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
Söderström P, Walker PM, Wu J, Liu H, Regan PH, Watanabe H, Doornenbal P, Korkulu Z, Lee P, Liu J, Lorusso G, Nishimura S, Phong V, Sumikama T, Xu F, Lalkovski S, Lotay GJ, Patel Z, Podolyak Z, Shand CM (2016) K-mixing in the doubly mid-shell nuclide 170Dy and the role of vibrational degeneracy,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 ² decay. We have measured the yrast band up to the spin-parity JÀ=6+ state, the K=2³ -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 KÀ=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) ¼s, 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 ³ -vibrational mixing from a near degeneracy of the isomer and the 6+ state of the ³ 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?.
Browne F, Bruce A, Sumikama T, Nishizuka I, Nishimura S, Doornenbal P, Lorusso G, Soderstrom P, Watanabe H, Daido R, Patel Z, Rice S, Sinclair L, Wu J, Xu Z, Yagi A, Baba H, Chiga N, Carroll R, Didierjean F, Fang Y, Fukuda N, Gey G, Ideguchi E, Inabe N, Isobe T, Kameda D, Kojouharov I, Kurz N, Kubo T, Lalkovski S, Li Z, Lozeva R, Nishibata N, Odahara A, Podolyak Z, Regan PH, Roberts O, Sakurai H, Schaffner H, Simpson G, Suzuki H, Takeda H, Tanaka M, Taprogge J, Werner V, Wieland O (2017) K-selection in the decay of the (½
5
2
[532]
3
2
[411])4-
isomeric state in 102Zr,Physical Review C96(2)024309 American Physical Society
The (½
5
2
[532]
3
2
[411]) 4? state in 102Zr, populated in the ²-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+
³ 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 ³ degree of freedom compared to 100Sr.
Rudigier M, Lalkovski S, Gamba E, Bruce A, Podolyak Z, Regan PH, Carpenter M, Zhu S, Ayangeakaa A (2017) Fast Timing Measurement Using an LaBr3(Ce) Scintillator Detector Array Coupled with Gammasphere,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
Gurgi LA, Regan PH, Söderström P, Watanabe H, Walker PM, Podolyak Z, Nishimura S, Berry TA, Doornenbal P, Lorusso G, Isobe T, Baba H, Xu Z, Sakurai H, Sumikama T, Catford WN, Bruce A, Browne F, Lane G, Kondev F, Odahara A, Wu J, Liu H, Xu F, Korkulu Z, Lee P, Liu J, Phong V, Yagi A, Zhang G, Alharbi T, Carroll R, Chae K, Dombradi Z, Estrade A, Fukuda N, Griffin C, Ideguchi E, Inabe N, Kanaoka H, Kojouharov I, Kubo T, Kubono S, Kurz N, Kuti I, Lalkovski S, Lee E, Lee C, Lotay GJ, Moon C, Nishizuka I, Nita C, Patel Z, Roberts O, Schaffner H, Shand CM, Suzuki H, Takeda H, Terashima S, Vajta Z, Kanaya S, Valiente-Dobón J (2017) Isomer Spectroscopy of Neutron-rich 165,167Tb,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.
Schlegel C, Regan PH, Pfutzner M, Gerl J, Hellstrom M, Podolyak Z, Caamano M, Mayet P, Aprahamian A, Benlliure J, Bruce AM, Butler PA, Gil DC, Cullen DM, Doring J, Enquist T, Farget E, Fox C, Narro JG, Gelletly W, Giovinazzo J, Gorska M, Grawe H, Grzywacz R, Kleinbohl A, Korten W, Lewitowicz M, Lucas R, Mach H, Mineva M, O'Leary C, De Oliveira F, Pearson CJ, Rejmund M, Sawicka M, Schaffner H, Schmidt K, Theisen C, Walker PM, Warner DD, Wheldon C, Wollersheim HJ, Wooding S, Xu F (2000) K-isomers in very neutron-rich nuclei around mass 180, PHYSICA SCRIPTAT88pp. 72-76 ROYAL SWEDISH ACAD SCIENCES
Vincent SM, Regan PH, Owen KE, Pearson CJ, Clough AS (2002) In-beam performance of CdZnTe detectors for proton and alpha-particle measurement, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT483(3)PII S0168-9002(01)01952-0pp. 758-763 ELSEVIER SCIENCE BV
Vincent SM, Regan PH, Blumenthal D, Carpenter M, Davids CN, Gelletly W, Janssens RVF, Lister CJ, Seweryniak D, Schwartz J, Simpson J, Warner DD (1999) Discrete line spectroscopy of Ga-62(31) with AYEBALL, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 679-683 IOP PUBLISHING LTD
Daniel T, Kisyov S, Regan PH, Marginean N, Podolyak Z, Marginean R, Nomura K, Rudigier M, Mihai R, Werner V, Carroll R, Gurgi LA, Oprea A, Berry TA, Serban A, Nita C, Sotty C, Suvaila R, Turturica A, Costache C, Stan L, Olacel A, Boromiza M, Toma S (2017) ³ -ray spectroscopy of low-lying excited states and shape competition in Os 194,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 ³ -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 ²eff = 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.
Wilson J, Lebois M, Qi L, Amador-Celdran P, Bleuel D, Briz J, Carroll R, Catford W, De Witte H, Doherty D, Eloirdi R, Georgiev G, Gottardo A, Goasduff A, HadyDska-Kl?k K, Hauschild K, Hess H, Ingeberg V, Konstantinopoulos T, Ljungvall J, Lopez-Martens A, Lorusso G, Lozeva R, Lutter R, Marini P, Matea I, Materna T, Mathieu L, Oberstedt A, Oberstedt S, Panebianco S, Podolyak Z, Porta A, Regan P, Reiter P, Rezynkina K, Rose S, Sahin E, Seidlitz M, Serot O, Shearman R, Siebeck B, Siem S, Smith A, Tveten G, Verney D, Warr N, Zeiser F, Zielinska M (2017) Anomalies in the Charge Yields of Fission Fragments from the U(n,f)238 Reaction,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 ³-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via ³?³ 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.
Bajoga A, Alazemi N, Shams H, Regan PH, Bradley DA (2016) Evaluation of naturally occurring radioactivity across the State of
Kuwait using high-resolution gamma-ray spectrometry,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.
Gadea A, Napoli DR, de Angelis G, Menegazzo R, Stefanini AM, Corradi L, Axiotis M, Berti L, Fioretto E, Kroell T, Latina A, Marginean N, Maron G, Martinez T, Rosso D, Rusu C, Toniolo N, Szilner S, Trotta M, Bazzacco D, Beghini S, Bellato M, Brandolini F, Farnea E, Isocrate R, Lenzi SM, Lunardi S, Montagnoli G, Pavan P, Alvarez CR, Scarlassara F, Ur C, Blasi N, Bracco A, Camera F, Leoni S, Million B, Pignanelli M, Pollarolo G, DeRosa A, Inglima C, La Commara M, La Rana G, Pierroutsakou D, Romoli M, Sandoli M, Bizzeti PG, Bizzeti-Sona AM, Lo Bianco G, Petrache CM, Zucchiatti A, Cocconi P, Quintana B, Beck C, Curien D, Duchene G, Haas F, Medina P, Papka P, Durell J, Freeman SJ, Smith A, Varley B, Fayz K, Pucknell V, Simpson J, Gelletly W, Regan P (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, EUROPEAN PHYSICAL JOURNAL A20(1)pp. 193-197 SPRINGER-VERLAG
Saitoh TR, Saitoh-Hashimoto N, Sletten G, Bark RA, Bergstrom M, Regan P, Tormanen S, Varmette PG, Walker PM, Wheldon C (2000) Collective and intrinsic structures in W-183 (vol 660, pg 171, 1999), NUCLEAR PHYSICS A669(3-4)pp. 381-406 ELSEVIER SCIENCE BV
Al-Dahan N, Regan PH, Podolyák Z, Walker PM, Alkhomashi N, Dracoulis GD, Farrelly G, Benlliure J, Pietri SB, Casten RF, Stevenson PD, Gelletly W, Steer SJ, Garnsworthy AB, Casarejos E, Gerl J, Wollersheim HJ, Grebosz J, Górska M, Kojouharov I, Schaffner H, Algora A, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Cullen IJ, Denis Bacelar AM, Deo AY, Estevez ME, Fujita Y, Hoischen R, Kumar R, Lalkovski S, Liu Z, Mason PJ, Mihai C, Molina F, Mücher D, Rubio B, Tamii A, Tashenov S, Valiente-Dobón JJ, Woods PJ (2012) Multiple ² - Decaying states in 194Re: Shape evolution in neutron-rich osmium isotopes,Physical Review C - Nuclear Physics85(3)034301 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. ³ decays were observed and correlated with these secondary ions on an event-by-event basis such that ³-ray transitions following from both internal (isomeric) and ² decays were recorded. A number of discrete, ²-delayed ³-ray transitions associated with ² decays from 194Re to excited states in 194Os have been observed, including previously reported decays from the yrast IÀ=(6+) state. Three previously unreported ³-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 ²?-decaying states in 194Re.
Regan P, Stevenson P (2005) Preface - NUSTAR 2005, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10) IOP PUBLISHING LTD
Regan PM, Chandler C, Pearson CJ, Blank B, Grzywacz R, Lewitowicz M, Bruce AM, Catford WN, Curtis N, Czajkowski S, Dessagne P, Fleury A, Gelletly W, Giovinazzo J, Janas Z, Longour C, Marchand C, Miehe C, Orr NA, Page RD, Pravikoff MS, Reed AT, Saint-Laurent MG, Vincent SM, Wadsworth R, Warner DD, Winfield JS (1997) Studies of isomeric states and limits of particle stability around N 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
Grieser M, Litvinov YA, Raabe R, Blaum K, Blumenfeld Y, Butler PA, Wenander F, Woods PJ, Aliotta M, Andreyev A, Artemyev A, Atanasov D, Aumann T, Balabanski D, Barzakh A, Batist L, Bernardes A-P, Bernhardt D, Billowes J, Bishop S, Borge M, Borzov I, Bosch F, Boston AJ, Brandau C, Catford W, Catherall R, Cederkall J, Cullen D, Davinson T, Dillmann I, Dimopoulou C, Dracoulis G, Duellmann CE, Egelhof P, Estrade A, Fischer D, Flanagan K, Fraile L, Fraser MA, Freeman SJ, Geissel H, Gerl J, Greenlees P, Grisenti RE, Habs D, von Hahn R, Hagmann S, Hausmann M, He JJ, Heil M, Huyse M, Jenkins D, Jokinen A, Jonson B, Joss DT, Kadi Y, Kalantar-Nayestanaki N, Kay BP, Kiselev O, Kluge H-J, Kowalska M, Kozhuharov C, Kreim S, Kroell T, Kurcewicz J, Labiche M, Lemmon RC, Lestinsky M, Lotay G, Ma XW, Marta M, Meng J, Muecher D, Mukha I, Mueller A, Murphy ASJ, Neyens G, Nilsson T, Nociforo C, Noertershaeuser W, Page RD, Pasini M, Petridis N, Pietralla N, Pfuetzner M, Podolyak Z, Regan P, Reed MW, Reifarth R, Reiter P, Repnow R, Riisager K, Rubio B, Sanjari MS, Savin DW, Scheidenberger C, Schippers S, Schneider D, Schuch R, Schwalm D, Schweikhard L, Shubina D, Siesling E, Simon H, Simpson J, Smith J, Sonnabend K, Steck M, Stora T, Stoehlker T, Sun B, Surzhykov A, Suzaki F, Tarasov O, Trotsenko S, Tu XL, Van Duppen P, Volpe C, Voulot D, Walker PM, Wildner E, Winckler N, Winters DFA, Wolf A, Xu HS, Yakushev A, Yamaguchi T, Yuan YJ, Zhang YH, Zuber K (2012) Storage ring at HIE-ISOLDE Technical design report, EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS207(1)pp. 1-117
Mason PJR, Alharbi T, Regan PH, Mrginean N, Podolyàk Z, Alkhomashi N, Bender PC, Bowry M, Bostan M, Bucurescu D, Bruce AM, Cta-Danil G, Cta-Danil I, Chakrabarti R, Deleanu D, Detistov P, Erduran MN, Filipescu D, Garg U, Glodariu T, Ghic D, Ghugre SS, Kusoglu A, Mrginean R, Mihai C, Nakhostin M, Negret A, Pascu S, Triguero CR, Sava T, Simpson EC, Sinha AK, Stroe L, Suliman G, Zamfir NV (2012) Half-life of the I À 4 - intruder state in 34P using LaBr 3 :Ce fast timing, Journal of Physics: Conference Series381(1)
The half-life of the I À 4 - intruder state at 2305 keV in 3415P19 has been measured using ³-ray coincident fast timing with LaBr 3:Ce scintillation detectors. Excited states in 34P were populated in the 18O( 18O,pn) 34P reaction at a beam energy of 36 MeV at the Tandem Laboratory at the National Institute of Physics and Nuclear Engineering, Bucharest, Romania. A half-life of t 1/2 < 2 ns was obtained for the 4 - state, giving an M2 reduced transition probability consistent with similar transitions in this mass region and confirming the intruder-parity nature of the state. © Published under licence by IOP Publishing Ltd.
Regan PH, Beausang CW, Zamfir NV, Casten RF, Zhang JY, Yamamoto AD, Caprio MA, Gurdal G, Hecht AA, Hutter C, Krucken R, Langdown SD, Meyer DA, Ressler JJ (2003) Signature for vibrational to rotational evolution along the yrast line, PHYSICAL REVIEW LETTERS90(15)ARTN 152502 AMERICAN PHYSICAL SOC
Roberts OJ, Nita CR, Bruce AM, Marginean N, Bucurescu D, Deleanu D, Filipescu D, Florea NM, Gheorghe I, Ghita D, Glodariu T, Lica R, Marginean R, Mihai C, Negret A, Sava T, Stroe L, Suvaila R, Toma S, Alharbi T, Alexander T, Aydin S, Brown BA, Browne F, Carroll RJ, Mulholland K, Podolyak Z, Regan PH, Smith JF, Smolen M, Townsley CM (2016) E3 and M2 transition strengths in Bi-209(83),PHYSICAL REVIEW C93(1)ARTN 01430 AMER PHYSICAL SOC
Blazhev A, Braun N, Grawe H, Boutachkov P, Nara Singh S, Brock T, Liu Z, Wadsworth R, Górska M, Jolie J, Nowacki F, Pietri S, Domingo-Pardo C, Kojouharov I, Caceres L, Engert T, Farinon F, Gerl J, Goel N, Gr)bosz J, Hoischen R, Kurz N, Nociforo C, Prochazka A, Schaffner H, Steer S, Weick H, Wollersheim HJ, Ataç A, Bettermann L, Eppinger K, Faestermann T, Finke F, Geibel K, Hinke C, Gottardo A, Ilie G, Iwasaki H, Krücken R, Merchan E, Nyberg J, Pfützner M, Podolyák Z, Regan P, Reiter P, Rinta-Antila S, Rudolph D, Scholl C, Söderström PA, Warr N, Woods P (2010) High-energy excited states in 98Cd, Journal of Physics: Conference Series205
In 98Cd a new high-energy isomeric ³-ray transition was identified, which confirms previous spin-parity assignments and enables for the first time the measurement of the E2 and E4 strength for the two decay branches of the isomer. Preliminary results on the 98Cd high-excitation level scheme are presented. A comparison to shell-model calculations as well as implications for the nuclear structure around 100Sn are discussed. © 2010 IOP Publishing Ltd.
Regan PH, Chandler C, Pearson CJ, Blank B, Grzywacz R, Lewitowicz M, Bruce AM, Catford WN, Curtis N, Czajkowski S, Dessagne P, Fleury A, Gelletly W, Giovinazzo J, Janas Z, Longour C, Marchand C, Miehe C, Orr NA, Page RD, Pravikoff MS, Reed AT, SaintLaurent MG, Vincent SM, Wadsworth R, Warner DD, Winfield JS (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, ACTA PHYSICA POLONICA B28(1-2)pp. 431-442 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Shams H, Bajoga AD, Alazemi N, Bradley DA, Regan PH (2016) A preliminary evaluation of naturally occurring radioactivity concentration levels across the State of Kuwait,APPLIED RADIATION AND ISOTOPES109pp. 479-481 PERGAMON-ELSEVIER SCIENCE LTD
Podolyak Z, Farrelly GF, Regan PH, Garnsworthy AB, Steer SJ, Gorska M, Benlliure J, Casarejos E, Pietri S, Gerl J, Wollersheim HJ, Kumar R, Molina F, Algora A, Alkhomashi N, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Caceres L, Cullen IJ, Bacelar AMD, Doornenbal P, Estevez ME, Fujita Y, Gelletly W, Geissel H, Grawe H, Grebosz J, Hoischen R, Kojouharov I, Lalkovski S, Liu Z, Maier KH, Mihai C, Muecher D, Rubio B, Schaffner H, Tamii A, Tashenov S, Valiente-Dobon JJ, Walker PM, Woods PJ (2009) Proton-hole excitation in the closed shell nucleus Au-205,PHYSICS LETTERS B672(2)pp. 116-119 ELSEVIER SCIENCE BV
Regan PH, Arrison JW, Huttmeier UJ, Balamuth DP (1996) Yrast gamma-ray spectroscopy of the neutron rich isotopes Co-61,Co-63, PHYSICAL REVIEW C54(3)pp. 1084-1097 AMERICAN PHYSICAL SOC
Al-Sulaiti H, Nasir T, Al Mugren KS, Alkhomashi N, Al-Dahan N, Al-Dosari M, Bradley DA, Bukhari S, Matthews M, Regan PH, Santawamaitre T, Malain D, Habib A (2012) Determination of the natural radioactivity levels in north west of Dukhan, Qatar using high-resolution gamma-ray spectrometry., 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.
Podolyák Z, Shand CM, Wilson E, Brown BA, Grawe H, Chiara CJ, Zhu S, Fornal B, Janssens RVF, Bowry M, Bunce M, Carpenter MP, Cieplicka N, Deo AY, Dracoulis GD, Hoffman CR, Kempley RS, Kondev FG, Lane GJ, Lauritsen T, Lotay G, Reed MW, Regan PH, Triguero CR, Seweryniak D, Szpak B, Walker PM (2015) Octupole transitions in the 208Pb region, Journal of Physics: Conference Series580(1)
© Published under licence by IOP Publishing Ltd.The 208Pb region is characterised by the existence of collective octupole states. Here we populated such states in 208Pb + 208Pb deep-inelastic reactions. ³-ray angular distribution measurements were used to infer the octupole character of several E3 transitions. The octupole character of the 2318 keV 17- 14+ in 208Pb, 2485 keV 19/2- 13/2+ in 207Pb, 2419 keV 15/2- 9/2+ in 209Pb and 2465 keV 17/2+ 11/2- in 207Tl transitions was demonstrated for the first time. In addition, shell model calculations were performed using two different sets of two-body matrix elements. Their predictions were compared with emphasis on collective octupole states.
Habib AS, Regan PH, Bradley DA, Matthews MC, Shutt AL, Alsulaiti H (2013) Characterization of naturally occurring radioactive materials in Libyan oil pipe scale using a germanium detector and Monte Carlo simulation, Radiation Physics and Chemistry
Radioactive scale formation in various oil production facilities is acknowledged to pose a potential significant health and environmental issue. The presence of such an issue in Libyan oil fields was recognized as early as 1998. The naturally occurring radioactive materials (NORM) involved in this matter are radium isotopes (Ra and Ra) and their decay products, precipitating into scales formed on the surfaces of production equipment. A field trip to a number of onshore Libyan oil fields has indicated the existence of elevated levels of specific activity in a number of locations in some of the more mature oil fields. In this study, oil scale samples collected from different parts of Libya have been characterized using gamma spectroscopy through use of a well shielded HPGe spectrometer. To avoid potential alpha-bearing dust inhalation and in accord with safe working practices at this University, the samples, contained in plastic bags and existing in different geometries, are not permitted to be opened. MCNP, a Monte Carlo simulation code, is being used to simulate the spectrometer and the scale samples in order to obtain the system absolute efficiency and then to calculate sample specific activities. The samples are assumed to have uniform densities and homogeneously distributed activity. Present results are compared to two extreme situations that were assumed in a previous study: (i) with the entire activity concentrated at a point on the sample surface proximal to the detector, simulating the sample lowest activity, and; (ii) with the entire activity concentrated at a point on the sample surface distal to the detector, simulating the sample highest activity. © 2013 Elsevier Ltd.
