazzo, D. Mengoni, B. Million, D. R. Napoli, F. Naqvi, C. Nociforo, A. Prochazka, W. Prokopowicz, F. Recchia, R. V. Ribas, M. W. Reed, E. Sahin, H. Schaffner, A. Sharma, B. Sitar, D. Siwal, K. Steiger, P. Strmen, T. P. D. Swan, I. Szarka, C. A. Ur, P.M. Walker, O. Wieland, H-J. Wollersheim, F. Nowacki, E. Maglione (2019)New spectroscopic information on 211;213Tl A changing structure beyond the N=126 shell closure, In: Physical Review C99(5)pp. 054326-1 American Physical Society
The neutron-rich isotopes 211;213Tl, beyond the N = 126 shell-closure, have been studied for the first time in isomer γ-ray decay, exploiting the fragmentation of a primary uranium beam at the FRS-RISING (FRagment Separator-Rare ISotopes INvestigation at GSI) setup at GSI. The observed isomeric states in 211;213Tl show a deviation from the seniority-like scheme of 209Tl. The possible interpretation of the data is discussed on the basis of energy-level systematics and shell-model calculations.
A. M. Bruce, P. M. Walker, P. H. Regan, G. D. Dracoulis, A. P. Byrne, T. Kibedi, G. J. Lane, K. C. Yeung (1994)A Kπ=8- isomer in 136Sm, In: Physical Review C50(480)pp. 480-482
Yang Sun, G.X. Zhang, H. Watanabe, F.G. Kondev, G.J. Lane, P.H. Regan, P.-A. Söderström, P.M. Walker, H. Kanaoka, Z. Korkulu, P.S Lee, J.J Liu, S. Nishimura, J. Wu, A. Yagi, D.S. Ahn, T. Alharbi, H. Baba, F. Browne, A.M. Bruce, R.J. Carroll, K.Y. Chae, Zs. Dombradi, P. Doornenbal, A. Estrade, N. Fukuda, C. Griffin, E. Ideguchi, N. Inabe, T. Isobe, S. Kanaya, I. Kojouharov, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, C.S. Lee, E.J. Lee, G. Lorusso, G. Lotay, C.-B Moon, I. Nishizuka, C.R. Nita, A. Odahara, Z. Patel, V.H. Phong, Zs. Podolyak, O.J. Roberts, H. Sakurai, H. Schaffner, C.M. Shand, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda, S. Terashima, Zs. Vajta, J.J. Valiente-Dóbon, Z.Y. Xu (2018)β-γ and isomeric decay spectroscopy of 168Dy, In: EPJ Web of Conferences178pp. 02023-1 EDP Sciences
This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.
TR Saitoh, N Saitoh-Hashimoto, G Sletten, RA Bark, M Bergstrom, P Regan, S Tormanen, PG Varmette, PM Walker, C Wheldon (2000)Collective and intrinsic structures in W-183 (vol 660, pg 171, 1999), In: NUCLEAR PHYSICS A669(3-4)pp. 381-406 ELSEVIER SCIENCE BV
TR Saitoh, N Saitoh-Hashimoto, G Sletten, RA Bark, M Bergstrom, P Regan, S Tormanen, PG Varmette, PM Walker (1999)Collective and intrinsic structures in W-183, In: NUCLEAR PHYSICS A660(2)pp. 171-196 ELSEVIER SCIENCE BV
MW Reed, PM Walker, IJ Cullen, YA Litvinov, K Blaum, F Bosch, C Brandau, JJ Carroll, DM Cullen, AY Deo, B Detwiler, C Dimopoulou, GD Dracoulis, F Farinon, H Geissel, E Haettner, M Heil, RS Kempley, R Knoebel, C Kozhuharov, J Kurcewicz, N Kuzminchuk, S Litvinov, Z Liu, R Mao, C Nociforo, F Nolden, WR Plass, A Prochazka, C Scheidenberger, D Shubina, M Steck, T Stoehlker, B Sun, TPD Swan, G Trees, H Weick, N Winckler, M Winkler, PJ Woods, T Yamaguchi, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, R Wadsworth, D Watts (2012)Technique for Resolving Low-lying Isomers in the Experimental Storage Ring (ESR) and the Occurrence of an Isomeric State in Re-192, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011381pp. ?-?
Laila Gurgi, Patrick Regan, P-A Söderström, H Watanabe, Philip Walker, Zsolt Podolyak, S Nishimura, Thomas Berry, P Doornenbal, G Lorusso, T Isobe, H Baba, ZY Xu, H Sakurai, T Sumikama, Wilton Catford, AM Bruce, F Browne, GJ Lane, FG Kondev, A Odahara, J Wu, HL Liu, FR Xu, Z Korkulu, P Lee, JJ Liu, VH Phong, A Yagi, GX Zhang, T Alharbi, RJ Carroll, KY Chae, Z Dombradi, A Estrade, N Fukuda, C Griffin, E Ideguchi, N Inabe, H Kanaoka, I Kojouharov, T Kubo, S Kubono, N Kurz, I Kuti, S Lalkovski, EJ Lee, CS Lee, Gavin Lotay, CB Moon, I Nishizuka, CR Nita, Z Patel, OJ Roberts, H Schaffner, Callum Shand, H Suzuki, H Takeda, S Terashima, Z Vajta, S Kanaya, J-J Valiente-Dobón (2017)Isomer Spectroscopy of Neutron-rich 165,167Tb, In: Acta Physica Polonica B48(3)pp. 601-608
We present information on the excited states in the prolate-deformed, neutron-rich nuclei 165;167Tb100;102. The nuclei of interest were synthesised following in-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm 9Be target at the Radioactive Ion-Beam Factory (RIBF), RIKEN, Japan. The exotic nuclei were separated and identified event-by-event using the BigRIPS separator, with discrete energy gamma-ray decays from isomeric states with half-lives in the s regime measured using the EURICA gamma-ray spectrometer. Metastable-state decays are identified in 165Tb and 167Tb and interpreted as arising from hindered E1 decay from the 7 2 [523] single quasi-proton Nilsson configuration to rotational states built on the 3 2 [411] single quasi-proton ground state. These data correspond to the first spectroscopic information in the heaviest, odd-A terbium isotopes reported to date and provide information on proton Nilsson configurations which reside close to the Fermi surface as the 170Dy doubly-midshell nucleus is approached.
E Wilson, Z Podolyak, B Fornal, RVF Janssens, M Bowry, M Bunce, MP Carpenter, CJ Chiara, N Cieplicka, AY Deo, GD Dracoulis, H Grawe, CR Hoffman, RS Kempley, FG Kondev, GJ Lane, T Lauritsen, MW Reed, PH Regan, CR Triguero, B Szpak, PM Walker, S Zhu (2013)CORE EXCITATIONS ACROSS THE NEUTRON SHELL GAP IN Tl-207, In: ACTA PHYSICA POLONICA B44(3)pp. 381-385 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Deep-inelastic collisions of a 208Pb beam on a 208Pb target were performed using the ATLAS accelerator at Argonne National Laboratory. Prompt and delayed γ-rays from the reaction products were detected using the GAMMASPHERE detector array. The cross-coincidence method was used to identify transitions in 207Tl, by gating on γ-rays from its better-characterised reaction partner 209Bi. A number of new transitions were found in 207Tl.
E Wilson, Z Podolyak, H Grawe, BA Brown, CJ Chiara, S Zhu, B Fornal, RVF Janssens, CM Shand, M Bowry, M Bunce, MP Carpenter, N Cieplicka-Orynczak, AY Deo, GD Dracoulis, CR Hoffman, RS Kempley, FG Kondev, GJ Lane, T Lauritsen, G Lotay, MW Reed, PH Regan, CR Triguero, D Seweryniak, B Szpak, PM Walker (2015)Core excitations across the neutron shell gap in Tl-207, In: PHYSICS LETTERS B747pp. 88-92 ELSEVIER SCIENCE BV
The single closed-neutron-shell, one proton-hole nucleus 207Tl was populated in deep-inelastic collisions of a 208Pb beam with a 208Pb target. The yrast and near-yrast level scheme has been established up to high excitation energy, comprising an octupole phonon state and a large number of core excited states. Based on shell-model calculations, all observed single core excitations were established to arise from the breaking of the N=126 neutron core. While the shell-model calculations correctly predict the ordering of these states, their energies are compressed at high spins. It is concluded that this compression is an intrinsic feature of shell-model calculations using two-body matrix elements developed for the description of two-body states, and that multiple core excitations need to be considered in order to accurately calculate the energy spacings of the predominantly three-quasiparticle states.
G A Jones, P H Regan, P M Walker, Z Podolyak, P D Stevenson, M P Carpenter, J J Carroll, R S Chakrawarthy, P Chowdhury, A B Garnsworthy, R V Janssens, T L Khoo, F G Kondev, G J Lane, Z Liu, D Seweryniak, N J Thompson, S Zhu, S J Williams (2007)Identification of a High-Spin Isomer in Mo-99, In: Physical Review C76(4)
A previously unreported isomer has been identified in Mo-99 at an excitation energy of E-x = 3010 keV, decaying with a half-life of T-1/2 = 8(2) ns. The nucleus of interest was produced following fusion-fission reactions between a thick Al-27 target frame and a Hf-178 beam at a laboratory energy of 1150 MeV. This isomeric state is interpreted as an energetically favored, maximally aligned configuration of nu h (11/2) circle times pi(g (9/2))(2).
PM Walker, KC Yeung, GD Dracoulis, PH Regan, GJ Lane, PM Davidson, AE Stuchbery (1993)Backbending in 180W: a t-band crossing, In: Physics Letters B309(1-2)pp. 17-22
A Fermi-aligned (i 13 2)2 rotational band, with K≈8, has been observed in an even-even nucleus, 180W. Its structure corresponds to a t-band in the tilted-cranking representation. It crosses the ground-state band at I = 16 h {combining short stroke overlay}, giving rise to backbending in the yrast sequence. Contrary to the usual interpretation, backbending in this case is not caused by the s-band. Comparison is made with other possible t-band crossings in the A ≈ 180 region. © 1993.
M. Rudigier, R.L. Canavan, P.H. Regan, P.-A. Söderström, M. Lebois, J.N. Wilson, N. Jovancevic, S. Bottoni, M. Brunet, N. Cieplicka-Orynczak, S. Courtin, D.T. Doherty, K. Hadynska-Klek, M. Heine, W. Iskra, V. Karayonchev, A. Kennington, P. Koseoglou, G. Lotay, G. Lorusso, M. Nakhostin, C.R. Nita, S. S. Oberstedt, Zs. Podolyak, L. Qi, J.-M. Régis, R. Shearman, P.M. Walker, W. Witt (2019)Isomer spectroscopy and sub-nanosecond half-live determination in 178w using the NuBall array, In: Acta Physica Polonica B50(3)pp. 661-667 Jagiellonian University
The reaction of a pulsed 18O beam on a 164Dy target was studied in the first experiment with the NuBall array at the IPN Orsay, France. Excited state half-lives were measured using the fast timing method with 20 LaBr3(Ce) detectors. The timing characteristics of the fully digital acquisition system is briefly discussed. A value for the previously unknown half-life of the first excited 4+ state in 178W is presented.
Z Podolyak, J Gerl, M Hellstrom, F Becker, KA Gladnishki, M Gorska, A Kelic, Y Kopatch, S Mandal, PH Regan, KH Schmidt, PM Walker, HJ Wollersheim, A Banu, G Benzoni, H Boardman, E Casarejos, J Ekman, H Geissel, H Grawe, D Hohn, I Kojouharov, J Leske, R Lozeva, MN Mineva, G Neyens, RD Page, CJ Pearson, M Portillo, D Rudolph, N Saito, H Schaffner, D Sohler, K Summerer, JJ Valiente-Dobon, C Wheldon, H Weick, M Winkler (2006)Neutron-deficient N approximate to 126 nuclei produced in U-238 fragmentation: Population of high-spin states, In: Frontiers in Nuclear Structure Astrophysics, and Reactions: FINUSTAR831pp. 114-118 AMER INST PHYSICS
The population of metastable states produced in relativistic-energy fragmentation of a U-238 beam has been measured. For states with high angular momentum, I=17h and I=21.5h, a higher population than expected has been observed, with the discrepancy increasing with angular momentum. By considering two sources for the angular momentum, related to single-particle and collective motions, a much improved description of the experimental results can be obtained. In addition, new results on the structure of Fr-208, Ra-211 and Ac-216 are reported.
PM Walker, DM Cullen, CS Purry, DE Appelbe, AP Byrne, GD Dracoulis, T Kibedi, FG Kondev, LY Lee, AO Macchiavelli, AT Reed, PH Regan, F Xu (1997)K-forbidden transitions from multi-quasiparticle states, In: PHYSICS LETTERS B408(1-4)pp. 42-46 ELSEVIER SCIENCE BV
M Caamãno, PM Walker, PH Regan, CJ Pearson, ZS Podolyak, P Mayet, J Gerl, C Schlegel, M Hellström, M Mlneva, M Pfützner (2001)Isomeric decays in200Pt, In: Acta Physica Polonica B32(3)pp. 763-766
A projectile fragmentation experiment has been performed to populate the neutron-rich A ∼ 190 mass region, approaching the Z = 82, N = 126 closed shell. A previously unreported isomer is found in 200Pt, being the first new example, from fragmentation reactions, of a seniority 4 state established from γ-γ coincidences.
Z Patel, Z Podolyak, PM Walker, PH Regan, P-A Söderström, H Watanabe, E Ideguchi, GS Simpson, S Nishimura, F Browne, P Doornenbal, P Lorusso, S Rice, L Sinclair, T Sumikama, J Wu, ZY Xu, N Aoi, H Baba, FL Bello Garrote, G Benzoni, R Daido, Z Dombrádi, Y Fang, N Fukuda, G Gay, S Go, A Gottardo, N Inabe, T Isobe, K Kameda, K Kobayashi, M Kobayashi, T Komatsubara, I Kojouharov, T Kubo, N Kurz, I Kuti, Z Li, HL Liu, M Matsushita, S Michimasa, CB Moon, H Nishibata, I Nishizuka, A Odahara, E Sahin, H Sakurai, H Schaffner, H Suzuki, H Takeda, J Taprogge, Z Vajta, FR Xu, A Yagi, R Yokoyama (2016)β-decay spectroscopy of neutron-rich 160,161,162Sm isotopes, In: EPJ Web of Conferences123 (2
Neutron-rich 160,161,162Sm isotopes have been populated at the RIBF, RIKEN via β first time. β-coincident γ rays were observed in all three isotopes including γ rays from the isomeric decay of 160Sm and 162Sm. The isomers in 160Sm and 162Sm have previously been observed but have been populated via β decay for the first time. The isomeric state in 162Sm is assigned a configuration based on the decay pattern. The level schemes of 160Sm and 162Sm are presented. The ground states in the parent nuclei 160Pm and 162Pm are both assigned a configuration based on the population of states in the daughter nuclei. Blocked BCS calculations were performed to further investigate the spin-parities of the ground states in 160Pm, 161Pm, and 162Pm, and the isomeric state in 162Sm
AM Bruce, AMD Bacelar, G Benzoni, A Gottardo, R Nicolini, E Sahin, A Gadea, A Algora, M Górska, S Pietri, P Boutachkov, ML Cortés, C Domingo-Prado, F Farinon, H Geissel, J Gerl, N Goel, E Gregor, T Haberman, R Hoischen, I Kojouharov, N Kurz, C Nociforo, A Prochazka, W Prokopowicz, H Schaffner, A Sharma, H Weick, H-J Wollersheim, JJ Valiente-Dobón, D Mengoni, Z Podolyák, N Al-Dahan, N Alkhomashi, M Bowry, M Bunce, AY Deo, GF Farrelly, PH Regan, PM Walker, JA Alcántara-Núñez, Y Ayyad, PRP Allegro, E Casarejos, M Doncel, K Eppinger, S Klupp, K Steiger, J Grȩbosz, D Rudolph, R Janik, B Sitar, P Strmen, I Szarka, S Lunardi, R Menegazzo, S Mandal, D Siwal, F Naqvi, T Pissulla (2012)β decay of Y produced in projectile fission of U, In: Journal of Physics: Conference Series381(1)
The population of Zr following the β decay of Y produced in the projectile fission of U at the GSI facility in Darmstadt, Germany has been studied. Y is known to decay into Zr via two states, one of high spin and the other low spin. These states preferentially populate different levels in the Zr daughter. In this paper the intensities of transitions in Zr observed are compared with those from the decay of the low-spin level studied at the TRISTAN facility at Brookhaven National Laboratory and of the high-spin level studied at the JOSEF separator at the Kernforschungsanlage Jülich. © Published under licence by IOP Publishing Ltd.
P. D. Stevenson, M. P. Brine, Zs. Podolyak, P. H. Regan, P. M. Walker, J. Rikovska Stone (2005)Shape evolution in the neutron-rich tungsten region, In: Physical Review C72(047303)
G. A. Jones, P. H. Regan, P. M. Walker, Zs. Podolyák, P. D. Stevenson, M. P. Carpenter, J. J. Carroll, R. S. Chakrawarthy, P. Chowdhury, A. B. Garnsworthy, R. V. F. Janssens, T. L. Khoo, F. G. Kondev, G. J. Lane, Z. Liu, D. Seweryniak, N. J. Thompson, S. Zhu, S. J. Williams (2007)Identification of a high-spin isomer in 99Mo, In: Physical Review C76(047303)
PE Garrett, CE Svensson, C Andreoiu, D Bandyopadhyay, P Finlay, GF Grinyer, B Hyland, E Illes, AA Phillips, MA Schumaker, JJ Valiente-dobón, J Wong, GC Ball, G Hackman, A Andreyev, S Chan, H Coombes, R Churchman, RS Chakrawarthy, AC Morton, CJ Pearson, MB Smith, EF Zganjar, SF Ashley, GA Jones, PH Regan, PM Walker, SJ Williams, RAE Austin, JA Becker, WD Kulp, JL Wood, JR Leslie, C Mattoon, F Sarazin, JJ Ressler, J Schwarzenberg, JC Waddington, LM Watters (2006)Gamma-ray spectroscopy at TRIUMF-ISAC, In: AIP Conference Proceedings819pp. 249-253
The 8π spectrometer at TRIUMF-ISAC consists of 20 Compton-suppressed germanium detectors and various auxiliary devices. The Ge array, once used for studies of nuclei at high angular momentum, has been transformed into the world's most powerful device dedicated to radioactive-decay studies. Many improvements in the spectrometer have been made, including a high-throughput data acquisition system, installation of a moving tape collector, incorporation of an array of 20 plastic scintillators for β-particle tagging, 5 Si(Li) detectors for conversion electrons, and 10 BaF detectors for fast-lifetime measurements. Experiments can be performed where data from all detectors are collected simultaneously, resulting in a very detailed view of the nucleus through radioactive decay. A number of experimental programmes have been launched that take advantage of the versatility of the spectrometer, and the intense beams available at TRIUMF-ISAC. © 2006 American Institute of Physics.
K A Gladnishki, Z Podolyak, P H Regan, J Gerl, M Hellstrom, Y Kopatch, S Mandal, M Gorska, R D Page, H J Wollersheim, A Banu, G Benzoni, H Boardman, M La Commara, J Ekman, C Fahlander, H Geissel, H Grawe, E Kaza, A Korgul, M Matos, M N Mineva, C J Pearson, C Plettner, D Rudolph, C Scheidenberger, K H Schmidt, V Shishkin, D Sohler, K Summerer, J J Valiente-Dobon, P M Walker, H Weick, M Winkler, O Yordanov (2004)Angular Momentum Population in the Projectile Fragmentation of U-238 at 750 MeV/nucleon, In: Physical Review C69(2)
A systematic study of the population probabilities of nanosecond and microsecond isomers produced following the projectile fragmentation of U-238 at 750 MeV/nucleon has been undertaken at the SIS/FRS facility at GSI. Approximately 15 isomeric states in neutron-deficient nuclei around A similar to 190 were identified and the corresponding. isomeric ratios determined. The results are compared with a model based on the statistical abrasion-ablation description of relativistic fragmentation and simple assumptions concerning gamma cascades in the final nucleus (sharp cutoff). This model represents an upper limit for the population of isomeric states in relativistic projectile fragmentation. When the decay properties of the states above the isomer are taken into account, as opposed to the sharp cutoff approximation, a good agreement between the experimental and calculated angular momentum population is obtained.
Z Podolyak, J Gerl, M Hellstrom, F Becker, KA Gladnishki, M Gorska, A Kelic, Y Kopatch, S Mandal, PH Regan, KH Schmidt, PM Walker, HJ Wollersheim, A Banu, G Benzoni, H Boardman, E Casarejos, J Ekman, H Geissel, H Grawe, D Hohn, I Kojouharov, J Leske, R Lozeva, MN Mineva, G Neyens, RD Page, CJ Pearson, M Portillo, D Rudolph, N Saito, H Schaffner, D Sohler, K Summerer, JJ Valiente-Dobon, C Wheldon, H Weick, M Winkler (2006)High angular momentum states populated in fragmentation reactions, In: PHYSICS LETTERS B632(2-3)pp. 203-206 ELSEVIER SCIENCE BV
TR Saitoh, N Saitoh-Hashimoto, G Sletten, RA Bark, M Bergström, P Regan, S Törmänen, PG Varmette, PM Walker, C Wheldon (2000)Erratum to "collective and intrinsic structures in 183W" [nucl. Phys. A 660 (1999) 171-196] *, In: Nuclear Physics A669(3-4)pp. 381-406
The structure of 183W has been studied by employing the 176Yb(14C,α 3n) reaction at 68 MeV. Five previously known rotational structure with one-quasiparticle configurations have been extended to higher spin states, and five new rotational bands with three- and five-quasiparticle configurations and a γ-vibration of a one-quasiparticle structure have been newly identified. In the ν7/2-[503] and ν11/2+[615] rotational structures, a signal of an admixture of an octupole- vibrational structure has been observed in their in-band B(M1)/B(E2) ratios and gΚ factors. In the Κπ = 19-M rotational band, a Coriolis effect on the ν1/2-[510] neutron has been identified. In all, 17 Κ-forbidden transitions have been observed. Energies of intrinsic states below 4 MeV have been calculated based on the Blocked BCS theory, and they are used in support of the configuration assignments. © 2000 Elsevier Science B.V. All rights reserved. PACS: 21.10.Re; 21.10.Tg; 23.20.En; 23.20.Lv; 27.70.+q.
M Dasgupta, GD Dracoulis, PM Walker, AP Byrne, T Kibédi, FG Kondev, GJ Lane, PH Regan (2000)Competition between high-K states and rotational structures in 177Ta, In: Physical Review C - Nuclear Physics61(4)pp. 443211-4432133
High-spin states in 177Ta have been studied using the 170Er(11B,4n) reaction. New intrinsic states have been observed corresponding to 3-, 5-, and 7-quasiparticle high-K structures. Rotational bands built on most of the 3-and 5-quasiparticle states and some transitions above the 7-quasiparticle states have been identified. Several isomers have been found, the longest lived being the 49/2-, 7-quasiparticle state with a meanlife of 192 μs. Configurations for the observed intrinsic states have been assigned on the basis of gK values, alignments, and decay properties. While the properties of most of the bands are consistent with their proposed configurations, the behavior of some, including the one built on Kπ = 21/2- 3-quasiparticle isomer, is not well understood. Multiquasiparticle blocking calculations based on the Lipkin-Nogami method, are in good agreement with the excitation energies of the experimentally observed states and all the predicted states close to the yrast line up to spin 49/2 have been observed experimentally. The calculations predict the existence of a 9-quasiparticle 67/2- yrast trap at ∼ 8.5 MeV.
MB Smith, PM Walker, RS Chakrawarthy, RAE Austin, GC Ball, JJ Carroll, E Cunningham, P Finlay, PE Garrett, GF Grinyer, G Hackman, B Hyland, K Koopmans, WD Kulp, JR Leslie, AA Phillips, R Propri, PH Regan, F Sarazin, MA Schumaker, HC Scraggs, T Shizuma, CE Svensson, J von Schwarzenberg, JC Waddington, D Ward, JL Wood, B Washbrook, EF Zganjar (2004)Studies of high-K isomers at TRIUMF-ISAC, In: Nuclear Physics A746(1-4 SP)
The properties of high-K isomers have been investigated by measuring γ rays from a source of the 31-year 178Hfm2 isomer and from the decay of implanted 178,179Lu beams. Low-intensity transitions have been identified in the decay of 178Hfm2, demonstrating a consistent extension of K-hindrance systematics to higher multipolarities, and elucidating the spin-dependence of the mixing between the two Kπ = 8- bands. A search is underway for new isomers in 178,179Lu and the preliminary results of the analysis are reported. © 2004 Elsevier B.V. All rights reserved.
Z Patel, Philip Walker, Zsolt Podolyak, Patrick Regan, Thomas Berry, P-A Söderström, H Watanabe, E Ideguchi, GS Simpson, S Nishimura, Q Wu, FR Xu, F Browne, P Doornenbal, G Lorusso, S Rice, L Sinclair, T Sumikama, J Wu, ZY Xu, N Aoi, H Baba, FL Bello Garrote, G Benzoni, R Daido, Zs Dombrádi, Y Fang, N Fukuda, G Gey, S Go, A Gottardo, N Inabe, T Isobe, D Kameda, K Kobayashi, M Kobayashi, T Komatsubara, I Kojouharov, T Kubo, N Kurz, I Kuti, Z Li, M Matsushita, S Michimasa, C-B Moon, H Nishibata, I Nishizuka, A Odahara, E Sahin, H Sakurai, H Schaffner, H Suzuki, H Takeda, M Tanaka, J Taprogge, Zs Vajta, A Yagi, R Yokoyama (2017)Isomer-delayed -ray spectroscopy of A = 159 - 164 midshell nuclei and the variation of K-forbidden E1 transition hindrance factors, In: Physical Review C96(3)034305 American Physical Society
Excited states have been studied in ____iso{159}{Sm}, ____iso{161}{Sm}, ____iso{162}{Sm} (Z~=~62), ____iso{163}{Eu} (Z~=~63), and ____iso{164}{Gd} (Z~=~64), populated by isomeric decay following 238U projectile fission at RIBF, RIKEN. The isomer half-lives range from 50 ns to 2.6 ____mus. In comparison with other published data, revised interpretations are proposed for ____iso{159}{Sm} and ____iso{163}{Eu}. The first data for excited states in ____iso{161}{Sm} are presented, where a 2.6 ____mus isomer is assigned a three-quasiparticle, K^____pi = 17/2^- structure. The interpretation is supported by multi-quasiparticle Nilsson-BCS calculations, including the blocking of pairing correlations. A consistent set of reduced E1 hindrance factors is obtained. Limited evidence is also reported for isomeric decay in 163Sm, 164Eu and 165Eu.
K. A. Gladnishki, Zs. Podolyák, P. H. Regan, J. Gerl, M. Hellström, Y. Kopatch, S. Mandal, M. Górska, R. D. Page, H. J. Wollersheim, A. Banu, G. Benzoni, H. Boardman, M. La Commara, J. Ekman, C. Fahlander, H. Geissel, H. Grawe, E. Kaza, A. Korgul, M. Matos, M. N. Mineva, C. J. Pearson, C. Plettner, D. Rudolph, Ch. Scheidenberger, K. -H. Schmidt, V. Shishkin, D. Sohler, K. Sümmerer, J. J. Valiente-Dobón, P. M. Walker, H. Weick, M. Winkler, O. Yordanov (2004)Angular momentum population in the projectile fragmentation of 238U at 750 MeV/nucleon, In: Physical Review C69(024617)
Z Patel, Z Podolyak, PM Walker, PH Regan, P-A Soederstroem, H Watanabe, E Ideguchi, GS Simpson, S Nishimura, F Browne, R Doornenbal, G Lorusso, S Rice, L Sinclair, T Sumikama, J Wu, ZY Xu, N Aoi, H Baba, FLB Garrote, G Benzoni, R Daido, Z Dombradi, Y Fang, N Fukuda, G Gey, S Go, A Gottardo, N Inabe, T Isobe, D Kameda, K Kobayashi, M Kobayashi, T Komatsubara, I Kojouharov, T Kubo, N Kurz, I Kuti, Z Li, HL Liu, M Matsushita, S Michimasa, C-B Moony, H Nishibata, I Nishizuka, A Odahara, E Sahin, H Sakurai, H Schaffner, H Suzuki, H Takeda, M Tanaka, J Taprogge, Z Vajta, FR Xu, A Yagi, R Yokoyama (2016)Decay spectroscopy of Sm-160: The lightest four-quasiparticle K isomer, In: PHYSICS LETTERS B753pp. 182-186 ELSEVIER SCIENCE BV
A Gottardo, JJ Valiente-Dobón, G Benzoni, R Nicolini, JA Núñez, A Algora, N Al-Dahan, GD Angelis, Y Ayyad, N Alkhomashi, PRP Allegro, J Benlliure, P Boutachkov, M Bowry, A Bracco, AM Bruce, M Bunce, E Casarejos, L Cortes, FCL Crespi, F Camera, A Corsi, AMD Bacelar, A Deo, C Domingo-Pardo, M Doncel, Z Dombradi, T Engert, K Eppinger, GF Farrelly, F Farinon, A Gadea, H Geissel, J Gerl, N Goel, M Górska, J Grebosz, E Gregor, T Haberman, R Hoischen, R Janik, S Klupp, I Kojouharov, N Kurz, S Leoni, S Lunardi, S Mandal, R Menegazzo, D Mengoni, B Million, DR Napoli, F Naqvi, C Nociforo, M Pfützner, S Pietri, Z Podolyak, A Prochazka, W Prokopowicz, F Recchia, RV Ribas, MW Reed, PH Regan, D Rudolph, E Sahin, H Schaffner, A Sharma, B Sitar, D Siwal, K Steger, P Strmen, TPD Swan, I Szarka, PM Walker, O Wieland, H Weick, H-J Wollersheim (2011)Isomers in neutron-rich lead isotopes populated via the fragmentation of 238U at 1 GeV A, In: Journal of Physics: Conference Series: International Nuclear Physics Conference312(Sectio)pp. 092019-?