Habib AS, Shutt AL, Regan PH, Matthews MC, Alsulaiti H, Bradley DA (2014) Characterization of naturally occurring radioactive materials in Libyan oil pipe scale using a germanium detector and Monte Carlo simulation, Radiation Physics and Chemistry95pp. 352-355
Radioactive scale formation in various oil production facilities is acknowledged to pose a potential significant health and environmental issue. The presence of such an issue in Libyan oil fields was recognized as early as 1998. The naturally occurring radioactive materials (NORM) involved in this matter are radium isotopes (226Ra and 228Ra) and their decay products, precipitating into scales formed on the surfaces of production equipment. A field trip to a number of onshore Libyan oil fields has indicated the existence of elevated levels of specific activity in a number of locations in some of the more mature oil fields. In this study, oil scale samples collected from different parts of Libya have been characterized using gamma spectroscopy through use of a well shielded HPGe spectrometer. To avoid potential alpha-bearing dust inhalation and in accord with safe working practices at this University, the samples, contained in plastic bags and existing in different geometries, are not permitted to be opened. MCNP, a Monte Carlo simulation code, is being used to simulate the spectrometer and the scale samples in order to obtain the system absolute efficiency and then to calculate sample specific activities. The samples are assumed to have uniform densities and homogeneously distributed activity. Present results are compared to two extreme situations that were assumed in a previous study: (i) with the entire activity concentrated at a point on the sample surface proximal to the detector, simulating the sample lowest activity, and; (ii) with the entire activity concentrated at a point on the sample surface distal to the detector, simulating the sample highest activity. © 2013 Elsevier Ltd.
Vincent SM, Regan PH, Mohammadi S, Gelletly W, Blumenthal D, Carpenter MP, Davids CN, Janssens RVF, Lister CJ, Pearson CJ, Simpson J, Seweryniak D, Schwartz J, Warner DD (1999) A yrast study of the A=61 isobars Cu-61(29) and Zn-61(30), JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 941-943 IOP PUBLISHING LTD
Ressler JJ, Casten RF, Zamfir NV, Beausang CW, Cakirli RB, Ai H, Amro H, Caprio MA, Hecht AA, Heinz A, Langdown SD, McCutchan EA, Meyer DA, Plettner C, Regan PH, Sciacchitano MJS, Yamamoto AD (2004) Transition from the seniority regime to collective motion, PHYSICAL REVIEW C69(3)ARTN 034317 AMERICAN PHYSICAL SOC
FREER M, CLARKE NM, CURTIS N, FULTON BR, HALL SJ, LEDDY MJ, POPLE JS, TUNGATE G, WARD RP, SIMMONS PM, RAE WDM, CHAPPELL SPG, FOX SP, JONES CD, WATSON DL, GYAPONG GJ, SINGER SM, CATFORD WN, REGAN PH (1995) BE-8 AND ALPHA-DECAY OF O-16, PHYSICAL REVIEW C51(4)pp. 1682-1692 AMERICAN PHYSICAL SOC
Bowry M, Podolyak Z, Pietri S, Kurcewicz J, Bunce M, Regan PH, Farinon F, Geissel H, Nociforo C, Prochazka A, Weick H, Al-Dahan N, Alkhomashi N, Allegro PRP, Benlliure J, Benzoni G, Boutachkov P, Bruce AM, Bacelar AMD, Farrelly GF, Gerl J, Gorska M, Gottardo A, Grebosz J, Gregor N, Janik R, Knoebel R, Kojouharov I, Kubo T, Kurz N, Litvinov YA, Merchan E, Mukha I, Naqvi F, Pfeiffer B, Pfuetzner M, Plass W, Pomorski M, Riese B, Ricciardi MV, Schmidt K-H, Schaffner H, Scheidenberger C, Simpson EC, Sitar B, Spiller P, Stadlmann J, Strmen P, Sun B, Tanihata I, Terashima S, Dobon JJV, Winfield JS, Wollersheim H-J, Woods PJ (2013) Population of high-spin isomeric states following fragmentation of U-238,PHYSICAL REVIEW C88(2)ARTN 024611 AMER PHYSICAL SOC
Wilson E, Podolyák Z, Grawe H, Brown BA, Chiara CJ, Zhu S, Fornal B, Janssens RVF, Shand CM, Bowry M, Bunce M, Carpenter MP, Cieplicka-OryDczak N, Deo AY, Dracoulis GD, Hoffman CR, Kempley RS, Kondev FG, Lane GJ, Lauritsen T, Lotay G, Reed MW, Regan PH, Rodríguez Triguero C, Seweryniak D, Szpak B, Walker PM (2015) Core excitations across the neutron shell gap in <sup>207</sup>Tl,Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics747pp. 88-92
© 2015 The Authors.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.
Regan PH (2000) New tools for exotic discrete line gamma-ray spectroscopy., ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY219pp. U81-U81 AMER CHEMICAL SOC
Bucurescu D, Rusu C, MÎrginean N, Ur CA, De Angelis G, Corradi L, Bazzacco D, Beghini S, Della Vedova F, Duchene G, Farnea E, Faul T, Fioretto E, Gadea A, Gelletly W, Guiot B, Ionescu-Bujor M, IordÎchescu A, Landown SD, Lenzi SM, Lunardi S, Mason P, Mihai C, MÎrginean R, Menegazzo R, Montagnoli G, Napoli D, Podolyák Z, Regan PH, Scarlassara F, Stefanini AM, Suliman G, Szilner S, Trotta M, Valiente-Dobón JJ, Zhang YH (2007) ³-ray spectroscopy of the neutron-rich nuclei Rb89, Y92, and Y93 with multinucleon transfer reactions, Physical Review C - Nuclear Physics76(6)
The positive-parity yrast states in the Rb89, Y92, and Y93 nuclei were studied using ³-ray spectroscopy with heavy-ion induced reactions. In the multinucleon transfer reactions Pb208+Zr90 (590 MeV) and U238+Se82 (505 MeV), several ³-ray transitions were identified in these nuclei by means of coincidences between recoiling ions identified with the PRISMA spectrometer and ³ rays detected with the CLARA ³-ray array in thin target experiments. Level schemes were subsequently determined from triple-³ coincidences recorded with the GASP array in a thick target experiment, in the reactions produced by a 470 MeV Se82 beam with a Os192 target. The observed level schemes are compared to shell-model calculations. © 2007 The American Physical Society.
Wadsworth R, Singh BSN, Liu Z, Grawe H, Brock TS, Boutachkov P, Braun N, Blazhev A, Gorska M, Pietri S, Rudolph D, Domingo-Pardo C, Steer SJ, Atac A, Bettermann L, Caceres L, Eppinger K, Engert T, Faestermann T, Farinon F, Finke F, Geibel K, Gerl J, Gernhauser R, Goel N, Gottardo A, Grebosz J, Hinke C, Hoischen R, Ilie G, Iwasaki H, Jolie J, Kaskas A, Kojouharov I, Krucken R, Kurz N, Merchan E, Nociforo C, Nyberg J, Pfutzner M, Prochazka A, Podolyak Z, Regan PH, Reiter P, Rinta-Antila S, Scholl C, Schaffner H, Soderstrom PA, Warr N, Weick H, Wollersheim HJ, Woods PJ, Nowacki F, Sieja K (2012) Spin-gap isomer in 96Cd, Journal of Physics: Conference Series381(1)
Evidence has been obtained for the existence of the long predicted 16 + spin-gap isomer in 96Cd. The decay of the isomer was identified and studied following the use of an 850 MeV/u beam of 124Xe 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.
Regan PH (2006) Isomers and structural evolution using the RISING array, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY231 AMER CHEMICAL SOC
Caamaño M, Walker PM, Regan PH, Pfützner M, Podolyák Z, Gerl J, Hellström M, Mayet P, Mineva MN, Aprahamian A, Benlliure J, Bruce AM, Butler PA, Cortina Gil D, Cullen DM, Döring J, Enqvist T, Fox C, Garcés Narro J, Geissel H, Gelletly W, Giovinazzo J, Górska M, Grawe H, Grzywacz R, Kleinböhl A, Korten W, Lewitowicz M, Lucas R, Mach H, O'Leary CD, De Oliveira F, Pearson CJ, Rejmund F, Rejmund M, Sawicka M, Schaffner H, Schlegel C, Schmidt K, Schmidt KH, Stevenson PD, Theisen C, Vivès F, Warner DD, Wheldon C, Wollersheim HJ, Wooding S, Xu F, Yordanov O (2005) Isomers in neutron-rich A H 190 nuclides from 208Pb fragmentation, European Physical Journal A23(2)pp. 201-215
Relativistic projectile fragmentation of 208Pb has been used to produce isomers in neutron-rich, A H 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of ³-rays emitted by stopped ions has led to the assignment of isomers in 188Ta, 190W, 192Re, 193Re, 195Os, 197Ir, 198Ir, 200Pt, 201Pt, 202Pt and 203Au, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for 174Er, 175Er, 185Hf, 191Re, 194Re and 199Ir. In most cases, time-correlated, singles ³-ray events provided the first spectroscopic data on excited states for each nuclide. In 200Pt and 201Pt, the assignments are supported by ³-³ coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics. © Società, Italiana, di Fisica/Springer-Verlag 2004.
Morales AI, Benlliure J, Kurtukián-Nieto T, Schmidt KH, Verma S, Regan PH, Podolyák Z, Górska M, Pietri S, Kumar R, Casarejos E, Al-Dahan N, Algora A, Alkhomashi N, Álvarez-Pol H, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Cáceres LS, Cullen IJ, Denis Bacelar AM, Doornenbal P, Estévez-Aguado ME, Farrelly G, Fujita Y, Garnsworthy AB, Gelletly W, Gerl J, Grebosz J, Hoischen R, Kojouharov I, Kurz N, Lalkovski S, Liu Z, Mihai C, Molina F, Mücher D, Rubio B, Shaffner H, Steer SJ, Tamii A, Tashenov S, Valiente-Dobón JJ, Walker PM, Wollersheim HJ, Woods PJ (2014) Half-life systematics across the N=126 shell closure: role of first-forbidden transitions in the ² decay of heavy neutron-rich nuclei.,Phys Rev Lett113(2)
This Letter reports on a systematic study of ²-decay half-lives of neutron-rich nuclei around doubly magic (208)Pb. The lifetimes of the 126-neutron shell isotone (204)Pt and the neighboring (200-202)Ir, (203)Pt, (204)Au are presented together with other 19 half-lives measured during the "stopped beam" campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden ² strength reveal significant deviations for most of the nuclei with N<126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during ² decay back to stability.
Myalski S, Maj A, Podolyak Z, Becker F, Bednarczyk P, Benzoni G, Blank B, Brandau C, Bruce AM, Caceres L, Camera F, Catford WN, Cullen IJ, Dombradi Z, Doornenbal P, Estevez E, Garnsworthy AB, Geissel H, Gelletly W, Gerl J, Corska M, Grawe H, Grebosz J, Heinz A, Hoischen R, Ilie G, Jones GA, Jungclaus A, Kelic A, Kmiecik M, Kojouharov I, Kondev FG, Kurtukian-Nieto T, Kurz N, Lalkovski S, Liu Z, Montes F, Pfuetzner M, Pietri S, Prokopowicz W, Regan PH, Rudolph D, Saito T, Schaffner H, Schwertel S, Shizuma T, Simon AJ, Steer SJ, Tashenov S, Walker PM, Werner-Malento E, Wieland O, Wollersheim HJ (2009) ISOMERIC RATIOS FOR NUCLEI WITH Z=62-67 AND A=142-152 PRODUCED IN THE RELATIVISTIC FRAGMENTATION OF Pb-208,ACTA PHYSICA POLONICA B40(3)pp. 879-883 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Benzoni G, Azaiez F, Leoni S, Battacharyya S, Borcea R, Bracco A, Corradi L, Curien D, De France G, Dombradi Z, Fioretto E, Franchoo S, Grevy S, Ibrahim F, Iulian S, Mukherjee G, Navin A, Pollarolo G, Redon N, Regan PH, Rejmund M, Schmitt C, Sletten G, Sohler D, Stanoiu M, Szilner S, Verney D (2007) In-beam gamma spectroscopy using DIC with a radioactive Ne beam, EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 83-86 EDP SCIENCES S A
Jolie J, Regis J-M, Wilmsen D, Ahmed S, Pfeiffer M, Saed-Samii N, Warr N, Blanc A, Jentschel M, Koester U, Mutti P, Soldner T, Simpson G, De France G, Urban W, Drouet F, Vancraeyenest A, Baczyk P, Czerwinski M, Korgul A, Mazzocchi C, Rzaca-Urban T, Bruce A, Roberts OJ, Fraile LM, Mach H, Paziy V, Ignatov A, Ilieva S, Kroell T, Scheck M, Thuerauf M, Ivanova D, Kisyov S, Lalkovski S, Podolyak Z, Regan PH, Korten W, Zielinska M, Salsac MD, Habs D, Thirolf PG, Ur CA, Bernards C, Casten RF, Cooper N, Werner V, Cakirli RB, Leoni S, Benzoni G, Bocchi G, Bottoni S, Crespi FCL, Fornal B, Cieplicka N, Szpak B, Petrache CM, Leguillon R, John R, Lorenz C, Massarczyk R, Schwengner R, Curien D, Lozeva R, Sengele L, Marginean N, Lica R (2015) The (n,gamma) campaigns at EXILL, CGS15 - CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS93 E D P SCIENCES
Morales AI, Benzoni G, Al-Dahan N, Vergani S, Podolyak Z, Regan PH, Swan TPD, Valiente-Dobon JJ, Bracco A, Boutachkov P, Crespi FCL, Gerl J, Gorska M, Pietri S, Walker PM, Wollersheim H-J (2015) First measurement of the beta-decay half-life of Au-206,EPL111(5)ARTN 52001 EPL ASSOCIATION, EUROPEAN PHYSICAL SOCIETY
Catford WN, Mohammadi S, Regan PH, Purry CS, Gelletly W, Walker PM, Gyapong GJ, Simpson J, Warner DD, Davinson T, Neal R, Page RD, Shotter AC, Hibbert IM, Wadsworth R, Forbes SA, Bruce AM, Thwaites C, Thirolf P, VanDuppen P, Galster W, Ninane A, Vervier J, Decrock P, Huyse M, Szerypo J, Wauters J (1996) High resolution gamma-ray spectroscopy with a radioactive beam,NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT371(3)pp. 449-459 ELSEVIER SCIENCE BV
Nakhostin M, Podolyak Z, Regan PH, Walker PM (2010) A digital method for separation and reconstruction of pile-up events in germanium detectors,REVIEW OF SCIENTIFIC INSTRUMENTS81(10)ARTN 103507 AMER INST PHYSICS
Yoshinaga N, Higashiyama K, Regan PH (2008) High-spin structure of neutron-rich Se, As, Ge, and Ga isotopes, PHYSICAL REVIEW C78(4)ARTN 044320 AMER PHYSICAL SOC
Curtis N, Murphy AS, Clarke NM, Freer M, Fulton BR, Hall SJ, Leddy MJ, Pople JS, Tungate G, Ward RP, Catford WN, Gyapong GJ, Singer SM, Chappell SPG, Fox SP, Jones CD, Watson DL, Rae WDM, Simmons PM, Regan PH (1996) Evidence for a highly deformed band in O-16+O-16 breakup of S-32, PHYSICAL REVIEW C53(4)pp. 1804-1810 AMERICAN PHYSICAL SOC
Pietri S, Regan PH, Podolyak Z, Rudolph D, Steer S, Garnsworthy AB, Werner-Malento E, Hoischen R, Gorska M, Gerl J, Wollersheim HJ, Kojouharov I, Schaffner H, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geissel H, Grebosz J, Kelic A, Kurz N, Montes F, Prokopowicz W, Saito T, Tashenov S, Heinz A, Pfuetzner M, Kurtukian-Nieto T, Benzoni G, Hellstrom M, Jungclaus A, Simpson J, Andersson L-L, Atanasova L, Balabanski D, Bentley MA, Blank B, Blazhev A, Brandau C, Brown JR, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Fahlander C, Gelletly W, Ilie G, Johansson EK, Jolie J, Jones GA, Kmiecik M, Kondev FG, Lalkovski S, Liu Z, Maj A, Myalski S, Shizuma T, Simons AJ, Schwertel S, Walker PM, Wieland O (2007) Recent results in fragmentation isomer spectroscopy with rising, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS261(1-2)pp. 1079-1083 ELSEVIER SCIENCE BV
Chandler C, Regan PH, Pearson CJ, Blank B, Bruce AM, Catford WN, Curtis N, Czajkowski S, Gelletly W, Grzywacz R, Janas Z, Lewitowicz M, Marchand C, Orr NA, Page RD, Petrovici A, Reed AT, Saint-Laurent MG, Vincent SM, Wadsworth R, Warner DD, Winfield JS (1997) Evidence for a highly deformed oblate 0(+) state in Kr-74(36), PHYSICAL REVIEW C56(6)pp. R2924-R2928 AMERICAN PHYSICAL SOC
Patel Z, Podolyak Z, Walker PM, Regan PH, Soederstroem P-A, Watanabe H, Ideguchi E, Simpson GS, Nishimura S, Browne F, Doornenbal R, Lorusso G, Rice S, Sinclair L, Sumikama T, Wu J, Xu ZY, Aoi N, Baba H, Garrote FLB, Benzoni G, Daido R, Dombradi Z, Fang Y, Fukuda N, Gey G, Go S, Gottardo A, Inabe N, Isobe T, Kameda D, Kobayashi K, Kobayashi M, Komatsubara T, Kojouharov I, Kubo T, Kurz N, Kuti I, Li Z, Liu HL, Matsushita M, Michimasa S, Moony C-B, Nishibata H, Nishizuka I, Odahara A, Sahin E, Sakurai H, Schaffner H, Suzuki H, Takeda H, Tanaka M, Taprogge J, Vajta Z, Xu FR, Yagi A, Yokoyama R (2016) Decay spectroscopy of Sm-160: The lightest four-quasiparticle K isomer,PHYSICS LETTERS B753pp. 182-186 ELSEVIER SCIENCE BV
Regan P (2011) A taste of the exotic, PHYSICS WORLD24(11)pp. 37-41 IOP PUBLISHING LTD
Alharbi T, Mason PJ, Regan PH, Podolyák Z, M?rginean N, Nakhostin M, Bowry M, Bucurescu D, C?ta-Danil G, C?ta-Danil I, Deleanu D, Filipescu D, Glodariu T, Ghic? D, M?rginean R, Mihai C, Negret A, Pascu S, Sava T, Stroe L, Suliman G, Zamfir NV, Bruce AM, Rodriguez Triguero C, Bender PC, Garg U, Erduran MN, Kusoglu A, Bostan M, Detistov P, Alkhomashi N, Sinha AK, Chakrabarti R, Ghugre SS (2012) Gamma-ray fast-timing coincidence measurements from the (18)O+(18)O fusion-evaporation reaction using a mixed LaBr(3)-HPGe array,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(À)=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.
Nakhostin M, Podolyak Z, Regan PH (2014) Digital processing of signals from LaBr3:Ce scintillation detectors,JOURNAL OF INSTRUMENTATION9ARTN C1204 IOP PUBLISHING LTD
Podolyak Z, Regan PH, Walker PM, Caamano M, Gladnishki K, Gerl J, Hellstrom M, Mayet P, Pfutzner M, Mineva M (2003) Heavy nuclei studied in projectile fragmentation, NUCLEAR PHYSICS A722pp. 273C-278C ELSEVIER SCIENCE BV
Pearson CJ, Regan PH, Divoli A (2001) The application of CdZnTe detectors for coincident alpha-gamma spectroscopy, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT462(3)pp. 393-396 ELSEVIER SCIENCE BV
Zakari-Issoufou AA, Porta A, Fallot M, Algora A, Tain JL, Valencia E, Rice S, Agramunt J, Äystö J, Bowry M, Bui VM, Caballero-Folch R, Cano-Ott D, Eloma V, Estévez E, Farrelly GF, Garcia A, Gelletly W, Gomez-Hornillos MB, Gorlychev V, Hakala J, Jokinen A, Jordan MD, Kankainen A, Kondev FG, Martinez T, Mendoza E, Molina F, Moore I, Perez A, Podolyak Z, Penttilä H, Regan PH, Rissanen J, Rubio B, Weber C (2013) Measurement of fission products ² decay properties using a total absorption spectrometer, 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.
Soederstroem P-A, Regan PH, Walker PM, Watanabe H, Doornenbal P, Korkulu Z, Lee P, Liu HL, Liu JJ, Lorusso G, Nishimura S, Sumikama T, Phong VH, Wu J, Xu FR, Yagi A, Zhang GX, Alharbi T, Baba H, Browne F, Bruce AM, Carroll R, Chae KY, Dombradi Z, Estrade A, Fukuda N, Griffin C, Ideguchi E, Inabe N, Isobe T, Kanaoka H, Kojouharov I, Kondev FG, Kubo T, Kubono S, Kurz N, Kuti I, Lalkovski S, Lane GJ, Lee CS, Lee EJ, Lotay G, Moon C-B, Nishizuka I, Nita CR, Odahara A, Patel Z, Podolyak Z, Roberts OJ, Sakurai H, Schaffner H, Shand CM, Suzuki H, Takeda H, Terashima S, Vajta Z, Valiente-Dobon JJ, Xu ZY, Yoshida S (2015) Heavy Rotation - Evolution of quadrupole collectivity centred at the neutron-rich doubly mid-shell nucleus Dy-170, NUCLEAR STRUCTURE AND DYNAMICS '151681 AMER INST PHYSICS
Browne F, Bruce AM, Sumikama T, Nishizuka I, Nishimura S, Doornenbal P, Lorusso G, Patel Z, Rice S, Sinclair L, Soederstroem P-A, Watanabe H, Wu J, Xu ZY, Baba H, Chiga N, Carroll R, Daido R, Didierjean F, Fang Y, Gey G, Ideguchi E, Inabe N, Isobe T, Kameda D, Kojouharov I, Kurz N, Kubo T, Lalkovski S, Li Z, Lozeva R, Naoki N, Nishibata H, Odahara A, Podolyak Z, Regan PH, Roberts OJ, Sakurai H, Schaffner H, Simpson GS, Suzuki H, Takeda H, Tanaka M, Taprogge J, Werner V, Wieland O, Yagi A (2015) GAMMA-RAY SPECTROSCOPY IN THE VICINITY OF Zr-108,ACTA PHYSICA POLONICA B46(3)pp. 721-724 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
The half-lives of 2+1 states were measured for 102,104Zr and 106,108Mo to test a new implementation of a LaBr3 (Ce) array at the RIBF, RIKEN, Japan. The nuclei of interest were produced through the fission of a 345 MeV/nucleon 238U beam and selected by the BigRIPS separator. Fission fragments were implanted into the WAS3ABi active stopper, surrounding which, 18 LaBr3 (Ce) detectors provided fast ³-ray detection. Timing between the LaBr3 (Ce) array and plastic scintillators allowed for the measurement of half-lives of low-lying states. The preliminary results, which agree with literature values, are presented along with experimental details.
Browne F, Bruce AM, Sumikama T, Nishizuka I, Nishimura S, Doornenbal P, Lorusso G, Soederstroem P-A, Watanabe H, Daido R, Patel Z, Rice S, Sinclair L, Wu J, Xu ZY, Yagi A, Baba H, Chiga N, Carroll R, Didierjean F, Fang Y, Fukuda N, Gey G, Ideguchi E, Inabe N, Isobe T, Kameda D, Kojouharov I, Kurz N, Kubo T, Lalkovski S, Li Z, Lozeva R, Nishibata H, Odahara A, Podolyak Z, Regan PH, Roberts OJ, Sakurai H, Schaffner H, Simpson GS, Suzuki H, Takeda H, Tanaka M, Taprogge J, Werner V, Wieland O (2015) Lifetime measurements of the first 2(+) states in Zr-104,Zr-106: Evolution of ground-state deformations,PHYSICS LETTERS B750pp. 448-452 ELSEVIER SCIENCE BV
Britton R, Regan PH, Burnett JL, Davies AV (2013) Characterisation of cascade summing effects in gamma spectroscopy using Monte Carlo simulations, Journal of Radioanalytical and Nuclear Chemistrypp. 1-6
A GEANT4 based Monte Carlo simulation has been successfully utilised to calculate peak efficiency characterisations and cascade summing (true coincidence summing) corrections in two source geometries commonly used for environmental monitoring. The cascade summing corrections are compared with values generated using an existing (validated) system, and found to be in excellent agreement for all radionuclides simulated. The calculated correction factors and peak efficiencies were also tested by analysing well defined sources used in the operation of the International Monitoring System, which undertakes radionuclide monitoring for verification of the Comprehensive Nuclear-Test-Ban Treaty. All abundances of the radionuclides measured matched the values that were previously determined using proprietary software. Using GEANT4 in this way, cascade summing corrections can now be extended to complex detector models and source matrices, such as Compton Suppression systems. © 2013 Akadémiai Kiadó, Budapest, Hungary.
Balabanski DL, Gladnishki KA, Lo Bianco G, Saltarelli A, Zamfir NV, McCutchan EA, Ai H, Casten RF, Heinz A, Meyer DA, Plettner C, Qian J, Werner V, Williams E, Akkus B, Amon L, Cakirli RB, Erduran MN, Oktem Y, Ashley SF, Regan PH, Rainovski G (2006) Evidence for X(5) critical point symmetry in 128Ce, 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 ³ 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 H 130 region. © World Scientific Publishing Company.
Yamamoto AD, Regan PH, Beausang CW, Xu FR, Caprio MA, Casten RF, Gurdal G, Hecht AA, Hutter C, Krucken R, Langdown SD, Meyer D, Ressler JJ, Zamfir NV (2002) High-j proton and neutron alignments in gamma-soft Ru-101, PHYSICAL REVIEW C66(2)ARTN 024302 AMERICAN PHYSICAL SOC
Regan PH, Jones GA, Podolyak Z, de Angelis G, Zhang YH, Gadea A, Ur CA, Abdullah M, Axiotis M, Bazzacco D, Broda R, Bucurescu D, Farnea E, Gelletly W, Ionescu-Bujor M, Iordachescu A, Kroell T, Langdown SD, Lenzi S, Lunardi S, Marginean N, Martinez T, Medina N, Menegazzo R, Napoli DR, Quintana B, Rubio B, Rusu C, Schwenger R, Tonev D, Valiente-Dobon JJ, von Oertzen W, Wollel G (2006) Nuclear structure and reaction mechanism studies with multinucleon reactions, FUSION06: Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier853pp. 271-276 AMER INST PHYSICS
Regan PH, Wheldon C, Yamamoto AD, Valiente-Dobon JJ, Cline D, Wu CY, Macchiavelli AO, Xu FR, Smith JF, Andgren K, Chakrawarthy RS, Cromaz M, Fallon P, Freeman SJ, Gorgen A, Hayes A, Hua H, Langdown SD, Lee IY, Pearson CJ, Podolyak Z, Teng R (2005) Vibrational and rotational sequences in Mo-101 and Ru-103,Ru-4 studied via multinucleon transfer reactions, ACTA PHYSICA POLONICA B36(4)pp. 1313-1322 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Alexander T, Podolyák Z, Cortes ML, Gerl J, Rudolph D, Sarmiento LG, Ameil F, Arici T, Bazzacco D, Bauer C, Bentley MA, Blazhev A, Bowry M, Boutachkov P, Carroll R, Fahlander C, Gadea A, Gellanki J, Gelletly W, Givechev A, Goel N, Golubev P, Górska M, Gottardo A, Gregor E, Guastalla G, Habermann T, Hackstein M, Jungclaus A, Kojouharov I, Korten W, Kumar S, Kurz N, Lalovic N, Lettmann M, Lizarazo C, Louchart C, Mandal S, Merchán E, Michelagnoli C, Möller T, Moschner K, Patel Z, Pietralla N, Pietri S, Ralet D, Reese M, Regan PH, Reiter P, Schaffner H, Singh P, Stahl C, Stegmann R, Stezowksi O, Taprogge J, Thöle P, Walker PM, Wieland O, Wendt A, Wilson E, Wood R, Wollersheim HJ (2015) Isomeric ratios in <sup>206</sup>Hg, Acta Physica Polonica B46(3)pp. 601-605
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-ray tracking array worked properly and that the tracking efficiency was independent of the time relative to the prompt flash.
Anagnostatou V, Regan PH, Bunce MR, McCarthy D, Werner V, Ahn T, Casperson RJ, Chevrier R, Cooper N, Heinz A, Ilie G, Smith MK, Williams E, Bettermann L, Radeck D, Beausang CW, Boniwell C, Pauerstein B (2011) MEASUREMENTS OF PICOSECOND LIFETIMES IN THE TRANSITIONAL NUCLEUS Pd-100 USING THE RDDM IN INVERSE KINEMATICS, ACTA PHYSICA POLONICA B42(3-4)pp. 807-811 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Catford WN, Mohammadi S, Regan PH, Purry CS, Gelletly W, Walker PM, Gyapong GJ, Simpson J, Warner DD, Davinson T, Neal R, Page RD, Shotter AC, Hibbert IM, Wadsworth R, Forbes SA, Bruce AM, Thwaites C, Thirolf P, VanDuppen P, Galster W, Ninane A, Vervier J, Decrock P, Huyse M, Szerypo J, Wauters J (1997) High resolution gamma-ray spectroscopy with a radioactive beam,NUCLEAR PHYSICS A616(1-2)pp. C303-C310 ELSEVIER SCIENCE BV
Regan PH, Xu FR, Walker PM, Oi M, Rath AK, Stevenson PD (2002) Structure of the doubly midshell nucleus Dy-170(66)104, PHYSICAL REVIEW C65(3)ARTN 037302 AMERICAN PHYSICAL SOC
Bruce AM, Bacelar AMD, Benzoni G, Gadea A, Górska M, Gottardo A, Pietri S, Podolyák Z, Valiente-Dobón JJ, Alcántara-Núñez JA, Al-Dahan N, Algora A, Alkhomashi N, Allegro PRP, Ayyad Y, Boutachkov P, Bowry M, Bunce M, Casarejos E, Cortés ML, Deo AY, Domingo-Prado C, Doncel M, Eppinger K, Farinon F, Farrelly GF, Geissel H, Gerl J, Goel N, Gr)bosz J, Gregor E, Haberman T, Hoischen R, Janik R, Klupp S, Kojouharov I, Kurz N, Lunardi S, Mandal S, Menegazzo R, Mengoni D, Naqvi F, Nicolini R, Nociforo C, Pissulla T, Prochazka A, Prokopowicz W, Regan PH, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steiger K, Strmen P, Szarka I, Walker PM, Weick H, Wollersheim HJ (2012) ² decay of 102Y produced in projectile fission of 238U,Journal of Physics: Conference Series381(1)
The population of 102Zr following the ² decay of 102Y produced in the projectile fission of 238U at the GSI facility in Darmstadt, Germany has been studied. 102Y is known to decay into 102Zr via two states, one of high spin and the other low spin. These states preferentially populate different levels in the 102Zr daughter. In this paper the intensities of transitions in 102Zr 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.
Gorska M, Caceres L, Grawe H, Pfuetzner M, Jungclaus A, Pietri S, Werner-Malento E, Podolyak Z, Regan PH, Rudolph D, Detistov R, Lalkovski S, Modamio V, Walker J, Beck T, Bednarczyk P, Doornenbal P, Geissel H, Gerl J, Grebosz J, Hoischen R, Kojouharov I, Kurz N, Prokopowicz W, Schaffner H, Weick H, Wollersheim H-J, Andgren K, Benlliure J, Benzoni G, Bruce AM, Casarejos E, Cederwall B, Crespi FCL, Hadinia B, Hellstrom M, Ilie G, Khaplanov A, Kmiecik M, Kumar R, Maj A, Mandal S, Montes F, Myalski S, Simpson GS, Steer SJ, Tashenov S, Wieland O, Dombradi Z, Reiter R, Sohler D (2009) Evolution of the N=82 shell gap below Sn-132 inferred from core excited states in In-131, PHYSICS LETTERS B672(4-5)pp. 313-316 ELSEVIER SCIENCE BV
Soderstrom P-A, Nyberg J, Regan PH, Algora A, de Angelis G, Ashley SF, Aydin S, Bazzacco D, Casperson RJ, Catford WN, Cederkall J, Chapman R, Corradi L, Fahlander C, Farnea E, Fioretto E, Freeman SJ, Gadea A, Gelletly W, Gottardo A, Grodner E, He CY, Jones GA, Keyes K, Labiche M, Liang X, Liu Z, Lunardi S, Marginean N, Mason P, Menegazzo R, Mengoni D, Montagnoli G, Napoli D, Ollier J, Pietri S, Podolyak Z, Pollarolo G, Recchia F, Sahin E, Scarlassara F, Silvestri R, Smith JF, Spohr K-M, Steer SJ, Stefanini AM, Szilner S, Thompson NJ, Tveten GM, Ur CA, Valiente-Dobon JJ, Werner V, Williams SJ, Xu FR, Zhu JY (2010) Spectroscopy of neutron-rich Dy-168,Dy-170: Yrast band evolution close to the NpNn valence maximum,PHYSICAL REVIEW C81(3)ARTN 034310 AMER PHYSICAL SOC
Caceres L, Gorska M, Jungclaus A, Pfutzner M, Grawe H, Nowacki F, Sieja K, Pietri S, Rudolph D, Podolyak Z, Regan PH, Werner-Malento E, Detistov P, Lalkovski S, Modamio V, Walker J, Andgren K, Bednarczyk P, Benlliure J, Benzoni G, Bruce AM, Casarejos E, Cederwall B, Crespi FCL, Doornenbal P, Geissel H, Gerl J, Grebosz J, Hadinia B, Hellstrom M, Hoischen R, Ilie G, Khaplanov A, Kmiecik M, Kojouharov I, Kumar R, Kurz N, Maj A, Mandal S, Montes F, Martinez-Pinedo G, Myalski S, Prokopowicz W, Schaffner H, Simpson GS, Steer SJ, Tashenov S, Wieland O, Wollersheim HJ (2009) Spherical proton-neutron structure of isomeric states in Cd-128,PHYSICAL REVIEW C79(1)ARTN 011301 AMER PHYSICAL SOC
Britton R, Burnett JL, Davies AV, Regan PH (2015) Coincidence corrections for a multi-detector gamma spectrometer,NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT769pp. 20-25 ELSEVIER SCIENCE BV
© 2014 Published by Elsevier B.V. All rights reserved.List-mode data acquisition has been utilised in conjunction with a high-efficiency ³-³ coincidence system, allowing both the energetic and temporal information to be retained for each recorded event. Collected data is re-processed multiple times to extract any coincidence information from the ³-spectroscopy system, correct for the time-walk of low-energy events, and remove accidental coincidences from the projected coincidence spectra. The time-walk correction has resulted in a reduction in the width of the coincidence delay gate of 18.4±0.4%, and thus an equivalent removal of 'background' coincidences. The correction factors applied to <5.6% of events up to <500 keV for a combined 137Cs and 60Co source, and are crucial for accurate coincidence measurements of low-energy events that may otherwise be missed by a standard delay gate. By extracting both the delay gate and a representative 'background' region for the coincidences, a coincidence background subtracted spectrum is projected from the coincidence matrix, which effectively removes <100% of the accidental coincidences (up to 16.6±0.7% of the total coincidence events seen during this work). This accidental-coincidence removal is crucial for accurate characterisation of the events seen in coincidence systems, as without this correction false coincidence signatures may be incorrectly interpreted.
McCutchan EA, Casten RF, Werner V, Williams E, Winkler R, Wolf A, Berant Z, Gurdal G, Qian J, Ai H, Amon L, Beausang CW, Brenner DS, Cakirli RB, Casperson RJ, Fitzpatrick CR, Frank D, Garnsworthy AB, Heinz A, Luettke R, Mertz AF, Oktem Y, Pietralla N, Regan PH, Shoraka B, Terry JR, Thompson NJ (2008) Enhanced mixing of intrinsic states in deformed Hf nuclei,PHYSICAL REVIEW C77(5)ARTN 054304 AMER PHYSICAL SOC
Simpson EC, Tostevin JA, Podolyak Z, Regan PH, Steer SJ (2010) Differential isomeric ratios following two-proton knockout from Pb-208,PHYSICAL REVIEW C82(3)ARTN 037602 AMER PHYSICAL SOC
Higashiyama K, Yoshinaga N, Regan P (2009) Shell model study of neutron rich Se and Ge isotopes,AIP Conference Proceedings1090pp. 599-600
Garnsworthy AB, Regan PH, Pietri S, Sun Y, Xu FR, Rudolph D, Gorska M, Caceres L, Podolyak Z, Steer SJ, Hoischen R, Heinz A, Becker F, Bednarczyk P, Doornenbal P, Geissel H, Gerl J, Grawe H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopwicz W, Saito T, Schaffner H, Tachenov S, Werner-Malento E, Wollersheim HJ, Benzoni G, Blank B, Brandau C, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Gelletly W, Ilie G, Jolie J, Jones GA, Jungclaus A, Kmiecik M, Kondev FG, Kurtukian-Nieto T, Lalkovski S, Liu Z, Maj A, Myalski S, Pfuetzner M, Schwertel S, Shizuma T, Simons AJ, Walker PM, Wieland O (2009) Isomeric states in neutron-deficient A similar to 80-90 nuclei populated in the fragmentation of Ag-107,PHYSICAL REVIEW C80(6)ARTN 064303 AMER PHYSICAL SOC
Jolie J, Regis J-M, Wilmsen D, Saed-Samii N, Pfeiffer M, Warr N, Blanc A, Jentschel M, Koester U, Mutti P, Soldner T, Simpson GS, De France G, Urban W, Drouet F, Vancraeyenest A, Bruce AM, Roberts OJ, Fraile LM, Paziy V, Ignatov A, Kroell T, Ivanova D, Kisyov S, Lalkovski S, Podolyak Z, Regan PH, Wilson E, Korten W, Ur CA, Lica R, Marginean N (2015) Test of the SO(6) selection rule in Pt-196 using cold-neutron capture,NUCLEAR PHYSICS A934pp. 1-7 ELSEVIER SCIENCE BV
© 2014 Elsevier B.V.At the PF1B cold-neutron beam line of the Institut Laue Langevin, the EXILL&FATIMA array, consisting of EXOGAM Ge detectors and fast LaBr3(Ce) scintillators, was used to perform fast electronic timing measurements after the 195Pt(n,³) reaction using a highly collimated cold-neutron beam. An upper lifetime limit was obtained for the third 0+ state in 196Pt. As this state is the lowest state of the Ã=N-2 set of SO(6) states, the selection rule which forbids E2 transitions to the lower lying Ã=N could be tested.
Longour C, Narro JG, Blank B, Lewitowicz M, Miehe C, Regan PH, Applebe D, Axelsson L, Bruce AM, Catford WN, Chandler C, Clark RM, Cullen DM, Czajkowski S, Daugas JM, Dessagne P, Fleury A, Frankland L, Gelletly W, Giovinazzo J, Greenhalgh B, Grzywacz R, Harder M, Jones KL, Kelsall N, Kszczot T, Page RD, Pearson CJ, Reed AT, Sorlin O, Wadsworth R (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, PHYSICAL REVIEW LETTERS81(16)pp. 3337-3340 AMERICAN PHYSICAL SOC
Longour C, Narro JG, Blank B, Lewitowicz M, Miehe C, Regan PH, Applebe D, Axelsson L, Bruce AM, Catford WN, Chandler C, Clark RM, Cullen DM, Czajkowski S, Daugas JM, Dessagne P, Fleury A, Frankland L, Gelletly W, Giovinazzo J, Greenhalgh B, Grzywacz R, Harder M, Jones KL, Kelsall N, Kszczot T, Page RD, Pearson CJ, Reed AT, Sorlin O, Wadsworth R (1999) Half-lives of the odd-odd N=Z nuclei Y-78, Nb-82, Tc-86, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 759-762 IOP PUBLISHING LTD
Pohl KR, Regan PH, Bush JE, Raines PE, Balamuth DP, Ward D, Galindo-Uribarri A, Janzen VP, Mullins SM, Pilotte S (1996) High-spin states in 107Pd, 108Pd, and 109Ag, Physical Review C - Nuclear Physics53(6)pp. 2682-2700
High-spin states in 107,108Pd and 109Ag have been studied by charged-particle-³, ³-³, and charged-particle-³-³ 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 (²2 = 0.2) prolate deformation.