Neutron-rich nuclei beyond N = 126 in the lead region were populated by fragmenting a 238U beam at 1 GeV A on a Be target and then separated by the Fragment Separator (FRS) at GSI. Their isomeric decays were observed, enabling study of the shell structure of neutron-rich nuclei around the Z=82 shell closure. Some preliminary results are reported in this paper.
M. Dasgupta, G. D. Dracoulis, P. M. Walker, A. P. Byrne, T. Kibédi, F. G. Kondev, G. J. Lane, P. H. Regan (2000)Competition between high-K states and rotational structures in 177Ta, In: Physical Review C61(044321)
A Gottardo, JJ Valiente-Dobon, G Benzoni, S Lunardi, A Gadea, A Algora, N Al-Dahan, G de Angelis, Y Ayyad, D Bazzacco, J Benlliure, P Boutachkov, M Bowry, A Bracco, AM Bruce, M Bunce, F Camera, E Casarejos, ML Cortes, FCL Crespi, A Corsi, AMD Bacelar, AY Deo, C Domingo-Pardo, M Doncel, T Engert, K Eppinger, GF Farrelly, F Farinon, E Farnea, H Geissel, J Gerl, N Goel, M Gorska, J Grebosz, E Gregor, T Habermann, R Hoischen, R Janik, PR John, S Klupp, I Kojouharov, N Kurz, SM Lenzi, S Leoni, S Mandal, R Menegazzo, D Mengoni, B Million, V Modamio, AI Morales, DR Napoli, F Naqvi, R Nicolini, C Nociforo, M Pfuetzner, S Pietri, Z Podolyak, A Prochazka, W Prokopowicz, F Recchia, PH Regan, MW Reed, D Rudolph, E Sahin, H Schaffner, A Sharma, B Sitar, D Siwal, K Steiger, P Strmen, TPD Swan, I Szarka, CA Ur, PM Walker, H Weick, O Wieland, H-J Wollersheim (2014)Isomeric decay spectroscopy of the Bi-217 isotope, In: PHYSICAL REVIEW C90(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
P-A Soederstroem, PH Regan, PM Walker, H Watanabe, P Doornenbal, Z Korkulu, P Lee, HL Liu, JJ Liu, G Lorusso, S Nishimura, T Sumikama, VH Phong, J Wu, FR Xu, A Yagi, GX Zhang, T Alharbi, H Baba, F Browne, AM Bruce, R Carroll, KY Chae, Z Dombradi, A Estrade, N Fukuda, C Griffin, E Ideguchi, N Inabe, T Isobe, H Kanaoka, I Kojouharov, FG Kondev, T Kubo, S Kubono, N Kurz, I Kuti, S Lalkovski, GJ Lane, CS Lee, EJ Lee, G Lotay, C-B Moon, I Nishizuka, CR Nita, A Odahara, Z Patel, Z Podolyak, OJ Roberts, H Sakurai, H Schaffner, CM Shand, H Suzuki, H Takeda, S Terashima, Z Vajta, JJ Valiente-Dobon, ZY Xu, S Yoshida (2015)Heavy Rotation - Evolution of quadrupole collectivity centred at the neutron-rich doubly mid-shell nucleus Dy-170, In: NUCLEAR STRUCTURE AND DYNAMICS '151681
MB Smith, PM Walker, RS Chakrawarthy, RAE Austin, GC Ball, JJ Carroll, E Cunningham, P Finlay, PE Garrett, GF Grinyer, G Hackman, B Hyland, K Koopmans, WD Kulp, JR Leslie, AA Phillips, R Propri, PH Regan, F Sarazin, MA Schumaker, HC Scraggs, T Shizuma, CE Svensson, J von Schwarzenberg, JC Waddington, D Ward, JL Wood, B Washbrook, EF Zganjar (2004)Studies of high-K isomers at TRIUMF-ISAC, In: NUCLEAR PHYSICS A746pp. 617C-620C
M Oi, PH Regan, FR Xu, PM Walker, AK Rath, PD Stevenson (2002)Cranked-Hartree-Fock-Bogoliubov analysis at the valence maximum: Yrast behaviour of Dy-170(66)104, In: PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT(146)pp. 609-610
Z Podolyak, CM Shand, E Wilson, BA Brown, H Grawe, CJ Chiara, S Zhu, B Fornal, RVF Janssens, M Bowry, M Bunce, MP Carpenter, N Cieplicka, AY Deo, GD Dracoulis, CR Hoffman, RS Kempley, FG Kondev, GJ Lane, T Lauritsen, G Lotay, MW Reed, PH Regan, CR Triguero, D Seweryniak, B Szpak, PM Walker, A Gargano, L Coraggio, N Itaco (2015)Octupole transitions in the Pb-208 region, In: 11TH INTERNATIONAL SPRING SEMINAR ON NUCLEAR PHYSICS: SHELL MODEL AND NUCLEAR STRUCTURE - ACHIEVEMENTS OF THE PAST TWO DECADES580ARTN 0pp. ?-? IOP PUBLISHING LTD
C Wheldon, PM Walker, PH Regan, T Saitoh, N Hashimoto, G Sletten, FR Xu (1999)High-K structures and triaxiality in Os-186, In: NUCLEAR PHYSICS A652(2)pp. 103-131 ELSEVIER SCIENCE BV
Z Patel, P-A Soederstroem, Z Podolyak, PH Regan, PM Walker, H Watanabe, E Ideguchi, GS Simpson, HL Liu, S Nishimura, Q Wu, FR Xu, F Browne, P Doornenbal, G Lorusso, S Rice, L Sinclair, T Sumikama, J Wu, ZY Xu, N Aoi, H Baba, FLB Garrote, G Benzoni, R Daido, Y Fang, N Fukuda, G Gey, S Go, A Gottardo, N Inabe, T Isobe, D Kameda, K Kobayashi, M Kobayashi, T Komatsubara, I Kojouharov, T Kubo, N Kurz, I Kuti, Z Li, M Matsushita, S Michimasa, C-B Moon, H Nishibata, I Nishizuka, A Odahara, E Sahin, H Sakurai, H Schaffner, H Suzuki, H Takeda, M Tanaka, J Taprogge, Z Vajta, A Yagi, R Yokoyama (2014)Isomer Decay Spectroscopy of Sm-164 and Gd-166: Midshell Collectivity Around N=100, In: PHYSICAL REVIEW LETTERS113(26)ARTN 2pp. ?-? AMER PHYSICAL SOC
M Pfutzner, PH Regan, PM Walker, Z Podolyak, M Caamano, J Gerl, M Hellstrom, P Mayet, MN Mineva (2001)Population of high spin states in relativistic fragmentation, In: ACTA PHYSICA POLONICA B32(9)pp. 2507-2518
S Al-Garni, PM Walker, PH Regan, JG Narro, HM El-Masri, E Roeckl, R Kirchner, M La Commara, C Mazzocchi, H Grawe, R Borcea, J Doring, SC Wooding, K Schmidt, C Wheldon, DM Cullen, WD Schmidt-Ott (2002)Evidence for a K approximate to.139/2 beta-decaying isomer in Lu-177, In: NUCLEAR PHYSICS IN THE 21ST CENTURY610pp. 854-858
CM Shand, E Wilson, Z Podolyak, H Grawe, BA Brown, B Fornal, RVF Janssens, M Bowry, M Bunce, MP Carpenter, RJ Carroll, CJ Chiara, N Cieplicka-Orynczak, AY Deo, GD Dracoulis, CR Hoffman, RS Kempley, FG Kondev, GJ Lane, T Lauritsen, G Lotay, MW Reed, PH Regan, C Rodriguez-Triguero, D Seweryniak, B Szpak, PM Walker, S Zhu (2015)STRUCTURE OF Pb-207 POPULATED IN Pb-208+Pb-208 DEEP-INELASTIC COLLISIONS, In: ACTA PHYSICA POLONICA B46(3)pp. 619-622 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
The yrast structure of 207Pb above the 13=2+ isomeric state has been investigated in deep-inelastic collisions of 208Pb and 208Pb at ATLAS, Argonne National Laboratory. New and previously observed transitions were measured using the Gammasphere detector array. The level scheme of 207Pb is presented up to ∼ 6 MeV, built using coincidence and γ-ray intensity analyses. Spin and parity assignments of states were made, based on angular distributions and comparisons to shell model calculations.
M Grieser, YA Litvinov, R Raabe, K Blaum, Y Blumenfeld, PA Butler, F Wenander, PJ Woods, M Aliotta, A Andreyev, A Artemyev, D Atanasov, T Aumann, D Balabanski, A Barzakh, L Batist, A-P Bernardes, D Bernhardt, J Billowes, S Bishop, M Borge, I Borzov, F Bosch, AJ Boston, C Brandau, W Catford, R Catherall, J Cederkäll, D Cullen, T Davinson, I Dillmann, C Dimopoulou, G Dracoulis, CE Düllmann, P Egelhof, A Estrade, D Fischer, K Flanagan, L Fraile, MA Fraser, SJ Freeman, H Geissel, J Gerl, P Greenlees, RE Grisenti, D Habs, R von Hahn, S Hagmann, M Hausmann, JJ He, M Heil, M Huyse, D Jenkins, A Jokinen, B Jonson, DT Joss, Y Kadi, N Kalantar-Nayestanaki, BP Kay, O Kiselev, H-J Kluge, M Kowalska, C Kozhuharov, S Kreim, T Kröll, J Kurcewicz, M Labiche, RC Lemmon, M Lestinsky, G Lotay, XW Ma, M Marta, J Meng, D Mücher, I Mukha, A Müller, AS Murphy, G Neyens, T Nilsson, C Nociforo, W Nörtershäuser, RD Page, M Pasini, N Petridis, N Pietralla, M Pfützner, Z Podolyák, P Regan, MW Reed, R Reifarth, P Reiter, R Repnow, K Riisager, B Rubio, MS Sanjari, DW Savin, C Scheidenberger, S Schippers, D Schneider, R Schuch, D Schwalm, L Schweikhard, D Shubina, E Siesling, H Simon, J Simpson, J Smith, K Sonnabend, M Steck, T Stora, T Stöhlker, B Sun, A Surzhykov, F Suzaki, O Tarasov, S Trotsenko, XL Tu, P Van Duppen, C Volpe, D Voulot, PM Walker, E Wildner, N Winckler, DFA Winters, A Wolf, HS Xu, A Yakushev, T Yamaguchi, YJ Yuan, YH Zhang, K Zuber (2012)Storage ring at HIE-ISOLDE: Technical design report: Technical design report, In: European Physical Journal: Special Topics207(1)pp. 1-117 EDP Sciences/Springer
We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams that is unique in the world. The envisaged physics programme is rich and varied, spanning from investigations of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. The TSR might also be employed for removal of isobaric contaminants from stored ion beams and for systematic studies within the neutrino beam programme. In addition to experiments performed using beams recirculating within the ring, cooled beams can also be extracted and exploited by external spectrometers for high-precision measurements. The existing TSR, which is presently in operation at the Max-Planck Institute for Nuclear Physics in Heidelberg, is well-suited and can be employed for this purpose. The physics cases as well as technical details of the existing ring facility and of the beam and infrastructure requirements at HIE-ISOLDE are discussed in the present technical design report.
Z Podolyak, M Caamano, PH Regan, PM Walker, P Mayet, J Gerl, C Schlegel, M Hellstrom, M Mineva, M Pfutzner (2002)Isomeric decays in neutron-rich W, Os and Pt nuclei, In: PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT(146)pp. 467-472
G Benzoni, AI Morales, A Bracco, F Camera, FCL Crespi, AM Corsi, S Leoni, B Million, R Nicolini, O Wieland, JJ Valiente-Dobón, A Gottardo, G de Angelis, DR Napoli, E Sahin, A Gottardo, S Lunardi, A Bracco, F Camera, FCL Crespi, AM Corsi, S Leoni, R Nicolini, A Gadea, A Algora, S Lunardi, D Bazzacco, E Farnea, R Menegazzo, D Mengoni, F Recchia, CA Ur, P Boutachkov, M Górska, S Pietri, H Weick, ML Cortes, C Domingo-Pardo, T Engert, F Farinon, H Geissel, J Gerl, N Goel, E Gregor, T Habermann, R Hoischen, I Kojouharov, N Kurz, F Naqvi, C Nociforo, A Prochazka, W Prokopowicz, H Schaffner, A Sharma, H-J Wollersheim, AM Bruce, AM Denis Bacelar, J Grebosz, Z Podolyak, PH Regan, N Al-Dahan, M Bowry, M Bunce, AY Deo, GF Farrelly, MW Reed, TPD Swan, PM Walker, M Pfützner, J Alcántara Núñez, Y Ayyad, J Benlliure, N Alkhomashi, PRP Allegro, RV Ribas, E Casarejos, M Doncel, Z Dombradi, K Eppinger, S Klupp, K Steiger, R Hoischen, D Rudolph, R Janik, B Sitar, P Strmen, I Szarka, S Mandal, D Siwal, F Naqvi, AM Corsi, N Al-Dahan, PM Walker (2012)First measurement of beta decay half-lives in neutron-rich Tl and Bi isotopes, In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics715(4-5)pp. 293-297 Elsevier
Neutron-rich isotopes around lead, beyond N= 126, have been studied exploiting the fragmentation of an uranium primary beam at the FRS-RISING setup at GSI. For the first time β-decay half-lives of Bi and Tl isotopes have been derived. The half-lives have been extracted using a numerical simulation developed for experiments in high-background conditions. Comparison with state of the art models used in r-process calculations is given, showing a systematic underestimation of the experimental values, at variance from close-lying nuclei. © 2012 Elsevier B.V.
S D Al-Garni, P H Regan, P M Walker, E Roeckl, R Kirchner, F R Xu, L Batist, A Blazhev, R Borcea, D M Cullen, J Doring, H M El-Masri, J G Narro, H Grawe, M La Commara, C Mazzoechi, I Mukha, C J Pearson, C Plettner, K Schmidt, W D Schmidt-Ott, Y Shimbara, C Wheldon, R Wood, S C Wooding (2004)Evidence for a High-Spin Beta-Decaying Isomer in Lu-177, In: Physical Review C69(2)
Nuclei in the A similar to 180 region have been populated and investigated in a series of multinucleon transfer and deep-inelastic reactions involving an 11.4 MeV per nucleon Xe-136 beam produced by the GSI UNILAC accelerator, impinging on a selection of tantalum and tungsten targets. The reaction products were released from a thermal ion source and subsequently mass selected using the GSI on-line mass separator. The unexpectedly high yield of gamma rays associated with the decay of the well established K-pi=37/2(-),t(1/2)=51.4 min isomer in Hf-177(72) and anomalous half-life characteristics associated with this decay lead to these data being interpreted as the beta(-) decay of a high-K isomer in the mother nucleus, Lu-177. By comparing the experimental findings with the predictions obtained from multi-quasiparticle blocked-BCS-Nilsson calculations, the proposed decay is suggested to be from a K-pi=39/2(-) five-quasiparticle state in Lu-177(71). A half-life of 7 +/- 2 min is determined for this beta-decay path which is estimated to have an excitation energy of approximate to3.9 MeV above the Lu-177 ground state.
C Wheldon, PM Walker, PH Regan, T Saitoh, N Hashimoto, G Sletten, FR Xu (1999)Triaxial nuclear shapes at high angular momentum, In: PHYSICAL REVIEW C59(5)pp. R2334-R2338 AMERICAN PHYSICAL SOC
M DASGUPTA, PM WALKER, GD DRACOULIS, AP BYRNE, PH REGAN, T KIBEDI, GJ LANE, KC YEUNG (1994)YRAST ISOMERS, MULTI-QUASI-PARTICLE STATES AND BLOCKING IN TA-176 AND TA-177, In: PHYSICS LETTERS B328(1-2)pp. 16-21 ELSEVIER SCIENCE BV
M Caamano, PM Walker, PH Regan, CJ Pearson, Z Podolyak, P Mayet, J Gerl, C Schlegel, M Hellstrom, M Mineva, M Pfutzner (2001)Isomeric decays in Pt-200, In: ACTA PHYSICA POLONICA B32(3)pp. 763-766
Laila Gurgi, Patrick Regan, P-A Söderström, H Watanabe, Philip Walker, Zsolt Podolyak, S Nishimura, Thomas Berry, P Doornenbal, G Lorusso, T Isobe, H Baba, ZY Xu, H Sakurai, T Sumikama, Wilton Catford, AM Bruce, F Browne, GJ Lane, FG Kondev, A Odahara, J Wu, HL Liu, FR Xu, Z Korkulu, P Lee, JJ Liu, VH Phong, A Yag, GX Zhang, T Alharbi, RJ Carroll, KY Chae, Zs Dombradi, A Estrade, N Fukuda, C Griffin, E Ideguchi, N Inabe, H Kanaoka, I Kojouharov, T Kubo, S Kubono, N Kurz, I Kuti, S Lalkovski, EJ Lee, CS Lee, Gavin Lotay, C-B Moon, I Nishizuka, CR Nita, Z Patel, OJ Roberts, H Schaffner, Callum Shand, H Suzuki, H Takeda, S Terashima, Zs Vajta, S Yoshida, JJ Valiente-Dòbon (2016)Isomer spectroscopy of neutron-rich 168Tb103, In: Radiation Physics and Chemistry140pp. 493-496 Elsevier
In-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm thick 9Be target has been used to produce and study the decays of a range of neutron-rich nuclei centred around the doubly mid-shell nucleus 170Dy at the RIBF Facility, RIKEN, Japan. The produced secondary fragments of interest were identified eventby- event using the BigRIPS separator. The fragments were implanted into the WAS3ABI position sensitive silicon active stopper which allowed pixelated correlations between implants and their subsequent β-decay. Discrete γ-ray transitions emitted following decays from either metastable states or excited states populated following beta decay were identified using the 84 coaxial high-purity germanium (HPGe) detectors of the EURICA spectrometer, which was complemented by 18 additional cerium-doped lanthanum bromide (LaBr3)
P.-A. Söderström, Philip Walker, J. Wu, H. L. Liu, Patrick Regan, H. Watanabe, P. Doornenbal, Z. Korkulu, P. Lee, J. J. Liu, G. Lorusso, S. Nishimura, V. H. Phong, T. Sumikama, F. R. Xu, A. Yagi, G. X. Zhang, D. S. Ahn, T. Alharbi, H. Baba, F. Browne, A. M. Bruce, R. J. Carroll, K. Y. Chae, Zs. Dombradi, A. Estrade, N. Fukuda, C. Griffin, E. Ideguchi, N Inabe, T. Isobe, H. Kanaoka, S. Kanaya, I. Kojouharov, F. G. Kondev, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, G. J. Lane, E. J. Lee, C. S. Lee, G. G. Lotay, C.-B. Moon, I. Nishizuka, C. R. Nita, A. Odahara, Z. Patel, Zsolt Podolyak, O. J. Roberts, H. Sakurai, H. Schaffner, C. M. Shand, H. Suzuki, H. Takeda, S. Terashima, Zs. Vajta, J. J. Valiente-Dòbon, Z. Y. Xui (2016)Collective And Single-particle Structures In The Neutron-rich Doubly Mid-shell Nucleus 170Dy, In: Proceedings of Science: The 26th International Nuclear Physics Conference
One of the most successful descriptions of the structure of atomic nuclei is the spherical shell model. It, however, becomes impractical when moving away from closed-shell nuclei. Instead, it is the interplay between the macroscopic shape degrees of freedom and the microscopic nature of the underlying single-particle structure in a deformed basis that determines the nuclear structure. Being the heaviest nucleus precisely in the middle of, known, closed proton and neutron shells, 170Dy has become a central calibration point for tests of collective models of nuclear physics. However, besides one candidate transition from a previous experiment in Legnaro, Italy, no experimental information is available for this nucleus. Using the EURICA setup at RIKEN, which couples the worlds highest intensity in-flight fission facility with a high-efficiency HPGe array, an experiment in November 2014 produced 170Dy nuclei by in-flight fission of a 238U beam. The results from this experiment provide a wealth of information on this elusive nucleus, including the evolution of quadrupole collectivity, rigidity and higher order deformations, as well as the long sought for isomeric K = 6+ state, predicted to be exceptionally pure at mid-shell. These results provide us with a rich level scheme for discussing both single-particle and collective structures at mid-shell.
A Gottardo, JJ Valiente-Dobon, G Benzoni, A Gadea, S Lunardi, P Boutachkov, AM Bruce, M Gorska, J Grebosz, S Pietri, Z Podolyak, M Pfuetzner, PH Regan, H Weick, J Alcantara Nunez, A Algora, N Al-Dahan, G de Angelis, Y Ayyad, N Alkhomashi, PRP Allegro, D Bazzacco, J Benlliure, M Bowry, A Bracco, M Bunce, F Camera, E Casarejos, ML Cortes, FCL Crespi, A Corsi, AMD Bacelar, AY Deo, C Domingo-Pardo, M Doncel, Z Dombradi, T Engert, K Eppinger, GF Farrelly, F Farinon, E Farnea, H Geissel, J Gerl, N Goel, E Gregor, T Habermann, R Hoischen, R Janik, PR John, S Klupp, I Kojouharov, N Kurz, SM Lenzi, S Leoni, S Mandal, R Menegazzo, D Mengoni, B Million, V Modamio, AI Morales, DR Napoli, F Naqvi, R Nicolini, C Nociforo, A Prochazka, W Prokopowicz, F Recchia, RV Ribas, MW Reed, D Rudolph, E Sahin, H Schaffner, A Sharma, B Sitar, D Siwal, K Steiger, P Strmen, TPD Swan, I Szarka, CA Ur, PM Walker, O Wieland, H-J Wollersheim, S Lunardi, PG Bizzeti, S Kabana, C Bucci, M Chiari, A Dainese, P DiNezza, R Menegazzo, A Nannini, C Signorini, JJ ValienteDobon (2014)New Isomers in the Neutron-Rich Region Beyond Pb-208, In: INPC 2013 - INTERNATIONAL NUCLEAR PHYSICS CONFERENCE, VOL. 166ARTN 0pp. ?-? E D P SCIENCES
H Watanabe, G Zhang, K Yoshida, Philip Walker, J Liu, J Wu, Patrick Regan, PA Soderstrom, H Kanaoka, Z Korkulu, PS Lee, S Nishimura, A Yagi, DS Ahn, T Alharbi, H Baba, F Browne, AM Bruce, RJ Fukuda, C Griffin, E Ideguchi, N Inabe, T Isobe, S Kanaya, I Kojouharov, FG Kondev, T Kubo, S Kubono, N Kurz, I Kuti, S Lalkovski, GJ Lane;, CS Lee, EJ Lee, G Lorusso, Gavin Lotay, CB Moon, I Nishizuka, CR Nita, A Odahara, Z Patel, VH Phong, Zsolt Podolyak, OJ Roberts, H Sakurai, H Schaffner, Callum Shand, Y Shimizu, T Sumikama, H Suzuki, H Takeda, S Terashima, Z Vajta;, JJ Valiente-Dobon, ZY Xu (2016)Long-lived K isomer and enhanced gamma vibration in the neutron-rich nucleus 172Dy: Collectivity beyond double midshell, In: Physics Letters B760(Sept)pp. 641-646 Elsevier
The level structure of 172Dy has been investigated for the first time by means of decay spectroscopy following in-flight fission of a 238U beam. A long-lived isomeric state with T1/2 = 0.71(5) s and K π = 8 − has been identified at 1278 keV, which decays to the ground-state and γ-vibrational bands through hindered electromagnetic transitions, as well as to the daughter nucleus 172Ho via allowed β decays. The robust nature of the K π = 8 − isomer and the ground-state rotational band reveals an axially-symmetric structure for this nucleus. Meanwhile, the γ-vibrational levels have been identified at unusually low excitation energy compared to the neighboring well-deformed nuclei, indicating the significance of the microscopic effect on the non-axial collectivity in this doubly mid-shell region. The underlying mechanism of enhanced γ vibration is discussed in comparison with the deformed Quasiparticle Random-Phase Approximation based on a Skyrme energy-density functional.
Z Podolyak, PH Regan, PM Walker, M Caamano, K Gladnishki, J Gerl, M Hellstrom, P Mayet, M Pfutzner, M Mineva (2003)Heavy nuclei studied in projectile fragmentation, In: NUCLEAR PHYSICS A722pp. 273C-278C
M Nakhostin, Z Podolyak, PH Regan, PM Walker (2010)A digital method for separation and reconstruction of pile-up events in germanium detectors, In: REVIEW OF SCIENTIFIC INSTRUMENTS81(10)ARTN 1pp. ?-? AMER INST PHYSICS
E Wilson, Z Podolyak, B Fornal, RVF Janssens, M Bowry, M Bunce, MP Carpenter, CJ Chiara, N Cieplicka, AY Deo, GD Dracoulis, H Grawe, CR Hoffman, RS Kempley, FG Kondev, GJ Lane, T Lauritsen, MW Reed, PH Regan, CR Triguero, B Szpak, PM Walker, S Zhu, S Lunardi, PG Bizzeti, S Kabana, C Bucci, M Chiari, A Dainese, P DiNezza, R Menegazzo, A Nannini, C Signorini, JJ ValienteDobon (2014)Study of (TI126)-T-207 Produced in Deep-Inelastic Reactions, In: INPC 2013 - INTERNATIONAL NUCLEAR PHYSICS CONFERENCE, VOL. 166ARTN 0pp. ?-? E D P SCIENCES
GA Jones, PH Regan, PM Walker, Z Podolyak, PD Stevenson, MP Carpenter, JJ Carroll, RS Chakrawarthy, P Chowdhury, AB Garnsworthy, RVF Janssens, TL Khoo, FG Kondev, GJ Lane, Z Liu, D Seweryniak, NJ Thompson, S Zhu, SJ Williams (2007)Identification of a high-spin isomer in (99)Mo, In: PHYSICAL REVIEW C76(4)ARTN 0pp. ?-? AMER PHYSICAL SOC
GA Jones, PM Walker, Z Podoydk, PH Regan, SJ Williams, MP Carpentert, JJ Carroll, RS Chakrawarthy, P Chowdhury, IJ Cullen, GD Dracoulis, AB Gamsworthy, G Hackman, RVF Janssens, TL Khoo, FG Kondev, GJ Lane, Z Liu, D Seweryniak, NJ Thompson, S Zhu (2006)Microsecond and nanosecond isomers populated in fission reactions, In: FUSION06: Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier853pp. 342-349
Sareh D. Al-Garni, P. H. Regan, P. M. Walker, E. Roeckl, R. Kirchner, F. R. Xu, L. Batist, A. Blazhev, R. Borcea, D. M. Cullen, J. Döring, H. M. El-Masri, J. R. Garces Narro, H. Grawe, M. La Commara, C. Mazzocchi, I. Mukha, C. J. Pearson, C. Plettner, K. Schmidt, W. -D. Schmidt-Ott, Y. Shimbara, C. Wheldon, R. Wood, S. C. Wooding (2004)Evidence for a high-spin beta-decaying isomer in 177Lu, In: Physical Review C69(024320)
PH REGAN, GD DRACOULIS, AP BYRNE, GJ LANE, T KIBEDI, PM WALKER, AM BRUCE (1995)HIGH-K STRUCTURES IN SM-136, In: PHYSICAL REVIEW C51(4)pp. 1745-1753 AMERICAN PHYSICAL SOC
P D Stevenson, M P Brine, Z Podolyak, P H Regan, P M Walker, J R Stone (2005)Shape Evolution in the Neutron-Rich Tungsten Region, In: Physical Review C72(4)
Recent experimental data on the low-lying states in W-190 show a change in the E(4(1)(+))/E(2(1)(+)) behavior compared to less neutron-rich neigbors. Self-consistent axially-deformed Hartree-Fock calculations, using a separable monopole interaction, of nuclei in the vicinity of W-190 are performed to systematically examine the evolution of ground state quadrupole deformations. It is found that the neutron number N=116 causes a coexistence of oblate and prolate shapes, with a weak dependence on proton number, thereby hindering the development of these isotones as well-deformed rotors.
P. H. Regan, F. R. Xu, P. M. Walker, M. Oi, A. K. Rath, P. D. Stevenson (2002)Structure of the doubly midshell nucleus 66170Dy104, In: Physical Review C65(037302)
AI Morales, G Benzoni, N Al-Dahan, S Vergani, Z Podolyak, PH Regan, TPD Swan, JJ Valiente-Dobon, A Bracco, P Boutachkov, FCL Crespi, J Gerl, M Gorska, S Pietri, PM Walker, H-J Wollersheim (2015)First measurement of the beta-decay half-life of Au-206, In: EPL111(5)ARTN 52001 EPL ASSOCIATION, EUROPEAN PHYSICAL SOCIETY
A Gottardo, JJ Valiente-Dobón, G de Angelis, V Modamio, DR Napoli, E Sahin, S Lunardi, A Algora, PR John, SM Lenzi, G Benzoni, A Bracco, F Camera, FCL Crespi, A Corsi, S Leoni, B Million, AI Morales, R Nicolini, O Wieland, A Gadea, D Bazzacco, E Farnea, R Menegazzo, D Mengoni, F Recchia, CA Ur, P Boutachkov, M Górska, S Pietri, H Weick, ML Cortes, C Domingo-Pardo, T Engert, F Farinon, H Geissel, J Gerl, N Goel, E Gregor, T Habermann, R Hoischen, I Kojouharov, N Kurz, F Naqvi, C Nociforo, A Prochazka, W Prokopowicz, H Schaffner, A Sharma, H-J Wollersheim, AM Bruce, M Bunce, AM Denis Bacelar, J Grebosz, Z Podolyák, PH Regan, N Al-Dahan, M Bowry, AY Deo, GF Farrelly, MW Reed, TPD Swan, PM Walker, M Pfützner, Y Ayyad, J Benlliure, J Alcántara Núñez, N Alkhomashi, PRP Allegro, RV Ribas, E Casarejos, M Doncel, Z Dombradi, K Eppinger, S Klupp, K Steiger, D Rudolph, R Janik, B Sitar, P Strmen, I Szarka, S Mandal, D Siwal (2013)New μs isomers in the neutron-rich Hg nucleus, In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics725(4-5)pp. 292-296
Neutron-rich nuclei in the lead region, beyond N=126, have been studied at the FRS-RISING setup at GSI, exploiting the fragmentation of a primary uranium beam. Two isomeric states have been identified in Hg: the 8 isomer expected from the seniority scheme in the νg shell and a second one at low spin and low excitation energy. The decay strength of the 8 isomer confirms the need of effective three-body forces in the case of neutron-rich lead isotopes. The other unexpected low-lying isomer has been tentatively assigned as a 3 state, although this is in contrast with theoretical expectations. © 2013 Elsevier B.V..
SM Vincent, PH Regan, KE Owen, CJ Pearson, AS Clough (2002)In-beam performance of CdZnTe detectors for proton and alpha-particle measurement, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT483(3)PII S0168-pp. 758-763 ELSEVIER SCIENCE BV
AS Clough, PH Regan (2003)Undergraduate courses with an integral research year, In: EUROPEAN JOURNAL OF PHYSICS24(3)PII S0143-pp. 321-328 IOP PUBLISHING LTD
Hibaaq Mohamud (2020)The use of carbon-based nanomaterials for the removal of radionuclides from aqueous solution. University of Surrey
The safe decommissioning of nuclear reactors, worldwide, is a major challenge facing the nuclear industry. Operational activities associated with nuclear decommissioning are expected to generate large volumes of high-level aqueous nuclear waste. Therefore, there is a growing need to develop new treatment processes. Previous work has shown nanomaterials are effective sorption materials for radionuclide removal. However, minimal research has been carried out on hybrid sorption materials consisting of selective functional groups and carbon-based nanomaterials. In this research, functionalised multi-walled carbon nanotubes (MWCNTs) and graphene oxide (GO), were prepared for the removal of long-lived radionuclides, namely, uranium (U(VI)) from aqueous solution. A series of synthesis procedures were applied to unmodified forms of MWCNTs and GO to enhance selectivity towards U(VI). This was accomplished by attaching surface complexing functional groups, such as, COOH, OH and CONH, onto the surface of the nanomaterial. For this work, chemical functionalisation was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The former technique involved monitoring the ratio of the Raman D and G bands (ID/IG), before and after functionalisation, via statistical Raman mapping studies. Overall, an increase in the ID/IG ratio was observed for each functionalised material. This suggests that the chemical functionalisation procedure applied to unmodified MWCNTs and GO materials was successful in introducing an increased number of defect sites suitable for the attachment of functional groups. This finding was further supported by high resolution XPS studies, which confirmed the presence of select surface groups of interest onto each material. The sorption behaviour of functionalised MWCNTs and GO materials towards U(VI) was investigated in the form of batch sorption studies with solution analysis by inductively coupled plasma mass spectrometry (ICP-MS). The following parameters, which are known to influence sorption behaviour were investigated, namely, the effect of pH, contact time and competing ions (Mg, Co, Zn, Sr, Pb and Th). This was done to assess the suitability of each material for nuclear waste treatment. Initial studies revealed that functionalised MWCNTs had minimal selectivity and loading capacity (Qmax) for U(VI) in aqueous solution. The results showed for the best-performing MWCNTs material (COOH-f MWCNTs), the U sorption and the distribution co-efficient (Kd) decreased, in the presence of competing ions from 97.4 ± 1.6 to 12.6 ± 1.0 % and 3.1×104 to 1.4×102 mL g-1, respectively. Moreover, a Qmax of 34.01 mg g-1 was observed for COOH-f MWCNTs under optimal pH conditions. In terms of all the sorption materials tested, COOH-f GO, exhibited the highest selectivity (Kd of 3.7×103 mL g-1) for U(VI) in aqueous solution with a Qmax of 169.20 mg g−1. The sorption performance of COOH-f GO was tested using a high salinity aqueous nuclear waste sample (Sellafield, UK), which showed minimal selectivity for uranium (Kd of 1.0×102 mL g-1) even after pH-adjustment. Furthermore, a higher affinity for competing ions was observed with 85.0 ± 6.9 %, 82.5 ± 5.2 % and 87.5 ± 4.9 % of Mg, Sr and Pb removed by COOH-f GO. The effect of combining the high sorption capacity of COOH-f GO for uranium with magnetic separation (i.e. Fe3O4-f GO) was investigated by batch sorption studies using sequentially-extracted soil samples from the Laguna Sirven Deposit, Santa Cruz, Argentina. Overall, the results showed that Fe3O4-f GO can remove up to 86.7 ± 2.3 % of uranium from sample matrices relevant to uranium remediation. As such, the research described in this thesis could potentially find use in many future applications, including nuclear decommissioning and environmental remediation studies.
H. Mohamud, E. Van Es, T. Sainsbury, P. Ivanov, B. Russell, P. Regan, N. Ward (2017)Progress towards the development of a rapid analytical approach for separation of 226Ra using dibenzo-18-crown-6 ether functionalised silica (SiO2) disks, In: Radiation physics and chemistry140pp. 57-60 Elsevier
A novel dibenzo-18-crown-6 ether (DB-18CE-6)- functionalised silica (SiO2) disk was found to be a capable source preparation technique for the rapid analysis of 226Ra by alpha-spectrometry. DB-18CE-6 was chemically immobilised onto the surface of SiO2 disks. It is anticipated that the high levels of selectivity of DB-18CE-6 for radium will allow for an efficient chemical separation of 226Ra from other elements present in sample matrices. 226Ra was adsorbed as a monolayer onto the surface of the silica disks, attaching to the functionalised centres of the DB-18CE-6 structure, forming a high resolution counting source for alpha-spectrometry. The chemical recovery of radium from synthetic samples was 2.3% at pH 2, with higher recoveries expected over the pH range of 4−10.
Hibaaq Mohamud, P. Ivanov, B. C. Russell, Patrick Regan, Neil Ward (2018)Selective sorption of uranium from aqueous solution by graphene oxide-modified materials, In: Journal of Radioanalytical and Nuclear Chemistry316(2)pp. 839-848 Springer Verlag
The effect of competing ions on the sorption behaviour of uranium onto carboxyl-functionalised graphene oxide (COOH-GO) were studied in batch experiments in comparison to graphene oxide (GO) and graphite. The effect of increasing the abundance of select chemical functional groups, such as carboxyl groups, on the selectivity of U sorption was investigated. In the course of the study, COOH-GO demonstrated superior performance as a sorbent material for the selective removal of uranyl ions from aqueous solution with a distribution coefficient of 3.72 ± 0.19 × 103 mL g−1 in comparison to 3.97 ± 0.5 × 102 and 2.68 ± 0.2 × 102 mL g−1 for GO and graphite, respectively.
Hibaaq Mohamud, Elsje Van Es, T Sainsbury, P Ivanov, B Russell, Patrick Regan, Neil Ward (2017)Progress towards the development of a rapid analytical approach for separation of 226Ra using dibenzo-18-crown-6 ether functionalised silica (SiO2) disks, In: Radiation Physics and Chemistry140pp. 57-60 Elsevier
A novel dibenzo-18-crown-6 ether (DB-18CE-6)- functionalised silica (SiO2) disk was found to be a capable source preparation technique for the rapid analysis of 226Ra by alpha-spectrometry. DB-18CE-6 was chemically immobilised onto the surface of SiO2 disks. It is anticipated that the high levels of selectivity of DB-18CE-6 for radium will allow for an efficient chemical separation of 226Ra from other elements present in sample matrices. 226Ra was adsorbed as a monolayer onto the surface of the silica disks, attaching to the functionalised centres of the DB-18CE-6 structure, forming a high resolution counting source for alpha-spectrometry. The chemical recovery of radium from synthetic samples was 2.3% at pH 2, with higher recoveries expected over the pH range of 4−10.
M. Jentschel, A. Blanc, G. de France, U. Köster, S. Leoni, P. Mutti, G. Simpson, T. Soldner, C. Ur, W. Urban, S. Ahmed, A. Astier, L. Augey, T. Back, P. Ba̧czyk, A. Bajoga, D. Balabanski, T. Belgya, G. Benzoni, C. Bernards, D.C. Biswas, G. Bocchi, S. Bottoni, R. Britton, B. Bruyneel, J. Burnett, R.B. Cakirli, R. Carroll, Wilton Catford, B. Cederwall, I. Celikovic, N. Cieplicka-Oryńczak, E. Clement, N. Cooper, F. Crespi, M. Csatlos, D. Curien, M. Czerwiński, L.S. Danu, A. Davies, F. Didierjean, F. Drouet, G. Duchêne, C. Ducoin, K. Eberhardt, S. Erturk, L.M. Fraile, A. Gottardo, L. Grente, L. Grocutt, C. Guerrero, D. Guinet, A.-L. Hartig, C. Henrich, A. Ignatov, S. Ilieva, D. Ivanova, B.V. John, R. John, J. Jolie, S. Kisyov, M. Krticka, T. Konstantinopoulos, A. Korgul, A. Krasznahorkay, T. Kröll, J. Kurpeta, I. Kuti, S. Lalkovski, C. Larijani, R. Leguillon, R. Lica, O. Litaize, R. Lozeva, C. Magron, C. Mancuso, E. Ruiz Martinez, R. Massarczyk, C. Mazzocchi, B. Melon, D. Mengoni, C. Michelagnoli, B. Million, C. Mokry, S. Mukhopadhyay, K. Mulholland, A. Nannini, D.R. Napoli, B. Olaizola, R. Orlandi, Z. Patel, V. Paziy, C. Petrache, M. Pfeiffer, N. Pietralla, Z. Podolyak, M. Ramdhane, N. Redon, Patrick Regan, J.M. Regis, D. Regnier, R. J. Oliver, Matthias Rudigier, J. Runke, T. Rza̧ca-Urban, N. Saed-Samii, M.D. Salsac, M. Scheck, R. Schwengner, L. Sengele, P. Singh, J. Smith, O. Stezowski, B. Szpak, T. Thomas, M. Thürauf, J. Timar, A. Tom, I. Tomandl, T. Tornyi, C. Townsley, A. Tuerler, S. Valenta, A. Vancraeyenest, V. Vandone, J. Vanhoy, V. Vedia, N. Warr, V. Werner, D. Wilmsen, E. Wilson, T. Zerrouki, M. Zielinska (2017)EXILL—a high-efficiency, high-resolution setup for γ-spectroscopy at an intense cold neutron beam facility, In: Journal of Instrumentation12(11)pp. P11003-P11003 IOP Publishing
In the EXILL campaign a highly efficient array of high purity germanium (HPGe) detectors was operated at the cold neutron beam facility PF1B of the Institut Laue-Langevin (ILL) to carry out nuclear structure studies, via measurements of γ-rays following neutron-induced capture and fission reactions. The setup consisted of a collimation system producing a pencil beam with a thermal capture equivalent flux of about 108 n s−1cm−2 at the target position and negligible neutron halo. The target was surrounded by an array of eight to ten anti-Compton shielded EXOGAM Clover detectors, four to six anti-Compton shielded large coaxial GASP detectors and two standard Clover detectors. For a part of the campaign the array was combined with 16 LaBr3:(Ce) detectors from the FATIMA collaboration. The detectors were arranged in an array of rhombicuboctahedron geometry, providing the possibility to carry out very precise angular correlation and directional-polarization correlation measurements. The triggerless acquisition system allowed a signal collection rate of up to 6 × 105 Hz. The data allowed to set multi-fold coincidences to obtain decay schemes and in combination with the FATIMA array of LaBr3:(Ce) detectors to analyze half-lives of excited levels in the pico- to microsecond range. Precise energy and efficiency calibrations of EXILL were performed using standard calibration sources of 133Ba, 60Co and 152Eu as well as data from the reactions 27Al(n,γ)28Al and 35Cl(n,γ)36Cl in the energy range from 30 keV up to 10 MeV.
L Knafla, P Alexa, U Köster, G Thiamova, J.M Régis, J Jolie, A Blanc, A.M Bruce, A Esmaylzadeh, L.M Fraile, G De France, G Häfner, S Ilieva, M Jentschel, V Karayonchev, W Korten, T Kröll, S Lalkovski, S Leoni, N Mărginean, H Mach, P Mutti, G Pascovici, V Paziy, Zs Podolyák, P.H Regan, O.J Roberts, N Saed-Samii, G.S Simpson, J.F Smith, T Soldner, C Townsley, C.A Ur, W Urban, A Vancraeyenest, ZSOLT PODOLYAK, N Warr (2020)Lifetime measurements in the odd-A nucleus $^{177}$Hf, In: Phys.Rev.C102(5) American Physical Society
Lifetimes of low- and high-spin states in the odd-A nucleus Hf177 were measured during the EXILL&FATIMA campaign using a spectrometer equipped with eight HPGe-Clover detectors and 16 fast-timing LaBr3(Ce) detectors. For the determination of lifetimes in the pico- to nanosecond regime, the well-established generalized centroid difference method was used. Lifetimes of the 9/2−, 9/2+, 11/2−, 11/2+ states were remeasured, the lifetimes of the 13/2−, 17/2−, 13/2+, 15/2+, and 17/2+ states were determined for the first time and an upper limit for the 19/2+ state has been established. From these lifetimes absolute reduced transition probabilities were extracted and compared to particle-rotor-model calculations and quasiparticle-phonon-model calculations showing the importance of including multipole-multipole interactions in the description of odd-A nuclei in the rare earth region.
Bo Li (2020)An inductive superconducting transition-edge nano-detector for nano-dosimetry applications. University of Surrey
In this thesis I have demonstrated the feasibility of using Inductive Superconducting Transition-Edge Sensor (ISTED) as an excellent nanodosimeter for nano-dosimetry applications. This thesis can be divided broadly into two parts. In the first part, I begin by addressing how the study of low energetic ionising particles in liquid water using concepts from classical mechanics is a valid approach, despite being inside the quantum-classical boundary regime. Based on the circumstantial validity condition, I showed that the percentage uncertainties in nanodosimetric quantities due to Heisenberg's uncertainty principle for sub- 1 keV electrons in liquid water as calculated by GEANT4-DNA is not significant enough to cause changes to their distributions. Important nanodosimetric quantities studied in details are ionisation cluster-size distribution, second order of moment for cluster-size distribution (M$_2$) and the cumulative frequency of ionisation cluster-size distribution from cluster-size two (F$_2$). In the second part of my thesis, I have focussed on the design, optimisation, fabrication, characterisation of the superconducting devices. An ISTED is made from three components: a) a Superconducting Quantum Interference Device (SQUID), b) a superconducting thin-film and c) a top layer of thin-film Carbon absorber. I have measured the magnetic flux noise of a nanoSQUID of loop dimension 350 nm and nano- Josephson junctions of dimensions 65 nm x 65 nm as $3 ____times 10^{-14} ____Phi_0^2$ in the white noise region. It is shown that the measured nanoSQUID is more than capable of sub- 10 eV energy detection.
Robert Shearman (2020)Development of a novel gamma-ray detection system for decay data measurement and beta-delayed spectroscopy of primary fission fragments at N~82. University of Surrey
The work presented in this thesis details three aspects of determining absolute properties of nuclear decay data. The first facet is the design and commissioning of the NAtional Nuclear Array (NANA) for the use of primary standardisation of gamma-cascade emitting nuclides, and to be used more widely as a gamma-ray coincidence spectrometer. Geant4 Monte Carlo simulations were created to characterise possible designs, which were subsequently validated by comparing the response of the constructed array with the model. The simulation was also used to provide correction factors for the absolute standardisation of 60Co. The second strand concerns the determination of absolute emission probabilities of several gamma rays of the medically relevant radioisotope 153Gd. Measurements of these values were made using highly characterised HPGe detectors at the National Physical Laboratory. The absolute gamma-ray emission probability of the 97.4~keV transition was found to be 30.15 (3) %, providing a new standard and correcting a possible discrepancy within the nuclear data of 153Gd reported by the Bureau Interntionale de Poids et Measures (BIPM) international reference system (SIR). The final branch of the thesis presents analyses of beta minus decays of neutron-rich primary fission products created at the RIKEN Research Institute, Tokyo Japan. Absolute beta-delayed gamma-ray emission probabilities and related limits of the beta-delayed neutron emission probabilities have been deduced for 120-124Rh decays to Palladium isotopes and astrophysically important N=82 isotone, 129Ag to states in 128,129Cd. Preliminary beta-delayed level schemes are presented for the daughter nuclei 120,122,124Pd as well as for the N=81, neutron-hole nucleus 129Cd.
Callum Shand, Zsolt Podolyak, M. Górska, P. Doornenbal, A. Obertelli, F. Nowacki, T. Otsuka, K. Sieja, Jeffrey Tostevin, Y. Tsunoda, G. Authelet, H. Baba, D. Calvet, A. Château, S. Chen, A. Corsi, A. Delbart, J.M. Gheller, A. Giganon, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama, T. Motobayashi, M. Niikura, H. Otsu, N. Paul, C. Péron, A. Peyaud, E.C. Pollacco, J.-Y. Roussé, H. Sakurai, C. Santamaria, M. Sasano, Y. Shiga, D. Steppenbeck, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang, K. Yoneda, T. Ando, T. Arici, A. Blazhev, F. Browne, A.M. Bruce, R.J. Carroll, L.X. Chung, M.L. Cortés, M. Dewald, B. Ding, Zs. Dombrádi, F. Flavigny, S. Franchoo, F. Giacoppo, A. Gottardo, K. Hadyńska-Klęk, A. Jungclaus, Z. Korkulu, S. Koyama, Y. Kubota, J. Lee, M. Lettmann, B.D. Linh, J. Liu, Z. Liu, C. Lizarazo, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, K. Moschner, M. Nagamine, N. Nakatsuka, S. Nishimura, C.R. Nita, C.R. Nobs, L. Olivier, S. Ota, R. Orlandi, Z. Patel, P.H. Regan, Matthias Rudigier, E. Şahin, T. Saito, P.-A. Söderström, I. Stefan, T. Sumikama, D. Suzuki, Zs. Vajta, V. Vaquero, V. Werner, K. Wimmer, J. Wu, Z.Y. Xu (2017)Shell evolution beyond Z = 28 and N = 50: Spectroscopy of 81,82,83,84 Zn, In: Physics Letters B773pp. 492-497 Elsevier
We report on the measurement of new low-lying states in the neutron-rich 81,82,83,84Zn nuclei via in-beam γ -ray spectroscopy. These include the View the MathML source41+→21+ transition in 82Zn, the View the MathML source21+→0g.s.+ and View the MathML source41+→21+ transitions in 84Zn, and low-lying states in 81,83Zn were observed for the first time. The reduced View the MathML sourceE(21+) energies and increased View the MathML sourceE(41+)/E(2+1) ratios at N=52N=52, 54 compared to those in 80Zn attest that the magicity is confined to the neutron number N=50N=50 only. The deduced level schemes are compared to three state-of-the-art shell model calculations and a good agreement is observed with all three calculations. The newly observed 2+2+ and 4+4+ levels in 84Zn suggest the onset of deformation towards heavier Zn isotopes, which has been incorporated by taking into account the upper sdg orbitals in the Ni78-II and the PFSDG-U models.
EC Simpson, JA Tostevin, Z Podolyak, PH Regan, SJ Steer (2010)Differential isomeric ratios following two-proton knockout from Pb-208, In: PHYSICAL REVIEW C82(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
EC Simpson, JA Tostevin, Z Podolyak, PH Regan, SJ Steer (2009)Population of low-seniority isomeric states of Hg-206 by two-proton knockout reactions at relativistic energies, In: PHYSICAL REVIEW C80(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
Z Podolyak, SJ Steer, G Farrelly, M Gorska, H Grawe, HK Maier, PH Regan, J Benlliure, S Pietri, J Gerl, HJ Wollersheim, M Milin, T Niksic, D Vretenar, S Szilner (2009)Structure of Neutron-rich N=126 Closed Shell Nuclei, In: NUCLEAR STRUCTURE AND DYNAMICS '091165pp. 86-89
K Higashiyama, N Yoshinaga, P Regan (2009)Shell model study of neutron rich Se and Ge isotopes, In: AIP Conference Proceedings1090pp. 599-600
P Regan, P Stevenson (2005)NUSTAR 2005, In: Journal of Physics G: Nuclear and Particle Physics31(10)
R Hoischen, D Rudolph, HL Ma, P Montuenga, M Hellstrom, S Pietri, Z Podolyak, PH Regan, AB Garnsworthy, SJ Steer, F Becker, P Bednarczyk, L Caceres, P Doornenbal, J Gerl, M Gorska, J Grebosz, I Kojouharov, N Kurz, W Prokopowicz, H Schaffner, HJ Wollersheim, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, A Blazhev, C Brandau, JR Brown, C Fahlander, EK Johansson, A Jungclaus (2011)Isomeric mirror states as probes for effective charges in the lower pf shell, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS38(3)ARTN 0pp. ?-? IOP PUBLISHING LTD
SJ Steer, Z Podolyák, S Pietri, M Górska, H Grawe, KH Maier, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen (2011)Isomeric states observed in heavy neutron-rich nuclei populated in the fragmentation of a 208Pb beam, In: Physical Review C - Nuclear Physics84(4)044313 American Physical Society
G Neyens, G Georgiev, R Grzywacz, M Hass, FD Santos, M Lewitowicz, DL Balabanski, C Bingham, C Borcea, N Coulier, R Coussement, JM Daugas, G Defrance, G Goldring, M Gorska, H Grawe, C O'Leary, I Macovei, H Mach, R Page, M Pfutzner, YE Penionzkevich, Z Podolyak, PH Regan, K Rykaczewski, M Sawicka, NA Smirnova, Y Sobolev, S Teughels, K Vyvey (2002)g-factors of isomers around N approximate to 40, Z approximate to 28 from time-dependent Larmor precession on spin-aligned projectile-like fragments, In: NUCLEAR PHYSICS A701pp. 403C-409C
G Georgiev, G Neyens, M Hass, DL Balabanski, C Bingham, C Borcea, N Coulier, R Coussement, JM Daugas, G de France, M Gorska, H Grawe, R Grzywacz, M Lewitowicz, H Mach, I Matea, FD Santos, RD Page, M Pfutzner, YE Penionzhkevich, Z Podolyak, PH Regan, K Rykaczewski, M Sawicka, NA Smirnova, Y Sobolev, M Stanoiu, S Teughels, K Vyvey (2004)G-factors of isomeric states in the neutron-rich nuclei, In: EUROPEAN PHYSICAL JOURNAL A20(1)pp. 93-94
V Anagnostatou, PH Regan, V Werner, FR Xu, GX Dong, MR Bunce, D McCarthy, L Bettermann, C Boniwell, R Casperson, R Chevrier, N Cooper, A Heinz, P Paurstein, D Radeck, MK Smith, E Williams (2011)Electromagnetic transition rates in (100,101)Pd using the Recoil Doppler Shift Technique., In: Appl Radiat Isot
The quadrupole deformations for the low-lying states in the transitional nuclei (100,101)Pd have been deduced through the measurement of their electric quadrupole transition probabilities using the Recoil Distance Doppler Shift Method. The nuclei were studied using a 268MeV (80)Se beam impinging on a thin, self-supporting (24)Mg target. States in (100)Pd and (101)Pd populated by the four and three neutron evaporation channels respectively, with reaction gamma-rays detected using the SPEEDY gamma-ray detection array. The recoiling nuclei were stopped in a copper foil and gamma-ray coincidence data taken at 10 separate target-stopper distances between 35μm and 750μm. The mean-lifetimes for the lowest lying 2(+) (in (100)Pd) and 15/2(-) (in (101)Pd) states were measured to be 13.3(9)ps and 10.8(8)ps respectively. These data are compared with predictions from nuclear Total Routhian Surface calculations, which are found to agree with the experimentally deduced values to within 10%.
R Wadsworth, BSN Singh, AN Steer, DC Jenkins, MA Bentley, T Brock, P Davies, R Glover, NS Pattabiraman, C Scholey, T Grahn, PT Greenlees, P Jones, U Jakobsson, R Julin, S Juutinen, S Ketelhut, M Leino, M Nyman, P Perua, J Pakarinen, P Rahkila, P Ruotslainen, J Sorri, J Uusitalo, CJ Lister, PA Butler, M Dimmock, DT Joss, J Thomson, S Rinta-Antila, B Cederwall, B Hadinia, M Sandzelius, A Atac, L Betterman, A Blazhev, N Braun, F Finke, K Geibel, G Ilie, H Iwasaki, J Jolie, P Reiter, C Scholl, N Warr, P Boutachkov, L Caceres, C Domingo, T Engert, F Farinon, J Gerl, N Goel, M Gorska, H Grawe, N Kurz, I Kojuharov, S Pietri, C Nociforo, A Prochazka, H-J Wollersheim, K Eppinger, T Faestermann, C Hinke, R Hoischen, R Kruecken, A Gottardo, Z Liu, P Woods, J Grebosz, E Merchant, J Nyberg, P-A Soderstrom, Z Podolyak, P Regan, S Steer, M Pfutzner, D Rudolph (2009)THE NORTHWEST FRONTIER: SPECTROSCOPY OF N similar to Z NUCLEI BELOW MASS 100, In: ACTA PHYSICA POLONICA B40(3)pp. 611-620
BS Nara Singh, Z Liu, R Wadsworth, H Grawe, TS Brock, P Boutachkov, N Braun, A Blazhev, M Górska, S Pietri, D Rudolph, C Domingo-Pardo, SJ Steer, A Ataç, L Bettermann, L Cáceres, K Eppinger, T Engert, T Faestermann, F Farinon, F Finke, K Geibel, J Gerl, R Gernhäuser, N Goel, A Gottardo, J Grabosz, C Hinke, R Hoischen, G Ilie, H Iwasaki, J Jolie, A Kaşkaş, I Kojouharov, R Krücken, N Kurz, E Merchán, C Nociforo, J Nyberg, M Pfützner, A Prochazka, Z Podolyák, PH Regan, P Reiter, S Rinta-Antila, C Scholl, H Schaffner, P-A Söderström, N Warr, H Weick, H-J Wollersheim, PJ Woods, F Nowacki, K Sieja (2011)16+ spin-gap isomer in Cd96, In: Physical Review Letters107(17)172502 American Physical Society
SPG CHAPPELL, DL WATSON, SP FOX, CD JONES, WDM RAE, PM SIMMONS, M FREER, BR FULTON, NM CLARKE, N CURTIS, MJ LEDDY, JS POPLE, SJ HALL, RP WARD, G TUNGATE, WN CATFORD, GJ GYAPONG, SM SINGER, PH REGAN (1995)C-12+C-12 6-ALPHA-CHAIN STATE RESONANCE, In: PHYSICAL REVIEW C51(2)pp. 695-700 AMERICAN PHYSICAL SOC
OJ Roberts, AM Bruce, F Browne, N Marginean, T Alexander, T Alharbi, D Bucurescu, D Deleanu, D Delion, D Filipescu, L Fraile, I Gheorghe, D Grita, T Glodariu, D Ivanova, S Kisyov, R Marginean, PJR Mason, C Mihai, K Mulholland, A Negret, C Nita, B Olaizola, S Pascu, P-A Soederstroem, PH Regan, T Sava, L Stroe, S Toma, C Townsley (2013)HALF-LIFE MEASUREMENTS OF EXCITED STATES IN Te-132, Xe-134, In: ACTA PHYSICA POLONICA B44(3)pp. 403-406 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
AN Mineva, M Hellstrom, M Bernas, J Gerl, H Grawe, M Pfutzner, PH Regan, M Rejmund, D Rudolph, F Becker, CR Bingham, T Enqvist, B Fogelberg, H Gausemel, H Geissel, J Genevey, M Gorska, R Grzywacz, K Hauschild, Z Janas, I Kojouharov, Y Kopatch, A Korgul, W Korten, J Kurcewicz, M Lewitowicz, R Lucas, H Mach, S Mandal, P Mayet, C Mazzocchi, JA Pinston, Z Podolyak, H Schaffner, C Schlegel, K Schmidt, K Summerer, HJ Wollersheim (2001)A new mu s isomer in Sb-136 produced in the projectile fission of U-238, In: EUROPEAN PHYSICAL JOURNAL A11(1)pp. 9-13 SPRINGER-VERLAG
A.I. Morales, G. Benzoni, H. Watanabe, G. de Angelis, S. Nishimura, L. Coraggio, A. Gargano, N. Itaco, T. Otsuka, Y. Tsunoda, P. Van Isacker, F. Browne, R. Daido, P. Doornenbal, Y. Fang, G. Lorusso, Z. Patel, S. Rice, L. Sinclair, P.-A. Söderström, T. Sumikama, J.J. Valiente-Dobón, J. Wu, Z.Y. Xu, A. Yagi, R. Yokoyama, H. Baba, R. Avigo, F.L. Bello Garrote, N. Blasi, A. Bracco, A.M. Bruce, F. Camera, S. Ceruti, F.C.L. Crespi, M.-C. Delattre, Zs. Dombradi, A. Gottardo, T. Isobe, I. Kojouharov, N. Kurz, I. Kuti, S Lalkovski, K. Matsui, B. Melon, D. Mengoni, T. Miyazaki, V. Modamio-Hoybjor, S. Momiyama, D.R. Napoli, M. Niikura, R. Orlandi, Zsolt Podolyak, Patrick Regan, H. Sakurai, E. Sahin, D. Sohler, H. Schaffner, R. Taniuchi, J. Taprogge, Zs. Vajta, O. Wieland, M. Yalcinkaya (2018)Is seniority a partial dynamic symmetry in the first ν g 9/2 shell?, In: Physics Letters B781pp. 706-712 Elsevier
The low-lying structures of the midshell νg9/2 Ni isotopes 72Ni and 74Ni have been investigated at the RIBF facility in RIKEN within the EURICA collaboration. Previously unobserved low-lying states were accessed for the first time following β decay of the mother nuclei 72Co and 74Co. As a result, we provide a complete picture in terms of the seniority scheme up to the first (8+) levels for both nuclei. The experimental results are compared to shell-model calculations in order to define to what extent the seniority quantum number is preserved in the first neutron g9/2 shell. We find that the disappearance of the seniority isomerism in the View the MathML source states can be explained by a lowering of the seniority-four (6+) levels as predicted years ago. For 74Ni, the internal de-excitation pattern of the newly observed View the MathML source state supports a restoration of the normal seniority ordering up to spin J=4. This property, unexplained by the shell-model calculations, is in agreement with a dominance of the single-particle spherical regime near 78Ni.