Al-Garni SD, Regan PH, Walker PM, Roeckl E, Kirchner R, Xu FR, Batist L, Blazhev A, Borcea R, Cullen DM, Doring J, El-Masri HM, Narro JG, Grawe H, La Commara M, Mazzoechi C, Mukha I, Pearson CJ, Plettner C, Schmidt K, Schmidt-Ott WD, Shimbara Y, Wheldon C, Wood R, Wooding SC (2004) Evidence for a high-spin beta-decaying isomer in Lu-177, PHYSICAL REVIEW C69(2)ARTN 024320 AMERICAN PHYSICAL SOC
Becker F, Korten W, Butler PA, Hannachi F, Paris P, Buforn N, Chandler C, Jansen A, Houry M, Hubel H, Greenlees P, Jones PM, Julin R, Kankaanpaa H, Liang CE, Lopez-Martens A, Mergel E, Le Coz Y, Lucas R, Regan PH, Schonwasser G, Theisen C (2000) Investigation of EO transition in Kr-74, PHYSICA SCRIPTAT88pp. 17-20 ROYAL SWEDISH ACAD SCIENCES
Britton R, Regan PH, Burnett JL, Davies AV (2014) Next Generation Detection Systems for Radioactive Material Analysis,NUCLEAR DATA SHEETS119pp. 410-412 ACADEMIC PRESS INC ELSEVIER SCIENCE
Gladnishki KA, Podolyak Z, Gerl J, Hellstrom M, Kopatch Y, Mandal S, Gorska M, Regan PH, Wollersheim HJ, Banu A, Benzoni G, Boardman H, La Commara M, Ekman J, Fahlander C, Geissel H, Grawe H, Kaza E, Korgul A, Matos M, Mineva MN, Page RD, Pearson CJ, Plettner C, Rudolph D, Scheidenberger C, Shishkin V, Sohler D, Summerer K, Valiente-Dobon JJ, Weick H, Winkler M (2003) Isomer spectroscopy in the neutron-deficient lead region following projectile fragmentation, ACTA PHYSICA POLONICA B34(4)pp. 2395-2398 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Ashley SF, Linnemann A, Jolie J, Regan PH, Andgren K, Dewald A, McCutchan EA, Melon B, Moeller O, Zamfir NV, Amon L, Boelaert N, Cakirli RB, Casten RF, Clark RM, Fransen C, Gelletly W, Gurdal G, Heidemann M, Keyes KL, Erduran MN, Meyer DA, Papenberg A, Plettner C, Rainovski G, Ribas RV, Thomas NJ, Vinson J, Warner DD, Werner V, Williams E, Zell KO (2007) Lifetime determination of excited states in Cd-106, ACTA PHYSICA POLONICA B38(4)pp. 1385-1388 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Anagnostatou V, Regan PH, Werner V, Xu FR, Dong GX, Bunce MR, McCarthy D, Bettermann L, Boniwell C, Casperson R, Chevrier R, Cooper N, Heinz A, Paurstein P, Radeck D, Smith MK, Williams E (2011) Electromagnetic transition rates in (100,101)Pd using the Recoil Doppler Shift Technique., 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 35¼m and 750¼m. 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%.
Roberts OJ, Bruce AM, Patel Z, Podolyák Z, Regan PH, Townsley CM, Smith A, Mulholland KF, Smith JF (2013) Development of a LaBr3 (Ce) Fast-timing Array for FAIR, EPJ Web of Conferences63
A ³-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.
DASGUPTA M, WALKER PM, DRACOULIS GD, BYRNE AP, REGAN PH, KIBEDI T, LANE GJ, YEUNG KC (1994) YRAST ISOMERS, MULTI-QUASI-PARTICLE STATES AND BLOCKING IN TA-176 AND TA-177, PHYSICS LETTERS B328(1-2)pp. 16-21 ELSEVIER SCIENCE BV
Andreyev AN, Butler PA, Page RD, Appelbe DE, Jones GD, Joss DT, Herzberg RD, Regan PH, Simpson J, Wadsworth R (2004) GEANT Monte Carlo simulations for the GREAT spectrometer, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT533(3)pp. 422-434 ELSEVIER SCIENCE BV
Vincent SM, Regan PH, Warner DD, Gelletly W, Simpson J, Bark R, Blumenthal D, Carpenter MP, Davids CN, Henderson DJ, Janssens RVF, Lister CJ, Nisius D, O'Leary CD, Pearson CJ, Saitoh T, Schwartz J, Seweryniak D, Tormanen S (1998) Probing the structure of the N=Z=31 nucleus Ga-62(31), ENAM 98: EXOTIC NUCLEI AND ATOMIC MASSES455pp. 450-455 AMER INST PHYSICS
Bowry M, Podolyak Z, Kurcewicz J, Pietri S, Bunce M, Regan PH, Farinon F, Geissel H, Nociforo C, Prochazka A, Weick H, Allegro P, Benlliure J, Benzoni G, Boutachkov P, Gerl J, Gorska M, Gottardo A, Gregor N, Janik R, Knoebel R, Kojouharov I, Kubo T, Litvinov YA, Merchan E, Mukha I, Naqvi F, Pfeiffer B, Pfuetzner M, Plass W, Pomorski M, Riese B, Ricciardi MV, Schmidt K-H, Schaffner H, Kurz N, Bacelar AMD, Bruce AM, Farrelly GF, Alkhomashi N, Al-Dahan N, Scheidenberger C, Sitar B, Spiller P, Stadlmann J, Strmen P, Sun B, Takeda H, Tanihata I, Terashima S, Dobon JJV, Winfield JS, Wollersheim H-J, Woods PJ (2012) Half-life Measurements of Isomeric States Populated in Projectile Fragmentation,NUCLEAR STRUCTURE AND DYNAMICS '121491pp. 317-320 AMER INST PHYSICS
Podolyak Z, Steer SJ, Pietri S, Werner-Malento E, Regan PH, Rudolph D, Garnsworthy AB, Hoischen R, Gorska M, Gerl J, Wollersheim HJ, Kurtukian-Nieto T, Benzoni G, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geissel H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Heinz A, Pfutzner M, Hellstrom M, Jungclaus A, Andersson L-L, Atanasova L, Balabanski DL, Bentley A, Blank B, Blazhev A, Brandau C, Brown J, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Fahlander C, Gelletly W, Ilie G, Johansson EK, Jolie J, Jones GA, Kmiecik M, Kondev FG, Lalkovski S, Liu Z, Maj A, Myalski S, Shizuma T, Simons AJ, Schwertel S, Walker PM, Wieland O, Brown BA (2007) Isomeric decay studies around Pt-204 and Tb-148, EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 165-168 EDP SCIENCES S A
Kurcewicz J, Farinon F, Geissel H, Pietri S, Nociforo C, Prochazka A, Weick H, Winfield JS, Estradé A, Allegro PRP, Bail A, Bélier G, Benlliure J, Benzoni G, Bunce M, Bowry M, Caballero-Folch R, Dillmann I, Evdokimov A, Gerl J, Gottardo A, Gregor E, Janik R, Keli?-Heil A, Knöbel R, Kubo T, Litvinov YA, Merchan E, Mukha I, Naqvi F, Pfützner M, Pomorski M, Podolyák Z, Regan PH, Riese B, Ricciardi MV, Scheidenberger C, Sitar B, Spiller P, Stadlmann J, Strmen P, Sun B, Szarka I, Taïeb J, Terashima S, Valiente-Dobón JJ, Winkler M, Woods P (2012) Discovery and cross-section measurement of neutron-rich isotopes in the element range from neodymium to platinum with the FRS,Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics717(4-5)pp. 371-375
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 60eZe78. 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.
Dasgupta M, Dracoulis GD, Walker PM, Byrne AP, Kibédi T, Kondev FG, Lane GJ, Regan PH (2000) Competition between high-K states and rotational structures in 177Ta, 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 ¼s. 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 KÀ = 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.
Collins SM, Pearce AK, Ferreira KM, Fenwick AJ, Regan PH, Keightley JD (2015) Direct measurement of the half-life of Ra-223,APPLIED RADIATION AND ISOTOPES99pp. 46-53 PERGAMON-ELSEVIER SCIENCE LTD
Radioactive decay half-life measurements of (223)Ra, a member of the (235)U naturally occurring radioactive decay series, have been performed of a radiochemically pure solution with an ionisation chamber. The radioactive decay of (223)Ra was followed for 50 days, approximately 4.4 half-lives. The deduced half-life of (223)Ra was found to be 11.4358 (28) days, supporting the other published direct measurements. A detailed uncertainty budget is presented. A new evaluation of the published half-life values was performed, indicating significant variation across the existing published values, suggesting that further measurements of the half-life of (223)Ra are required. A new evaluated half-life has been calculated using a power moderated weighted mean of selected experimental values, with a new value of the recommended half-life for (223)Ra of 11.4354 (17) days.
Britton R, Burnett J, Davies A, Regan PH (2013) Determining the efficiency of a broad-energy HPGe detector using Monte Carlo simulations, Journal of Radioanalytical and Nuclear Chemistry295(3)pp. 2035-2041
Broad-energy HPGe detectors have a useful range of 3 keV to 3 MeV, making them ideal for the assay of environmental samples. Such measurements however, are hindered by variations in the sample matrix, summing effects, and the Compton continuum. Detectors may be characterised by proprietary software in such a situation, however Monte-Carlo modelling is a useful, inexpensive alternative that also provides greater flexibility when determining the detector response and efficiency during a measurement. In the current work, a full GEANT4 model of a broad-energy HPGe detector is presented, and simulations of various samples are compared to experimental data. These are found to be accurate within 3 % at a confidence level of 95 % for energies from 30 to 3,000 keV, with greater variations below 100 keV due to an increased sensitivity to geometrical inaccuracies. © 2012 Akadémiai Kiadó, Budapest, Hungary.
Jones GA, Podolyak Z, Schunck N, Walker PM, De Angelis G, Zhang YH, Axiotis M, Bazzacco D, Bizzeti PG, Brandolini F, Broda R, Bucurescu D, Farnea E, Gelletly W, Gadea A, Ionescu-Bujor M, Iordachescu A, Kroll T, Langdown SD, Lunardi S, Marginean N, Martinez T, Medina NH, Quintana B, Regan PH, Rubio B, Ur CA, Valiente-Dobon JJ, Williams SJ (2005) Oblate collectivity in the yrast structure of Pt-194, ACTA PHYSICA POLONICA B36(4)pp. 1323-1327 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Regan PH, Alkhomashi N, Al-Dahan N, PodolyÁk Z, Pietri SB, Steer SJ, Garnsworthy AB, Suckling EB, Stevenson PD, Farrelly G, Cullen IJ, Gelletly W, Walker PM, Benlliure J, Morales AI, Casajeros E, Estevez ME, Gerl J, GÓrska M, Wollersheim HJ, Boutachkov P, Tashenov S, Kojouharov I, Schaffner H, Kurz N, Kumar R, Rubio B, Algora A, Molina F, Grebosz J, Benzoni G, MÜcher D, Bruce AM, Bacelar AMD, Lalkovski S, Fujita Y, Tamii A, Hoischen R, Liu Z, Woods PJ, Mihai C, Valiente-DobÓn JJ (2008) First results with the rising active stopper, International Journal of Modern Physics E17(SUPPL. 1)pp. 8-20
Morales AI, Benlliure J, Górska M, Grawe H, Verma S, Regan PH, Podolyák Z, Pietri S, Kumar R, Casarejos E, Algora A, Alkhomashi N, Álvarez-Pol H, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Cáceres LS, Cullen IJ, Denis Bacelar AM, Doornenbal P, Estévez-Aguado ME, Farrelly G, Fujita Y, Garnsworthy AB, Gelletly W, Gerl J, Grebosz J, Hoischen R, Kojouharov I, Kurz N, Lalkovski S, Liu Z, Mihai C, Molina F, Mücher D, Prokopowicz W, Rubio B, Schaffner H, Steer SJ, Tamii A, Tashenov S, Valiente-Dobón JJ, Walker PM, Wollersheim HJ, Woods PJ (2013) ²-delayed ³-ray spectroscopy of 203,204Au and 200-202Pt,Physical Review C - Nuclear Physics88(1)
The ² decay of five heavy, neutron-rich nuclei, 203,204Pt and 200-202Ir, has been investigated following relativistic cold fragmentation reactions of lead projectiles using the FRS+RISING setup at GSI. This paper reports on the study of the low-lying states in the decay daughter nuclei 203,204Au and 200-202Pt. The characteristic ³ rays for each nucleus have been determined using ²-delayed ³-ray spectroscopy. Tentative level schemes, relative intensities, and apparent ² feedings are provided. These data are compared with shell-model calculations, which indicate a substantial contribution to the total ² strength from high-energy first-forbidden ²-decay transitions in this mass region. © 2013 American Physical Society.
Alharbi T, Mason PJR, Regan PH, Marginean N, Podolyak Z, Algora A, Alazemi N, Bruce AM, Britton R, Bunce MR, Bucurescu D, Cooper N, Deleanu D, Filipescu D, Gelletly W, Ghita D, Glodariu T, Ilie G, Kisyov S, Lintott J, Lalkovski S, Liddick S, Mihai C, Mulholland K, Marginean R, Negret A, Nakhostin M, Roberts OJ, Rice S, Smith JF, Stroe L, Sava T, Townsley C, Wilson E, Werner V, Zhekova M, Zamfir NV (2012) Electromagnetic Transition Rate Measurements in the N=80 Isotone, Ce-138, RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011381 IOP PUBLISHING LTD
Garnsworthy AB, Regan PH, Caceres L, Pietri S, Sun Y, Rudolph D, Gorska M, Podolyak Z, Steer SJ, Hoischen R, Heinz A, Becker F, Bednarczyk P, Doornenbal P, Geissel H, Gerl J, Grawe H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tachenov S, Werner-Malento E, Wollersheim HJ, Benzoni G, Blank BB, Brandau C, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Gelletly W, Ilie G, Jolie J, Jones GA, Jungclaus A, Kmiecik M, Kondev FG, Kurtukian-Nieto T, Lalkovski S, Liu Z, Maj A, Myalski S, Pfutzner M, Schwertel S, Shizuma T, Simons AJ, Walker PM, Wielandi O, Xu FR (2008) Neutron-proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei Nb-82(41) and Tc-86(43),PHYSICS LETTERS B660(4)pp. 326-330 ELSEVIER SCIENCE BV
Mohammadi S, Podolyak Z, de Angelis G, Axiotis M, Bazzacco D, Bizzeti PG, Brandolini F, Broda R, Bucurescu D, Farnea E, Gelletly W, Gadea A, Ionescu-Bujor M, Iordachescu A, Kroll T, Longdown S, Lunardi S, Marginean N, Martinez T, Medina NH, Quintana B, Regan PH, Rubio B, Ur CA, Dobon JJV, Walker PM, Zhang YH (2004) High-spin states populated in deep-inelastic reactions,BRAZILIAN JOURNAL OF PHYSICS34(3A)pp. 792-795 SOCIEDADE BRASILEIRA FISICA
Alharbi T, Regan PH, Marginean N, Podolyak Z, Roberts OJ, Bruce AM, Alkhomashi N, Britton R, Bucurescu D, Deleanu D, Filipescu D, Ghita D, Glodariu T, Mihai C, Mulholland K, Lica R, Marginean R, Nakhostin M, Negret A, Nita CR, Stroe L, Sava T, Townsley C, Zamfir NV (2015) Lifetime of the yrast I-pi=5(-) state and E1 hindrance in the transitional nucleus Ce-136(58),PHYSICAL REVIEW C91(2)ARTN 02730 AMER PHYSICAL SOC
© 2015 American Physical Society.The half-lives of the IÀ=5- and IÀ=7- yrast states with Ex=1978 keV and Ex=2307 keV in the N=78 isotone Ce136, have been measured to be 496(23) ps and 270(24) ps, respectively, using the coincident fast-timing spectroscopy technique following population by a Sn124(O16,4n) fusion-evaporation reaction at an incident beam energy of 68 MeV. The extracted B(E1;5-4+)=1.8(3)×10-6 W.u. value is compared with the systematics of the region and is found to be in line with typical E1 strengths for single-particle-type decays, rather than showing any evidence for the additional E1 decay hindrance associated with K-quantum number violation in axially deformed systems observed in lighter Ce isotopes.
Roberts OJ, Bruce AM, Regan PH, Podolyák Z, Townsley CM, Smith JF, Mulholland KF, Smith A (2014) A LaBr3 : Ce fast-timing array for DESPEC at FAIR, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment748pp. 91-95
The design of a fast-timing ³-ray detection array aimed at measuring sub-nanosecond half-lives using LaBr3:Ce scintillation crystals is presented. This array will complement novel and existing charged particle and neutron detector arrays at the low-energy branch of a fragment separator (Super-FRS) to be built within the NuSTAR collaboration as part of the future Facility for Anti-proton and Ion Research (FAIR). The array will be used in conjunction with the Advanced Implantation Detector Array (AIDA), to measure implant-decay correlations. Monte-Carlo simulations have been performed to determine the design of the proposed fast-timing array around a localised implantation point. In particular, simulations were used to determine the full-energy peak efficiencies for single cylindrical, conical and 'hybrid' detector geometries, as well as complete array configurations of 'hybrid' and â?...1.5 in.×2 in. cylindrical crystals. Timing precision calculations were then used to determine the timing response for each configuration based on its simulated efficiency. An informed decision based on the simulated efficiencies and timing precision calculations allowed the optimum configuration for the array to be determined. © 2014 Elsevier B.V.
Régis JM, Mach H, Simpson GS, Jolie J, Pascovici G, Saed-Samii N, Warr N, Bruce A, Degenkolb J, Fraile LM, Fransen C, Ghita DG, Kisyov S, Koester U, Korgul A, Lalkovski S, MÎrginean N, Mutti P, Olaizola B, Podolyak Z, Regan PH, Roberts OJ, Rudigier M, Stroe L, Urban W, Wilmsen D (2013) The generalized centroid difference method for picosecond sensitive determination of lifetimes of nuclear excited states using large fast-timing arrays, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment726
A novel method for direct electronic "fast-timing" lifetime measurements of nuclear excited states via ³-³ coincidences using an array equipped with Nâ??N equally shaped very fast high-resolution LaBr3(Ce) scintillator detectors is presented. Analogous to the mirror symmetric centroid difference method, the generalized centroid difference method provides two independent "start" and "stop" time spectra obtained by a superposition of the N(N-1) ³-³ time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific ³-³ cascade. Provided that the energy response and the electronic time pick-off of the detectors are almost equal, a mean prompt response difference between start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing arrays mean ³-³ time-walk characteristics can be determined for 40keV
Regan PH, Podolyák Z, Alharbi T, Mason PJR, Bruce AM, Townsley C, Roberts OJ, MÎrginean N, MÎrginean R, GhitÎ D, Mullholland K, Smith JF, Britton R, Patel Z, Nakhostin M, Rice S, Wilson E, Alazemi N, Alkhomashi N, Bucurescu D, Cata-Danil G, Deleanu D, Filipescu D, Glodariu T, Cata-Danil I, Mihai C, Negret A, Nita CR, Sava T, Stroe L, Suliman G, Detistov P, Garg U, Bender PC, Algora A, Liddick S, Cooper N, Werner V, Lalkovski S, Kisyov S, Browne F, Söderström PA, Watanabe H, Sumikama T (2013) Precision lifetime measurements using LaBr3 detectors with stable and radioactive beams, EPJ Web of Conferences63
A range of high resolution gamma-ray spectroscopy measurements have been carried out using arrays which include a number of Cerium-doped Lanthanum-Tribromide (LrBr3(Ce)) scintillation detectors used in conjunction with high-resolution hyper-pure germanium detectors. Examples of the spectral and temporal responses of such set-ups, using both standard point radioactive sources 152Eu and 56Co, and in-beam fusionevaporation reaction experiments for precision measurements of nuclear excited states in 34P and 138Ce are presented. The current and future use of such arrays at existing (EURICA at RIKEN) and future (NUSTAR at FAIR) secondary radioactive beam facilities for precision measurements of excited nuclear state lifetimes in the 10 ps to 10 ns regime are also discussed. © Owned by the authors, published by EDP Sciences, 2013.