AK Rath, RD Stevenson, PH Regan, FR Xu, RM Walker (2003)Self-consistent description of dysprosium isotopes in the doubly midshell region, In: PHYSICAL REVIEW C68(4)ARTN 0pp. ?-? AMERICAN PHYSICAL SOC
A. Jungclaus, L. Cáceres, M. Górska, M. Pfützner, S. Pietri, E. Werner-Malento, H. Grawe, K. Langanke, G. Martínez-Pinedo, F. Nowacki, A. Poves, J. J. Cuenca-García, D. Rudolph, Zs. Podolyak, P. H. Regan, P. Detistov, S. Lalkovski, V. Modamio, J. Walker, P. Bednarczyk, P. Doornenbal, H. Geissel, J. Gerl, J. Grebosz, I. Kojouharov, N. Kurz, W. Prokopowicz, H. Schaffner, H. J. Wollersheim, K. Andgren, J. Benlliure, G. Benzoni, A. M. Bruce, E. Casarejos, B. Cederwall, F. C. L. Crespi, B. Hadinia, M. Hellström, R. Hoischen, G. Ilie, J. Jolie, A. Khaplanov, M. Kmiecik, R. Kumar, A. Maj, S. Mandal, F. Montes, S. Myalski, G. S. Simpson, S. J. Steer, S. Tashenov, O. Wieland (2007)Observation of Isomeric Decays in the r-Process Waiting-Point Nucleus 130Cd82, In: Physical Review Letters99(132501)
AT Reed, O Tarasov, RD Page, D Guillemaud-Mueller, YE Penionzhkevich, RG Allatt, JC Angelique, R Anne, C Borcea, V Burjan, WN Catford, Z Dlouhy, C Donzaud, S Grevy, M Lewitowicz, SM Lukyanov, FM Marques, G Martinez, AC Mueller, PJ Nolan, J Novak, NA Orr, F Pougheon, PH Regan, MG Saint-Laurent, T Siiskonen, E Sokol, O Sorlin, J Suhonen, W Trinder, SM Vincent (1999)Radioactivity of neutron-rich oxygen, fluorine, and neon isotopes, In: PHYSICAL REVIEW C60(2)ARTN 02431 AMERICAN PHYSICAL SOC
M Bunce, PH Regan, V Werner, CW Beausang, V Anagnostatou, M Bowry, RJ Casperson, D Chen, N Cooper, PM Goddard, RO Hughes, G Ilie, PJR Mason, B Pauerstein, MW Reed, TJ Ross, EC Simpson (2013)High-spin study of the shell model nucleus Y-88(49), In: PHYSICAL REVIEW C87(4)ARTN 04433 AMER PHYSICAL SOC
F Naqvi, M Gorska, L Caceres, A Jungclaus, M Pfuetzner, H Grawe, F Nowacki, K Sieja, S Pietri, E Werner-Malento, PH Regan, D Rudolf, Z Podolyak, J Jolie, K Andgren, T Beck, P Bednarczyk, J Benlliure, G Benzoni, AM Bruce, E Casarejos, B Cederwall, FCL Crespi, P Detistov, Z Dombradi, P Doornenbal, H Geissel, J Gerl, J Grebosz, B Hadinia, M Hellstrom, R Hoischen, G Ilie, A Khaplanov, I Kojouharov, M Kmiecik, N Kurz, S Lalkovski, A Maj, S Mandal, V Modamio, F Montes, S Myalski, W Prokopowicz, P Reiter, H Schaffner, G Simpson, D Sohler, SJ Steer, S Tashenov, J Walker, O Wieland, HJ Wollersheim (2010)Isomer spectroscopy of Cd-127, In: PHYSICAL REVIEW C82(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
G Georgiev, DL Balabanski, C Bingham, C Borcea, N Coulier, R Coussement, JM Daugas, G Defrance, F De Oliveira Santos, G Goldring, M Górska, H Grawe, R Grzywacz, M Hass, C O'Leary, M Lewitowicz, H Mach, I Macovei, R Page, M Pfützner, YE Penionzkevich, Z Podolyák, PH Regan, K Rykaczewski, M Sawicka, NA Smirnova, YG Sobolev, M Stanoiu, S Teughels, K Vyvey, G Neyens (2001)Measurement of the g factors of isomers near the proposed N ≈ 40 subshell closure, In: Physics of Atomic Nuclei64(7)pp. 1181-1185
We report results from a pioneering experiment to measure the g factors of isomeric states of neutron-rich nuclei around 68Ni, far from the valley of β stability. For the first time, the time-dependent perturbed angular distribution method was applied in combination with the heavy-ion-γ correlation technique to study g factors of spin-aligned isomers produced in a projectile fragmentation reaction and mass-separated. Some technical aspects are discussed and illustrated with preliminary results. © 2001 MAIK "Nauka/Interperiodica".
R Britton, JL Burnett, AV Davies, PH Regan (2014)Maximising the sensitivity of a gamma spectrometer for low-energy, low-activity radionuclides using Monte Carlo simulations, In: JOURNAL OF ENVIRONMENTAL RADIOACTIVITY134pp. 1-5 ELSEVIER SCI LTD
Laila Gurgi, Patrick Regan, T Daniel, Zsolt Podolyak, AM Bruce, PJR Mason, N Mǎrginean, R Mǎrginean, V Werner, T Alharbi, N Alkhomashi, AD Bajoga, R Britton, I Cǎta-Danil, RJ Carroll, D Deleanu, D Bucurescu, N Florea, I Gheorghe, DG Ghita, R Lice, C Mihai, KF Mulholland, A Negret, A Olacel, OJ Roberts, T Sava, P-A Söderström, L Stroe, R Suvaila, S Toma, E Wilson, RT Wood (2016)Nanosecond lifetime measurements of Iπ¼9/2- intrinsic excited states and low-lying B(E1)strengths in 183Re using combined HPGe-LaBr3 coincidence spectroscopy, In: Radiation Physics and Chemistry137pp. 7-11 Elsevier
This paper presents precision measurements of electromagnetic decay probabilities associated with electric dipole transitions in the prolate-deformed nucleus 183Re. The nucleus of interest was formed using the fusion evaporation reaction 180Hf(7Li,4n)183Re at a beam energy of 30 MeV at the tandem accelerator at the HH-IFIN Institute, Bucharest Romania. Coincident decay gamma rays from near-yrast cascades were detected using the combined HPGe-LaBr3 detector array ROSPHERE. The time differences between cascade gamma rays were measured using the LaBr3 detectors to determine the half-lives of the two lowest lying spin-parity 9/2- states at excitation energies of 496 and 617 keV to be 5.65(5) and 2.08(3) ns respectively. The deduced E1 transition rates from these two states are discussed in terms of the K-hindrance between the low-lying structures in this prolate-deformed nucleus.
F Browne, AM Bruce, T Sumikama, I Nishizuka, S Nishimura, P Doornenbal, G Lorusso, P-A Soderstrom, H Watanabe, R Daido, Z Patel, S Rice, L Sinclair, J Wu, ZY Xu, A Yagi, H Baba, N Chiga, R Carroll, F Didierjean, Y Fang, N Fukuda, G Gey, E Ideguchi, N Inabe, T Isobe, D Kameda, I Kojouharov, N Kurz, T Kubo, S Lalkovski, Z Li, R Lozeva, N Nishibata, A Odahara, Zsolt Podolyak, Patrick Regan, OJ Roberts, H Sakurai, H Schaffner, GS Simpson, H Suzuki, H Takeda, M Tanaka, J Taprogge, V Werner, O Wieland (2017)K-selection in the decay of the (ν 5 2 [532] ⊗ 3 2 [411])4- isomeric state in 102Zr, In: Physical Review C96(2)024309 American Physical Society
The (ν 5 2 [532] ⊗ 3 2 [411]) 4− state in 102Zr, populated in the β-decay of 102Y, has been measured to be isomeric with a mean lifetime of 9.5(7) ns. It decays via four transitions, two of which are ∆K = 2 (to the 3+ and 4+ members of the 2+ γ band) and one is ∆K = 4 (to the 4+ member of the ground state 0+ band). The fourth (low-energy) transition is inferred to decay to an as-yet unassigned state. Hindrances of 106 were derived for the ∆K = 2 transitions compared to Weisskopf estimates and the ∆K = 4 transition hindered by a factor of 109 . These values are consistent with the decay pattern of the analogous isomeric state in the neighbouring N = 62 nucleus 100Sr and with the broader systematics of such transitions. A comparison of the hindrances for the ∆K = 4 transitions suggests that 102Zr is hardened against the γ degree of freedom compared to 100Sr.
OJ Roberts, AM Bruce, PH Regan, Z Podolyak, CM Townsley, JF Smith, KF Mulholland, A Smith (2014)A LaBr3: Ce fast-timing array for DESPEC at FAIR, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT748pp. 91-95 ELSEVIER SCIENCE BV
P Spagnoletti, GS Simpson, R Carroll, J-M Regis, A Blanc, M Jentschel, U Koster, P Mutti, T Soldner, G de France, CA Ur, W Urban, AM Bruce, F Drouet, LM Fraile, LP Gaffney, DG Ghit˘a, S Ilieva, J Jolie, W Korten, T Kroll, C Larijarni, S Lalkovski, R Lica, H Mach, N Marginean, V Paziy, Zsolt Podolyak, Patrick Regan, M Scheck, N Saed-Samii, G Thiamova, C Townsley, A Vancraeyenest, V Vedia, A Gargano, P Van Isacker (2017)Half-life of the 15/2+ state of 135I: A test of E2 seniority relations, In: Physical Review C: Nuclear Physics95021302 American Physical Society
The half-life of the 15/2+ 1 state of the 3-valence-proton nucleus 135I has been measured to be 1.74(8) ns using the EXILL-FATIMA mixed array of Ge and LaBr3 detectors. The nuclei were produced following the cold neutron-induced fission of a 235U target at the PF1B beam line of the Institut Laue-Langevin. The extracted B(E2; 15/2+ → 11/2+) value enabled a test of seniority relations for the first time between E2 transition rates. Large-scale shell-model calculations were performed for 134Te and 135I, and reinterpreted in a single-orbit approach. The results show that the two-body component of the E2 operator can be large whereas energy shifts due to the three-body component of the effective interaction are small.
M.A Goodwin, R. Britton, A.V. Davies, S.J. Bell, S.M Collins, P.H Regan (2020)A high-resolution β−γ coincidence spectrometry system for radioxenon measurements, In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment978164452 Elsevier
GBL15, the UK’s noble gas certified Comprehensive Nuclear-Test-Ban Treaty (CTBT) radionuclide laboratory supports the International Monitoring System (IMS) through measurement of environmental radioxenon samples using coincidence spectrometry. GBL15 currently utilises a system comprised of NaI(Tl) -detectors and plastic scintillator -detectors to measure coincident emissions from the four radioxenon isotopes of interest: Xe, Xe, Xe and Xe. This paper reports on the setup, calibration and assessment of the CEA/Mirion-developed PIPSBox, used in coincidence setup with a high-purity germanium detector. The system has been configured to measure the signals from the four radionuclides of interest and demonstrates improved discrimination between signals and less interference compared to the current system. The coincident detection efficiencies are quantified through measurement of spiked radioxenon samples.
OJ Roberts, CR Nita, AM Bruce, N Marginean, D Bucurescu, D Deleanu, D Filipescu, NM Florea, I Gheorghe, D Ghita, T Glodariu, R Lica, R Marginean, C Mihai, A Negret, T Sava, L Stroe, R Suvaila, S Toma, T Alharbi, T Alexander, S Aydin, BA Brown, F Browne, RJ Carroll, K Mulholland, Z Podolyak, PH Regan, JF Smith, M Smolen, CM Townsley (2016)E3 and M2 transition strengths in Bi-209(83), In: PHYSICAL REVIEW C93(1)ARTN 01430 AMER PHYSICAL SOC
JJ Ressler, CW Beausang, H Ai, H Amro, MA Caprio, RF Casten, AA Hecht, SD Langdown, EA McCutchan, DA Meyer, PH Regan, MJS Sciacchitano, A Yamamoto, NV Zamfir (2004)Isomer decay tagging in the heavy nuclei: Ra-210 and Ra-209, In: PHYSICAL REVIEW C69(3)ARTN 03433 AMERICAN PHYSICAL SOC
M Descovich, PJ Nolan, AJ Boston, J Dobson, S Gros, JR Cresswell, J Simpson, I Lazarus, PH Regan, JJ Valiente-Dobon, P Sellin, CJ Pearson (2005)The position response of a large-volume segmented germanium detector, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT553(3)pp. 512-521 ELSEVIER SCIENCE BV
T Nasir, H Al-Sulaiti, PH Regan (2012)Assessment of radioactivity in some soil samples of qatar by gamma-ray spectroscopy and the derived dose rates, In: Pakistan Journal of Scientific and Industrial Research Series A: Physical Sciences55(3)pp. 128-134
The activity concentrations of some natural and artificial radionuclides have been measured in soil samples by gamma-ray spectroscopy using a high purity germanium detector. From the obtained gamma-ray spectra, the activity concentrations of 238U and 232Th natural decay series and the long-lived naturally occurring radionuclide 40K have been determined, in addition to the fission product 137Cs. A wide range of different gamma-ray lines ranging from -100 keV up to 2.6 MeV, associated with the decay products of238U and232Th series have been analyzed independently to obtain more statistically significant overall results. The data have been analyzed, when secular equilibrium of the radionuclides is achieved within the samples. The weighted activity concentrations of 238U and232Th series vary from 4.4 to 64.4 and 0.8 to 7.6 Bq/kg, respectively. The activity concentrations of 40K and 137Cs have been found in the range of13.6 to 179.5 and 0.3 to 3.7 Bq/kg, respectively. Based on the measured activity concentrations, dose rate, radium equivalent, radiation hazard index and annual effective dose rates have been estimated. The values obtained are within the recommended safety limits.
PM SIMMONS, WDM RAE, SPG CHAPPELL, SP FOX, CD JONES, DL WATSON, M FREER, BR FULTON, NM CLARKE, N CURTIS, MJ LEDDY, JS POPLE, SJ HALL, RP WARD, G TUNGATE, WN CATFORD, GJ GYAPONG, SM SINGER, PH REGAN (1995)SEARCH FOR A 7-ALPHA CHAIN STATE, In: PHYSICAL REVIEW C51(6)pp. 3500-3503 AMERICAN PHYSICAL SOC
A Wolf, Z Berant, NV Zamfir, DS Brenner, EA McCutchan, H Ai, RF Casten, K Dusling, A Heinz, DA Meyer, EA Millman, N Pietralla, C Plettner, J Qian, PH Regan, D Swanson, J Vinson, E Williams, R Winkler (2005)g factor of the 2(1)(+) state of Er-160, In: PHYSICAL REVIEW C72(2)ARTN 02730 AMERICAN PHYSICAL SOC
S Mandal, J Gerl, H Geissel, K Hauschild, M Hellstrom, Z Janas, I Kojouharov, Y Kopatch, RC Lemmon, P Mayet, Z Podolyak, PH Regan, H Schaffner, C Schlegel, J Simpson, HJ Wollersheim (2001)Gamma-ray spectroscopy with relativistic exotic heavy-ions, In: PRAMANA-JOURNAL OF PHYSICS57(1)pp. 161-164
IH Lazarus, DE Appelbe, PA Butler, PJ Coleman-Smith, JR Cresswell, SJ Freeman, RD Herzberg, I Hibbert, DT Joss, SC Letts, RD Page, VFE Pucknell, PH Regan, J Sampson, J Simpson, J Thornhill, R Wadsworth (2001)The GREAT triggerless total data readout method, In: IEEE TRANSACTIONS ON NUCLEAR SCIENCE48(3)pp. 567-569
MN Mineva, M Hellström, M Bernas, J Gerl, H Grawe, M Pfützner, PH Regan, M Rejmund, D Rudolph, F Becker, CR Bingham, T Enqvist, B Fogelberg, H Gausemel, H Geissel, J Genevey, M Górska, R Grzywacz, K Hauschild, Z Janas, I Kojouharov, Y Kopatch, A Korgul, W Korten, J Kurcewicz, M Lewitowicz, R Lucas, H Mach, S Mandal, P Mayet, C Mazzocchi, JA Pinston, Z Podolyàk, H Schaffner, C Schlegel, K Schmidt, K Sümmerer, HJ Wollersheim (2001)A new μs isomer in 136Sb produced in the projectile fission of 238U, In: European Physical Journal A11(1)pp. 9-13
The neutron-rich isotope 136Sb has been produced following the relativistic projectile fission of 238U in an experiment performed at the Fragment Separator at GSI, Darmstadt. Delayed γ-ray spectroscopy of the fission products has been performed after isotope separation. A new isomeric state in 136Sb has been populated, and its lifetime measured as T1/2 = 565(50) ns. Realistic and empirical shell-model calculations have been performed and are compared to the experimental observables.
A. Vogt, M. Siciliano, B. Birkenbach, P. Reiter, K. Hadyńska-Klęk, C. Wheldon, J.J. Valiente-Dobón, E Teruya, N. Yoshinaga, K. Arnswald, D. Bazzacco, A. Blazhev, A. Bracco, B Bruyneel, R.S. Chakrawarthy, R. Chapman, D. Cline, L. Corradi, F.C.L. Crespi, M. Cromaz, G. de Angelis, J. Eberth, P. Fallon, E. Farnea, E. Fioretto, H. Hess, R. Hetzenegger, R. Hirsch, H. Hua, P.R. John, J. Jolie, A. Jungclaus, V. Karayonchev, L. Kaya, W. Korten, I.Y. Lee, S. Leoni, X. Liang, S. Lunardi, A.O. Macchiavelli, R. Menegazzo, D. Mengoni, C. Michelagnoli, T. Mijatovic, G. Montagnoli, D. Montanari, C. Müller-Gatermann, D. Napoli, C.J. Pearson, Zsolt Podolyak, G. Pollarolo, A. Pullia, M. Queiser, F. Recchia, P.H. Regan, J.-M. Régis, N. Saed-Samii, E. Sahin, F. Scarlassara, M. Seidlitz, B. Siebeck, G. Sletten, J.F. Smith, P.-A. Söderström, A.M. Stefanini, O. Stezowski, S. Szilner, B. Szpak, R. Teng, C. Ur, D.D. Warner, K. Wolf, C.Y. Wu, K.O. Zell (2017)High-spin structures in ¹³²_mathrmXe and ¹³³_mathrmXe and evidence for isomers along the ℕ=79 isotones, In: Physical Review C - Nuclear Physics96(2)pp. 024321-1 American Physical Society
The 50 N,Z 82 region of the Segrè chart, spanning the nuclei “northwest” of doubly-magic 132Sn, is an intriguing study ground to test the suitability and predictive power of nuclear models at both low and high spins. Low-spin excited states in the nearly spherical nuclei near proton- and neutronshell closures are well described as anharmonic vibrations [1] with a gradual change to rotational structures further away from the closed shells. Further on, quasiparticle excitations play a key role and are responsible for the presence of yrast-trap isomers. These long-lived states interrupt and fragment the decay flux in spectroscopic investigations. High-j couplings involving the unique-parity h11/2 neutron-hole orbital give rise to a wealth of high-spin states with multi-quasiparticle character. In particular, detailed knowledge of isomers is crucial to ascertain the active quasiparticle configurations in the specific nucleus.
CM Parry, AJ Boston, C Chandler, A Galindo-Uribarri, IM Hibbert, VP Janzen, DT Joss, SM Mullins, PJ Nolan, ES Paul, PH Regan, SM Vincent, R Wadsworth, D Ward, R Wyss (1998)Yrast structures in the neutron-deficient 12759 Pr68 and 13161 Pm70 nuclei, In: Physical Review C - Nuclear Physics57(5)pp. 2215-2221
The odd-proton nuclei 127Pr and 131Pm have been investigated using the 96Ru(35Cl,2p2n) and 96Ru(40Ca,αp)/96Ru(39K,2p2n) reactions, respectively, at beam energies of 164, 180, and 186 MeV. States belonging to the yrast bands of 127Pr and 131Pm, which are interpreted as being based upon the h11/2 [541]3/2- proton configuration, have been observed from the 11/2- band head to spin 47/2-. The properties of these two new structures are observed to be different to those of similar configurations in the heavier odd mass isotopes. The systematics of the band crossings in the πh11/2 bands of the odd mass Pr and Pm isotopes are discussed and compared with extended total Routhian surface calculations.
K Nomura, T Otsuka, R Rodriguez-Guzman, LM Robledo, P Sarriguren, PH Regan, PD Stevenson, Z Podolyak (2011)Spectroscopic calculations of the low-lying structure in exotic Os and W isotopes, In: PHYSICAL REVIEW C83(5)ARTN 0pp. ?-? AMER PHYSICAL SOC
M Bowry, Z Podolyak, J Kurcewicz, S Pietri, M Bunce, PH Regan, F Farinon, H Geissel, C Nociforo, A Prochazka, H Weick, P Allegro, J Benlliure, G Benzoni, P Boutachkov, J Gerl, M Gorska, A Gottardo, N Gregor, R Janik, R Knoebel, I Kojouharov, T Kubo, YA Litvinov, E Merchan, I Mukha, F Naqvi, B Pfeiffer, M Pfuetzner, W Plass, M Pomorski, B Riese, MV Ricciardi, K-H Schmidt, H Schaffner, N Kurz, AMD Bacelar, AM Bruce, GF Farrelly, N Alkhomashi, N Al-Dahan, C Scheidenberger, B Sitar, P Spiller, J Stadlmann, P Strmen, B Sun, H Takeda, I Tanihata, S Terashima, JJV Dobon, JS Winfield, H-J Wollersheim, PJ Woods, T Niksic, M Milin, D Vretenar, S Szilner (2012)Half-life Measurements of Isomeric States Populated in Projectile Fragmentation, In: NUCLEAR STRUCTURE AND DYNAMICS '121491pp. 317-320
RD Page, AN Andreyev, DE Appelbe, PA Butler, SJ Freeman, PT Greenlees, RD Herzberg, DG Jenkins, GD Jones, P Jones, DT Joss, R Julin, H Kettunen, M Leino, P Rahkila, PH Regan, J Simpson, J Uusitalo, SM Vincent, R Wadsworth (2003)The GREAT spectrometer, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS204pp. 634-637
M Lewitowicz, JM Daugas, R Grzywacz, L Achouri, JC Angélique, D Baiborodin, R Bentida, R Béraud, C Bingham, C Borcea, W Catford, A Emsallem, G De France, M Glogowski, H Grawe, D Guillemaud-Mueller, M Houry, S Hurskanen, KL Jones, RC Lemmon, AC Mueller, A Nowak, F De Oliveira-Santos, A Płochocki, M Pfützner, PH Regan, K Rykaczewski, MG Saint-Laurent, JE Sauvestre, M Sawicka, M Schaefer, G Sletten, O Sorlin, M Stanoiu, J Szerypo, W Trinder, S Viteritti, J Winfield (1999)Study of μs-isomers in neutron-rich nuclei around Z=28 and N=40 shell closures, In: Nuclear Physics A654(1 SUPP)
P-A Soderstrom, F Recchia, J Nyberg, A Gadea, SM Lenzi, A Poves, A Atac, S Aydin, D Bazzacco, P Bednarczyk, M Bellato, B Birkenbach, D Bortolato, AJ Boston, HC Boston, B Bruyneel, D Bucurescu, E Calore, B Cederwall, L Charles, J Chavas, S Colosimo, FCL Crespi, DM Cullen, G de Angelis, P Desesquelles, N Dosme, G Duchene, J Eberth, E Farnea, F Filmer, A Gorgen, A Gottardo, J Grebosz, M Gulmini, H Hess, TA Hughes, G Jaworski, J Jolie, P Joshi, DS Judson, A Jungclaus, N Karkour, M Karolak, RS Kempley, A Khaplanov, W Korten, J Ljungvall, S Lunardi, A Maj, G Maron, W Meczynski, R Menegazzo, D Mengoni, C Michelagnoli, P Molini, DR Napoli, PJ Nolan, M Norman, A Obertelli, Z Podolyak, A Pullia, B Quintana, N Redon, PH Regan, P Reiter, AP Robinson, E Sahin, J Simpson, MD Salsac, JF Smith, O Stezowski, C Theisen, D Tonev, C Unsworth, CA Ur, JJ Valiente-Dobon, A Wiens (2012)High-spin structure in K-40, In: PHYSICAL REVIEW C86(5)ARTN 05432 AMER PHYSICAL SOC
KA Gladnishki, Z Podolyak, J Gerl, M Hellstrom, Y Kopatch, S Mandal, M Gorska, PH Regan, HJ Wollersheim, A Banu, G Benzoni, H Boardman, M La Commara, J Ekman, C Fahlander, H Geissel, H Grawe, E Kaza, A Korgul, M Matos, MN Mineva, RD Page, CJ Pearson, C Plettner, D Rudolph, C Scheidenberger, V Shishkin, D Sohler, K Summerer, JJ Valiente-Dobon, H Weick, M Winkler (2003)Isomer spectroscopy in the neutron-deficient lead region following projectile fragmentation, In: ACTA PHYSICA POLONICA B34(4)pp. 2395-2398
J Tain, J Agramunt, D Ahn, A Algora, J Allmond, H Baba, S Bae, N Brewer, R Caballero Folch, F Calvino, P Coleman-Smith, G Cortes, T Davinson, I Dillmann, C Domingo-Pardo, A Estrade, N Fukuda, S Go, C Griffin, R Grzywacz, J Ha, O Hall, L Harkness-Brennan, T Isobe, D Kahl, M Karny, G Kiss, M Kogimtzis, A Korgul, S Kubono, M Labiche, I Lazarus, J Lee, J Liu, G Lorusso, K Matsui, K Miernik, F Montes, B Moon, A Morales, N Nepal, S Nishimura, R Page, Zsolt Podolyak, V Pucknell, B Rasco, Patrick Regan, A Riego, B Rubio, K Rykaczewski, Y Saito, H Sakurai, Y Shimizu, J Simpson, P Soderstrom, D Stracener, T Sumikama, R Surman, H Suzuki, M Takechi, H Takeda, A Tarifeno-Saldiva, S Thomas, A Tolosa-Delgado, V Phong, P Woods (2018)The BRIKEN Project: Extensive Measurements of β-delayed Neutron Emitters for the Astrophysical r Process, In: Acta Physica Polonica B49(3)pp. 417-428 Jagiellonian University
An ambitious program to measure decay properties, primarily β-delayed neutron emission probabilities and half-lives, for a significant number of nuclei near or on the path of the rapid neutron capture process, has been launched at the RIKEN Nishina Center. We give here an overview of the status of the project.
PH Regan, CW Beausang, NV Zamfir, RF Casten, JY Zhang, AD Yamamoto, MA Caprio, G Gurdal, AA Hecht, C Hutter, R Krucken, SD Langdown, DA Meyer, JJ Ressler (2003)Signature for vibrational to rotational evolution along the yrast line, In: PHYSICAL REVIEW LETTERS90(15)ARTN 15250 AMERICAN PHYSICAL SOC
SM Jerome, P Ivanov, C Larijani, DJ Parker, PH Regan (2014)The production of Neptunium-236g, In: JOURNAL OF ENVIRONMENTAL RADIOACTIVITY138pp. 315-322 ELSEVIER SCI LTD
IH Lazarus, DE Appelbe, PA Butler, PJ Coleman-Smith, JR Cresswell, SJ Freeman, RD Herzberg, I Hibbert, DT Joss, SC Letts, RD Page, VFE Pucknell, PH Regan, J Sampson, J Simpson, J Thornhill, R Wadsworth (2000)The GREAT triggerless total data readout method, In: IEEE Nuclear Science Symposium and Medical Imaging Conference2
Recoil Decay Tagging (RDT) is a very powerful method for the spectroscopy of exotic nuclei. RDT is a delayed coincidence technique between detectors usually at the target position and at the focal plane of a spectrometer. Such measurements are often limited by dead time. This paper describes a novel triggerless data acquisition method which is being developed for the Gamma Recoil Electron Alpha Tagging (GREAT) spectrometer that overcomes this limitation by virtually eliminating dead time. Our solution is a Total Data Readout (TDR) method where all channels run independently and are associated in software to reconstruct events. The TDR method allows all the data from both target position and focal plane to be collected with practically no dead time losses. Each data word is associated with a timestamp generated from a global 100MHz clock. Events are then reconstructed in real time in the event builder using temporal and spatial associations defined by the physics of the experiment.