Regan P, Stevenson P (2005) NUSTAR 2005, Journal of Physics G: Nuclear and Particle Physics31(10)
Alharbi T, Mason PJR, Regan PH, Podolyák Z, Mârginean N, Nakhostin M, Bowry M, Bucurescu D, Câta-Danil G, Câta-Danil I, Deleanu D, Filipescu D, Glodariu T, Ghicâ D, Mârginean R, Mihai C, Negret A, Pascu S, Sava T, Stroe L, Suliman G, Zamfir NV, Bruce AM, Rodriguez Triguero C, Bender PC, Garg U, Erduran MN, Kusoglu A, Bostan M, Detistov P, Alkhomashi N, Sinha AK, Chakrabarti R, Ghugre SS (2012) Gamma-ray fast-timing coincidence measurements from the 18O+ 18O fusion-evaporation reaction using a mixed LaBr 3 -HPGe array, Applied Radiation and Isotopes70(7)pp. 1337-1339
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 33,34P and 33S following fusion-evaporation reactions between an 18O beam and an isotopically enriched 18O 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 À=4 - "intruder" state previously reported in the N=19 isotone 34P. The extracted lifetime is consistent with a mainly single-particle M2 multipolarity associated with a f 7/2d 5/2 single particle transition. © 2011 Elsevier Ltd.
Santawamaitre T, Malain D, Al-Sulaiti HA, Matthews M, Bradley DA, Regan PH (2011) Study of natural radioactivity in riverbank soils along the Chao Phraya river basin in Thailand, SORMA XII 2010: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment652(1)pp. 920-924 Elsevier
Mohammadi S, Regan PH, Vincent SM, Blumenthal D, Carpenter M, Davids CN, Gelletly W, Janssens RVF, Lister CJ, Pearson CJ, Simpson J, Seweryniak D, Schwartz J, Warner DD (1999) High spin states in Ni-58, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 909-912 IOP PUBLISHING LTD
Daugas JM, Faul T, Grawe H, Pfuetzner M, Grzywacz R, Lewitowicz M, Achouri NL, Angelique JC, Baiborodin D, Bentida R, Beraud R, Borcea C, Bingham CR, Catford WN, Emsallem A, de France G, Grzywacz KL, Lemmon RC, Jimenez MJL, Santos FDO, Regan PH, Rykaczewski K, Sauvestre JE, Sawicka M, Stanoiu M, Sieja K, Nowacki F (2010) Low-lying isomeric levels in Cu-75,PHYSICAL REVIEW C81(3)ARTN 034304 AMER PHYSICAL SOC
Podolyak Z, Steer SJ, Pietri S, Xu FR, Liu HL, Regan PH, Rudolph D, Garnsworthy AB, Hoischen R, Gorska M, Gerl J, Wollersheim HJ, Kurtukian-Nieto T, Benzoni G, Shizuma T, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geissel H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Heinz A, Pfutzner M, Jungclaus A, Balabanski DL, Brandau C, Bruce AM, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Gelletly W, Ilie G, Jolie J, Jones GA, Kmiecik M, Kondev FG, Kruecken R, Lalkovski S, Liu Z, Maj A, Myalski S, Schwertel S, Walker PM, Werner-Malento E, Wieland O (2009) Weakly deformed oblate structures in Os-198(76)122,PHYSICAL REVIEW C79(3)ARTN 031305 AMER PHYSICAL SOC
Rudolph D, Pietri S, Podolyak Z, Regan PH, Garnsworthy AB, Hoischen R, Steer SJ, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geissel H, Gerl J, Gorska M, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Werner-Malento E, Wollersheim HJ, Andersson L-L, Atanasova L, Balabanski DL, Bentley MA, Benzoni G, Blank B, Blazhev A, Brandau C, Brown JR, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Fahlander C, Gelletly W, Heinz A, Hellstrom M, Ilie G, Johansson EK, Jolie J, Jones GA, Jungclaus A, Kmiecik M, Kondev FG, Kurtukian-Nieto T, Lalkovski S, Liu Z, Maj A, Myalski S, Pfutzner M, Shizuma T, Simons AJ, Schwertel S, Walker PM, Wieland O (2007) Exciting isomers from the first stopped-beam RISING campaign, EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 173-176 EDP SCIENCES S A
Al-Sulaiti H, Alkhomashi N, Al-Dahan N, Al-Dosari M, Bradley DA, Bukhari S, Matthews M, Regan PH, Santawamaitre T (2011) Determination of the natural radioactivity in Qatarian building materials using high-resolution gamma-ray spectrometry,Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment652(1)pp. 915-919 Elsevier
Thompson NJ, Regan PH, Garnsworth AB, Ayangeakaa AD, Ai HC, Amon L, Cakirli RB, Casten RF, Fitzpatrick CR, Freeman SJ, Gurdal G, Heinz A, Jones GA, McCutchan EA, Qian J, Werner V, Williams SJ, Winkler R (2007) Spectroscopy of Zr-91(51) at medium to high spins, ACTA PHYSICA POLONICA B38(4)pp. 1381-1384 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Benzoni G, Morales AI, Bracco A, Camera F, Crespi FCL, Corsi AM, Leoni S, Million B, Nicolini R, Wieland O, Valiente-Dobón JJ, Gottardo A, de Angelis G, Napoli DR, Sahin E, Gottardo A, Lunardi S, Bracco A, Camera F, Crespi FCL, Corsi AM, Leoni S, Nicolini R, Gadea A, Algora A, Lunardi S, Bazzacco D, Farnea E, Menegazzo R, Mengoni D, Recchia F, Ur CA, Boutachkov P, Górska M, Pietri S, Weick H, Cortes ML, Domingo-Pardo C, Engert T, Farinon F, Geissel H, Gerl J, Goel N, Gregor E, Habermann T, Hoischen R, Kojouharov I, Kurz N, Naqvi F, Nociforo C, Prochazka A, Prokopowicz W, Schaffner H, Sharma A, Wollersheim H-J, Bruce AM, Denis Bacelar AM, Grebosz J, Podolyak Z, Regan PH, Al-Dahan N, Bowry M, Bunce M, Deo AY, Farrelly GF, Reed MW, Swan TPD, Walker PM, Pfützner M, Alcántara Núñez J, Ayyad Y, Benlliure J, Alkhomashi N, Allegro PRP, Ribas RV, Casarejos E, Doncel M, Dombradi Z, Eppinger K, Klupp S, Steiger K, Hoischen R, Rudolph D, Janik R, Sitar B, Strmen P, Szarka I, Mandal S, Siwal D, Naqvi F (2012) First measurement of beta decay half-lives in neutron-rich Tl and Bi isotopes,Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
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 ²-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. All rights reserved.
Britton R, Regan PH, Burnett JL, Davies AV (2013) Monte-Carlo based background reduction and shielding optimisation for a large hyper-pure germanium detector, Journal of Radioanalytical and Nuclear Chemistrypp. 1-9
The performance of a radiation shielding system for a hyper-pure germanium detector has been characterised for Terrestrial radiation sources, Cosmic muons, X-ray fluorescence and the Compton scattering of source photons. Several methods to reduce the background seen are quantified, including increasing the inner radius of the Pb cave, and increasing the thickness of the shielding. Substantial improvements in the reduction of fluorescence X-rays are found to be achievable by modifying the liner thicknesses used. Increasing the Sn liner from 1.5 to 2.5 mm will increase the shielding of Pb X-rays from 95 to 99.5 %. Reducing the Cu liner from 1.0 to 0.5 mm maintains a 99.5 % level of shielding for Sn/Cd X-rays, however it greatly reduces the amount of Compton scattering of source photons into the detector (a process that is shown to cause an order of magnitude more events in the background than X-ray fluorescence). Cosmic muons were found to increase the amount of background radiation seen, both through direct interaction and the production of secondary radiation. The Cosmic muon contribution, however, was found to produce a much smaller effect than that caused by Terrestrial radiation and Compton scattered photons/fluorescence from the source. The total level of background radiation entering the detector chamber was found to decrease up to the full 200 mm of Pb shielding simulated. © 2013 Akadémiai Kiadó, Budapest, Hungary.
Regan PH, Wheldon C, Yamamoto AD, Wu CY, Ashley S, Mumby-Croft P, Seaborne D, Macchiavelli AO, Cline D, Smith JF, Chakrawarthy RS, Cromaz M, Fallon P, Freeman SJ, Gelletly W, Gorgen A, Hayes A, Hua H, Langdown SD, Lee IY, Pearson CJ, Podolyak Z, Teng R, Valiente-Dobon JJ (2004) Structural evolution in the (N,Z,I-pi) coordinate frame for A-100, NUCLEAR PHYSICS, LARGE AND SMALL726pp. 157-162 AMER INST PHYSICS
BRUCE AM, WALKER PM, REGAN PH, DRACOULIS GD, BYRNE AP, KIBEDI T, LANE GJ, YEUNG KC (1994) A K-PI=8- ISOMER IN SM-136, PHYSICAL REVIEW C50(1)pp. 480-482 AMERICAN PHYSICAL SOC
Simpson EC, Tostevin JA, Podolyak Z, Regan PH, Steer SJ (2009) Population of low-seniority isomeric states of Hg-206 by two-proton knockout reactions at relativistic energies,PHYSICAL REVIEW C80(6)ARTN 064608 AMER PHYSICAL SOC
Al-Sulaiti L, Shipley D, Thomas R, Kacperek A, Regan P, Palmans H (2010) Water equivalence of various materials for clinical proton dosimetry by experiment and Monte Carlo simulation, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 344-347 ELSEVIER SCIENCE BV
Wolf A, Berant Z, Heinz A, Werner V, McCutchan EA, Gurdal G, Cakirli RB, Oktem Y, Ai J, Amon L, Beausang CW, Brenner DS, Casten RF, Casperson RJ, Dusling K, Fitzpatrick CR, Gransworthy AB, Pietralla N, Qian J, Regan PH, Thompson NJ, Williams E, Winkler R (2007) g factor of the 2(1)(+) state of (170)Hf, PHYSICAL REVIEW C76(4)ARTN 047308 AMER PHYSICAL SOC
Jerome SM, Ivanov P, Larijani C, Parker DJ, Regan PH (2014) The production of Neptunium-236g., J Environ Radioact138pp. 315-322
Radiochemical analysis of (237)Np is important in a number of fields, such as nuclear forensics, environmental analysis and measurements throughout the nuclear fuel cycle. However analysis is complicated by the lack of a stable isotope of neptunium. Although various tracers have been used, including (235)Np, (239)Np and even (236)Pu, none are entirely satisfactory. However, (236g)Np would be a better candidate for a neptunium yield tracer, as its long half-life means that it is useable as both a radiometric and mass spectrometric measurements. This radionuclide is notoriously difficult to prepare, and limited in scope. In this paper, we examine the options for the production of (236g)Np, based on work carried out at NPL since 2011. However, this work was primarily aimed at the production of (236)Pu, and not (236g)Np and therefore the rate of production are based on the levels of (236)Pu generated in the irradiation of (i) (238)U with protons, (ii) (235)U with deuterons, (iii) (236)U with protons and (iv) (236)U with deuterons. The derivation of a well-defined cross section is complicated by the relevant paucity of information on the variation of the (236m)Np:(236g)Np production ratio with incident particle energy. Furthermore, information on the purity of (236g)Np so produced is similarly sparse. Accordingly, the existing data is assessed and a plan for future work is presented.
Ressler JJ, Beausang CW, Ai H, Amro H, Caprio MA, Casten RF, Hecht AA, Langdown SD, McCutchan EA, Meyer DA, Regan PH, Sciacchitano MJS, Yamamoto A, Zamfir NV (2004) Isomer decay tagging in the heavy nuclei: Ra-210 and Ra-209, PHYSICAL REVIEW C69(3)ARTN 034331 AMERICAN PHYSICAL SOC
Podolyak Z, Steer S, Pietri S, Regan P, Rudolph D, Garnsworthy A, Hoischen R, Werner-Malento E, Gerl J, Gorska M, Wollersheim H-J (2006) NUCL 40-Nuclear structure and reaction studies: Isomers used as a tool, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY232 AMER CHEMICAL SOC
Steer SJ, Podolyak Z, Pietri S, Gorska M, Grawe H, Maier KH, Regan PH, Rudolph D, Garnsworthy AB, Hoischen R (2011) Isomeric states observed in heavy neutron-rich nuclei populated in the fragmentation of a (208)Pb beam,PHYSICAL REVIEW C84(4)ARTN 044313 American Physical Society
Al-Dahan N, Podolyák Z, Regan PH, Steer SJ, Bacelar AMD, Alkhomashi N, Górska M, Gerl J, Wollersheim HJ, Pietri SB, Grawe H, Deo AY, Farrelly G, Boutachkov P, Domingo-Pardo C, Algora A, Benlliure J, Bracco A, Bruce AM, Calore E, Casarejos E, Cullen IJ, Detistov P, Dombrádi Z, Doncel M, Farinon F, Geissel H, Gelletly W, Goel N, Grebosz J, Hoischen R, Kojouharov I, Kurz N, Lalkovski S, Leoni S, Molina F, Montanari D, Morales AI, Musumarra A, Napoli DR, Nicolini R, Nociforo C, Prochazka A, Prokopowicz W, Rubio B, Rudolph D, Schaffner H, Strmen P, Szarka I, Swan T, Valiente-Dobon JJ, Verma S, Walker PM, Weick H (2009) Isomeric states in 208Hg and 209Tl populated in fragmentation of 238U, Acta Physica Polonica B40(3)pp. 871-874 Jagellonian University
The nuclear structure of neutron-rich N > 126 nuclei has been investigated following their production via relativistic projectile fragmentation of a E/A = 1 GeV (238)U beam on a Be target. The preliminary analysis indicates the presence of previously unreported isomeric states in the N = 128 isotones (208)Hg and (209)Tl.
Regis J-M, Jolie J, Mach H, Simpson GS, Blazhev A, Pascovici G, Pfeiffer M, Rudigier M, Saed-Samii N, Warr N, Blanc A, de France G, Jentschel M, Koester U, Mutti P, Soldner T, Ur CA, Urban W, Bruce AM, Drouet F, Fraile LM, Ilieva S, Korten W, Kroell T, Lalkovski S, Marginean N, Paziy V, Podolyak Z, Regan PH, Stezowski O, Vancraeyenest A (2015) The Generalized Centroid Difference method for lifetime measurements via gamma-gamma coincidences using large fast-timing arrays, CGS15 - CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS93 E D P SCIENCES
Alkhomashi N, Regan PH, Podoyak Z, Pietri SB, Garnsworthy AB, Steer SJ, Benlliure J, Caserejos E, Gorska M, Gerl J, Wollersheim HJ, Grebosz J, Kurz N, Kojouharov I, Schaffner H, Alcora A, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Caceres L, Doornenbal P, Bacelar AMD, Cullen IJ, Estevez ME, Farrelly G, Fujita Y, Gelletly W, Hoischen R, Kumar R, Lalkovski S, Liu Z, Mihai C, Molina F, Muecher D, Rubio B, Tamii A, Tashenov S, Valiente-Dobon JJ, Walker PM, Woods PJ (2009) beta(-)-DELAYED AND ISOMER SPECTROSCOPY OF NEUTRON-RICH Ta AND W ISOTOPES,ACTA PHYSICA POLONICA B40(3)pp. 875-878 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Collins SM, Pearce AK, Regan PH, Keightley JD (2015) Precise measurements of the absolute gamma-ray emission probabilities of Ra-223 and decay progeny in equilibrium,APPLIED RADIATION AND ISOTOPES102pp. 15-28 PERGAMON-ELSEVIER SCIENCE LTD
Precise measurements of the absolute ³-ray emission probabilities have been made of radiochemically pure solutions of (223)Ra in equilibrium with its decay progeny, which had been previously standardised by 4À(liquid scintillation)-³ digital coincidence counting techniques. Two high-purity germanium ³-ray spectrometers were used which had been accurately calibrated using a suite of primary and secondary radioactive standards. Comparison of the activity concentration determined by the primary technique against ³-ray spectrometry measurements using the nuclear data evaluations of the Decay Data Evaluation Project exhibited a range of ~18% in the most intense ³-ray emissions (>1% probability) of the (223)Ra decay series. Absolute ³-ray emission probabilities and standard uncertainties have been determined for the decay of (223)Ra, (219)Rn, (215)Po, (211)Pb, (211)Bi and (207)Tl in equilibrium. The standard uncertainties of the measured ³-ray emission probabilities quoted in this work show a significant improvement over previously reported ³-ray emission probabilities. Correlation coefficients for pairs of the measured ³-ray emission probabilities from the decays of the radionuclides (223)Ra, (219)Rn and (211)Pb have been determined and are presented. The ±-transition probabilities of the (223)Ra have been deduced from P(³+ce) balance using the ³-ray emission probabilities determined in this work with some agreement observed with the published experimental values of the ±-emission probabilities.
Bucurescu D, Rusu C, Marginean N, Ur CA, de Angelis G, Corradi L, Bazzacco D, Beghini S, Della Vedova F, Duchene G, Farnea E, Faul T, Fioretto E, Gadea A, Gelletly W, Guiot B, Ionescu-Bujor M, Iordachescu A, Landown SD, Lenzi SM, Lunardi S, Mason P, Mihai C, Marginean R, Menegazzo R, Montagnoli G, Napoli D, Podolyak Z, Regan PH, Scarlassara F, Stefanini AM, Suliman G, Szilner S, Trotta M, Valiente-Dobon JJ, Zhang YH (2007) gamma-ray spectroscopy of the neutron-rich nuclei (89)Rb, (92)Y, and (93)Y with multinucleon transfer reactions,PHYSICAL REVIEW C76(6)ARTN 064301 AMER PHYSICAL SOC
Brock TS, Nara Singh BS, Boutachkov P, Braun N, Blazhev A, Liu Z, Wadsworth R, Górska M, Grawe H, Pietri S, Domingo-Pardo C, Rudolph D, Steer SJ, Ataç A, Bettermann L, Cáceres L, Engert T, Eppinger K, Faestermann T, Farinon F, Finke F, Geibel K, Gerl J, Gernhäuser R, Goel N, Gottardo A, Gr)bosz J, Hinke C, Hoischen R, Ilie G, Iwasaki H, Jolie J, Ka_ka_ A, Kojuharov I, Krücken R, Kurz N, Merchán E, Nociforo C, Nyberg J, Pfützner M, Prochazka A, Podolyák Z, Regan PH, Reiter P, Rinta-Antila S, Schaffner H, Scholl C, Söderström P-A, Warr N, Weick H, Wollersheim H-J, Woods PJ (2010) Observation of a new high-spin isomer in Pd94,Physical Review C - Nuclear Physics82(6)
Walker PM, Yeung KC, Dracoulis GD, Regan PH, Lane GJ, Davidson PM, Stuchbery AE (1993) Backbending in 180W: a t-band crossing, Physics Letters B309(1-2)pp. 17-22
A Fermi-aligned (i 13 2)2 rotational band, with KH8, 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 H 180 region. © 1993.
Zakari-Issoufou AA, Algora A, Agramunt J, Aysto J, Bowry M, Bui VM, Caballero-Folch R, Cano-Ott D, Eloma V, Estevez E, Fallot M, Farrelly GF, Garcia A, Gelletly W, Gomez-Hornillos MB, Gorlychev V, Hakala J, Jokinen A, Jordan MD, Kankainen A, Kondev FG, Martinez T, Mendoza E, Molina F, Moore I, Perez A, Porta A, Podolyak Z, Penttila H, Regan PH, Rice S, Rissanen J, Rubio B, Tain JL, Valencia E, Weber C (2013) The total absorption spectroscopy technique for reactor technology and basic nuclear physics, IEEE Nuclear Science Symposium Conference Record
Understanding the ²-decay properties of fission products is very important for nuclear reactor monitoring & safety. Indeed, the ²-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. ²-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 ²-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.