JJ Ressler, RF Casten, NV Zamfir, CW Beausang, RB Cakirli, H Ai, H Amro, MA Caprio, AA Hecht, A Heinz, SD Langdown, EA McCutchan, DA Meyer, C Plettner, PH Regan, MJS Sciacchitano, AD Yamamoto (2004)Transition from the seniority regime to collective motion, In: PHYSICAL REVIEW C69(3)ARTN 03431 AMERICAN PHYSICAL SOC
F Browne, AM Bruce, T Sumikama, I Nishizuka, S Nishimura, P Doornenbal, G Lorusso, Z Patel, S Rice, L Sinclair, P-A Soederstroem, H Watanabe, J Wu, ZY Xu, H Baba, N Chiga, R Carroll, R Daido, F Didierjean, Y Fang, G Gey, E Ideguchi, N Inabe, T Isobe, D Kameda, I Kojouharov, N Kurz, T Kubo, S Lalkovski, Z Li, R Lozeva, N Naoki, H Nishibata, A Odahara, Z Podolyak, PH Regan, OJ Roberts, H Sakurai, H Schaffner, GS Simpson, H Suzuki, H Takeda, M Tanaka, J Taprogge, V Werner, O Wieland, A Yagi (2015)GAMMA-RAY SPECTROSCOPY IN THE VICINITY OF Zr-108, In: ACTA PHYSICA POLONICA B46(3)pp. 721-724 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
A Tarifeno-Saldivia, JL Tain, C Domingo-Pardo, F Calvino, G Cortes, VH Phong, A Riego, J Agramunt, A Algora, N Brewer, R Caballero-Folch, P Coleman-Smith, T Davinson, I Dillmann, A Estrade, C Griffin, R Grzywacz, L Harkness-Brennan, GG Kiss, M Kogimtzis, I Lazarus, G Lorusso, K Matsui, K Miernik, F Montes, A Morales, S Nishimura, RD Page, Z Podolyak, VF Pucknell, BC Rasco, Patrick Regan, P Rubio, KP Rykaczewski, H Sakurai, J Simpson, E Sokol, R Surman, A Svirkhin, SL Thomas, A Tolosa, P Woods (2017)Conceptual design of a hybrid neutron-gamma detector for study of -delayed neutrons at the RIB facility of RIKEN, In: Journal of Instrumentation12 Institute of Physics
The conceptual design of the BRIKEN neutron detector at the radioactive ion beam factory (RIBF) of the RIKEN Nishina Center is reported. The BRIKEN setup is a complex system aimed at detecting heavy-ion implants, β particles, γ rays and β-delayed neutrons. The whole setup includes the Advanced Implantation Detection Array (AIDA), two HPGe Clover detectors and up to 166 3He-filled counters embedded in a high-density polyethylene moderator. The design is quite complex due to the large number and different types of 3He-tubes involved and the additional constraints introduced by the ancillary detectors for charged particles and γ rays. This article reports on a novel methodology developed for the conceptual design and optimisation of the 3He-counter array, aiming for the best possible performance in terms of neutron detection. The algorithm is based on a geometric representation of two selected detector parameters of merit, namely, the average neutron detection efficiency and the efficiency flatness as a function of a reduced number of geometric variables. The response of the neutron detector is obtained from a systematic Monte Carlo simulation implemented in Geant4. The robustness of the algorithm allowed us to design a versatile detection system, which operated in hybrid mode includes the full neutron counter and two clover detectors for high-precision gamma spectroscopy. In addition, the system can be reconfigured into a compact mode by removing the clover detectors and re-arranging the 3He tubes in order to maximize the neutron detection performance. Both operation modes shows a rather flat and high average efficiency. In summary, we have designed a system which shows an average efficiency for hybrid mode (3He tubes + clovers) of 68.6% and 64% for neutron energies up to 1 and 5 MeV, respectively. For compact mode (only 3He tubes), the average efficiency is 75.7% and 71% for neutron energies up to 1 and 5 MeV, respectively. The performance of the BRIKEN detection system has been also quantified by means of Monte Carlo simulations with different neutron energy distributions.
MA Caprio, NV Zamfir, EA McCutchan, RF Casten, Z Berant, H Amro, CJ Barton, CW Beausang, DS Brenner, JR Cooper, RL Gill, G Gurdal, AA Hecht, C Hutter, R Krucken, DA Meyer, JR Novak, N Pietralla, PH Regan, JJ Ressler (2003)Measurement of 2(1)(+) level lifetimes in Yb-162 and Er-162 by fast electronic scintillation timing, In: EUROPEAN PHYSICAL JOURNAL A16(2)pp. 177-180 SPRINGER-VERLAG
TS Brock, BS Nara Singh, P Boutachkov, N Braun, A Blazhev, Z Liu, R Wadsworth, M Górska, H Grawe, S Pietri, C Domingo-Pardo, D Rudolph, SJ Steer, A Ataç, L Bettermann, L Cáceres, T Engert, K Eppinger, T Faestermann, F Farinon, F Finke, K Geibel, J Gerl, R Gernhäuser, N Goel, A Gottardo, J Grȩbosz, C Hinke, R Hoischen, G Ilie, H Iwasaki, J Jolie, A Kaşkaş, I Kojuharov, R Krücken, N Kurz, E Merchán, C Nociforo, J Nyberg, M Pfützner, A Prochazka, Z Podolyák, PH Regan, P Reiter, S Rinta-Antila, H Schaffner, C Scholl, P-A Söderström, N Warr, H Weick, H-J Wollersheim, PJ Woods (2010)Observation of a new high-spin isomer in Pd94, In: Physical Review C - Nuclear Physics82(6)
CR Nita, D Bucurescu, N Marginean, M Avrigeanu, G Bocchi, S Bottoni, A Bracco, AM Bruce, G Cata-Danil, G Colo, D Deleanu, D Filipescu, DG Ghita, T Glodariu, S Leoni, C Mihai, PJR Mason, R Marginean, A Negret, D Pantelica, Z Podolyak, PH Regan, T Sava, L Stroe, S Toma, CA Ur, E Wilson (2014)Fast-timing lifetime measurements of excited states in Cu-67, In: PHYSICAL REVIEW C89(6)ARTN 06431 AMER PHYSICAL SOC
J-M Regis, GS Simpson, A Blanc, G de France, M Jentschel, U Koester, P Mutti, V Paziy, N Saed-Samii, T Soldner, CA Ur, W Urban, AM Bruce, F Drouet, LM Fraile, S Ilieva, J Jolie, W Korten, T Kroell, S Lalkovski, H Mach, N Marginean, G Pascovici, Z Podolyak, PH Regan, OJ Roberts, JF Smith, C Townsley, A Vancraeyenest, N Warr (2014)Germanium-gated gamma-gamma fast timing of excited states in fission fragments using the EXILL&FATIMA spectrometer, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT763pp. 210-220 ELSEVIER SCIENCE BV
K Andgren, SF Ashley, PH Regan, EA McCutchan, NV Zamfir, L Amon, RB Cakirli, RF Casten, RM Clark, G Gurdal, KL Keyes, DA Meyer, MN Erduran, A Papenberg, N Pietralla, C Plettner, G Rainovski, RV Ribas, NJ Thomas, J Vinson, DD Warner, V Werner, E Williams (2005)RDM lifetime measurements in Cd-107, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1563-S1568
SJ Bell, SM Judge, PH Regan (2012)An investigation of HPGe gamma efficiency calibration software (ANGLE V.3) for applications in nuclear decommissioning., In: Appl Radiat Isot70(12)pp. 2737-2741
High resolution gamma spectrometry offers a rapid method to characterise waste materials on a decommissioning nuclear site. To meet regulatory requirements, measurements must be traceable to national standards, meaning that the spectrometers must be calibrated for a wide range of materials. Semi-empirical modelling software (such as ANGLE™) offers a convenient method to carry out such calibrations. This paper describes an assessment of the modelling software for use by a small laboratory based on a nuclear site. The results confirmed the need for accurate information on the detection construction if the calibration were to be accurate to within 10%.
R Britton, JL Burnett, AV Davies, PH Regan (2014)Monte-Carlo optimisation of a Compton suppression system for use with a broad-energy HPGe detector, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT762pp. 42-53 ELSEVIER SCIENCE BV
JJ Ressler, CW Beausang, RF Casten, NV Zamfir, H Ai, H Amro, M Babilon, RB Cakirli, JA Caggiano, G Gurdal, A Heinz, RO Hughes, SD Langdown, EA McCutchan, DA Meyer, C Plettner, J Qian, PH Regan, MJS Sciacchitano, NJ Thomas, E Williams, A Yamamoto (2005)Isomers and seniority in the trans-Pb nuclei, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1605-S1610
CM Parry, IM Hibbert, R Wadsworth, AN Wilson, ES Paul, A Galindo-Uribarri, VP Janzen, D Ward, SM Mullins, PH Regan, CE Svensson, R Wyss (1999)Evidence for highly deformed bands in Sm-133(62)71, In: PHYSICAL REVIEW C60(5)ARTN 05431 AMERICAN PHYSICAL SOC
P Doornenbal, A Bürger, D Rudolph, H Grawe, H Hübel, PH Regan, P Reiter, A Banu, T Beck, F Becker, P Bednarczyk, L Caceres, H Geissel, J Gerl, M Górska, J Grȩbosz, M Kavatsyuk, O Kavatsyuk, A Kelic, I Kojouharov, N Kurz, R Lozeva, F Montes, W Prokopowicz, N Saito, T Saito, H Schaffner, S Tashenov, H Weick, E Werner-Malento, M Winkler, HJ Wollersheim, A Al-Khatib, LL Andersson, L Atanasova, DL Balabanski, MA Bentley, G Benzoni, A Blazhev, A Bracco, S Brambilla, C Brandau, P Bringel, JR Brown, F Camera, S Chmel, E Clément, FCL Crespi, C Fahlander, AB Garnsworthy, A Görgen, G Hammond, M Hellström, R Hoischen, H Honma, EK Johansson, A Jungclaus, M Kmieciek, W Korten, A Maj, S Mandal, W Meczynski, B Million, A Neußer, F Nowacki, T Otsuka, M Pfützner, S Pietri, Z Podolyák, A Richard, M Seidlitz, SJ Steer, T Striepling, T Utsuno, J Walker, N Warr, C Wheldon, O Wieland (2007)RISING: Gamma-ray spectroscopy with radioactive beams at GSI, In: AIP Conference Proceedings891pp. 99-107
The Rare Isotope Spectroscopic INvestigation at GSI (RISING) project is a major pan-European collaboration. Its physics aims are the studies of exotic nuclear matter with abnormal proton-to-neutron ratios compared with naturally occurring isotopes. RISING combines the FRagment Separator (FRS) which allows relativistic energies and projectile fragmentation reactions with EUROBALL Ge Cluster detectors for γ spectroscopic research. The RISING setup can be used in two different configurations. Either the nuclei of interest are investigated after being stopped or the heavy ions hit a secondary target at relativistic energies and the thereby occurring excitations are studied. For the latter case, MINIBALL Ge detectors and the HECTOR array are used in addition. Example achievements of the Fast Beam setup are presented and compared to various shell model calculations, while for the Stopped Beam setup initial results are shown. © 2007 American Institute of Physics.
M Bunce, PH Regan, V Werner, V Anagnotatou, CW Beausang, M Bowry, RJ Casperson, D Chen, N Cooper, P Goddard, RO Hughes, G Ilie, PJR Mason, B Pauerstein, MW Reed, TJ Ross, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, B Wadsworth, D Watts (2012)A shell model study of the high spin states of Y-88, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS381ARTN 01206 IOP PUBLISHING LTD
PH Regan, NJ Thompson, AB Garnsworthy, HC Ai, L Amon, RB Cakirli, RF Casten, CR Fitzpatrick, SJ Freeman, G Gurdal, A Heinz, GA Jones, EA McCutchan, J Qian, V Werner, SJ Williams, R Winkler (2006)Isomer and in-beam spectroscopy of medium-spin states in Zr-91,Zr-92, In: Capture Gamma-Ray Spectroscopy and Related Topics819pp. 35-39
M. Heine, S. Courtin, G. Fruet, D.G. Jenkins, L. Morris, D. Montanari, M. Rudigier, P. Adsley, D. Curien, S. Della Negra, J. Lesrel, C. Beck, L. Charles, P. Dené, F. Haas, F. Hammache, G. Heitz, M. Krauth, A. Meyer, Zs. Podolyak, P.H. Regan, M. Richer, N. de Séréville, C. Stodel (2018)The STELLA apparatus for particle-Gamma coincidence fusion measurements with nanosecond timing, In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment903pp. 1-7 Elsevier
The STELLA (STELlar LAboratory) experimental station for the measurement of deep sub-barrier light heavy-ion fusion cross sections has been installed at the Andromède accelerator at the Institut de Physique Nucléaire, Orsay (France). The setup is designed for the direct experimental determination of heavy-ion fusion cross sections as low as tens of picobarn. The detection concept is based on the coincident measurement of emitted gamma rays with the UK FATIMA (FAst TIMing Array) and evaporated charged particles using a silicon detector array. Key developments relevant to reaching the extreme sub-barrier fusion region are a rotating target mechanism to sustain beam intensities above 10μA, an ultra-high vacuum of 10−8 mbar to prevent carbon built-up and gamma charged-particle timing in the order of nanoseconds sufficient to separate proton and alpha particles.
N Curtis, AS Murphy, NM Clarke, M Freer, BR Fulton, SJ Hall, MJ Leddy, JS Pople, G Tungate, RP Ward, WN Catford, GJ Gyapong, SM Singer, SPG Chappell, SP Fox, CD Jones, DL Watson, WDM Rae, PM Simmons, PH Regan (1996)Evidence for a highly deformed band in O-16+O-16 breakup of S-32, In: PHYSICAL REVIEW C53(4)pp. 1804-1810 AMERICAN PHYSICAL SOC
CB Hinke, M Boehmer, P Boutachkov, T Faestermann, H Geissel, J Gerl, R Gernhaeuser, M Gorska, A Gottardo, H Grawe, JL Grebosz, R Kruecken, N Kurz, Z Liu, L Maier, F Nowacki, S Pietri, Z Podolyak, K Sieja, K Steiger, K Straub, H Weick, H-J Wollersheim, PJ Woods, N Al-Dahan, N Alkhomashi, A Atac, A Blazhev, NF Braun, IT Celikovic, T Davinson, I Dillmann, C Domingo-Pardo, PC Doornenbal, G de France, GF Farrelly, F Farinon, N Goel, TC Habermann, R Hoischen, R Janik, M Karny, A Kaskas, IM Kojouharov, T Kroell, Y Litvinov, S Myalski, F Nebel, S Nishimura, C Nociforo, J Nyberg, AR Parikh, A Prochazka, PH Regan, C Rigollet, H Schaffner, C Scheidenberger, S Schwertel, P-A Soederstroem, SJ Steer, A Stolz, P Strmen (2012)Superallowed Gamow-Teller decay of the doubly magic nucleus Sn-100, In: NATURE486(7403)pp. 341-345 NATURE PUBLISHING GROUP
Patrick H Regan, Steven M Judge, John D Keightley, Andy K Pearce (2018)Radionuclide Metrology and Standards in Nuclear Physics, In: Nuclear Physics News28(3)pp. 25-29 Taylor & Francis
The development of radionuclide standards for metrology has underpinned nuclear physics since its inception. The current frontier of radionuclide metrology relies on developments in radiation detection and signal processing combined with accurate nuclear decay data evaluations and contributes to a myriad of scientific disciplines. Radionuclide metrology represents a crucial part of the scientific jigsaw that enables societal benefits from nuclear physics research.
PJR Mason, T Alharbi, PH Regan, N Marginean, Z Podolyak, EC Simpson, N Alkhomashi, PC Bender, M Bowry, M Bostan, D Bucurescu, AM Bruce, G Cata-Danil, I Cata-Danil, R Chakrabarti, D Deleanu, P Detistov, MN Erduran, D Filipescu, U Garg, T Glodariu, D Ghita, SS Ghugre, A Kusoglu, R Marginean, C Mihai, M Nakhostin, A Negret, S Pascu, CR Triguero, T Sava, AK Sinha, L Stroe, G Suliman, NV Zamfir (2012)Half-life of the I-pi=4(-) intruder state in P-34: M2 transition strengths approaching the island of inversion, In: PHYSICAL REVIEW C85(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
M Caamano, PH Regan, Z Podolyka, CJ Pearson, P Mayet, J Gerl, C Schlegel, M Pfutzner, M Hellstrom, M Mineva (2001)Nuclear structure of heavy neutron rich systems: Fragmentation spectroscopy with a 1 GeV per nucleon Pb-208 beam, In: NUCLEAR PHYSICS A682pp. 223C-228C
C Wheldon, JG Narro, CJ Pearson, PH Regan, Z Podolyak, DD Warner, P Fallon, AO Macchiavelli, M Cromaz (2001)Yrast states in Os-194: The prolate-oblate transition region, In: PHYSICAL REVIEW C63(1)ARTN 01130 AMERICAN PHYSICAL SOC
SJ Steer, Z Podolyak, S Pietri, M Gorska, H Grawe, KH Maier, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen (2011)Isomeric states observed in heavy neutron-rich nuclei populated in the fragmentation of a (208)Pb beam, In: PHYSICAL REVIEW C84(4)ARTN 0 American Physical Society
M Pfutzner, P Armbruster, T Baumann, J Benlliure, M Bernas, WN Catford, D Cortina-Gil, JM Daugas, H Geissel, M Gorska, H Grawe, R Grzywacz, M Hellstrom, N Iwasa, Z Janas, AR Junghans, M Karny, S Leenhardt, M Lewitowicz, AC Mueller, F de Oliviera, PH Regan, M Rejmund, K Rykaczewski, K Summerer (1998)New isotopes and isomers produced by the fragmentation of U-238 at 1000 MeV/nucleon, In: PHYSICS LETTERS B444(1-2)pp. 32-37 ELSEVIER SCIENCE BV
PH Regan, R Shearman, SM Judge, G Lorusso, P Main, S Bell, SM Collins, P Ivanov, SM Jerome, JD Keightley, C Larijani, G Lotay, AK Pearce (2015)Development of NANA: A Fast-Scintillator, Coincidence Gamma-ray Array for Radioactive Source Characterisation and Absolute Activity Measurements at the UK National Physical Laboratory, In: APPLICATIONS OF NOVEL SCINTILLATORS FOR RESEARCH AND INDUSTRY (ANSRI 2015)620
C Larijani, OL Pickford, SM Collins, P Ivanov, SM Jerome, JD Keightley, AK Pearce, PH Regan (2015)Progress towards the production of the (NP)-N-236g standard sources and competing fission fragment production, In: RADIATION PHYSICS AND CHEMISTRY116pp. 69-73 PERGAMON-ELSEVIER SCIENCE LTD
J Jolie, JM Régis, D Wilmsen, S Ahmed, M Pfeiffer, N Saed-Samii, N Warr, A Blanc, M Jentschel, U Köster, P Mutti, T Soldner, G Simpson, G De France, W Urban, AM Bruce, OJ Roberts, LM Fraile, V Paziy, A Ignatov, S Ilieva, T Kröll, M Scheck, M Thürauf, D Ivanova, S Kisyov, S Lalkovski, Z Podolyak, PH Regan, W Korten, D Habs, PG Thirolf, CA Ur (2014)First results of the (n,γ) EXILL campaigns at the Institut Laue Langevin using EXOGAM and FATIMA, In: Journal of Physics: Conference Series533(1)
At the PF1B cold neutron beam line at the Institut Laue Langevin the EXILL array consisting of EXOGAM, GASP and LOHENGRIN detectors was used to perform (n,γ) measurements under very high coincidence rates. About ten different reactions were then measured in autumn 2012. In spring 2013 the EXOGAM array was combined with 16 LaBr3(Ce) scintillators in the FATIMA@EXILL campaign for the measurement of lifetimes using the generalised centroid difference method. We report on the properties of both set-ups and present first results on Pt isotopes from both campaigns.
DL Balabanski, KA Gladnishki, G Lo Bianco, A Saltarelli, NV Zamfir, EA McCutchan, H Ai, RF Casten, A Heinz, DA Meyer, C Plettner, J Qian, V Werner, E Williams, B Akkus, L Amon, RB Cakirli, MN Erduran, Y Oktem, SF Ashley, PH Regan, G Rainovski (2006)Evidence for X(5) critical point symmetry in 128Ce, In: International Journal of Modern Physics E15(8)pp. 1735-1740
Lifetimes of excited states in 128Ce were measured using the recoil distance Doppler-shift (RDDS) and the Doppler-shift attenuation (DSAM) methods. The experiments were performed at the Wright Nuclear Structure Laboratory of Yale University. Excited states of 128Ce were populated in the 100Mo(32Si,4n) reaction at 120 MeV and the nuclear γ decay was measured with an array of eight Clover detectors positioned at forward and backward angles. The deduced yrast transition strengths together with the energies of the levels within the ground-state (gs) band of 128Ce are in agreement with the predicted values for the X(5) critical point symmetry. Thus, we suggest 128Ce as a benchmark X(5) nucleus in the mass A ≈ 130 region. © World Scientific Publishing Company.
EA McCutchan, RF Casten, V Werner, E Williams, R Winkler, A Wolf, Z Berant, G Gurdal, J Qian, H Ai, L Amon, CW Beausang, DS Brenner, RB Cakirli, RJ Casperson, CR Fitzpatrick, D Frank, AB Garnsworthy, A Heinz, R Luettke, AF Mertz, Y Oktem, N Pietralla, PH Regan, B Shoraka, JR Terry, NJ Thompson (2008)Enhanced mixing of intrinsic states in deformed Hf nuclei, In: PHYSICAL REVIEW C77(5)ARTN 0pp. ?-? AMER PHYSICAL SOC
F Becker, W Korten, F Hannachi, P Paris, N Buforn, C Chandler, M Houry, H Hubel, A Jansen, Y Le Coz, CF Liang, A Lopez-Martens, R Lucas, E Mergel, PH Regan, G Schonwasser, C Theisen (1999)Investigation of prolate-oblate shape-coexistence in Kr-74, In: EUROPEAN PHYSICAL JOURNAL A4(2)pp. 103-105 SPRINGER VERLAG
T Alharbi, PH Regan, N Marginean, Z Podolyak, A Bajoga, R Britton, D Bucurescu, D Deleanu, D Filipescu, D Ghita, T Glodariu, C Mihai, K Mulholland, R Marginean, A Negret, CR Nita, Z Patel, OJ Roberts, L Stroe, T Sava, C Townsley, NV Zamfir (2014)Sub-nanosecond Half-life Measurement of the Yrast I-pi=5(-) State in the N=78 Nucleus Ce-136(58) using Fast-timing Coincident Gamma-ray Spectroscopy, In: NUCLEAR DATA SHEETS120pp. 59-61 ACADEMIC PRESS INC ELSEVIER SCIENCE
R Britton, JL Burnett, AV Davies, PH Regan (2013)Improving the effectiveness of a low-energy Compton suppression system, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT729pp. 64-68 ELSEVIER SCIENCE BV
R Kumar, FG Molina, S Pietri, E Casarejos, A Algora, J Benlliure, P Doornenbal, J Gerl, M Gorska, I Kojouharov, Z Podolyak, W Prokopowicz, PH Regan, B Rubio, H Schaffner, S Tashenov, H-J Wollersheim (2009)Testing of a DSSSD detector for the stopped RISING project, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT598(3)pp. 754-758 ELSEVIER SCIENCE BV
M Lewitowicz, B Blank, JM Daugas, H Grawe, R Grzywacz, G Neyens, M Pfutzner, PH Regan, K Rykaczewski (2001)Nuclear structure studies by means of short-lived isomers at intermediate energies, In: NUCLEAR PHYSICS A682pp. 175C-182C
G Benzoni, F Azaiez, S Leoni, S Battacharyya, R Borcea, A Bracco, L Corradi, D Curien, G De France, Z Dombradi, E Fioretto, S Franchoo, S Grevy, F Ibrahim, S Iulian, G Mukherjee, A Navin, G Pollarolo, N Redon, PH Regan, M Rejmund, C Schmitt, G Sletten, D Sohler, M Stanoiu, S Szilner, D Verney (2007)In-beam gamma spectroscopy using DIC with a radioactive Ne beam, In: EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 83-86
J-M Regis, J Jolie, N Saed-Samii, N Warr, M Pfeiffer, A Blanc, M Jentschel, U Koester, P Mutti, T Soldner, GS Simpson, F Drouet, A Vancraeyenest, G de France, E Clement, O Stezowski, CA Ur, W Urban, PH Regan, Z Podolyak, C Larijani, C Townsley, R Carroll, E Wilson, LM Fraile, H Mach, V Paziy, B Olaizola, V Vedia, AM Bruce, OJ Roberts, JF Smith, T Kroell, A-L Hartig, A Ignatov, S Ilieva, M Thuerauf, S Lalkovski, D Ivanova, S Kisyov, W Korten, M-D Salsac, M Zielinska, N Marginean, DG Ghita, R Lica, CM Petrache, A Astier, R Leguillon (2014)B(E2; 2(1)(+) -> 0(1)(+)) value in Kr-90, In: PHYSICAL REVIEW C90(6)ARTN 06730 AMER PHYSICAL SOC
BSN Singh, TS Brock, R Wadsworth, H Grawe, P Boutachkov, N Braun, A Blazhev, Z Liu, M Gorska, S Pietri, D Rudolph, C Domingo-Pardo, SJ Steer, A Atac, L Bettermann, L Caceres, T Engert, T Faestermann, F Farinon, F Finke, K Geibel, J Gerl, R Gernhaeuser, N Goel, A Gottardo, J Grebosz, C Hinke, R Hoischen, G Ilie, H Iwasaki, J Jolie, A Kaskas, I Kojouharov, R Kruecken, N Kurz, E Merchan, C Nociforo, J Nyberg, M Pfuetzner, A Prochazka, Z Podolyak, PH Regan, P Reiter, S Rinta-Antila, C Scholl, H Schaffner, P-A Soderstrom, N Warr, H Weick, H-J Wollersheim, PJ Woods, F Nowacki (2012)Influence of the np interaction on the beta decay of Pd-94, In: PHYSICAL REVIEW C86(4)ARTN 0pp. ?-? AMER PHYSICAL SOC
V Anagnostatou, PH Regan, MR Bunce, D McCarthy, V Werner, T Ahn, RJ Casperson, R Chevrier, N Cooper, A Heinz, G Ilie, MK Smith, E Williams, L Bettermann, D Radeck, CW Beausang, C Boniwell, B Pauerstein (2011)MEASUREMENTS OF PICOSECOND LIFETIMES IN THE TRANSITIONAL NUCLEUS Pd-100 USING THE RDDM IN INVERSE KINEMATICS, In: ACTA PHYSICA POLONICA B42(3-4)pp. 807-811
N Yoshinaga, K Higashiyama, PH Regan (2008)High-spin structure of neutron-rich Se, As, Ge, and Ga isotopes, In: PHYSICAL REVIEW C78(4)ARTN 04432 AMER PHYSICAL SOC
PH Regan, Z Podolyak, T Alharbi, PJR Mason, AM Bruce, C Townsley, OJ Roberts, N Marginean, R Marginean, D Ghita, K Mullholland, JF Smith, R Britton, Z Patel, M Nakhostin, S Rice, E Wilson, N Alazemi, N Alkhomashi, D Bucurescu, G Cata-Danil, D Deleanu, D Filipescu, T Glodariu, I Cata-Danil, C Mihai, A Negret, CR Nita, T Sava, L Stroe, G Suliman, P Detistov, U Garg, PC Bender, A Algora, S Liddick, N Cooper, V Werner, S Lalkovski, S Kisyov, F Browne, P-A Soederstroem, H Watanabe, T Sumikama (2013)Precision Lifetime Measurements Using LaBr3 Detectors With Stable and Radioactive Beams., In: HEAVY ION ACCELERATOR SYMPOSIUM 201363ARTN 01008 E D P SCIENCES
F Browne, AM Bruce, T Sumikama, I Nishizuka, S Nishimura, P Doornenbal, G Lorusso, P-A Soederstroem, H Watanabe, R Daido, Z Patel, S Rice, L Sinclair, J Wu, ZY Xu, A Yagi, H Baba, N Chiga, R Carroll, F Didierjean, Y Fang, N Fukuda, G Gey, E Ideguchi, N Inabe, T Isobe, D Kameda, I Kojouharov, N Kurz, T Kubo, S Lalkovski, Z Li, R Lozeva, H Nishibata, A Odahara, Z Podolyak, PH Regan, OJ Roberts, H Sakurai, H Schaffner, GS Simpson, H Suzuki, H Takeda, M Tanaka, J Taprogge, V Werner, O Wieland (2015)Lifetime measurements of the first 2(+) states in Zr-104,Zr-106: Evolution of ground-state deformations, In: PHYSICS LETTERS B750pp. 448-452 ELSEVIER SCIENCE BV
T Daniel, S Kisyov, Patrick Regan, N Marginean, Zsolt Podolyak, R Marginean, K Nomura, Matthias Rudigier, R Mihai, V Werner, RJ Carroll, Laila Gurgi, A Oprea, Thomas Berry, A Serban, CR Nita, C Sotty, R Suvaila, A Turturica, C Costache, L Stan, A Olacel, M Boromiza, S Toma (2017)γ -ray spectroscopy of low-lying excited states and shape competition in Os 194, In: Physical Review C95(2)024328 American Physical Society
The properties of excited states in the neutron-rich nucleus 194Os have been investigated using the 192Os(18O,16O)194Os reaction with an 80 MeV beam provided by the IFIN-HH Laboratory, Bucharest. Discrete γ -ray decays from excited states have been measured using the hybrid HPGe-LaBr3(Ce) array RoSPHERE. The current work identifies a number of previously unreported low-lying nonyrast states in 194Os as well as the first measurement of the half-life of the yrast 2+ state of 302(50) ps. This is equivalent to a B(E2 : 2+ → 0+) = 45(16) W.u. and intrinsic quadrupole deformation of βeff = 0.14(1). The experimental results are compared with Hartree-Fock-Bogoliubov–interacting-boson-model calculations and are consistent with a reduction in a quadrupole collectivity in Os isotopes with increasing neutron number.
PH Regan (2015)Precision measurement of sub-nanosecond lifetimes of excited nuclear states using fast-timing coincidences with LaBr3(Ce) detectors, In: RADIATION PHYSICS AND CHEMISTRY116pp. 38-42 PERGAMON-ELSEVIER SCIENCE LTD
PH Regan (2000)New tools for exotic discrete line gamma-ray spectroscopy., In: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY219pp. U81-U81 AMER CHEMICAL SOC
CJ Pearson, JJV Dobon, PH Regan, PJ Sellin, E Morton, PJ Nolan, A Boston, M Descovich, J Thornhill, J Cresswell, I Lazarus, J Simpson (2002)Digital gamma-ray tracking algorithms in segmented germanium detectors, In: IEEE TRANSACTIONS ON NUCLEAR SCIENCE49(3)pp. 1209-1215
J Jolie, J-M Regis, D Wilmsen, S Ahmed, M Pfeiffer, N Saed-Samii, N Warr, A Blanc, M Jentschel, U Koester, P Mutti, T Soldner, G Simpson, G De France, W Urban, F Drouet, A Vancraeyenest, P Baczyk, M Czerwinski, A Korgul, C Mazzocchi, T Rzaca-Urban, A Bruce, OJ Roberts, LM Fraile, H Mach, V Paziy, A Ignatov, S Ilieva, T Kroell, M Scheck, M Thuerauf, D Ivanova, S Kisyov, S Lalkovski, Z Podolyak, PH Regan, W Korten, M Zielinska, MD Salsac, D Habs, PG Thirolf, CA Ur, C Bernards, RF Casten, N Cooper, V Werner, RB Cakirli, S Leoni, G Benzoni, G Bocchi, S Bottoni, FCL Crespi, B Fornal, N Cieplicka, B Szpak, CM Petrache, R Leguillon, R John, C Lorenz, R Massarczyk, R Schwengner, D Curien, R Lozeva, L Sengele, N Marginean, R Lica (2015)The (n,gamma) campaigns at EXILL, In: CGS15 - CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS93
J-M Regis, J Jolie, H Mach, GS Simpson, A Blazhev, G Pascovici, M Pfeiffer, M Rudigier, N Saed-Samii, N Warr, A Blanc, G de France, M Jentschel, U Koester, P Mutti, T Soldner, CA Ur, W Urban, AM Bruce, F Drouet, LM Fraile, S Ilieva, W Korten, T Kroell, S Lalkovski, N Marginean, V Paziy, Z Podolyak, PH Regan, O Stezowski, A Vancraeyenest (2015)The Generalized Centroid Difference method for lifetime measurements via gamma-gamma coincidences using large fast-timing arrays, In: CGS15 - CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS93
MJL Jimenez, B Blank, M Chartier, S Czajkowski, P Dessagne, G de France, J Giovinazzo, D Karamanis, M Lewitowicz, V Maslov, C Miehe, PH Regan, M Stanoiu, M Wiescher (2002)Half-life measurements of proton-rich Kr-78 fragments, In: PHYSICAL REVIEW C66(2)ARTN 02580 AMERICAN PHYSICAL SOC
AD Yamamoto, PH Regan, CW Beausang, FR Xu, MA Caprio, RF Casten, G Gurdal, AA Hecht, C Hutter, R Krucken, SD Langdown, D Meyer, JJ Ressler, NV Zamfir (2002)High-j proton and neutron alignments in gamma-soft Ru-101, In: PHYSICAL REVIEW C66(2)ARTN 02430 AMERICAN PHYSICAL SOC
L Caceres, M Gorska, A Jungclaus, M Pfutzner, H Grawe, F Nowacki, K Sieja, S Pietri, D Rudolph, Z Podolyak, PH Regan, E Werner-Malento, P Detistov, S Lalkovski, V Modamio, J Walker, K Andgren, P Bednarczyk, J Benlliure, G Benzoni, AM Bruce, E Casarejos, B Cederwall, FCL Crespi, P Doornenbal, H Geissel, J Gerl, J Grebosz, B Hadinia, M Hellstrom, R Hoischen, G Ilie, A Khaplanov, M Kmiecik, I Kojouharov, R Kumar, N Kurz, A Maj, S Mandal, F Montes, G Martinez-Pinedo, S Myalski, W Prokopowicz, H Schaffner, GS Simpson, SJ Steer, S Tashenov, O Wieland, HJ Wollersheim (2009)Spherical proton-neutron structure of isomeric states in Cd-128, In: PHYSICAL REVIEW C79(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
R Britton, JL Burnett, AV Davies, PH Regan (2014)Monte Carlo characterisation of a Compton suppressed broad-energy HPGe detector, In: JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY300(3)pp. 1253-1259 SPRINGER
Z Podolyak, KA Gladnishki, J Gerl, M Hellstrom, Y Kopatch, S Mandal, M Gorska, PH Regan, HJ Wollersheim, KH Schmidt, O Yordanov, A Bracco, CA Kalfas (2004)Angular momentum population in projectile fragmentation, In: LABYRINTH IN NUCLEAR STRUCTURE701pp. 280-284
L Al-Sulaiti, D Shipley, R Thomas, P Owen, A Kacperek, PH Regan, H Palmans (2012)Water equivalence of some plastic-water phantom materials for clinical proton beam dosimetry., In: Appl Radiat Isot70(7)pp. 1052-1057
Plastic-water phantom materials are not exactly water equivalent since they have a different elemental composition and different interaction cross sections for protons than water. Several studies of the water equivalence of plastic-water phantom materials have been reported for photon and electron beams, but none for clinical proton beams. In proton beams, the difference between non-elastic nuclear interactions in plastic-water phantom materials compared to those in water should be considered. In this work, the water equivalence of Plastic Water® (PW)1, Plastic Water® Diagnostic Therapy (PWDT)1 and solid water (WT1)2 phantoms was studied for clinical proton energies of 60 MeV and 200 MeV. This was done by evaluating the fluence correction factor at equivalent depths; first with respect to water and then with respect to graphite by experiment and Monte Carlo (MC) simulations using FLUKA. MC simulations showed that the fluence correction with respect to water was less than 0.5% up to the entire penetration depth of the protons at 60 MeV and less than 1% at 200 MeV up to 20 cm depth for PWDT, PW and WT1. With respect to graphite the fluence correction was about 0.5% for 60 MeV and about 4% for 200 MeV. The experimental results for modulated and un-modulated 60 MeV proton beams showed good agreement with the MC simulated fluence correction factors with respect to graphite deviating less than 1% from unity for the three plastic-water phantoms.
G Georgiev, G Neyens, M Hass, DL Balabanski, C Bingham, C Borcea, N Coulier, R Coussement, JM Daugas, G De France, FD Santos, M Gorska, H Grawe, R Grzywacz, M Lewitowicz, H Mach, I Matea, RD Page, M Pfutzner, YE Penionzhkevich, Z Podolyak, PH Regan, K Rykaczewski, M Sawicka, NA Smirnova, YG Sobolev, M Stanoiu, S Teughels, K Vyvey (2002)g factor measurements of mu s isomeric states in neutron-rich nuclei around Ni-68 produced in projectile-fragmentation reactions, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS28(12)PII S0954-pp. 2993-3006 IOP PUBLISHING LTD
JM Daugas, R Grzywacz, M Lewitowicz, L Achouri, JC Angelique, D Baiborodin, K Bennaceur, R Bentida, R Beraud, C Borcea, C Bingham, WN Catford, A Emsallem, G de France, H Grawe, KL Jones, RC Lemmon, MJL Jimenez, F Nowacki, FD Santos, M Pfutzner, PH Regan, K Rykaczewski, JE Sauvestre, M Sawicka, G Sletten, M Stanoiu (2000)The 8(+) isomer in Zn-78 and the doubly magic character of Ni-78, In: PHYSICS LETTERS B476(3-4)pp. 213-218 ELSEVIER SCIENCE BV
EA McCutchan, NV Zamfir, MA Caprio, RF Casten, H Amro, CW Beausang, DS Brenner, AA Hecht, C Hutter, SD Langdown, DA Meyer, PH Regan, JJ Ressler, AD Yamamoto (2004)Low spin states in Yb-162 and the X(5) critical point symmetry, In: PHYSICAL REVIEW C69(2)ARTN 02430 AMERICAN PHYSICAL SOC
K Andgren, SF Ashley, PH Regan, EA McCutchan, NV Zamfir, L Amon, RB Cakirli, RF Casten, RM Clark, MN Erduran, G Gürdal, KL Keyes, DA Meyer, A Papenberg, N Pietralla, C Plettner, G Rainovski, RV Ribas, NJ Thomas, J Vinson, DD Warner, V Werner, E Williams (2006)Recoil distance method lifetime measurements in 107Cd and 103Pd, In: AIP Conference Proceedings831pp. 391-393
Preliminary lifetime values have been measured for a number of near-yrast states in the odd-A transitional nuclei 107Cd and 103Pd. The reaction used to populate the nuclei of interest was 98Mo( 12C,3nxα)107Cd, 103Pd, with the beam delivered by the tandem accelerator of the Wright Nuclear Structure Laboratory at an incident beam energy of 60 MeV. Our experiment was aimed at the investigation of collective excitations built on the unnatural parity, ν h11/2 orbital, specifically by measuring the B(E2) values of decays from the excited levels built on this intrinsic structure, using the Doppler Recoil Distance Method. We report lifetimes and associated transition probabilities for decays from the 15/2- and the 19/2- states in 107Cd and the first measurement of the 15/2- state in 103Pd. These results suggest that neither a simple rotational or vibrational interpretation is sufficient to explain the observed structures. © 2006 American Institute of Physics.
P. Koseoglou, V. Werner, N. Pietralla, S. Ilieva, M. Thürauf, C. Bernards, A. Blanc, A. M. Bruce, R. B. Cakirli, N. Cooper, L. M. Fraile, G. de France, M. Jentschel, J. Jolie, U. Koester, W. Korten, T. Kröll, S. Lalkovski, H. Mach, N. Mărginean, P. Mutti, Z. Patel, V. Paziy, Z. Podolyák, P. H. Regan, J.-M. Régis, O. J. Roberts, N. Saed-Samii, G. S. Simpson, T. Soldner, C. A. Ur, W. Urban, D. Wilmsen, E. Wilson (2018)The boundary of the N=90 shape phase transition: 148Ce, In: Journal of Physics: Conference Series1023pp. 012022-1 IOP Publishing
The even-even N=90 isotones with Z=60-66 are known to undergo a first order phase transition. Such a phase transition in atomic nuclei is characterized by a sudden change of the shape of the nucleus due to changes in the location of the potential minimum. In these proceedings we report a measurement of the B4/2 ratio of 148Ce, which will probe the location of the low-Z boundary of the N=90 phase transitional region. The measured B4/2 value is compared to the prediction from the X(5) symmetry within the interacting boson model at the critical point between the geometrical limits of vibrators and rigid/axial rotors. The EXILL&FATIMA campaign took place at the high-flux reactor of the Institut Laue Langevin, Grenoble, were 235U and 241Pu fission fragments were measured by a hybrid spectrometer consisting of high-resolution HPGe and fast LaBr3(Ce)-scintillator detectors. The fast LaBr3(Ce) detectors in combination with the generalized centroid difference method allowed lifetime measurements in the picosecond region. Furthermore, this kind of analysis can serve as preparation for the FATIMA experiments at FAIR.
J. N. Wilson, M. Lebois, L. Qi, P. Amador-Celdran, D. Bleuel, J. A. Briz, R. Carroll, Wilton Catford, H. De Witte, D. T. Doherty, R. Eloirdi, G. Georgiev, A. Gottardo, A. Goasduff, K. Hadyńska-Klęk, K. Hauschild, H. Hess, V. Ingeberg, T. Konstantinopoulos, J. Ljungvall, A. Lopez-Martens, G. Lorusso, R. Lozeva, R. Lutter, P. Marini, I. Matea, T. Materna, L. Mathieu, A. Oberstedt, S. Oberstedt, S. Panebianco, Zsolt Podolyak, A. Porta, Patrick Regan, P. Reiter, K. Rezynkina, S. J. Rose, E. Sahin, M. Seidlitz, O. Serot, Robert Shearman, B. Siebeck, S. Siem, A. G. Smith, G. M. Tveten, D. Verney, N. Warr, F. Zeiser, M. Zielinska (2017)Anomalies in the Charge Yields of Fission Fragments from the U(n,f)238 Reaction, In: Physical Review Letters118(22)pp. 222501-1 American Physical Society
Fast-neutron-induced fission of 238U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ−γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.
Z Berant, E Oster, RJ Casperson, A Wolf, V Werner, A Heinz, RF Casten, G Gurdal, EA McCutchan, DS Brenner, JR Terry, R Winkler, E Williams, J Qian, A Schmidt, MK Smith, T Ahn, CW Beausang, PH Regan, T Ross, M Bunce, B Darakchieva, DA Meyer, J LeBlanc, K Dudziak, C Bauer, G Henning (2009)g factor of the 2(1)(+) state of Hf-172, In: PHYSICAL REVIEW C80(5)ARTN 05730 AMER PHYSICAL SOC
G Benzoni, F Azaiez, S Leoni, S Battacharyya, R Borcea, A Bracco, L Corradi, D Curien, G De France, Z Dombradi, E Fioretto, S Franchoo, S Grevy, F Ibrahim, S Iulian, G Mukherjee, A Navin, G Pollarolo, N Redon, PH Regan, M Rejmund, C Schmitt, G Sletten, D Sohler, M Stanoiu, S Szilner, D Verney (2006)In-beam γ spectroscopy using DIC with a radioactive Ne beam, In: AIP Conference Proceedings853pp. 49-54
The preferred production mechanisms used to investigate the region of light nuclei, such as O, Ne and F, have been transfer reactions and, more recently, two-step fragmentation. Multi-nucleon transfer reactions can be an important complementary tool to populate this mass region. Deep-inelastic and multi-nucleon transfer reactions have been largely used to study heavier systems, however no information is yet available regarding the effectiveness of these reaction mechanisms going towards lighter nuclei. In this proceeding we present promising preliminary results from an experiment performed with a radioactive 24Ne beam from SPIRAL facility at GANIL using the VAMOS spectrometer in conjunction with the EXOGAM array. © 2006 American Institute of Physics.
Z Podolyak, S Steer, S Pietri, P Regan, D Rudolph, A Garnsworthy, R Hoischen, E Werner-Malento, J Gerl, M Gorska, H-J Wollersheim (2006)NUCL 40-Nuclear structure and reaction studies: Isomers used as a tool, In: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY232 AMER CHEMICAL SOC
SM Collins, S Pomme, SM Jerome, KM Ferreira, PH Regan, AK Pearce (2015)The half-life of Th-227 by direct and indirect measurements, In: APPLIED RADIATION AND ISOTOPES104pp. 203-211 PERGAMON-ELSEVIER SCIENCE LTD
SM Judge, Patrick Regan (2017)Radionuclide metrology research for nuclear site decommissioning, In: Radiation Physics and Chemistry140pp. 463-465 Elsevier
The safe and cost-effective decommissioning of legacy nuclear sites relies on accurate measurement of the radioactivity content of the waste materials, so that the waste can be assigned to the most appropriate disposal route. Such measurements are a new challenge for the science of radionuclide metrology which was established largely to support routine measurements on operating nuclear sites and other applications such as nuclear medicine. In this paper, we provide a brief summary of the international measurement system that is established to enable nuclear site operators to demonstrate that measurements are accurate, independent and fit for purpose, and highlight some of the projects that are underway to adapt the measurement system to meet the changing demands from the industry.
PD Stevenson, S Fracasso, EB Suckling, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, R Wadsworth, D Watts (2012)The tensor-kinetic field in nuclear collisions, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011381pp. ?-?
SJ Williams, PM Jenneson, PE Garrett, PH Regan, C Andreoiu, GC Ball, RS Chakrawarthy, JJ Daoud, GF Grinyer, G Hackman, B Hyland, NA Mlwilo, AC Morton, CJ Pearson, JJ Ressler, MA Schumaker, MB Smith, CE Svensson, JJV Dobon (2005)Testing the integration of BaF2 detectors into the 8 pi array: fast-timing measurements at TRIUMF, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1979-S1984
P. Koseoglou, V. Werner, N. Pietralla, S. Ilieva, T. Nikšić, D. Vretenar, P. Alexa, M. Thűrauf, C. Bernards, A. Blanc, A. M. Bruce, R. B. Cakirli, N. Cooper, L. M. Fraile, G. de France, M. Jentschel, J. Jolie, U. Kőster, W. Korten, T. Krőll, S. Lalkovski, H. Mach, N. Mărginean, P. Mutti, Z. Patel, V. Paziy, Zs. Podolyak, Patrick Regan, J.-M. Régis, O. J. Roberts, N. Saed-Samii, G. S. Simpson, T. Soldner, C. A. Ur, W. Urban, D. Wilmsen, E. Wilson (2020)Low-Z boundary of the N = 88-90 shape phase transition: 148Ce near the critical point, In: Physical Review C101(1)014303 American Physical Society
Excited states of the neutron-rich nucleus 148Ce have been populated by neutron-induced fission of 235U and 241Pu samples. Their electromagnetic decays were studied by means of γ-ray coincidence spectroscopy with fast-timing capabilities. Lifetimes of the 2+1 and 4+1 states of 148Ce were obtained and their E2 decay rates deduced. The B4=2 = B(E2; 4+1 → 2+1)=B(E2; 2+1 → 0+1) ratio indicates that 148Ce is a transitional nucleus while the N = 88/90 shape phase transition evolves into a gradual change of nuclear deformation for proton numbers Z < 60.
R Britton, JL Burnett, AV Davies, PH Regan (2014)Characterisation of cascade summing effects in gamma spectroscopy using Monte Carlo simulations, In: JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY299(1)pp. 447-452 SPRINGER
P Regan, B Blank (2000)Exploring nuclear frontiers, In: PHYSICS WORLD13(1)pp. 29-34 IOP PUBLISHING LTD
NJ Thompson, PH Regan, AB Garnsworth, AD Ayangeakaa, HC Ai, L Amon, RB Cakirli, RF Casten, CR Fitzpatrick, SJ Freeman, G Gurdal, A Heinz, GA Jones, EA McCutchan, J Qian, V Werner, SJ Williams, R Winkler (2007)Spectroscopy of Zr-91(51) at medium to high spins, In: ACTA PHYSICA POLONICA B38(4)pp. 1381-1384
BS Nara Singh, R Wadsworth, P Boutachkov, A Blazhev, Z Liu, H Grawe, TS Brock, N Braun, M Go, S Pietri, D Rudolph, C Domingo-Pardo, SJ Steer, A Atac, L Bettermann, L Cáceres, K Eppinger, T Engert, T Faestermann, F Farinon, F Finke, K Geibel, J Gerl, R Gernhäuser, N Goel, A Gottardo, J Grȩbosz, C Hinke, R Hoischen, G Llie, H Iwasaki, J Jolie, A Kaşkaş, I Kojouharov, R Krücken, N Kurz, E Merchánt, C Nociforo, J Nyberg, M Pfützner, A Prochazka, Z Podolyák, PH Regan, P Reiter, S Rinta-Antila, C Scholl, H Schaffner, P-A Söderström, N Warr, H Weick, H-J Wollersheim, PJ Woods, F Nowacki, K Sieja (2011)Exotic nuclear studies around and below A=100, In: AIP Conference Proceedings1409pp. 19-24
A RISING experiment with an aim to study exotic Cd nuclei was carried out at GSI‐FRS facility. Some preliminary results from this experiment are presented here. In particular, the β decay of 96Cd to 96Ag revealed the existence of a high spin isomer predicted a few decades ago. In this context, the structures of both these nuclei are discussed. Shell model calculations using the Gross‐Frenkel interaction are used to interpret the results.
PH Regan (2012)From RISING to the DESPEC fast-timing project within NUSTAR at FAIR: sub-nanosecond nuclear timing spectroscopy with LaBr3 scintillators., In: Appl Radiat Isot70(7)pp. 1125-1130
This paper summarises a presentation given at the IRRMA8 conference in June 2011 which reviewed briefly the topic of current research studies in the evolution of nuclear structure with changing proton and neutron numbers. A short review of relevant contemporary spectroscopic studies of the structure of nuclei with highly exotic N/Z ratios using projectile fragmentation and fission reactions is given, together with an overview of some of the physics research aims to be attacked using the proposed Decay Spectroscopy (DESPEC) LaBr3 Fast-Timing gamma-ray array for the NUSTAR project at the upcoming Facility for Anti-Proton and Ion Research (FAIR). Examples of recent results using both 'isomer' and β--delayed gamma-ray decay measurements with the Stopped RISING hyper-pure germanium array at GSI are summarised and used to highlight some of the fundamental physics studies which are expected to become available in this area of research in the coming decade. Examples of the performance of cerium-doped LaBr3 detectors from 'in-beam' test experiments are presented together with initial plans for the geometry of the planned multi-detector LaBr3(Ce) array for DESPEC.
KR Pohl, PH Regan, JE Bush, PE Raines, DP Balamuth, D Ward, A Galindo-Uribarri, VP Janzen, SM Mullins, S Pilotte (1996)High-spin states in 107Pd, 108Pd, and 109Ag, In: Physical Review C - Nuclear Physics53(6)pp. 2682-2700
High-spin states in 107,108Pd and 109Ag have been studied by charged-particle-γ, γ-γ, and charged-particle-γ-γ coincidence measurements of heavy-ion fusion-evaporation reactions. The high-spin level schemes of these nuclides have been significantly extended and new deformed rotational bands have been found in each nuclide. These bands exhibit the general property of back bends corresponding to the rotational alignment of a pair of h11/2 quasineutrons. Band properties are compared with predictions of the cranked shell model and total Routhian surface calculations. The properties of the yrast and near-yrast bands of all three nuclides are generally consistent with predictions of moderate (β2 = 0.2) prolate deformation.
JN Wilson, M Lebois, L Qi, P Amador-Celdran, D Bleuel, JA Briz, R Carroll, Wilton Catford, H De Witte, D Doherty, R Eloirdi, G Georgiev, A Gottardo, A Goasduff, K Hadynska-Klek, K Hauschild, M Hess, V Ingeberg, T Konstantinopoulos, J Ljungvall, A Lopez-Martens, G Lorusso, R Lozeva, R Lutter, P Marini, I Matea, T Materna, L Mathieu, A Oberstedt, S Oberstedt, S Panebianco, Zsolt Podolyak, D Porta, Patrick Regan, P Reiter, K Rezynkina, SJ Rose, E Sahin, M Seidlitz, Robert Shearman, B Siebeck, S Siem, AG Smith, GM Tveten, D Verney, N Warr, F Zeiser, M Zielinska (2017)PRODUCTION AND STUDY OF NEUTRON-RICH NUCLEI USING THE LICORNE DIRECTIONAL NEUTRON SOURCE, In: Acta Physica Polonica B48(3)pp. 395-401 Państwowe Wydawn. Naukowe
We have recently successfully demonstrated a new technique for production and study of many of the most exotic neutron-rich nuclei at moderate spins. LICORNE, a newly developed directional inverse-kinematic fast neutron source at the IPN Orsay, was coupled to the MINIBALL high resolution -ray spectrometer to study nuclei the furthest from stability using the 238U(n; f) reaction. This reaction and 232Th(n; f) are the most neutron-rich fission production mechanisms achievable and can be used to simultaneously populate hundreds of neutron-rich nuclei up to spins of 16 ~. High selectivity in the experiment was achieved via triple -ray coincidences and the use of a 400 ns period pulsed neutron beam, a technique which is unavailable to other population mechanisms such as 235U(nth; f) and 252Cf(SF). The pulsing allows time correlations to be exploited to separate delayed rays from isomeric states in the hundreds of nuclei produced, which are then used to cleanly select a particular nucleus and its exotic binary partners. In the recent experiment, several physics cases are simultaneously addressed such as shape coexistence, the evolution of shell closures far from stability, and the spectroscopy of nuclei in the r-process path near N = 82. Preliminary physics results on anomalies in the 238U(n; f) fission yields and the structure of the 138Te and 100Sr nuclei will soon be published. A future project, -ball, to couple LICORNE with a hybrid escape-suppressed spectrometer to refine further the technique and achieve a large increase in the observational limit is discussed.
J. Wiederhold, V. Werner, R. Kern, N. Pietralla, D. Bucurescu, R. Carroll, N Cooper, T. Daniel, D. Filipescu, N. Florea, R-B. Gerst, D. Ghita, Laila Gurgi, J. Jolie, Ralitsa Ilieva, R. Lica, N. Marginean, R. Marginean, C. Mihai, I. O. Mitu, F. Naqvi, C. Nita, Matthias Rudigier, S. Stegemann, S. Pascu, Patrick Regan (2019)Evolution of E2 strength in the rare-earth isotopes Hf174,176,178,180, In: Physical Review C99(2)
Mean lifetimes of yrast states of the isotopes 174,176,178,180Hf have been measured using fast- electronic scintillation timing. Excited states of 74,176,178Hf were populated via β decay, while 180Hf was populated via Coulomb excitation. The lifetimes of the 2+ 1 and 4+ 1 states of all isotopes and the lifetimes of the 6+ 1 states of 174,178Hf were measured, using the slope and the centroid shift methods. The mean lifetime, τ (4+ 1 ) = 85(13) ps, of 178Hf has been determined for the first time. In addition, the mean lifetimes of the 2− 1 and the 3− 1 states of 176Hf have been determined. Systematic uncertainties on the evolution of data as a function of neutron number were reduced by using the same setup for all the isotopes of interest. The data are in agreement with other recent lifetime measurements where available and shows a shift of the maximum of collectivity for the Hf isotopic chain from neutron midshell at N = 104 to N = 100.
A. Wolf, Z. Berant, A. Heinz, V. Werner, E. A. McCutchan, G. Gürdal, R. B. Cakirli, Y. Oktem, J. Ai, L. Amon, C. W. Beausang, D. S. Brenner, R. F. Casten, R. J. Casperson, K. Dusling, C. R. Fitzpatrick, A. B. Gransworthy, N. Pietralla, J. Qian, P. H. Regan, N. J. Thompson, E. Williams, R. Winkler (2007)g factor of the 2+1 state of 170Hf , In: Physical Review C76(047308)
R Britton, J Burnett, A Davies, PH Regan (2013)Determining the efficiency of a broad-energy HPGe detector using Monte Carlo simulations, In: JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY295(3)pp. 2035-2041 SPRINGER
A Jungclaus, L Caceres, M Gorska, M Pfutzner, S Pietri, E Werner-Malento, H Grawe, K Langanke, G Martinez-Pinedo, F Nowacki, A Poves, J J Cuenca-Garcia, D Rudolph, Z Podolyak, P H Regan, P Detistov, S Lalkovski, V Modamio, J Walker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, J Grebosz, I Kojouharov, N Kurz, W Prokopowicz, H Schaffner, H J Wollersheim, K Andgren, J Benlliure, G Benzoni, A M Bruce, E Casarejos, B Cederwall, F C Crespi, B Hadinia, M Hellstrom, R Hoischen, G Ilie, J Jolie, A Khaplanov, M Kmiecik, R Kumar, A Maj, S Mandal, F Montes, S Myalski, G S Simpson, S J Steer, S Tashenov, O Wieland (2007)Observation of Isomeric Decays in the R-Process Waiting-Point Nucleus Cd-130(82), In: Physical Review Letters99(13)
The gamma decay of excited states in the waiting-point nucleus Cd-130(82) has been observed for the first time. An 8(+) two-quasiparticle isomer has been populated both in the fragmentation of a Xe-136 beam as well as in projectile fission of U-238, making Cd-130 the most neutron-rich N=82 isotone for which information about excited states is available. The results, interpreted using state-of-the-art nuclear shell-model calculations, show no evidence of an N=82 shell quenching at Z=48. They allow us to follow nuclear isomerism throughout a full major neutron shell from Cd-98(50) to Cd-130(82) and reveal, in comparison with Ni-76(48) one major proton shell below, an apparently abnormal scaling of nuclear two-body interactions.