Regan PH, Garnsworthy AB, Pietri S, Caceres L, Gorska M, Rudolph D, Podolyak Z, Steer SJ, Hoischen R, Gerl J, Wollersheim HJ, Grebosz J, Schaffner H, Prokopwicz W, Kojouharov I, Becker F, Bednarczyk P, Doornenball P, Geissel H, Grawe H, Kelic A, Kurz N, Montes F, Saito T, Tashenov S, Werner-Malento E, Heinz A, Atanasova L, Balabanski D, Benzoni G, Blank B, Blazhev A, Brandau C, Bruce AM, Camera F, Cullen IJ, Estevez ME, Fahlander C, Gelletly W, Ilie G, Jungclaus A, Jolie J, Kurtukian-Nieto T, Liu Z, Kmiecik M, Maj A, Myalski S, Schwertel S, Shizuma T, Simons AJ, Walker PM, Wieland O (2007) Isomer spectroscopy using relativistic projectile fragmentation at the N=Z line for A similar to 80 -> 90., NUCLEAR PHYSICS A787pp. 491C-498C ELSEVIER SCIENCE BV
Wheldon C, Valiente-Dobon JJ, Regan PH, Pearson CJ, Wu CY, Smith JF, Macchiavelli AO, Cline D, Chakrawarthy RS, Chapman R, Cromaz M, Fallon P, Freeman SJ, Gelletly W, Goergen AG, Hayes AB, Hua H, Langdown SD, Lee IY, Liang X, Podolyak Z, Sletten G, Teng R, Ward D, Warner DD, Yamamoto AD (2006) Observation of an isomeric state in Au-197,PHYSICAL REVIEW C74(2)ARTN 027303 AMERICAN PHYSICAL SOC
Page RD, Andreyev AN, Appelbe DE, Butler PA, Freeman SJ, Greenlees PT, Herzberg RD, Jenkins DG, Jones GD, Jones P, Joss DT, Julin R, Kettunen H, Leino M, Rahkila P, Regan PH, Simpson J, Uusitalo J, Vincent SM, Wadsworth R (2003) The GREAT spectrometer, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS204pp. 634-637 ELSEVIER SCIENCE BV
Caamano M, Regan PH, Podolyka Z, Pearson CJ, Mayet P, Gerl J, Schlegel C, Pfutzner M, Hellstrom M, Mineva M (2001) Nuclear structure of heavy neutron rich systems: Fragmentation spectroscopy with a 1 GeV per nucleon Pb-208 beam, NUCLEAR PHYSICS A682pp. 223C-228C ELSEVIER SCIENCE BV
Wilson E, Podolyák Z, Fornal B, Janssens RVF, Bowry M, Bunce M, Carpenter MP, Chiara CJ, Cieplicka N, Deo AY, Dracoulis GD, Grawe H, Hoffman CR, Kempley RS, Kondev FG, Lane GJ, Lauritsen T, Reed MW, Regan PH, Rodríguez Triguero C, Szpak B, Walker PM, Zhu S (2014) Study of 207Tl126 produced in deep-inelastic reactions,EPJ Web of Conferences66
Deep-inelastic collisions of a 208Pb beam on a 208Pb target were performed using the ATLAS accelerator at Argonne National Laboratory. The Gammasphere detector array was used for the detection of prompt and delayed gamma-rays of the reaction products.207Tl is one proton away from the 208Pb doubly-magic nucleus. Its low-energy level structure is dominated by the single proton-hole states Às1/2-1, Àd3/2-1 and Àh11/2-1. The 11/2- state is isomeric with T1/2 = 1.33(11) s. The reaction partner of 207Tl is 209Bi, which has arelatively well established level scheme compared to 207Tl. Cross-coincidences between these two nuclei were used to confirm or establish levels above the 11/2- isomeric state in 207Tl. These states are obtained via breaking of the neutron core. Angular correlation analysis was performed on known transitions in 208Pb, proving the applicability of this method for multipolarity assignment. © Owned by the authors, published by EDP Sciences, 2014.
Wheldon C, Walker PM, Regan PH, Saitoh T, Hashimoto N, Sletten G, Xu FR (1999) High-K structures and triaxiality in Os-186, NUCLEAR PHYSICS A652(2)pp. 103-131 ELSEVIER SCIENCE BV
Benzoni G, Morales AI, Valiente-Dobón JJ, Gottardo A, Bracco A, Camera F, Crespi FCL, Corsi AM, Leoni S, Million B, Nicolini R, Wieland O, Gadea A, Lunardi S, Boutachkov P, Bruce AM, Górska M, Grebosz J, Pietri S, Podolyak Z, Pfützner M, Regan PH, Weick H, Alcántara Núñez J, Algora A, Al-Dahan N, de Angelis G, Ayyad Y, Alkhomashi N, Allegro PRP, Bazzacco D, Benlliure J, Bowry M, Bunce M, Casarejos E, Cortes ML, Denis Bacelar AM, Deo AY, Domingo-Pardo C, Doncel M, Dombradi Z, Engert T, Eppinger K, Farrelly GF, Farinon F, Farnea E, Geissel H, Gerl J, Goel N, Gregor E, Habermann T, Hoischen R, Janik R, Klupp S, Kojouharov I, Kurz N, Mandal S, Menegazzo R, Mengoni D, Napoli DR, Naqvi F, Nociforo C, Prochazka A, Prokopowicz W, Recchia F, Ribas RV, Reed MW, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steiger K, Strmen P, Swan TPD, Szarka I, Ur CA, Walker PM, Wollersheim HJ (2012) First measurement of beta decay half-lives in neutron-rich Tl and Bi isotopes, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics715(4-5)pp. 293-297
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 ²-decay half-lives of Bi 219 and Tl 211,212,213 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.
Gottardo A, Valiente-Dobón JJ, de Angelis G, Modamio V, Napoli DR, Sahin E, Lunardi S, John PR, Lenzi SM, Benzoni G, Bracco A, Camera F, Crespi FCL, Corsi A, Leoni S, Million B, Morales AI, Nicolini R, Wieland O, Gadea A, Algora A, Bazzacco D, Farnea E, Menegazzo R, Mengoni D, Recchia F, Ur CA, Boutachkov P, Górska M, Pietri S, Weick H, Cortes ML, Domingo-Pardo C, Engert T, Farinon F, Geissel H, Gerl J, Goel N, Gregor E, Habermann T, Hoischen R, Kojouharov I, Kurz N, Naqvi F, Nociforo C, Prochazka A, Prokopowicz W, Schaffner H, Sharma A, Wollersheim H-J, Bruce AM, Bunce M, Denis Bacelar AM, Grebosz J, Podolyák Z, Regan PH, Al-Dahan N, Bowry M, Deo AY, Farrelly GF, Reed MW, Swan TPD, Walker PM, Pfützner M, Alcántara Núñez J, Ayyad Y, Benlliure J, Alkhomashi N, Allegro PRP, Ribas RV, Casarejos E, Doncel M, Dombradi Z, Eppinger K, Klupp S, Steiger K, Rudolph D, Janik R, Sitar B, Strmen P, Szarka I, Mandal S, Siwal D (2013) New ¼s isomers in the neutron-rich Hg nucleus, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
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 ½ g 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. All rights reserved.
Bacelar AMD, Bruce AM, Podolyak Z, Lalkovski S, Pietri S, Al-Dahan N, Gorska M, Algora A, Alkhomashi N, Benlliure J, Boutachkov P, Bracco A, Calore E, Casarejos E, Cullen IJ, Deo AY, Detistov P, Dombradi Z, Domingo-Pardo C, Doncel M, Farinon F, Farrelly GF, Geissel H, Gelletly W, Gerl J, Goel N, Grebosz J, Hoischen R, Kojouharov I, Kurz N, Leoni S, Molina F, Morales AI, Montanari D, Musumarra A, Nicolini R, Napoli DR, Nociforo C, Prochazka A, Prokopowicz W, Regan PH, Rubio B, Rudolph D, Verma S, Steer SJ, Strmen P, Swan TPD, Szarka I, Valiente-Dobon JJ, Walker PM, Weick H, Wollersheim HJ (2009) ANGULAR MOMENTUM POPULATION IN FRAGMENTATION REACTIONS,ACTA PHYSICA POLONICA B40(3)pp. 889-892 POLISH ACAD SCIENCES INST PHYSICS
Al-Sulaiti L, Shipley D, Thomas R, Owen P, Kacperek A, Regan PH, Palmans H (2012) Water equivalence of some plastic-water phantom materials for clinical proton beam dosimetry., 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.
NicÎ CR, Bucurescu D, MÎrginean N, Avrigeanu M, Bocchi G, Bottoni S, Bracco A, Bruce AM, CÎta-Danil G, Coló G, Deleanu D, Filipescu D, GhicÎ DG, Glodariu T, Leoni S, Mihai C, Mason PJR, MÎrginean R, Negret A, PantelicÎ D, Podolyak Z, Regan PH, Sava T, Stroe L, Toma S, Ur CA, Wilson E (2014) Fast-timing lifetime measurements of excited states in Cu 67, Physical Review C - Nuclear Physics89(6)
The half-lives of the 9/2+, 13/2+, and 15/2+ yrast states in the neutron-rich Cu67 nucleus were determined by using the in-beam fast-timing technique. The experimentally deduced E3 transition strength for the decay of the 9/2+ level to the 3/2- ground state indicates that the wave function of this level might contain a collective component arising from the coupling of the odd proton p3/2 with the 3- state in Ni66. Theoretical interpretations of the 9/2+ state are presented within the particle-vibration weak-coupling scheme involving the unpaired proton and the 3- state from Ni66 and within shell-model calculations with a Ni56 core using the jj44b residual interaction. The shell model also accounts reasonably well for the other measured electromagnetic transition probabilities. © 2014 American Physical Society.
Georgiev G, Neyens G, Hass M, Balabanski DL, Bingham C, Borcea C, Coulier N, Coussement R, Daugas JM, de France G, Gorska M, Grawe H, Grzywacz R, Lewitowicz M, Mach H, Matea I, Santos FD, Page RD, Pfutzner M, Penionzhkevich YE, Podolyak Z, Regan PH, Rykaczewski K, Sawicka M, Smirnova NA, Sobolev Y, Stanoiu M, Teughels S, Vyvey K (2004) G-factors of isomeric states in the neutron-rich nuclei, EUROPEAN PHYSICAL JOURNAL A20(1)pp. 93-94 SPRINGER
Wadsworth R, Singh BSN, Steer AN, Jenkins DC, Bentley MA, Brock T, Davies P, Glover R, Pattabiraman NS, Scholey C, Grahn T, Greenlees PT, Jones P, Jakobsson U, Julin R, Juutinen S, Ketelhut S, Leino M, Nyman M, Perua P, Pakarinen J, Rahkila P, Ruotslainen P, Sorri J, Uusitalo J, Lister CJ, Butler PA, Dimmock M, Joss DT, Thomson J, Rinta-Antila S, Cederwall B, Hadinia B, Sandzelius M, Atac A, Betterman L, Blazhev A, Braun N, Finke F, Geibel K, Ilie G, Iwasaki H, Jolie J, Reiter P, Scholl C, Warr N, Boutachkov P, Caceres L, Domingo C, Engert T, Farinon F, Gerl J, Goel N, Gorska M, Grawe H, Kurz N, Kojuharov I, Pietri S, Nociforo C, Prochazka A, Wollersheim H-J, Eppinger K, Faestermann T, Hinke C, Hoischen R, Kruecken R, Gottardo A, Liu Z, Woods P, Grebosz J, Merchant E, Nyberg J, Soderstrom P-A, Podolyak Z, Regan P, Steer S, Pfutzner M, Rudolph D (2009) THE NORTHWEST FRONTIER: SPECTROSCOPY OF N similar to Z NUCLEI BELOW MASS 100,ACTA PHYSICA POLONICA B40(3)pp. 611-620 POLISH ACAD SCIENCES INST PHYSICS
Clough AS, Regan PH (2003) Undergraduate courses with an integral research year, EUROPEAN JOURNAL OF PHYSICS24(3)PII S0143-0807(03)58882-1pp. 321-328 IOP PUBLISHING LTD
Mason PJR, Podolyak Z, Arginean NM, Regan PH, Alexander T, Algora A, Alharbi T, Bowry M, Britton R, Bucurescu D, Bruce AM, Bunce M, Cata-Danil G, Cata-Danil I, Cooper N, Deleanu D, Delion D, Filipescu D, Gelletly W, Glodariu T, Gheorghe I, Ghita D, Ilie G, Ivanova D, Kisyov S, Lalkovski S, Lica R, Liddick SN, Marginean R, Mihai C, Mulholland K, Negret A, Nita CR, Rice S, Roberts OJ, Sava T, Smith JF, Soederstroem P-A, Stevenson PD, Stroe L, Toma S, Townsley C, Werner V, Wilson E, Wood RT, Zamfir NV, Zhekova M (2012) Li-7-Induced Reactions for Fast-Timing With LaBr3:Ce Detectors,NUCLEAR STRUCTURE AND DYNAMICS '121491pp. 93-96 AMER INST PHYSICS
Mohammadi S, Podolyák Z, De Angelis G, Axiotis M, Bazzacco D, Bizzeti PG, Brandolini F, Broda R, Bucurescu D, Farnea E, Gelletly W, Gadea A, Ionescu-Bujor M, Iordachescu A, Kröll T, Longdown S, Lunardi S, Marginean N, Martinez T, Medina NH, Quintana B, Regan PH, Rubio B, Ur CA, Valiente Dobón JJ, Walker PM, Zhang YH (2004) High-spin states populated in deep-inelastic reactions,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 H21. The observed new structures are tentatively interpreted as fragments of rotational bands built on multi-quasiparticle configurations.
Ashley SF, Regan PH, Andgren K, McCutchan EA, Zamfir NV, Amon L, Cakirli RB, Casten RF, Clark RM, Gelletly W, Guerdal G, Keyes KL, Meyer DA, Erduran MN, Papenberg A, Pietralla N, Plettner C, Rainovski G, Ribas RV, Thomas NJ, Vinson J, Warner DD, Werner V, Williams E, Liu HL, Xu FR (2007) Intrinsic state lifetimes in (103)Pd and (106,107)Cd,PHYSICAL REVIEW C76(6)ARTN 064302 AMER PHYSICAL SOC
Alkhomashi N, Regan PH, Podolyak Z, Pietri S, Garnsworthy AB, Steer SJ, Benlliure J, Caserejos E, Casten RF, Gerl J, Wollersheim HJ, Grebosz J, Farrelly G, Gorska M, Kojouharov I, Schaffner H, Algora A, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Bacelar AMD, Cullen IJ, Caceres L, Doornenbal P, Estevez ME, Fujita Y, Gelletly W, Hoischen R, Kumar R, Kurz N, Lalkovski S, Liu Z, Mihai C, Molina F, Morales AI, Muecher D, Prokopowicz W, Rubio B, Shi Y, Tamii A, Tashenov S, Valiente-Dobon JJ, Walker PM, Woods PJ, Xu FR (2009) beta(-)-delayed spectroscopy of neutron-rich tantalum nuclei: Shape evolution in neutron-rich tungsten isotopes,PHYSICAL REVIEW C80(6)ARTN 064308 AMER PHYSICAL SOC
Podolyak Z, Gladnishki KA, Gerl J, Hellstrom M, Kopatch Y, Mandal S, Gorska M, Regan PH, Wollersheim HJ, Schmidt KH, Yordanov O (2004) Angular momentum population in projectile fragmentation,LABYRINTH IN NUCLEAR STRUCTURE701pp. 280-284 AMER INST PHYSICS
Baxter AM, Byrne AP, Dracoulis GD, Davidson PM, McGoram TR, Regan PH, Chandler C, Gelletly W, Wheldon C, Julin R, Cocks JFC, Helariutta K, Jones P, Juutinen S, Kankaanpaa H, Kettunen H, Kuusiniemi P, Leino M, Muikku M, Savelius A, Janssens RVF, Brown T, Carpenter MP, Davids CN, Lauritsen T, Nisius D, Greenlees PT (1998) Identification of yrast states in Pb-187, PHYSICAL REVIEW C58(5)pp. 2671-2676 AMERICAN PHYSICAL SOC
Parry CM, Hibbert IM, Wadsworth R, Wilson AN, Paul ES, Galindo-Uribarri A, Janzen VP, Ward D, Mullins SM, Regan PH, Svensson CE, Wyss R (1999) Evidence for highly deformed bands in Sm-133(62)71, PHYSICAL REVIEW C60(5)ARTN 054314 AMERICAN PHYSICAL SOC
Anagnostatou V, Regan PH, Werner V, Xu FR, Dong GX, Bunce MR, McCarthy D, Bettermann L, Boniwell C, Casperson R, Chevrier R, Cooper N, Heinz A, Paurstein P, Radeck D, Smith MK, Williams E (2012) Electromagnetic transition rates in 100,101Pd using the Recoil Doppler Shift Technique, Applied Radiation and Isotopes70(7)pp. 1321-1324
The quadrupole deformations for the low-lying states in the transitional nuclei 100,101Pd 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 80Se beam impinging on a thin, self-supporting 24Mg target. States in 100Pd and 101Pd 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 35¼m and 750¼m. The mean-lifetimes for the lowest lying 2+ (in 100Pd) and 15/2- (in 101Pd) 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%. © 2011 Elsevier Ltd.
Lalkovski S, Bruce AM, Bacelar AMD, Gorska M, Pietri S, Podolyak Z, Bednarczyk P, Caceres L, Casarejos E, Cullen IJ, Doornenbal P, Farrelly GF, Garnsworthy AB, Geissel H, Gelletly W, Gerl J, Grebosz J, Hinke C, Ilie G, Ivanova D, Jaworski G, Kisyov S, Kojouharov I, Kurz N, Minkov N, Myalski S, Palacz M, Petkov P, Prokopowicz W, Regan PH, Schaffner H, Steer S, Tashenov S, Walker PM, Wollersheim HJ (2013) Submicrosecond isomer in Rh-117(45)72 and the role of triaxiality in its electromagnetic decay rate,PHYSICAL REVIEW C88(2)ARTN 024302 AMER PHYSICAL SOC
Algora A, Valencia E, Taín JL, Jordan MD, Agramunt J, Rubio B, Estevez E, Molina F, Montaner A, Guadilla V, Fallot M, Porta A, Zakari-Issoufou AA, Bui VM, Rice S, Podolyák Z, Regan PH, Gelletly W, Bowry M, Mason P, Farrelly GF, Rissanen J, Eronen T, Moore I, Penttilä H, Äystö J, Eloma V, Hakala J, Jokinen A, Kolkinen V, Reponen M, Sonnenschein V, Cano-Ott D, Martínez T, Mendoza E, Garcia AR, Gomez-Hornillos MB, Gorlychev V, Caballero-Folch R, Kondev FG, Sonzogni AA (2014) Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure, Nuclear Data Sheets120pp. 12-15
An overview is given of our activities related to the study of the beta decay of neutron rich nuclei relevant for nuclear applications. Recent results of the study of the beta decay of 87,88Br using a new segmented total absorption spectrometer are presented. The measurements were performed at the IGISOL facility using trap-assisted total absorption spectroscopy. © 2014 Elsevier Inc..
Podolyak Z, Steer SJ, Farrelly G, Gorska M, Grawe H, Maier HK, Regan PH, Benlliure J, Pietri S, Gerl J, Wollersheim HJ (2009) Structure of Neutron-rich N=126 Closed Shell Nuclei,NUCLEAR STRUCTURE AND DYNAMICS '091165pp. 86-89 AMER INST PHYSICS
Rudolph D, Hoischen R, Hellstrom M, Pietri S, Podolyak Z, Regan PH, Garnsworthy AB, Steer SJ, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Gerl J, Gorska M, Grebosz J, Kojouharov I, Kurz N, Prokopowicz W, Schaffner H, Wollersheim HJ, Andersson L-L, Atanasova L, Balabanski DL, Bentley MA, Blazhev A, Brandau C, Brown JR, Fahlander C, Johansson EK, Jungclaus A, Lenzi SM (2008) Isospin symmetry and proton decay: Identification of the 10(+) isomer in (54)Ni,PHYSICAL REVIEW C78(2)ARTN 021301 AMER PHYSICAL SOC
McCutchan EA, Zamfir NV, Caprio MA, Casten RF, Amro H, Beausang CW, Brenner DS, Hecht AA, Hutter C, Langdown SD, Meyer DA, Regan PH, Ressler JJ, Yamamoto AD (2004) Low spin states in Yb-162 and the X(5) critical point symmetry, PHYSICAL REVIEW C69(2)ARTN 024308 AMERICAN PHYSICAL SOC
Daugas JM, Sawicka M, Pfützner M, Matea I, Grawe H, Grzywacz R, Achouri NL, Angélique JC, Baiborodin D, Becker F, Bélier G, Bentida R, Béraud R, Bingham C, Borcea C, Borcea R, Bouchez E, Buta A, Catford WN, Dragulescu E, Emsallem A, De France G, Giovinazzo J, Girod M, Goutte H, Gorgiev G, Grzywacz-Jones KL, Hammache F, Ibrahim F, Lemmon RC, Lewitowicz M, Lopez-Jimenez MJ, Mayet P, Méot V, Negoita F, De Oliveira-Santos F, Perru O, Regan PH, Roig O, Rykaczewski K, Saint-Laurent MG, Sauvestre JE, Sletten G, Sorlin O, Stanoiu M, Stefan I, Stodel C, Theisen C, Verney D, Zylicz J (2006) Isomeric island in the vicinity of 66Fe, 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 ½g 9/2 shell. Moreover, the excitation energy of the first 2+ and 4+ states in the 68Fe have been established by ²-³ 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.
Podolyak Z, Steer SJ, Pietri S, Gorska M, Regan PH, Rudolph D, Garnsworthy AB, Hoischen R, Gerl J, Wollersheim HJ, Grawe H, Maier KH, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geissel H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Heinz A, Kurtukian-Nieto T, Benzoni G, Pfuetzner M, Jungclaus A, Balabanski DL, Brandau C, Brown BA, Bruce AM, Catford WN, Cullen IJ, Dombradi Z, Estevez ME, Gelletly W, Ilie G, Jolie J, Jones GA, Kmiecik M, Kondev FG, Kruecken R, Lalkovski S, Liu Z, Maj A, Myalski S, Schwertel S, Shizuma T, Walker PM, Werner-Malento E, Wieland O (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(+)),EUROPEAN PHYSICAL JOURNAL A42(3)pp. 489-493 SPRINGER
Al-Dahan N, Regan PH, Podolyák Z, Walker PM, Alkhomashi N, Dracoulis GD, Farrelly G, Benlliure J, Pietri SB, Casten RF, Stevenson PD, Gelletly W, Steer SJ, Garnsworthy AB, Casarejos E, Gerl J, Wollersheim HJ, Grebosz J, Górska M, Kojouharov I, Schaffner H, Algora A, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Cullen IJ, Denis Bacelar AM, Deo AY, Estevez ME, Fujita Y, Hoischen R, Kumar R, Lalkovski S, Liu Z, Mason PJ, Mihai C, Molina F, Mücher D, Rubio B, Tamii A, Tashenov S, Valiente-Dobón JJ, Woods PJ (2012) Multiple ² - Decaying states in 194Re: Shape evolution in neutron-rich osmium isotopes, Physical Review C - Nuclear Physics85(3)
² 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. ³ decays were observed and correlated with these secondary ions on an event-by-event basis such that ³-ray transitions following from both internal (isomeric) and ² decays were recorded. A number of discrete, ²-delayed ³-ray transitions associated with ² decays from 194Re to excited states in 194Os have been observed, including previously reported decays from the yrast IÀ=(6 +) state. Three previously unreported ³-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 ² --decaying states in 194Re. © 2012 American Physical Society.
REGAN PH, DRACOULIS GD, BYRNE AP, LANE GJ, KIBEDI T, WALKER PM, BRUCE AM (1995) HIGH-K STRUCTURES IN SM-136, PHYSICAL REVIEW C51(4)pp. 1745-1753 AMERICAN PHYSICAL SOC
Larijani C, Pickford OL, Collins SM, Ivanov P, Jerome SM, Keightley JD, Pearce AK, Regan PH (2015) Progress towards the production of the (NP)-N-236g standard sources and competing fission fragment production,RADIATION PHYSICS AND CHEMISTRY116pp. 69-73 PERGAMON-ELSEVIER SCIENCE LTD
© 2015 Elsevier Ltd. The isobaric distribution of fission residues produced following the bombardment of a natural uranium target with a beam of 25MeV protons has been evaluated. Decay analysis of thirteen isobarically distinct fission residues were carried out using high-resolution ³-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 238U at energies of 14MeV. Higher 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.
Morales AI, Benlliure J, Agramunt J, Algora A, Alkhomashi N, Alvarez-Pol H, Boutachkov P, Bruce AM, Caceres LS, Casarejos E, Bacelar AMD, Doornenbal P, Dragosavac D, Farrelly G, Gadea A, Gelletly W, Gerl J, Gorska M, Grebosz J, Kojouharov I, Molina F, Perez-Loureiro D, Pietri S, Podolyak Z, Regan PH, Rubio B, Shaffner H, Steer SJ, Tashenov S, Verma S, Wollersheim HJ (2011) Synthesis of N=127 isotones through (p,n) charge-exchange reactions induced by relativistic Pb-208 projectiles,PHYSICAL REVIEW C84(1)ARTN 011601 AMER PHYSICAL SOC
Regan PH, Jones GA, Podolyak Z, Yoshinaga N, Higashiyama K, de Angelis G, Zhang YH, Gadea A, Ur CA, Axiotis M, Bazzacco D, Broda R, Bucurescu D, Farnea E, Gelletly W, Ionescu-Bujor M, Iordachescu A, Kroll T, Langdown SD, Lenzi S, Lunardi S, Marginean N, Martinez T, Medina N, Menegazzo R, Napoli DR, Quintana B, Rubio B, Rusu C, Schwenger R, Tonev D, Valiente Dobon JJ, von Oertzen W (2006) Multinucleon transfer reactions to study single-particle evolution in Se isotopes, Capture Gamma-Ray Spectroscopy and Related Topics819pp. 464-471 AMER INST PHYSICS
Regan PH, Alkhomashi N, Al-Dahan N, Podolyak Z, Suckling EB, Stevenson PD, Pietri SB, Steer SJ, Garnsworthy AB, Gelletly W, Benlliure J, Morales AI, Gerl J, Gorska M, Wollersheim HJ, Kumar R, Grebosz J, Algora A, Benzoni G, Boutachkov P, Bruce AM, Casarejos E, Cullen IJ, Bacelar AMD, Blazhev A, Estevez ME, Farrelly G, Fujita Y, Hoischen R, Lalkovski S, Liu Z, Kojouharov I, Kurz N, Mihai C, Molina F, Muecher D, Rubio B, Schaffner H, Tashenov S, Tamii A, Dobon JJV, Walker PM, Woods PJ (2009) New Insights into the Structure of Exotic Nuclei Using the RISING Active Stopper,CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS1090pp. 122-129 AMER INST PHYSICS
Watanabe H, Zhang G, Yoshida K, Walker PM, Liu J, Wu J, Regan PH, Soderstrom P, Kanaoka H, Korkulu Z, Lee P, Nishimura S, Yagi A, Ahn D, Alharbi T, Baba H, Browne F, Bruce A, Fukuda R, Griffin C, Ideguchi E, Inabe N, Isobe T, Kanaya S, Kojouharov I, Kondev F, Kubo T, Kubono S, Kurz N, Kuti I, Lalkovski S, Lane; G, Lee C, Lee E, Lorusso G, Lotay GJ, Moon C, Nishizuka I, Nita C, Odahara A, Patel Z, Phong V, Podolyak Z, Roberts O, Sakurai H, Schaffner H, Shand CM, Shimizu Y, Sumikama T, Suzuki H, Takeda H, Terashima S, Vajta; Z, Valiente-Dobon J, Xu Z (2016) Long-lived K isomer and enhanced gamma vibration in the neutron-rich nucleus 172Dy: Collectivity beyond double midshell,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 À = 8 ? has been identified at 1278 keV, which decays to the ground-state and ³-vibrational bands through hindered electromagnetic transitions, as well as to the daughter nucleus 172Ho via allowed ² decays. The robust nature of the K À = 8 ? isomer and the ground-state rotational band reveals an axially-symmetric structure for this nucleus. Meanwhile, the ³-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 ³ vibration is discussed in comparison with the deformed Quasiparticle Random-Phase Approximation based on a Skyrme energy-density functional.
Bentley MA, Williams SJ, Joss DT, O'Leary CD, Bruce AM, Cameron JA, Carpenter MP, Fallon P, Frankland L, Gelletly W, Lister CJ, Martinez-Pinedo G, Poves A, Regan PH, Reiter P, Rubio B, Solano JS, Seweryniak D, Svensson CE, Vincent SM, Warner DD (2000) Mirror symmetry at high spin in Fe-51 and Mn-51, PHYSICAL REVIEW C62(5)ARTN 051303 AMERICAN PHYSICAL SOC
Pfutzner M, Regan PH, Walker PM, Caamano M, Gerl J, Hellstrom M, Mayet P, Schmidt KH, Podolyak Z, Mineva MN, Aprahamian A, Benlliure J, Bruce AM, Butler PA, Gil DC, Cullen DM, Doring J, Enquist T, Fox C, Garces Narro J, Geissel H, Gelletly W, Giovinazzo J, Gorska M, Grawe H, Grzywacz R, Kleinbohl A, Korten W, Lewitowicz M, Lucas R, Mach H, O'Leary CD, De Oliveira F, Pearson CJ, Rejmund F, Rejmund M, Sawicka M, Schaffner H, Schlegel C, Schmidt K, Theisen C, Vives F, Warner DD, Wheldon C, Wollersheim HJ, Wooding S (2002) Angular momentum population in the fragmentation of Pb-208 at 1 GeV/nucleon,PHYSICAL REVIEW C65(6)ARTN 064604 AMERICAN PHYSICAL SOC
Regan PH, Valiente-Dobon JJ, Wheldon C, Wu CY, Smith JF, Macchiavelli AO, Cline D, Chakrawarthy RS, Chapman R, Cromaz M, Fallon P, Freeman SJ, Gorgen A, Gelletly W, Hayes A, Langdown SD, Lee IY, Liang X, Pearson CJ, Podolyak Z, Teng R, Ward D, Warner DD, Yamamoto AD (2004) Production of exotic nuclear isomers in multi-nucleon transfer reactions, LASER PHYSICS LETTERS1(6)pp. 317-324 IOP PUBLISHING LTD
Tain JL, Algora A, Agramunt J, Guadilla V, Jordan MD, Montaner-Piza A, Rubio B, Valencia E, Cano-Ott D, Gelletly W, Martinez T, Mendoza E, Podolyak Z, Regan P, Simpson J, Smith AJ, Strachan J (2015) A decay total absorption spectrometer for DESPEC at FAIR,NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT803pp. 36-46 ELSEVIER SCIENCE BV
Garrett PE, Svensson CE, Ball GC, Hackman G, Zganjar EF, Andreoiu C, Andreyev A, Ashley SF, Austin RAE, Bandyopadhyay D, Becker JA, Chan S, Coombes H, Churchman R, Chakrawarthy RS, Finlay P, Grinyer GF, Hyland B, Illes E, Jones GA, Kulp WD, Leslie JR, Mattoon C, Morton AC, Pearson CJ, Phillips AA, Regan PH, Ressler JJ, Sarazin F, Schumaker MA, Schwarzenberg J, Smith MB, Valiente-dobón JJ, Walker PM, Williams SJ, Waddington JC, Watters LM, Wong J, Wood JL (2006) Gamma-ray spectroscopy at TRIUMF-ISAC,AIP Conference Proceedings819pp. 249-253
The 8À 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 ²-particle tagging, 5 Si(Li) detectors for conversion electrons, and 10 BaF2 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.
Valiente-Dobón JJ, Regan PH, Wheldon C, Wu CY, Yoshinaga N, Higashiyama K, Smith JF, Cline D, Chakrawarthy RS, Chapman R, Cromaz M, Fallon P, Freeman SJ, Görgen A, Gelletly W, Hayes A, Hua H, Langdown SD, Lee IY, Liang X, Macchiavelli AO, Pearson CJ, Podolyák Z, Sletten G, Teng R, Ward D, Warner DD, Yamamoto AD (2004) 136Ba studied via deep-inelastic collisions: Identification of the (½h11/2)10+-2 isomer, 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 ³-ray spectroscopy, evidence for an IÀ=(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 ³-ray fold versus the scattering angle of the recoils.
Gottardo A, Valiente-Dobón JJ, Benzoni G, Gadea A, Lunardi S, Boutachkov P, Bruce AM, Górska M, Grebosz J, Pietri S, Podolyák Z, Pfützner M, Regan PH, Weick H, Núñez JA, Algora A, Al-Dahan N, De Angelis G, Ayyad Y, Alkhomashi N, Allegro PRP, Bazzacco D, Benlliure J, Bowry M, Bracco A, Bunce M, Camera F, Casarejos E, Cortes ML, Crespi FCL, Corsi A, Bacelar AMD, Deo AY, Domingo-Pardo C, Doncel M, Dombradi Z, Engert T, Eppinger K, Farrelly GF, Farinon F, Farnea E, Geissel H, Gerl J, Goel N, Gregor E, Habermann T, Hoischen R, Janik R, John PR, Klupp S, Kojouharov I, Kurz N, Lenzi SM, Leoni S, Mandal S, Menegazzo R, Mengoni D, Million B, Modamio V, Morales AI, Napoli DR, Naqvi F, Nicolini R, Nociforo C, Prochazka A, Prokopowicz W, Recchia F, Ribas RV, Reed MW, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steiger K, Strmen P, Swan TPD, Szarka I, Ur CA, Walker PM, Wieland O, Wollersheim HJ (2014) New isomers in the neutron-rich region beyond 208Pb,EPJ Web of Conferences66
The region of neutron-rich nuclei beyond 208Pb has been very difficult to explore due to its high mass and exoticity. However, recent experimental improvements allowed one to perform a quite extended isomer decay spectroscopy of these nuclei. © Owned by the authors, published by EDP Sciences, 2014.
Britton R, Regan PH, Burnett JL, Davies AV (2014) Monte Carlo characterisation of a Compton suppressed broad-energy HPGe detector, Journal of Radioanalytical and Nuclear Chemistrypp. 1-7
GEANT4 Monte Carlo simulations have been successfully utilised to characterise a Compton suppressed broad-energy HPGe detector. The detector setup has been fully recreated in the simulation, which has been optimised to consistently reproduce the detector response. The peak efficiencies for both the primary BEGe detector and NaI(Tl) guard detectors agree with the simulated values for multiple test sources within 3 %. Compton suppression has also been simulated, with good agreement seen between the simulated and actual CSF values (<10 %) for multiple radionuclides. A secondary reference source was also simulated, which contained up to 30 radionuclides in a different geometry to that of the previous source. This showed excellent agreement with experimental data in both unsuppressed and suppressed modes of operation. © 2014 Akadémiai Kiadó, Budapest, Hungary.