S Courtin, G Fruet, DG Jenkins, M Heine, D Montanari, LG Morris, Gavin Lotay, Patrick Regan, OS Kirsebom, S Della Negra, F Hammache, N De Sereville, B Bastin, F de Oliveira, G Randisi, C Stodel, C Beck, F Haas (2017)Fusion Cross Sections of Astrophysics Interest Within the STELLA Project., In: Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016) 2017021001 Physical Society of Japan
Low energy fusion between light heavy-ions is a key feature of the evolution of massive stars. In systems of astrophysical interest, the process may be strongly affected by molecular configurations of the compound nucleus, leading to resonant S factors. In particular, the 12C+12C fusion reaction has been the object of numerous experimental investigations. The STELLA project has been developed to extend these investigations to lower energies towards the Gamow window.
P Boutachkov, N Braun, T Brock, BSN Singh, A Blazhev, Z Liu, R Wadsworth, M Górska, H Grawe, S Pietri, C Domingo-Pardo, T Faestermann, F Farinon, J Grebosz, I Kojuharov, N Kurz, C Nociforo, Z Podolyák, A Prochazka, S Steer, L Cáceres, T Engert, J Gerl, N Goel, R Hoischen, H Schaffner, H Weick, HJ Wollersheim, L Bettermann, F Finke, K Geibel, G Ilie, H Iwasaki, J Jolie, J Nyberg, P Reiter, C Scholl, PA Söderström, N Warr, K Eppinger, A Gottardo, C Hinke, R Krücken, M Pfützner, P Regan, S Rinta-Antila, D Rudolph, P Woods, A Ataç, E Merchán (2011)Isomer and β-decay spectroscopy of Tz=1 isotopes below the N=Z=50 shell gap, In: Journal of Physics: Conference Series312(SECTIO)
The RISING setup at the GSI-FRS facility was used to investigate the isomer and beta decays in N∼Z∼50 Cd, Ag and Pd isotopes. A preliminary analysis of the data has revealed new results on the Tz=1, 94Pd, 96Ag and 98Cd isotopes. In 94Pd a new high-spin isomer was observed, whilst in 96Ag 3 new isomeric states were identified, including core-excited states. In 98Cd a new high-energy isomeric γ-ray transition is observed, thus enabling us to confirm the previous spin assignment for the core-excited 12+ isomer.
T Alharbi, PH Regan, N Marginean, Z Podolyak, OJ Roberts, AM Bruce, N Alkhomashi, R Britton, D Bucurescu, D Deleanu, D Filipescu, D Ghita, T Glodariu, C Mihai, K Mulholland, R Lica, R Marginean, M Nakhostin, A Negret, CR Nita, L Stroe, T Sava, C Townsley, NV Zamfir (2015)Lifetime of the yrast I-pi=5(-) state and E1 hindrance in the transitional nucleus Ce-136(58), In: PHYSICAL REVIEW C91(2)ARTN 02730 AMER PHYSICAL SOC
R Britton, J Burnett, A Davies, PH Regan (2012)Preliminary simulations of NaI(Tl) detectors, and coincidence analysis using event stamping, In: Journal of Radioanalytical and Nuclear Chemistrypp. 1-5 Springer
This paper discusses preliminary work into the modelling and processing of coincidence measurements, for which a Monte-Carlo simulation and a post-processing program have both been developed. In the current work, a GEANT4 code is used to simulate a pair of NaI(Tl) scintillators, which are used experimentally to both develop the post-processing program and validate the GEANT4 model. This is found to be accurate to within 9% at a confidence level of 93.0% for energies from 30 to 3,000 keV.
J Jolie, J-M Regis, D Wilmsen, N Saed-Samii, M Pfeiffer, N Warr, A Blanc, M Jentschel, U Koester, P Mutti, T Soldner, GS Simpson, G De France, W Urban, F Drouet, A Vancraeyenest, AM Bruce, OJ Roberts, LM Fraile, V Paziy, A Ignatov, T Kroell, D Ivanova, S Kisyov, S Lalkovski, Z Podolyak, PH Regan, E Wilson, W Korten, CA Ur, R Lica, N Marginean (2015)Test of the SO(6) selection rule in Pt-196 using cold-neutron capture, In: NUCLEAR PHYSICS A934pp. 1-7 ELSEVIER SCIENCE BV
Z Podolyak, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, B Wadsworth, D Watts (2012)Prolate-oblate shape transition in heavy neutron-rich nuclei, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS381ARTN 0pp. ?-? IOP PUBLISHING LTD
R Wadsworth, BSN Singh, TS Brock, Z Liu, A Gottardo, PJ Woods, H Grawe, P Boutachkov, M Gorska, S Pietri, C Domingo-Pardo, L Caceres, T Engert, F Farinon, J Gerl, N Goel, R Hoischen, I Kojouharov, N Kurz, E Merchan, C Nociforo, A Prochazka, H Schaffner, H Weick, H-J Wollersheim, N Braun, A Blazhev, L Bettermann, F Finke, K Geibel, G Ilie, H Iwasaki, J Jolie, P Reiter, C Scholl, N Warr, D Rudolph, SJ Steer, Z Podolyak, PH Regan, A Atac, A Kaskas, K Eppinger, T Faestermann, R Gernhauser, C Hinke, R Krucken, J Grebosz, J Nyberg, P-A Soderstrom, M Pfutzner, S Rinta-Antila, F Nowacki, K Sieja (2012)Spin-gap isomer in Cd, In: Journal of Physics: Conference Series381(1)
Evidence has been obtained for the existence of the long predicted 16 spin-gap isomer in Cd. The decay of the isomer was identified and studied following the use of an 850 MeV/u beam of Xe impinging on a Be target and the fragment recoil separator at the GSI Laboratory. Gamma decays from the fragments were detected using the RISING gamma ray array, in its stopped beam configuration, plus a silicon active stopper. The data obtained have been compared with shell model predictions, which indicate that the isoscalar neutron-proton interaction plays a key role in the formation of the isomer. © Published under licence by IOP Publishing Ltd.
P Regan, P Stevenson (2005)Preface - NUSTAR 2005, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10) IOP PUBLISHING LTD
L Al-Sulaiti, D Shipley, R Thomas, A Kacperek, P Regan, H Palmans (2010)Water equivalence of various materials for clinical proton dosimetry by experiment and Monte Carlo simulation, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 344-347
OJ Roberts, AM Bruce, Z Patel, Z Podolyák, PH Regan, CM Townsley, A Smith, KF Mulholland, JF Smith (2013)Development of a LaBr3 (Ce) Fast-timing Array for FAIR, In: EPJ Web of Conferences63
A γ-ray spectrometer with fast-timing capabilities, constructed of LaBr3(Ce:5%) detectors, is under development for use at the future Facility for Anti-proton and Ion Research (FAIR). The physics aims of this device are to measure the half-lives of excited states in the region of ∼50 ps to several ns, in exotic nuclei. Monte-Carlo simulations using the GEANT4 software package have determined the final design of this fast-timing array by calculating the full-energy peak efficiencies of several different detector geometries. The results of the simulated efficiencies for each configuration were used to calculate the timing precision. Consequently, an array of thirty six, ø3.8×5.1 cm cylindrical crystals was found to be the optimum configuration. The detectors were purchased and subsequently characterised, with each detector found to have intrinsic energy and timing resolutions of ∼ 2.8 % (FWHM) and ∼ 210 ps (FWHM) for the 1173 and 1332 keV decays from 60Co. © Owned by the authors, published by EDP Sciences, 2013.
JM Daugas, T Faul, H Grawe, M Pfuetzner, R Grzywacz, M Lewitowicz, NL Achouri, JC Angelique, D Baiborodin, R Bentida, R Beraud, C Borcea, CR Bingham, WN Catford, A Emsallem, G de France, KL Grzywacz, RC Lemmon, MJL Jimenez, FDO Santos, PH Regan, K Rykaczewski, JE Sauvestre, M Sawicka, M Stanoiu, K Sieja, F Nowacki (2010)Low-lying isomeric levels in Cu-75, In: PHYSICAL REVIEW C81(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
N. Jovančević, M. Lebois, J.N. Wilson, D. Thisse, L. Qi, I. Matea, F. Ibrahim, D. Verney, M. Babo, C. Delafosse, F. Adsley, G. Tocabens, A. Gottardo, Y. Popovitch, J. Nemer, R. Canavan, M. Rudigier, K. Belvedere, A. Boso, P. Regan, Zs. Podolyak, R. Shearman, M. Bunce, P. Inavov, S. Oberstedt, A. Lopez-Martens, K. Hauschild, J. Ljungvall, R. Chakma, R. Lozeva, P.-A. Söderström, A. Oberstedt, D. Etasse, D. Ralet, A. Blazhev, R.-B. Gerst, G. Hafner, N. Cieplicka-Oryńczak, L. Iskra, B. Fornal, G. Benzoni, S. Leoni, S. Bottoni, C. Henrich, P. Koseoglou, J. Wiederhold, I. Homm, C. Surder, T. Kroll, D. Knezevic, A. Dragic, L. Cortes, N. Warr, K. Miernik, E. Adamska, M. Piersa, K. Rezynkina, L. Fraile, J. Benito Garcia, V. Sanchez, A. Algora, P. Davies, V. Guadilla-Gomez, M. Fallot, T. Kurtukian-Nieto, C. Schmitt, M. Heine, D. Reygadas Tello, M. Yavachova, M. Diakaki, F. Zeiser, W. Paulson, D. Gestvang (2019)Spectroscopy of neutron induced reactions with the ʋ-ball spectrometer, In: Acta Physica Polonica B50(3)pp. 297-304 Jagiellonian University
The ʋ-ball is a high-efficiency hybrid spectrometer which consists of both germanium (Ge) detectors and associated anti-Compton BGO shields, coupled to lanthanum bromide (LaBr3) detectors. The hybrid configuration provides a combination of both excellent energy and timing resolutions. The ʋ-ball geometry allows the coupling with the LICORNE directional neutron source at the ALTO facility of the IPN, Orsay. This opens the possibility to perform precise spectroscopy of neutron induced reactions and was used for two experiments during the recent experimental campaign. These two experiments are described here: 1. Spectroscopy of the neutron-rich fission fragments produced in the 238U(n; f) and 232Th(n; f) reactions; 2. Spectroscopy above the shape isomer in 238U. The 238U(n; f) and 232Th(n; f) reactions produce hundreds of neutron-rich nuclei on which gamma-ray spectroscopy can be performed. The main goal of the experiment aiming to populate the shape isomer in 238U is the measurement of the gamma-ray and fission decay branches as well as determination of level scheme in the super-deformed minimum. The shape isomer is populated by 238U(n; n') reaction, which gives a very advantageous population cross section over other reactions. More detailed descriptions of these two ʋ-ball experiments will be presented here.
J Kurcewicz, F Farinon, H Geissel, S Pietri, C Nociforo, A Prochazka, H Weick, JS Winfield, A Estradé, I Dillmann, A Evdokimov, J Gerl, E Gregor, A Kelić-Heil, R Knöbel, Y Litvinov, E Merchan, I Mukha, F Naqvi, M Pfützner, B Riese, MV Ricciardi, C Scheidenberger, P Spiller, J Stadlmann, S Terashima, M Winkler, F Farinon, H Geissel, A Prochazka, I Dillmann, A Evdokimov, B Riese, C Scheidenberger, B Sun, A Estradé, PRP Allegro, A Bail, G Bélier, J Taïeb, J Benlliure, G Benzoni, M Bunce, M Bowry, Z Podolyák, PH Regan, R Caballero-Folch, A Gottardo, JJ Valiente-Dobón, R Janik, B Sitar, P Strmen, I Szarka, T Kubo, S Terashima, Y Litvinov, E Merchan, F Naqvi, M Pfützner, M Pomorski, B Sun, P Woods (2012)Discovery and cross-section measurement of neutron-rich isotopes in the element range from neodymium to platinum with the FRS, In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics717(4-5)pp. 371-375 ELSEVIER SCIENCE BV
Using the high-resolution performance of the fragment separator FRS at GSI we have discovered 60 new neutron-rich isotopes in the atomic number range of 60≥Z≥78. The new isotopes were unambiguously identified in reactions with a U238 beam impinging on a Be target at 1 GeV/nucleon. The production cross-section for the new isotopes have been measured down to the pico-barn level and compared with predictions of different model calculations. For elements above hafnium fragmentation is the dominant reaction mechanism which creates the new isotopes, whereas fission plays a dominant role for the production of the new isotopes up to thulium. © 2012 Elsevier B.V.
AB Garnsworthy, CJ Lister, PH Regan, BB Blank, IJ Cullen, S Gros, DJ Henderson, GA Jones, Z Liu, D Seweryniak, BR Shumard, NJ Thompson, SJ Williams, S Zhu (2008)Optimizing recoil-isomer tagging with the Argonne fragment mass analyzer, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT594(2)pp. 184-187 ELSEVIER SCIENCE BV
PH Regan, C Wheldon, AD Yamamoto, JJ Valiente-Dobon, D Cline, CY Wu, AO Macchiavelli, FR Xu, JF Smith, K Andgren, RS Chakrawarthy, M Cromaz, P Fallon, SJ Freeman, A Gorgen, A Hayes, H Hua, SD Langdown, IY Lee, CJ Pearson, Z Podolyak, R Teng (2005)Vibrational and rotational sequences in Mo-101 and Ru-103,Ru-4 studied via multinucleon transfer reactions, In: ACTA PHYSICA POLONICA B36(4)pp. 1313-1322
EC Simpson, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, B Wadsworth, D Watts (2012)Spectroscopy and correlations probed in direct two-nucleon knockout reactions, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS381ARTN 01210 IOP PUBLISHING LTD
P. Spagnoletti, G. Simpson, S. Kisyov, D. Bucurescu, J.-M. Régis, N. Saed-Samii, A. Blanc, M. Jentschel, U. Köster, P. Mutti, T. Soldner, G. de France, C. A. Ur, W. Urban, A. M. Bruce, C. Bernards, F. Drouet, L. M. Fraile, L. P. Gaffney, D. G. Ghită, S. Ilieva, J. Jolie, W. Korten, T. Kröll, S. Lalkovski, C. Larijarni, R. Lică, H. Mach, N. Mărginean, V. Paziy, Zs. Podolyak, P. H. Regan, M. Scheck, J. F. Smith, G. Thiamova, C. Townsley, A. Vancraeyenest, V. Vedia, N. Warr, V. Werner, M. Zielińska (2019)Lifetimes and shape-coexisting states of 99Zr, In: Physical Review C100(1)014311pp. 014311-1 American Physical Society
Lifetimes of intermediate-spin states in two rotational bands of 99Zr have been measured. These states were populated following the neutron-induced fission of 235U at the PF1B beamline of the Institut Laue-Langevin, Grenoble, during the EXILL-FATIMA campaign. The nucleus 99Zr59 exhibits shape coexistence and lies precisely on the border of an abrupt change in ground-state deformation when going from N=58 to N=60, making its study interesting for understanding the mechanisms involved in the rapid onset of deformation here. The B(E2) values extracted for decays in the ν3/2[541] band allow quadrupole deformations of β2=0.34(1) and 0.26(3) to be determined for the 821.6- and 1236.6-keV members, whereas β2=0.32(3) was found for the 850.5-keV member of the ν3/2[411]band. Some of the excited states known in 99Zr have been reasonably described with interacting boson-fermion model (IBFM) calculations. Type-II shell evolution is proposed to play a major role in modifying single-particle energies in 99Zr.
SM Collins, AK Pearce, PH Regan, JD Keightley (2015)Precise measurements of the absolute gamma-ray emission probabilities of Ra-223 and decay progeny in equilibrium, In: APPLIED RADIATION AND ISOTOPES102pp. 15-28 PERGAMON-ELSEVIER SCIENCE LTD
PH Regan, JW Arrison, UJ Huttmeier, DP Balamuth (1996)Yrast gamma-ray spectroscopy of the neutron rich isotopes Co-61,Co-63, In: PHYSICAL REVIEW C54(3)pp. 1084-1097 AMERICAN PHYSICAL SOC
Matthias Rudigier, S Lalkovski, ER Gamba, AM Bruce, Zsolt Podolyak, Patrick Regan, M Carpenter, S Zhu, AD Ayangeakaa (2017)Fast Timing Measurement Using an LaBr3(Ce) Scintillator Detector Array Coupled with Gammasphere, In: Acta Physica Polonica B48(3)pp. 351-357
A fast-timing experiment was performed at the Argonne National Laboratory in December 2015 and January 2016, measuring decay radiation of fission products from a 252Cf fission source. Details of the set-up, integration with Digital Gammasphere, and the data acquisition system are presented. The timing performance of the set-up, capable of measuring lifetimes from the nanosecond region down to tens of picoseconds, is discussed. First preliminary results from the fast-timing analysis of the fission fragment data are presented
G Benzoni, F Azaiez, GI Stefan, S Franchoo, S Battacharyya, R Borcea, A Bracco, L Corradi, D Curien, G de France, Z Dombradi, E Fioretto, S Grevy, F Ibrahim, S Leoni, D Montanari, G Mukherjee, G Pollarolo, N Redon, PH Regan, C Schmitt, G Sletten, D Sohler, M Stanoiu, S Szilner, D Verney (2010)Study of collisions of the radioactive 24Ne beam at 7.9 MeV/u on 208Pb, In: European Physical Journal A45(3)pp. 287-292
S Pietri, A Jungclaus, M Gorska, H Grawe, M Pfuetzner, L Caceres, P Detistov, S Lalkovski, V Modamio, Z Podolyak, PH Regan, D Rudolph, J Walker, E Werner-Malento, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, J Grebosz, I Kojouharov, N Kurz, W Prokopowicz, H Schaffner, HJ Wollersheim, K Andgren, J Benlliure, G Benzoni, AM Bruce, E Casarejos, B Cederwall, FCL Crespi, B Hadinia, M Hellstrom, R Hoischen, G Ilie, A Khaplanov, M Kmiecik, R Kumar, A Maj, S Mandal, F Montes, S Myalski, G Simpson, SJ Steer, S Tashenov, O Wieland (2011)First observation of the decay of a 15(-) seniority v=4 isomer in Sn-128, In: PHYSICAL REVIEW C83(4)ARTN 0pp. ?-? AMER PHYSICAL SOC
M Bowry, Z Podolyak, S Pietri, J Kurcewicz, M Bunce, PH Regan, F Farinon, H Geissel, C Nociforo, A Prochazka, H Weick, N Al-Dahan, N Alkhomashi, PRP Allegro, J Benlliure, G Benzoni, P Boutachkov, AM Bruce, AMD Bacelar, GF Farrelly, J Gerl, M Gorska, A Gottardo, J Grebosz, N Gregor, R Janik, R Knoebel, I Kojouharov, T Kubo, N Kurz, YA Litvinov, E Merchan, I Mukha, F Naqvi, B Pfeiffer, M Pfuetzner, W Plass, M Pomorski, B Riese, MV Ricciardi, K-H Schmidt, H Schaffner, C Scheidenberger, EC Simpson, B Sitar, P Spiller, J Stadlmann, P Strmen, B Sun, I Tanihata, S Terashima, JJV Dobon, JS Winfield, H-J Wollersheim, PJ Woods (2013)Population of high-spin isomeric states following fragmentation of U-238, In: PHYSICAL REVIEW C88(2)ARTN 0pp. ?-? AMER PHYSICAL SOC
R Britton, PH Regan, JL Burnett, AV Davies (2014)Next Generation Detection Systems for Radioactive Material Analysis, In: NUCLEAR DATA SHEETS119pp. 410-412 ACADEMIC PRESS INC ELSEVIER SCIENCE
AN Andreyev, PA Butler, RD Page, DE Appelbe, GD Jones, DT Joss, RD Herzberg, PH Regan, J Simpson, R Wadsworth (2004)GEANT Monte Carlo simulations for the GREAT spectrometer, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT533(3)pp. 422-434 ELSEVIER SCIENCE BV
G Lorusso, R Shearman, PH Regan, SM Judge, S Bell, SM Collins, C Larijani, P Ivanov, SM Jerome, JD Keightley, S Lalkovski, AK Pearce, Z Podolyak (2016)Development of the NPL gamma-ray spectrometer NANA for traceable nuclear decay and structure studies, In: APPLIED RADIATION AND ISOTOPES109pp. 507-511 PERGAMON-ELSEVIER SCIENCE LTD
PH Regan (2006)Isomers and structural evolution using the RISING array, In: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY231
PH REGAN, AE STUCHBERY, SS ANDERSSEN (1995)MEASUREMENT OF THE G-FACTOR OF THE YRAST-10(+)-STATE IN CD-11O, In: NUCLEAR PHYSICS A591(3)pp. 533-547 ELSEVIER SCIENCE BV
SM Collins, AV Harms, PH Regan (2016)Half-life determination of the ground state decay of Ag-111, In: APPLIED RADIATION AND ISOTOPES108pp. 143-147 PERGAMON-ELSEVIER SCIENCE LTD
Cyrus Kouroush Larijani, SM Jerome, G Lorusso, P Ivanov, B Russell, AK Pearce, Patrick Regan (2017)Progress on the chemical separation of fission fragments from 236Np produced by proton irradiation of natural uranium target, In: Radiation Physics and Chemistry140pp. 480-486 Elsevier
The aim of the current work is to develop and validate a radiochemical separation scheme capable of separating both 236gNp and 236Pu from a uranium target of natural isotopic composition (~1 g uranium) and ~200 MBq of fission decay products. A target containing 1.2 g of UO2 was irradiated with a beam of 25 MeV protons with a typical beam current of 30 μA for 19 h in December 2013 at the University of Birmingham Cyclotron facility. Using literature values for the production cross-section for fusion of protons with uranium targets, we estimate that an upper limit of approximately 250 Bq of activity from the 236Np ground state was produced in this experiment. Using a radiochemical separation scheme, Np and Pu fractions were separated from the produced fission decay products, with analyses of the target-based final reaction products made using Inductively Couple Plasma Mass Spectrometry (ICP-MS) and high-resolution α particle and γ-ray spectrometry.
Patrick Regan, Cyrus Kouroush Larijani, P Schwendner, C Cockell, P Ivanov, B Russell, P Aitken-Smith (2017)Destructive and non-destructive measurements of NORM in monazite-rich sands of Brazil, In: Radiation Physics and Chemistry140pp. 180-185 Elsevier
The specific activity concentration of eight sand samples from three locations in the State of Espirito Santo, South Eastern Brazil have been determined for members of the 238U and 232Th decay series, as well as the primordial radionuclide 40K. The calculated activity concentration values and associated radiation hazard indices were evaluated. The thorium decay chain activities are significantly higher than that of comparable studies from other areas of the world, leading to calculated absorbed dose rate in air and radium equivalent activities which are higher than world averages. This is attributed to the geology of the monazite material which is ubiquitous in this region of Brazil. Trace elemental analysis was also carried out on these samples using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
CJ Pearson, PH Regan, A Divoli (2001)The application of CdZnTe detectors for coincident alpha-gamma spectroscopy, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT462(3)pp. 393-396 ELSEVIER SCIENCE BV
R Britton, JL Burnett, AV Davies, PH Regan (2013)Monte-Carlo based background reduction and shielding optimisation for a large hyper-pure germanium detector, In: JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY298(3)pp. 1491-1499 SPRINGER
CM Parry, AJ Boston, C Chandler, A Galindo-Uribarri, IM Hibbert, VP Janzen, DT Joss, SM Mullins, PJ Nolan, ES Paul, PH Regan, SM Vincent, R Wadsworth, D Ward, R Wyss (1998)Yrast structures in the neutron-deficient Pr-127(59)68 and Pm-131(61)70 nuclei, In: PHYSICAL REVIEW C57(5)pp. 2215-2221 AMERICAN PHYSICAL SOC
J-M Regis, H Mach, GS Simpson, J Jolie, G Pascovici, N Saed-Samii, N Warr, A Bruce, J Degenkolb, LM Fraile, C Fransen, DG Ghita, S Kisyov, U Koester, A Korgul, S Lalkovski, N Marginean, P Mutti, B Olaizola, Z Podolyak, PH Regan, OJ Roberts, M Rudigier, L Stroe, W Urban, D Wilmsen (2013)The generalized centroid difference method for picosecond sensitive determination of lifetimes of nuclear excited states using large fast-timing arrays, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT726pp. 191-202 ELSEVIER SCIENCE BV
JM Daugas, M Sawicka, M Pfützner, I Matea, H Grawe, R Grzywacz, NL Achouri, JC Angélique, D Baiborodin, F Becker, G Bélier, R Bentida, R Béraud, C Bingham, C Borcea, R Borcea, E Bouchez, A Buta, WN Catford, E Dragulescu, A Emsallem, G De France, J Giovinazzo, M Girod, H Goutte, G Gorgiev, KL Grzywacz-Jones, F Hammache, F Ibrahim, RC Lemmon, M Lewitowicz, MJ Lopez-Jimenez, P Mayet, V Méot, F Negoita, F De Oliveira-Santos, O Perru, PH Regan, O Roig, K Rykaczewski, MG Saint-Laurent, JE Sauvestre, G Sletten, O Sorlin, M Stanoiu, I Stefan, C Stodel, C Theisen, D Verney, J Zylicz (2006)Isomeric island in the vicinity of 66Fe, In: AIP Conference Proceedings831pp. 427-429
An island of isomers have recently been observed on both sides of the N=40 shell below the Ni isotopes. Isomeric states in the 65Fe and 67Fe allow the knowledge of the single particle structure around the νg 9/2 shell. Moreover, the excitation energy of the first 2+ and 4+ states in the 68Fe have been established by β-γ correlation. The evolution of the structure of the Fe isotopes going far away from the valley of stability is, for the first time, given for N>40. © 2006 American Institute of Physics.
M Gorska, L Caceres, H Grawe, M Pfuetzner, A Jungclaus, S Pietri, E Werner-Malento, Z Podolyak, PH Regan, D Rudolph, R Detistov, S Lalkovski, V Modamio, J Walker, T Beck, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, J Grebosz, R Hoischen, I Kojouharov, N Kurz, W Prokopowicz, H Schaffner, H Weick, H-J Wollersheim, K Andgren, J Benlliure, G Benzoni, AM Bruce, E Casarejos, B Cederwall, FCL Crespi, B Hadinia, M Hellstrom, G Ilie, A Khaplanov, M Kmiecik, R Kumar, A Maj, S Mandal, F Montes, S Myalski, GS Simpson, SJ Steer, S Tashenov, O Wieland, Z Dombradi, R Reiter, D Sohler (2009)Evolution of the N=82 shell gap below Sn-132 inferred from core excited states in In-131, In: PHYSICS LETTERS B672(4-5)pp. 313-316 ELSEVIER SCIENCE BV
M. Rudigier, Zs. Podolyak, P.H. Regan, A.M. Bruce, S. Lalkovski, R.L. Canavan, E.R. Gamba, O. Roberts, I. Burrows, D.M. Cullen, L.M. Fraile, L. Gerhard, J. Gerl, M. Gorska, A. Grant, J. Jolie, V. Karayonchev, N. Kurz, W. Korten, I.H. Lazarus, C.R. Nita, V.F.E. Pucknell, J.-M. Régis, H. Schaffner, J. Simpson, P. Singh, C.M. Townsley, J.F. Smith, J. Vesic (2020)FATIMA — FAst TIMing Array for DESPEC at FAIR, In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment969163967 Elsevier
The components, working principle and characteristics of FATIMA (FAst TIMing Array), a fast-timing detector system for DESPEC at FAIR, are described. The core system includes 36 LaBr3(Ce) scintillator detectors, a mounting frame for the DESPEC station and a VME-based fast-timing data acquisition system. The current electronic timing circuit is based on V812 constant fraction discriminators and V1290 time-to-digital converters. Gamma-ray energies are measured using V1751 digitisers. Characteristics of the core FATIMA system including efficiency, energy, and coincidence resolving time, as well as limitations, are discussed on the basis of test measurements performed in the S4 cave at GSI, Germany. The coincidence γ-γ time resolution for the prompt 60Co cascade is determined to be ~320 ps full width at half maximum. The total full energy peak efficiency at 1 MeV for the 36 detector array in the DESPEC setup is 2.9%. The energy-dependent prompt response centroid curve with the current CFD/TDC combination is shown to be smooth; the centroid shift method can be applied for the measurement of half-lives below 200 ps. An overview of applications of the FATIMA detectors as an ancilliary system in combination with other detector arrays during recent years is given. Data on the operation of the detectors in the presence of magnetic fields are presented.
A Jungclaus, L Caceres, M Gorska, M Pfutzner, S Pietri, E Werner-Malento, H Grawe, K Langanke, G Martinez-Pinedo, F Nowacki, A Poves, JJ Cuenca-Garcia, D Rudolph, Z Podolyak, PH Regan, P Detistov, S Lalkovski, V Modamio, J Walker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, J Grebosz, I Kojouharov, N Kurz, W Prokopowicz, H Schaffner, HJ Wollersheim, K Andgren, J Benlliure, G Benzoni, AM Bruce, E Casarejos, B Cederwall, FCL Crespi, B Hadinia, M Hellstrom, R Hoischen, G Ilie, J Jolie, A Khaplanov, M Kmiecik, R Kumar, A Maj, S Mandal, F Montes, S Myalski, GS Simpson, SJ Steer, S Tashenov, O Wieland (2007)Observation of isomeric decays in the r-process waiting-point nucleus Cd-130(82), In: PHYSICAL REVIEW LETTERS99(13)ARTN 1pp. ?-? AMER PHYSICAL SOC
M Nakhostin, Z Podolyak, PH Regan (2014)Digital processing of signals from LaBr3:Ce scintillation detectors, In: JOURNAL OF INSTRUMENTATION9ARTN C1204 IOP PUBLISHING LTD
D Rudolph, R Hoischen, M Hellstrom, S Pietri, Zsolt Podolyak, PH Regan, AB Garnsworthy, SJ Steer, F Becker, P Bednarczyk, L Caceres, P Doornenbal, J Gerl, M Gorska, J Grebosz, I Kojouharov, N Kurz, W Prokopowicz, H Schaffner, HJ Wollersheim, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, A Blazhev, C Brandau, JR Brown, C Fahlander, EK Johansson, A Jungclaus, SM Lenzi (2008)Isospin symmetry and proton decay: Identification of the 10(+) isomer in (54)Ni, In: PHYSICAL REVIEW C78(2)ARTN 0pp. ?-? AMER PHYSICAL SOC
The gamma decays from an isomeric 10(+) state at 6457 keV in the nucleus Ni-54(28)26 have been identified using the GSI fragment separator in conjunction with the RISING Ge-detector array. The state is interpreted as the isobaric analog of the 6527-keV 10(+) isomer in Fe-54(26)28.The results are discussed in terms of isospin-dependent shell-model calculations. Clear evidence is presented for a discrete l = 5 proton decay branch into the first excited 9/2(-) state of the daughter Co-53. This decay is the first of its kind observed following projectile fragmentation reactions.
PJR Mason, T Alharbi, PH Regan, N Marginean, Z Podolyak, N Alkhomashi, PC Bender, M Bowry, M Bostan, D Bucurescu, AM Bruce, G Cata-Danil, I Cata-Danil, R Chakrabarti, D Deleanu, P Detistov, MN Erduran, D Filipescu, U Garg, T Glodariu, D Ghita, SS Ghugre, A Kusoglu, R Marginean, C Mihai, M Nakhostin, A Negret, S Pascu, CR Triguero, T Sava, EC Simpson, AK Sinha, L Stroe, G Suliman, NV Zamfir, S Freeman, A Andreyev, A Bruce, A Deacon, D Jenkins, D Joss, D MacGregor, P Regan, J Simpson, G Tungate, B Wadsworth, D Watts (2012)Half-life of the I-pi=4(-) Intruder State in P-34 Using LaBr3:Ce Fast Timing, In: RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS381ARTN 0pp. ?-? IOP PUBLISHING LTD
J. Ha, T. Sumikama, F. Browne, N. Hinohara, A. M. Bruce, S. Choi, I. Nishizuka, S. Nishimura, P. Doornenbal, G. Lorusso, P.-A. Söderström, H. Watanabe, R. Daido, Z. Patel, S. Rice, L. Sinclair, J. Wu, Z. Y. Xu, A. Yagi, H. Baba, N. Chiga, R. Carroll, F. Didierjean, Y. Fang, N. Fukuda, G. Gey, E. Ideguchi, N. Inabe, T. Isobe, D. Kameda, I. Kojouharov, N. Kurz, T. Kubo, S. Lalkovski, Z. Li, R. Lozeva, H. Nishibata, A. Odahara, Zs. Podolyak, P. H. Regan, O. J. Roberts, H. Sakurai, H. Schaffner, G. S. Simpson, H. Suzuki, H. Takeda, M. Tanaka, J. Taprogge, V. Werner, O. Wieland (2020)Shape evolution of neutron-rich 106,108,110Mo isotopes in the triaxial degree of freedom, In: Physical Review C101(4)044311 American Physical Society
Background: Neutron-rich nuclei with mass number between 100 and 110 attract much attention, since several kinds of shapes, such as spherical, prolate, oblate, and triaxial shapes, are predicted. In particular, for neutron-rich Mo isotopes, different models predict different magnitudes and rigidity of triaxial deformation. Previous interpretations of experimental results based solely on low-lying 2+2 states are insufficient to distinguish between the rigid triaxial shape, γ vibration, or γ -soft rotor.
Purpose: The shape evolution of 106Mo, 108Mo, and 110Mo is investigated through their 2+1-state lifetimes, decay-branching ratios of the 2+2 state, and energies of the low-lying collective excited states with Kπ = 0+, 2+, and 4+.
Method: β -delayed γ -ray spectroscopy was employed for neutron-rich Nb and Zr isotopes produced at the RIKEN RI Beam Factory to populate excited states in 106Mo , 108Mo , and 110Mo . The EUroball-RIKEN Cluster Array was used for high-resolution γ -ray detection and lifetimes of the 2+1 states were determined using the UK fast-timing array of LaBr3(Ce) detectors.
Results: New γ -ray transitions and levels are reported, including newly assigned 0+2 states in 108,110Mo . Quadrupole deformations were obtained for 106,108,110Mo from their 2+1 energies and lifetimes. The β -delayed neutron-emission probabilities of 108 Nb and 110 Nb were determined by examining the γ rays of their respective daughter decays.
Conclusions: The even-odd energy staggering in the 2+2 band was compared with typical patterns of the γ -vibrational band, rigid triaxial rotor, and γ -soft rotor. The very small even-odd staggering of 106 Mo, 108Mo, and 110Mo favors a γ -vibrational band assignment. The kinematic moment of inertia for the 2+2 band showed a trend similar to the ground-state band, which is as expected for the γ -vibrational band. Beyond-mean-field calculations employing the constrained Hartree-Fock-Bogoliubov and local quasiparticle-random-phase approximation method using the SLy 5 + T interaction reproduced the ground and 2+2 bands in 106Mo and 108Mo . The collective wave functions are consistent with the interpretation of the 2+2 band as the γ -vibrational band of the prolate shape. However, the staggering pattern observed in 110Mo differs from the one suggested in the calculations which predict a γ -soft rotor. There was no experimental indication of the oblate shape or the γ -soft rotor predicted in these Mo isotopes.
J.-M. Régis, J. Jolie, N. Saed-Samii, N. Warr, M. Pfeiffer, A. Blanc, M. Jentschel, U. Köster, P. Mutti, T. Soldner, G. S. Simpson, F. Drouet, A. Vancraeyenest, G. de France, E. Clément, O. Stezowski, C. A. Ur, W. Urban, Patrick Regan, Zsolt Podolyak, Cyrus Kouroush Larijani, C. Townsley, R. Carroll, E. Wilson, L. M. Fraile, H. Mach, V. Paziy, B. Olaizola, V. Vedia, A. M. Bruce, O. J. Roberts, J. F. Smith, M. Scheck, T. Kröll, A.-L. Hartig, A. Ignatov, S. Ilieva, S. Lalkovski, W. Korten, N. Mărginean, T. Otsuka, N. Shimizu, T. Togashi, Y. Tsunoda (2017)Abrupt shape transition at neutron number N=60 : B(E2) values in Sr94,96,98 from fast γ−γ timing, In: Physical Review C95(5)054319pp. 054319-1 American Physical Society
Lifetimes of low-lying yrast states in neutron-rich 94,96,98Sr have been measured by Germanium-gated γ−γ fast timing with LaBr3(Ce) detectors using the EXILL&FATIMA spectrometer at the Institut Laue-Langevin. Sr fission products were generated using cold-neutron-induced fission of 235U and stopped almost instantaneously within the thick target. The experimental B(E2) values are compared with results of Monte Carlo shell-model calculations made without truncation on the occupation numbers of the orbits spanned by eight proton and eight neutron orbits and show good agreement. Similarly to the Zr isotopes, the abrupt shape transition in the Sr isotopes near neutron number N=60 is identified as being caused by many-proton excitations to its g9/2 orbit.
V. H. Phong, G. Lorusso, T. Davinson, A. Estrade, O. Hall, J. Liu, K. Matsui, F. Montes, S. Nishimura, A. Boso, P. H. Regan, R. Shearman, Z. Y. Xu, J. Agramunt, J. M. Allmond, D. S. Ahn, A. Algora, H. Baba, N. T. Brewer, C. G. Bruno, R. Caballero-Folch, F. Calvino, M. Wolińska-Cichocka, G. Cortes, I. Dillmann, C. Domingo-Pardo, A. Gargano, S. Go, C. J. Griffin, R. K. Grzywacz, L. Harkness-Brennan, T. Isobe, A. Jungclaus, D. Kahl, L. H. Khiem, G. Kiss, A. Korgul, S. Kubono, K. Miernik, A. I. Morales, N. Nepal, M. Piersa, Zs. Podolyak, B. C. Rasco, K. P. Rykaczewski, H. Sakurai, Y. Shimizu, D. W. Stacener, T. Sumikama, H. Suzuki, H. Takeda, J. L. Tain, A. Tarifeño-Saldivia, A. Tolosa-Delgado, V. Vaquero, P. J. Woods, R. Yokoyama, C. Yuan (2019)Observation of a μs isomer in ¹³⁴₄₉In₈₅ : Proton-neutron coupling "southeast" of ¹³²₅₀Sn₈₂, In: Physical Review C100011302(R)pp. 011302-1 American Physical Society
We report on the observation of a microsecond isomeric state in the single-proton-hole, three-neutron-particle nucleus ¹³⁴In. The nuclei of interest were produced by in-flight fission of a ²³⁸U beam at the Radioactive Isotope Beam Factory at RIKEN. The isomer depopulates through a γ ray of energy 56.7(1) keV and with a half-life of T1/2=3.5(4)μs. Based on the comparison with shell-model calculations, we interpret the isomer as the Iπ=5− member of the π0g−19/2⊗ν1f37/2 multiplet, decaying to the Iπ=7− ground state with a reduced-transition probability of B(E2;5−→7−)=0.53(6)W.u.Observation of this isomer, and lack of evidence in the current work for a Iπ=5− isomer decay in ¹³²In, provides a benchmark of the proton-neutron interaction in the region of the nuclear chart “southeast” of ¹³²Sn, where experimental information on excited states is sparse.
N Schunck, J Dudek, A Gozdz, PH Regan (2004)Tetrahedral symmetry in ground and low-lying states of exotic A similar to 110 nuclei, In: PHYSICAL REVIEW C69(6)ARTN 06130 AMERICAN PHYSICAL SOC
M Goerska, A Banu, P Bednarczyk, A Bracco, A Buerger, F Camera, E Caurier, P Doornenbal, J Gerl, H Grawe, M Honma, H Huebel, A Jungclaus, A Maj, G Neyens, F Nowacki, T Otsuka, T Pfutzner, S Pietri, Z Podolyak, A Poves, PH Regan, P Reiter, D Rudolph, HJ Wollersheim (2007)Nuclear structure far off stability - Rising campaigns, In: ACTA PHYSICA POLONICA B38(4)pp. 1219-1228
F Becker, W Korten, PA Butler, F Hannachi, P Paris, N Buforn, C Chandler, A Jansen, M Houry, H Hubel, P Greenlees, PM Jones, R Julin, H Kankaanpaa, CE Liang, A Lopez-Martens, E Mergel, Y Le Coz, R Lucas, PH Regan, G Schonwasser, C Theisen (2000)Investigation of EO transition in Kr-74, In: PHYSICA SCRIPTAT88pp. 17-20
Natasa Lalovic, Dirk Rudolph, Zsolt Podolyak, Luis Sarmiento, Edward C Simpson, Tom Alexander, Martha Liliana Cortes Sua, Juergen Gerl, Pavel Golubev, Frederic Ameil, Tugba Arici, Christopher Bauer, Dino Bazzacco, Michael A Bentley, Plamen Boutachkov, Michael Bowry, Claes Fahlander, Andres Gadea, Jnaneswari Gellanki, Angel Givechev, Namita Goel, M Gorska, A. Gottardo, Eleonora Gregor, Giulia Guastalla, Tobias Habermann, Mathias Hackstein, A. Jungclaus, Ivan Kojouharov, Rakesh Kumar, Nikolaus Kurz, Marc Lettmann, Cesar Lizarazo, Corinne Louchart-Henning, Edana Merchan, Caterina Michelagnoli, T Moeller, Kevin Moschner, Zena Patel, Norbert Pietralla, Stephane Pietri, Damian Ralet, Michael Reese, Patrick Regan, Peter Reiter, Henning Schaffner, Pushpendra P Singh, Christian Stahl, Robert Stegmann, Olivier Stézowski, Jan Taprogge, P Thoele, Andreas Wendt, Oliver Wieland, Emma Wilson, Rachael Wood, Hans-Juergen Wollersheim, Benedikt Birkenbach, Bart Bruyneel, Ian Burrows, Emmanuel Clement, Pierre Desesquelles, Cesar Domingo-Pardo, Juergen Eberth, Vicente Gonzales Millan, Herbert Hess, Jan Jolie, Daniel Judson, Roberto Menegazzo, Daniele Mengoni, Daniel Napoli, Alberto Pullia, Begona Quintana Arnes, G I Rainovski, Marie-Delphine Salsac, Esteban Sanchis, John Simpson, Jose Javier Valiente Dobón (2018)Study of Isomeric States in 198,200,202,206Pb and 206Hg Populated in Fragmentation Reactions, In: Journal of Physics G: Nuclear and Particle Physics45035105 IOP Publishing
Isomeric states in isotopes in the vicinity of doubly-magic 208Pb were populated following reactions of a relativistic 208Pb primary beam impinging on a 9Be fragmentation target. Secondary beams of 198;200;202;206Pb and 206Hg were isotopically separated and implanted in a passive stopper positioned in the focal plane of the GSI Fragment Separator. Delayed γ rays were detected with the Advanced GAmma Tracking Array (AGATA). Decay schemes were re-evaluated and interpreted with shell-model calculations. The momentum-dependent population of isomeric states in the two-nucleon hole nuclei 206Pb/206Hg was found to differ from the population of multi neutron-hole isomeric states in 198;200;202Pb.
M FREER, NM CLARKE, N CURTIS, BR FULTON, SJ HALL, MJ LEDDY, JS POPLE, G TUNGATE, RP WARD, PM SIMMONS, WDM RAE, SPG CHAPPELL, SP FOX, CD JONES, DL WATSON, GJ GYAPONG, SM SINGER, WN CATFORD, PH REGAN (1995)BE-8 AND ALPHA-DECAY OF O-16, In: PHYSICAL REVIEW C51(4)pp. 1682-1692 AMERICAN PHYSICAL SOC
N Yoshinaga, K Higashiyama, PH Regan (2009)Shell model study of neutron rich Se and Ge isotopes, In: AIP Conference Proceedings: 6th Japan‐Italy Symposium on Heavy‐Ion Physics1120pp. 255-259
Nuclear structure of the neutron‐rich Se, and Ge isotopes is theoretically studied in terms of the spherical full shell model with the monopole and quadrupole pairing plus quadrupole‐quadrupole interaction. The experimental energy levels of low‐lying states as well as high‐spin states are well reproduced. The shell model results are examined in details in a pair‐truncated shell model. The analysis shows the alignment of two g9/2 neutrons at high spins.
R Britton, JL Burnett, AV Davies, PH Regan (2015)Coincidence corrections for a multi-detector gamma spectrometer, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT769pp. 20-25 ELSEVIER SCIENCE BV
SM Collins, AK Pearce, KM Ferreira, AJ Fenwick, PH Regan, JD Keightley (2015)Direct measurement of the half-life of Ra-223, In: APPLIED RADIATION AND ISOTOPES99pp. 46-53 PERGAMON-ELSEVIER SCIENCE LTD
T Alharbi, PJ Mason, PH Regan, Z Podolyák, N Mărginean, M Nakhostin, M Bowry, D Bucurescu, G Căta-Danil, I Căta-Danil, D Deleanu, D Filipescu, T Glodariu, D Ghiţă, R Mărginean, C Mihai, A Negret, S Pascu, T Sava, L Stroe, G Suliman, NV Zamfir, AM Bruce, C Rodriguez Triguero, PC Bender, U Garg, MN Erduran, A Kusoglu, M Bostan, P Detistov, N Alkhomashi, AK Sinha, R Chakrabarti, SS Ghugre (2012)Gamma-ray fast-timing coincidence measurements from the (18)O+(18)O fusion-evaporation reaction using a mixed LaBr(3)-HPGe array, In: Appl Radiat Isot70(7)pp. 1337-1339 Elsevier
We report on a gamma-ray coincidence analysis using a mixed array of hyperpure germanium and cerium-doped lanthanum tri-bromide (LaBr(3):Ce) scintillation detectors to study nuclear electromagnetic transition rates in the pico-to-nanosecond time regime in (33,34)P and (33)S following fusion-evaporation reactions between an (18)O beam and an isotopically enriched (18)O implanted tantalum target. Energies from decay gamma-rays associated with the reaction residues were measured in event-by-event coincidence mode, with the measured time difference information between the pairs of gamma-rays in each event also recorded using the ultra-fast coincidence timing technique. The experiment used the good full-energy peak resolution of the LaBr(3):Ce detectors coupled with their excellent timing responses in order to determine the excited state lifetime associated with the lowest lying, cross-shell, I(π)=4(-) "intruder" state previously reported in the N=19 isotone (34)P. The extracted lifetime is consistent with a mainly single-particle M2 multipolarity associated with a f(7/2)→d(5/2) single particle transition.
The use of neutron sensors is a key requirement across many technology areas, including medical particle accelerators, nuclear power technologies, personnel dosimetry, national defence, and a wide range of scientific experiments. With a zero electric charge, neutrons present particular challenges for their effective detection. In the present study I report the first demonstration of a solid-state, direct conversion sensor for thermal neutrons based on a polymer/inorganic nanocomposite. Sensors were fabricated from ultra-thick films of poly(triarylamine) (PTAA) semiconducting polymer, with thicknesses up to 100 micrometres. Boron nanoparticles were dispersed throughout the PTAA film to provide the neutron stopping power arising from the high thermal neutron cross-section of the isotope Boron-10. To maximise the quantum efficiency of the sensor to thermal neutrons, a high volume fraction of homogeneously dispersed boron nanoparticles was achieved in the thick PTAA film using an optimised processing method. Thick active layers were realised using a high molecular weight of the PTAA (Mw=350 kg/mol), so that molecular entanglements provide a high cohesive strength. A non-ionic surfactant was used to stabilise the boron dispersion in solvent and hence suppress the formation of agglomerates and associated electrical pathways. Boron nanoparticle loadings of up to 17 vol.% were achieved, with thermal neutron quantum efficiency estimates up to 6 % resulting. The sensors’ neutron responses were characterised under a high flux thermal neutron exposure, showing a linear correlation between the response current and the thermal neutron flux. The sensitivity reached up to 194 pC at maximum thermal neutron flux. Polymer-based boron nanocomposite sensors offer a new neutron detection technology that uses low-cost, scalable solution processing, and provides an alternative to traditional neutron sensors that use rare isotopes, such as Helium-3.
P. Humby (2017)Investigation of discrete states and quasi-discrete features in 150,152Sm via the (p,t) reaction.
The (p,t) reaction was used to identify new levels and gamma-ray transitions in 150,152Sm utilising the particle-gamma and particle-gamma-gamma coincidence techniques. The experiment was performed using the STARLiTeR array located at the Cyclotron Institute of Texas A&M University. The relative partial cross sections for the observed levels, angle averaged between 34 and 58 degrees, were measured. A narrow peak-like structure was observed between 2.3-3.0 MeV excitation energy, in between the region of strongly populated discrete states at low energy and the high energy continuum region. In 150Sm, 39(4)% of the strength of the peak-like structure could be accounted for by the observed discrete states, which compares to a value of 93(15)% for 152Sm. The orbital angular-momentum transfer was probed by comparison of the experimental angular distributions to those calculated using the DWBA theory. The experimental angular distributions for the population of the peak-like structures are very similar in the two reactions, and significantly different to both the angular distribution of the background under the structures, and to the distribution obtained from the nearby continuum region at higher excitation energy. Post irradiation, the half-lives of isomeric states in 152Eu, populated in the 154Sm(p,3n) reaction, were obtained by measuring the decrease in intensity of the gamma rays emitted in the decay of these long lived levels. The half-life of the J^pi = 8^- isomer 152m2Eu was measured to be 95.8(4) min, which is a factor of 2.5 reduction in uncertainty compared to the previous literature value of 96(1) min.
The NPL graphite proton calorimeter is used to measure the dose deposited from irradiation by proton beams. This thesis describes the first measurements carried out with the calorimeter in proton pencil beams as well as well as an analysis of the calorimeter data in scanned proton beams. In doing this analysis, a greater understanding of the response and heat flows within the calorimeter was achieved. These measurement results are compared to simulations carried out using COMSOL Multiphysics®, a finite-element simulation software package. A model of the calorimeter was built in TOPAS, a Monte Carlo platform which wraps and extends the GEANT-4 simulation toolkit. This model was used to calculate two correction factors: the gap correction factor, which increased with energy from 1.00064(08) at 60 MeV to 1.00359(15) at 230 MeV; and the volume averaging correction factor which was 0.99936(44) at 60 MeV and 1.00515(154) at 230 MeV. TOPAS was also used to build a model of the Clatterbridge beamline, producing Bragg peak and modulated depth-dose curves for the 62 MeV proton beam. This can be used for future, more detailed investigations and coupled TOPAS/COMSOL simulations.
Abubakar D. Bajoga (2016)Evaluation of natural and anthropogenic radioactivity in environmental samples from Kuwait using high-resolution gamma-ray spectrometry.
A study of natural radioactivity from ninety different soil samples across the state of Kuwait was carried out with a view to ascertain the level of natural and/or man-made radioactivity from that area. There has been some concern on the levels of NORM following the First Gulf War in which approximately 300 tons of depleted uranium shells were used and in particular, whether it has a significant impact in the surrounding environment. This study uses gamma-spectroscopy in a low background measuring system employing a high resolution Hyper-Pure Germanium detector. The calculated specific activity concentrations are determined for the radionuclides 226Ra, 214Pb, 214Bi and 228Ac, 212Pb, 208Tl following the decays of the primordial radionuclides 238U and 232Th, respectively. The analysis also includes evaluations for the 235U decay chain. In particular, the 186 keV doublet transition is used together with the activity concentration values established from the decays of 214Bi and 214Pb to establish the 226Ra and 235U specific activity concentrations, which can be used to estimate the 235U:238U isotopic ratios and compare to the accepted value for naturally occurring material of 1:138. Specific activity concentration values have also been determined for the 40K and the anthropogenic radionuclide 137Cs (from fallout) were detected within the same samples. Results of the activity concentration gives mean value of 16.99±0.21, 12.79±0.14, 333±37 and 2.18±0.11 Bq/kg for 238U, 232Th, 40K, and 137Cs, respectively. The associated radiological hazard indices from these samples were found to have mean values of 29.13±0.35 nG/hr, 60.20±0.68 Bq/kg, and 35.30±0.40 µSv/year for the dose rates, radium equivalent, and annual dose equivalent, respectively. Analysed results of elemental concentrations of Uranium, Thorium and Potassium were also determined, and were found to range from 0.96±0.02 ppm to 2.53±0.02 ppm, 2.26±0.04 ppm to 5.23±0.05 ppm and a mean value of 1.21±0.03 % for 40K for the northern region, respectively. Overall result indicates values within the world average range. The results obtained for the 235U:238U isotopic ratio gives a mean value of 0.0462, which is consistent with the presence of natural material from the measured location.
Ashraf A. Almahwasi (2016)Analysis of giant-nucleated cell formation following x-ray and proton irradiations.
Radiation-induced genetic instability has been observed in survivors of irradiated cancerous and normal cells in vitro and in vivo and has been determined in different forms, such as delayed cell death, chromosomal aberration or mutation. A well defined and characterized normal human-diploid AG1522 fibroblast cell line was used to study giant-nucleated cell (GCs) formation as the ultimate endpoint of this research. The average nuclear cross-sectional areas of the AG1522 cells were measured in um^2. The doubling time required by the AG1522 cells to divide was measured. The potential toxicity of the Hoechst dye at a working concentration on the live AG1522 cells was assessed. The yield of giant cells was determined at 7, 14 and 21 days after exposure to equivalent clinical doses of 0.2, 1 or 2 Gy of X-ray or proton irradiation. Significant differences were found to exist between X-ray or proton irradiation when compared with sham-irradiated control populations. The frequency of GCs induced by X-rays was also compared to those formed in proton irradiated cultures. The results confirm that 1 Gy X-rays are shown to induce higher rates of mitotically arrested GCs, increasing continually over time up to 21 days post-irradiation. The yield of GCs was significantly greater (10%) compared to those formed in proton populations (2%) 21 days postirradiation. The GCs can undergo a prolonged mitotic arrest that significantly increases the length of cell cycle. The arrest of GCs at the mitotic phase for longer periods of time might be indicative of a strategy for cell survival, as it increases the time available for DNA repair and enables an alternative route to division for the cells. However, the reduction in their formation 21 days after both types of radiation might favour GCs formation, ultimately contributing to carcinogenesis or cancer therapy resistance. The X-ray experiments revealed a dose-dependent increase in the GCs up to 14 days after irradiation. Although the proton irradiation was less efficient in producing GCs, their frequency was elevated in a dose-dependent manner 7 days after irradiation, with persistent expression of nuclear deformity as an indicator of genetic instability. In addition to the quantification of the GCs, the proliferation of a small fraction of giant cells formed at 14 days after 0.2 Gy of proton irradiation was observed to divide into asymmetrical, normal-sized daughter cells. These results might have important implications in evaluating risk estimates, or could act as a potential radioprotective assay for a dose-limiting parameter for delayed effects in healthy tissues during radiation therapy treatment.
Star clusters are collisional and dark matter (DM) free stellar systems, where their evolution is ruled by two-body interactions and the galactic potential. Using direct summation N-body simulations, I study how the observational properties of star clusters can be used to: (i) distinguish between DM free and DM dominated objects. From observations, the nature of several faint stellar systems in the Milky Way halo is not clear, therefore, I quantify the contribution of star clusters to the faint stellar systems population. (ii) Probe the underlying DM density of their host galaxy. I apply a new method to the recently discovered Eridanus~II ultra-faint dwarf galaxy that hosts a star cluster in its centre. I find that a cored DM density profile naturally reproduces the observed properties of Eridanus II’s star cluster. (iii) Infer their progenitor properties if they are accreted star clusters, such as Crater. From its properties I find that Crater is likely to be tidally stripped from a dwarf galaxy, and it must have formed extended and with a low concentration. Throughout this thesis, the comparison of simulations and data took into consideration observational biases and uncertainties. I show that the initial conditions of star clusters can heavily influence its present-day properties, and that the stellar evolution prescriptions can also impact the final star cluster properties, such as the neutron stars natal kick distribution. I conclude, through a series of test cases, that N-body simulations can be used to reproduce the observed properties of star clusters, and these can ultimately probe their host galaxy DM distribution.
A series of measurements of stable nickel isotopes were performed at the Australian National University in Canberra. Excited states in 58,60,62Ni were populated via inelastic scattering of proton beams delivered by the 14UD Pelletron accelerator. Multiple setups were used in order to determine the structure of low-lying states. The CAESAR array of Compton-suppressed HPGe detectors was used to measure the (E2/M1) mixing ratio of transitions from angular distributions of gamma rays. The Super-e spectrometer was used to measure conversion coefficients for a number of J to J transitions. The data obtained from both devices was combined with previously measured parent lifetimes and branching ratios to determine E0 transition strengths between J-pi transitions. The E0 transition strength for the second 0+ to first 0+ transitions in 60,62Ni have been measured for the first time through internal conversion electron detection. The experimental value of 132(+59,-70) for 62Ni agrees within 2 sigma of the previous result obtained from internal pair formation. However it is likely that the previous experimental results used an outdated theoretical model for internal pair formation emission. This work also represents the first measurements of E0 transition strengths between 2+ states in Ni isotopes. There is generally large E0 strength between the 2+ states, particularly in the second 2+ to first 2+ transition, however there is also a large uncertainty in the measurements owing to the difficulties involved in measuring conversion coefficients. In 62Ni, the E0 transition strength of 172(+62,-77) for the second 2+ to first 2+ transition gives further weight to the argument against the spherical vibrator model, as an E0 transition is forbidden if there is a change of only one phonon. The large measurement also indicates the presence of shape coexistence, complementing the recent experimental work carried out in the neutron-rich Ni isotopes.
C. Larijani (2017)Production and evaluation of 236gNp and reference materials for naturally occurring radioactive materials.
This thesis is based on the development of a radiochemical separation scheme capable of separating both 236gNp and 236Pu from a uranium target of natural isotopic composition (~1 g uranium) and ~200 MBq of fission decay products. The isobaric distribution of fission residues produced following the bombardment of a natural uranium target with a beam of 25 MeV protons has been evaluated. Decay analysis of thirteen isobarically distinct fission residues were carried out using high-resolution γ-ray spectrometry at the UK National Physical Laboratory. Stoichiometric abundances were calculated via the determination of absolute activity concentrations associated with the longest-lived members of each isobaric chain. This technique was validated by computational modelling of likely sequential decay processes through an isobaric decay chain. The results were largely in agreement with previously published values for neutron bombardments on natural uranium at energies of 14 MeV. Higher relative yields of products with mass numbers A~110–130 were found, consistent with the increasing yield of these radionuclides as the bombarding energy is increased. Using literature values for the production cross-section for fusion of protons with uranium targets, it is estimated that an upper limit of approximately 250 Bq of activity from the 236Np ground state was produced in this experiment. Using a radiochemical separation scheme, Np and Pu fractions were separated from the produced fission decay products, with analyses of the target-based final reaction products made using Inductively Couple Plasma Mass Spectrometry (ICP-MS) and high-resolution α and γ-ray spectrometry. In a separate research theme, reliable measurement of Naturally Occurring Radioactive Materials is of significance in order to comply with environmental regulations and for radiological protection purposes. The thesis describes the standardisation of three reference materials, namely Sand, Tuff and TiO2 which can serve as quality control materials to achieve traceability, method validation and instrument calibration. The sample preparation, material characterization via γ, α and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the assignment of values for both the 4n Thorium and 4n + 2 Uranium decay series are presented.