Akkoyun S, Algora A, Alikhani B, Ameil F, De Angelis G, Arnold L, Astier A, Ataç A, Aubert Y, Aufranc C, Austin A, Aydin S, Azaiez F, Badoer S, Balabanski DL, Barrientos D, Baulieu G, Baumann R, Bazzacco D, Beck FA, Beck T, Bednarczyk P, Bellato M, Bentley MA, Benzoni G, Berthier R, Berti L, Beunard R, Lo Bianco G, Birkenbach B, Bizzeti PG, Bizzeti-Sona AM, Le Blanc F, Blasco JM, Blasi N, Bloor D, Boiano C, Borsato M, Bortolato D, Boston AJ, Boston HC, Bourgault P, Boutachkov P, Bouty A, Bracco A, Brambilla S, Brawn IP, Brondi A, Broussard S, Bruyneel B, Bucurescu D, Burrows I, Bürger A, Cabaret S, Cahan B, Calore E, Camera F, Capsoni A, Carrió F, Casati G, Castoldi M, Cederwall B, Cercus J-L, Chambert V, El Chambit M, Chapman R, Charles L, Chavas J, Clément E, Cocconi P, Coelli S, Coleman-Smith PJ, Colombo A, Colosimo S, Commeaux C, Conventi D, Cooper RJ, Corsi A, Cortesi A, Costa L, Crespi FCL, Cresswell JR, Cullen DM, Curien D, Czermak A, Delbourg D, Depalo R, Descombes T, Désesquelles P, Detistov P, Diarra C, Didierjean F, Dimmock MR, Doan QT, Domingo-Pardo C, Doncel M, Dorangeville F, Dosme N, Drouen Y, Duchêne G, Dulny B, Eberth J, Edelbruck P, Egea J, Engert T, Erduran MN, Ertürk S, Fanin C, Fantinel S, Farnea E, Faul T, Filliger M, Filmer F, Finck C, De France G, Gadea A, Gast W, Geraci A, Gerl J, Gernhäuser R, Giannatiempo A, Giaz A, Gibelin L, Givechev A, Goel N, González V, Gottardo A, Grave X, Gr)bosz J, Griffiths R, Grint AN, Gros P, Guevara L, Gulmini M, Görgen A, Ha HTM, Habermann T, Harkness LJ, Harroch H, Hauschild K, He C, Hernández-Prieto A, Hervieu B, Hess H, Hüyük T, Ince E, Isocrate R, Jaworski G, Johnson A, Jolie J, Jones P, Jonson B, Joshi P, Judson DS, Jungclaus A, Kaci M, Karkour N, Karolak M, Ka_ka_ A, Kebbiri M, Kempley RS, Khaplanov A, Klupp S, Kogimtzis M, Kojouharov I, Korichi A, Korten W, Kröll T, Krücken R, Kurz N, Ky BY, Labiche M, Lafay X, Lavergne L, Lazarus IH, Leboutelier S, Lefebvre F, Legay E, Legeard L, Lelli F, Lenzi SM, Leoni S, Lermitage A, Lersch D, Leske J, Letts SC, Lhenoret S, Lieder RM, Linget D, Ljungvall J, Lopez-Martens A, Lotodé A, Lunardi S, Maj A, Van Der Marel J, Mariette Y, Marginean N, Marginean R, Maron G, Mather AR, M)czyDski W, Mendéz V, Medina P, Melon B, Menegazzo R, Mengoni D, Merchan E, Mihailescu L, Michelagnoli C, Mierzejewski J, Milechina L, Million B, Mitev K, Molini P, Montanari D, Moon S, Morbiducci F, Moro R, Morrall PS, Möller O, Nannini A, Napoli DR, Nelson L, Nespolo M, Ngo VL, Nicoletto M, Nicolini R, Le Noa Y, Nolan PJ, Norman M, Nyberg J, Obertelli A, Olariu A, Orlandi R, Oxley DC, Özben C, Ozille M, Oziol C, Pachoud E, Palacz M, Palin J, Pancin J, Parisel C, Pariset P, Pascovici G, Peghin R, Pellegri L, Perego A, Perrier S, Petcu M, Petkov P, Petrache C, Pierre E, Pietralla N, Pietri S, Pignanelli M, Piqueras I, Podolyak Z, Le Pouhalec P, Pouthas J, Pugnére D, Pucknell VFE, Pullia A, Quintana B, Raine R, Rainovski G, Ramina L, Rampazzo G, La Rana G, Rebeschini M, Recchia F, Redon N, Reese M, Reiter P, Regan PH, Riboldi S, Richer M, Rigato M, Rigby S, Ripamonti G, Robinson AP, Robin J, Roccaz J, Ropert J-A, Rossé B, Rossi Alvarez C, Rosso D, Rubio B, Rudolph D, Saillant F, ^ahin E, Salomon F, Salsac M-D, Salt J, Salvato G, Sampson J, Sanchis E, Santos C, Schaffner H, Schlarb M, Scraggs DP, Seddon D, ^enyiçit M, Sigward M-H, Simpson G, Simpson J, Slee M, Smith JF, Sona P, Sowicki B, Spolaore P, Stahl C, Stanios T, Stefanova E, Stézowski O, Strachan J, Suliman G, Söderström P-A, Tain JL, Tanguy S, Tashenov S, Theisen C, Thornhill J, Tomasi F, Toniolo N, Touzery R, Travers B, Triossi A, Tripon M, Tun-Lanoë KMM, Turcato M, Unsworth C, Ur CA, Valiente-Dobon JJ, Vandone V, Vardaci E, Venturelli R, Veronese F, Veyssiere C, Viscione E, Wadsworth R, Walker PM, Warr N, Weber C, Weisshaar D, Wells D, Wieland O, Wiens A, Wittwer G, Wollersheim HJ, Zocca F, Zamfir NV, Zi)bliDski M, Zucchiatti A (2012) AGATA - Advanced GAmma Tracking Array,Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment668pp. 26-58 Elsevier
Valiente-Dobon JJ, Pearson CJ, Regan PH, Sellin PJ, Gelletly W, Morton E, Boston A, Descovich M, Nolan PJ, Simpson J, Lazarus I, Warner D (2003) Performance of a 6x6 segmented germanium detector for gamma-ray tracking, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT505(1-2)pp. 174-177 ELSEVIER SCIENCE BV
Garnsworthy AB, Regan PH, Pietri S, Rudolph D, Caceres L, Gorska M, Podolyak Z, Steer SJ, Heinz A, Becker F, Bednarczyk P, Doornenbal P, Geissel H, Gerl J, Grawe H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopwicz W, Saito T, Schaffner H, Tachenov S, Werner-Malento E, Wollersheim HJ, Benzoni G, Blank B, Brandau C, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Gelletly W, Hoischen R, Ilie G, Jolie J, Jones GA, Jungclaus A, Kmiecik M, Kondev FG, Kurtukian-Nieto T, Lalkovski S, Liu Z, Maj A, Myalski S, Pfutzner M, Shizuma T, Simons AJ, Schwertel S, Walker PM, Wieland O (2007) Isomeric states in the light Tc isotopes, ACTA PHYSICA POLONICA B38(4)pp. 1265-1269 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Al-Dahan N, Podolyak Z, Regan PH, Gorska M, Grawe H, Maier KH, Gerl J, Pietri SB, Wollersheim HJ, Alkhomashi N, Deo AY, Bacelar AMD, Farrelly G, Steer SJ, Bruce AM, Boutachkov P, Domingo-Pardo C, Algora A, Benlliure J, Bracco A, Calore E, Casarejos E, Cullen IJ, Detistov P, Dombradi Z, Doncel M, Farinon F, Gelletly W, Geissel H, Goel N, Grebosz J, Hoischen R, Kojouharov I, Kurz N, Lalkovski S, Leoni S, Molina F, Montanari D, Morales AI, Musumarra A, Napoli DR, Nicolini R, Nociforo C, Prochazka A, Prokopowicz W, Rubio B, Rudolph D, Schaffner H, Strmen P, Szarka I, Swan T, Thomas JS, Valiente-Dobon JJ, Verma S, Walker PM, Weick H (2009) Nuclear structure "southeast" of Pb-208: Isomeric states in Hg-208 and Tl-209,PHYSICAL REVIEW C80(6)ARTN 061302 AMER PHYSICAL SOC
Alkhomashi N, Regan PH, Podolyák Z, Pietri S, Garnsworthy AB, Steer SJ, Benlliure J, Caserejos E, Casten RF, Gerl J, Wollersheim HJ, Grebosz J, Farrelly G, Górska M, Kojouharov I, Schaffner H, Algora A, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Bacelar AMD, Cullen IJ, Cáceres L, Doornenbal P, Estevez ME, Fujita Y, Gelletly W, Hoischen R, Kumar R, Kurz N, Lalkovski S, Liu Z, Mihai C, Molina F, Morales AI, Mücher D, Prokopowicz W, Rubio B, Shi Y, Tamii A, Tashenov S, Valiente-Dobón JJ, Walker PM, Woods PJ, Xu FR (2009) ² - Dcopy of neutron-rich tantalum nuclei: Shape evolution in neutron-rich tungsten isotopes,Physical Review C - Nuclear Physics80(6)064308pp. 1-12
Kempley RS, Podolyak Z, Bazzacco D, Gadea A, Farnea E, Valiente-Dobon JJ, Mengoni D, Recchia F, Sahin E, Gottardo A, Corradi L, Fioretto E, Szilner S, Anagnostatou V, Al-Dahan N, De Angelis G, Bellato M, Berti B, Bortolato D, Bowry M, Bunce M, Cocconi P, Colombo A, Dombradi Z, Fanin C, Gelletly W, Isocrate R, Ketenci S, Kondratyev N, Kuti I, Mason PJR, Michelagnoli C, Mijatovic T, Molini P, Montagnioli G, Montanari D, Nakhostin M, Napoli DR, Pellegrini D, Regan PH, Rampazzo G, Reiter P, Rosso D, Scarlassara F, Stefanini A, Singh P, Toniolo N, Ur CA (2011) CROSS-COINCIDENCES IN THE Xe-136+Pb-208 DEEP-INELASTIC REACTION,ACTA PHYSICA POLONICA B42(3-4)pp. 717-720 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Gottardo A, Valiente-Dobón JJ, Benzoni G, Nicolini R, Gadea A, Lunardi S, Boutachkov P, Bruce AM, Górska M, Grebosz J, Pietri S, Podolyák Z, Pfützner M, Regan PH, Weick H, Alcántara Núñez J, Algora A, Al-Dahan N, De Angelis G, Ayyad Y, Alkhomashi N, Allegro PRP, Bazzacco D, Benlliure J, Bowry M, Bracco A, Bunce M, Camera F, Casarejos E, Cortes ML, Crespi FCL, Corsi A, Denis Bacelar AM, Deo AY, Domingo-Pardo C, Doncel M, Dombradi Z, Engert T, Eppinger K, Farrelly GF, Farinon F, Farnea E, Geissel H, Gerl J, Goel N, Gregor E, Habermann T, Hoischen R, Janik R, Klupp S, Kojouharov I, Kurz N, Lenzi SM, Leoni S, Mandal S, Menegazzo R, Mengoni D, Million B, Morales AI, Napoli DR, Naqvi F, Nociforo C, Prochazka A, Prokopowicz W, Recchia F, Ribas RV, Reed MW, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steiger K, Strmen P, Swan TPD, Szarka I, Ur CA, Walker PM, Wieland O, Wollersheim HJ, Nowacki F, Maglione E, Zuker AP (2012) New isomers in the full seniority scheme of neutron-rich lead isotopes: The role of effective three-body forces,Physical Review Letters109(16)
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.
Smith MB, Walker PM, Chakrawarthy RS, Austin RAE, Ball GC, Carroll JJ, Cunningham E, Finlay P, Garrett PE, Grinyer GF, Hackman G, Hyland B, Koopmans K, Kulp WD, Leslie JR, Phillips AA, Propri R, Regan PH, Sarazin F, Schumaker MA, Scraggs HC, Shizuma T, Svensson CE, von Schwarzenberg J, Waddington JC, Ward D, Wood JL, Washbrook B, Zganjar EF (2004) Studies of high-K isomers at TRIUMF-ISAC,Nuclear Physics A746(1-4 SP)
The properties of high-K isomers have been investigated by measuring ³ 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 KÀ = 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.
Yoshinaga N, Higashiyama K, Regan PH (2009) Shell model study of neutron rich Se and Ge isotopes,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.
Wilson E, Podolyák Z, Fornal B, Janssens RVF, Bowry M, Bunce M, Carpenter MP, Chiara CJ, Cieplicka N, Deo AY, Dracoulis GD, Grawe H, Hoffman CR, Kempley RS, Kondev FG, Lane GJ, Lauritsen T, Reed MW, Regan PH, Rodríguez Triguero C, Szpak B, Walker PM, Zhu S (2013) Core excitations across the neutron shell gap in 207Tl, Acta Physica Polonica B44(3)pp. 381-385
Deep-inelastic collisions of a 208Pb beam on a 208Pb target were performed using the ATLAS accelerator at Argonne National Laboratory. Prompt and delayed »-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 »-rays from its bettercharacterised reaction partner 209Bi. A number of new transitions were found in 207Tl.
Janas Z, Chandler C, Blank B, Regan PH, Bruce AM, Catford WN, Curtis N, Czajkowski S, Dessagne P, Fleury A, Gelletly W, Giovinazzo J, Grzywacz R, Lewitowicz M, Longour C, Marchand C, Miehé C, Orr NA, Page RD, Pearson CJ, Pravikoff MS, Reed AT, Saint-Laurent MG, Sheikh JA, Vincent SM, Wadsworth R, Warner DD, Winfield JS (1999) Observation of the Z = N + 1 Nuclei 7739Y, 7949Zr, and 8342Mo, 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.
Gladnishki KA, Podolyak Z, Regan PH, Gerl J, Hellstrom M, Kopatch Y, Mandal S, Gorska M, Page RD, Wollersheim HJ, Banu A, Benzoni G, Boardman H, La Commara M, Ekman J, Fahlander C, Geissel H, Grawe H, Kaza E, Korgul A, Matos M, Mineva MN, Pearson CJ, Plettner C, Rudolph D, Scheidenberger C, Schmidt KH, Shishkin V, Sohler D, Summerer K, Valiente-Dobon JJ, Walker PM, Weick H, Winkler M, Yordanov O (2004) Angular momentum population in the projectile fragmentation of U-238 at 750 MeV/nucleon, PHYSICAL REVIEW C69(2)ARTN 024617 AMERICAN PHYSICAL SOC
Parry CM, Boston AJ, Chandler C, Galindo-Uribarri A, Hibbert IM, Janzen VP, Joss DT, Mullins SM, Nolan PJ, Paul ES, Regan PH, Vincent SM, Wadsworth R, Ward D, Wyss R (1998) Yrast structures in the neutron-deficient Pr-127(59)68 and Pm-131(61)70 nuclei, PHYSICAL REVIEW C57(5)pp. 2215-2221 AMERICAN PHYSICAL SOC
Rath AK, Stevenson RD, Regan PH, Xu FR, Walker RM (2003) Self-consistent description of dysprosium isotopes in the doubly midshell region,PHYSICAL REVIEW C68(4)ARTN 044315 AMERICAN PHYSICAL SOC
Stevenson PD, Brine MP, Podolyak Z, Regan PH, Walker PM, Stone JR (2005) Shape evolution in the neutron-rich tungsten region, PHYSICAL REVIEW C72(4)ARTN 047303 AMERICAN PHYSICAL SOC
Regan PH (2012) From RISING to the DESPEC fast-timing project within NUSTAR at FAIR: Sub-nanosecond nuclear timing spectroscopy with LaBr 3 scintillators, Applied Radiation and Isotopes70(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) LaBr 3 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 --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 LaBr 3 detectors from 'in-beam' test experiments are presented together with initial plans for the geometry of the planned multi-detector LaBr 3(Ce) array for DESPEC. © 2012 Elsevier Ltd.
Britton R, Burnett J, Davies A, Regan PH (2013) Preliminary simulations of NaI(Tl) detectors, and coincidence analysis using event stamping, Journal of Radioanalytical and Nuclear Chemistry295(1)pp. 573-577
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. © 2012 Akadémiai Kiadó, Budapest, Hungary.
Bunce M, Regan PH, Werner V, Anagnostatou V, Beausang CW, Bowry M, Casperson RJ, Chen D, Cooper N, Goddard P, Hughes RO, Ilie G, Mason PJR, Pauerstein B, Reed MW, Ross TJ (2012) A shell model study of the high spin states of Y-88, RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011381 IOP PUBLISHING LTD
Regan PH, Menezes TM, Pearson CJ, Gelletly W, Purry CS, Walker PM, Juutinen S, Julin R, Helariutta K, Savelius A, Jones P, Jamsen P, Muikku M, Butler PA, Jones G, Greenlees P (1997) Observation of (h(11/2))(2) neutron alignments in Mo-100, Ru-104, and Pd-108 using deep inelastic reactions, PHYSICAL REVIEW C55(5)pp. 2305-2313 AMERICAN PHYSICAL SOC
Becker F, Korten W, Hannachi F, Paris P, Buforn N, Chandler C, Houry M, Hubel H, Jansen A, Le Coz Y, Liang CF, Lopez-Martens A, Lucas R, Mergel E, Regan PH, Schonwasser G, Theisen C (1999) Investigation of prolate-oblate shape-coexistence in Kr-74, EUROPEAN PHYSICAL JOURNAL A4(2)pp. 103-105 SPRINGER VERLAG
Santawamaitre T, Regan PH, Bradley DA, Matthews M, Malain D, Al-Sulaiti HA (2010) An evaluation of the level of naturally occurring radioactive material in soil samples along the Chao Phraya river basin, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 453-456 ELSEVIER SCIENCE BV
Patel Z, Söderström PA, Podolyák Z, Regan PH, Walker PM, Watanabe H, Ideguchi E, Simpson GS, Liu HL, Nishimura S, Wu Q, Xu FR, Browne F, Doornenbal P, Lorusso G, Rice S, Sinclair L, Sumikama T, Wu J, Xu ZY, Aoi N, Baba H, Bello Garrote FL, Benzoni G, Daido R, Fang Y, Fukuda N, Gey G, Go S, Gottardo A, Inabe N, Isobe T, Kameda D, Kobayashi K, Kobayashi M, Komatsubara T, Kojouharov I, Kubo T, Kurz N, Kuti I, Li Z, Matsushita M, Michimasa S, Moon CB, Nishibata H, Nishizuka I, Odahara A, ^ahin E, Sakurai H, Schaffner H, Suzuki H, Takeda H, Tanaka M, Taprogge J, Vajta Z, Yagi A, Yokoyama R (2014) Isomer decay spectroscopy of Sm 164 and Gd 166: Midshell collectivity around N=100,Physical Review Letters113(26)
© 2014 American Physical Society.Excited states in the N=102 isotones Gd166 and Sm164 have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for Gd166 and Sm164, respectively. Based on the decay patterns and potential energy surface calculations, including ²6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground-band energies of Gd166 and Sm164 (N=102) compared to Gd164 and Sm162 (N=100), respectively, presents evidence for the predicted deformed shell closure at N=100.
Al-Sulaiti H, Nasir T, Al Mugren KS, Alkhomashi N, Al-Dahan N, Al-Dosari M, Bradley DA, Bukhari S, Matthews M, Regan PH, Santawamaitre T, Malain D, Habib A (2012) Determination of the natural radioactivity levels in north west of Dukhan, Qatar using high-resolution gamma-ray spectrometry, Applied Radiation and Isotopes70(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 ~100keV up to 2.6MeV 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 35Bq/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 400Bq/kg, respectively. Our previous study reported a value of 201.9±1.5 Stat.±13 Syst.Bq/kg for 226Ra in one sample and further investigation in the current work determined a measured value for 226Ra of 342.00±1.9 Stat.±25 Syst.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. © 2011 Elsevier Ltd.
Tain JL, Valencia E, Algora A, Agramunt J, Rubio B, Rice S, Gelletly W, Regan P, Zakari-Issoufou A-A, Fallot M, Porta A, Rissanen J, Eronen T, Aysto J, Batist L, Bowry M, Bui VM, Caballero-Folch R, Cano-Ott D, Elomaa V-V, Estevez E, Farrelly GF, Garcia AR, Gomez-Hornillos B, Gorlychev V, Hakala J, Jordan MD, Jokinen A, Kolhinen VS, Kondev FG, Martinez T, Mendoza E, Moore I, Penttila H, Podolyak Z, Reponen M, Sonnenschein V, Sonzogni AA (2015) Enhanced gamma-Ray Emission from Neutron Unbound States Populated in beta Decay,PHYSICAL REVIEW LETTERS115(6)ARTN 06250 AMER PHYSICAL SOC
Doornenbal P, Bürger A, Rudolph D, Grawe H, Hübel H, Regan PH, Reiter P, Banu A, Beck T, Becker F, Bednarczyk P, Caceres L, Geissel H, Gerl J, Górska M, Gr)bosz J, Kavatsyuk M, Kavatsyuk O, Kelic A, Kojouharov I, Kurz N, Lozeva R, Montes F, Prokopowicz W, Saito N, Saito T, Schaffner H, Tashenov S, Weick H, Werner-Malento E, Winkler M, Wollersheim HJ, Al-Khatib A, Andersson LL, Atanasova L, Balabanski DL, Bentley MA, Benzoni G, Blazhev A, Bracco A, Brambilla S, Brandau C, Bringel P, Brown JR, Camera F, Chmel S, Clément E, Crespi FCL, Fahlander C, Garnsworthy AB, Görgen A, Hammond G, Hellström M, Hoischen R, Honma H, Johansson EK, Jungclaus A, Kmieciek M, Korten W, Maj A, Mandal S, Meczynski W, Million B, Neußer A, Nowacki F, Otsuka T, Pfützner M, Pietri S, Podolyák Z, Richard A, Seidlitz M, Steer SJ, Striepling T, Utsuno T, Walker J, Warr N, Wheldon C, Wieland O (2007) RISING: Gamma-ray spectroscopy with radioactive beams at GSI, 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 ³ 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.
Smith MB, Walker PM, Chakrawarthy RS, Austin RAE, Ball GC, Carroll JJ, Cunningham E, Finlay P, Garrett PE, Grinyer GF, Hackman G, Hyland B, Koopmans K, Kulp WD, Leslie JR, Phillips AA, Propri R, Regan PH, Sarazin F, Schumaker MA, Scraggs HC, Shizuma T, Svensson CE, von Schwarzenberg J, Waddington JC, Ward D, Wood JL, Washbrook B, Zganjar EF (2004) Studies of high-K isomers at TRIUMF-ISAC,NUCLEAR PHYSICS A746pp. 617C-620C ELSEVIER SCIENCE BV
Britton R, Burnett JL, Davies AV, Regan PH (2013) Improving the effectiveness of a low-energy Compton suppression system, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment729pp. 64-68
A novel method for collecting and processing coincidence data from a Compton Suppressed Low Energy Photon Spectrometer (LEPS) is presented, greatly simplifying the current setup and extending the suppression abilities of the system. Offline analysis is used, eliminating the need to discard coincidence data when vetoing coincident events with fast-timing electronics. Additional coincident events are identified that are usually missed, and which represent interactions in the active NaI(Tl) shield prior to an interaction in the LEPS detector. By suppressing these events, the Compton Suppression factor was improved by 144% for the 661.66 keV decay line in a 137Cs source. The geometry used for this particular Compton suppression system is highly sensitive to these effects, however similar event profiles are expected in all coincidence systems. © 2013 Elsevier B.V.
Britton R, Burnett JL, Davies AV, Regan PH (2013) Monte-Carlo based background reduction and shielding optimisation for a large hyper-pure germanium detector, Journal of Radioanalytical and Nuclear Chemistry298(3)pp. 1491-1499
The performance of a radiation shielding system for a hyper-pure germanium detector has been characterised for Terrestrial radiation sources, Cosmic muons, X-ray fluorescence and the Compton scattering of source photons. Several methods to reduce the background seen are quantified, including increasing the inner radius of the Pb cave, and increasing the thickness of the shielding. Substantial improvements in the reduction of fluorescence X-rays are found to be achievable by modifying the liner thicknesses used. Increasing the Sn liner from 1.5 to 2.5 mm will increase the shielding of Pb X-rays from 95 to 99.5 %. Reducing the Cu liner from 1.0 to 0.5 mm maintains a 99.5 % level of shielding for Sn/Cd X-rays, however it greatly reduces the amount of Compton scattering of source photons into the detector (a process that is shown to cause an order of magnitude more events in the background than X-ray fluorescence). Cosmic muons were found to increase the amount of background radiation seen, both through direct interaction and the production of secondary radiation. The Cosmic muon contribution, however, was found to produce a much smaller effect than that caused by Terrestrial radiation and Compton scattered photons/fluorescence from the source. The total level of background radiation entering the detector chamber was found to decrease up to the full 200 mm of Pb shielding simulated. © 2013 Akadémiai Kiadó, Budapest, Hungary.
Berant Z, Oster E, Casperson RJ, Wolf A, Werner V, Heinz A, Casten RF, Gurdal G, McCutchan EA, Brenner DS, Terry JR, Winkler R, Williams E, Qian J, Schmidt A, Smith MK, Ahn T, Beausang CW, Regan PH, Ross T, Bunce M, Darakchieva B, Meyer DA, LeBlanc J, Dudziak K, Bauer C, Henning G (2009) g factor of the 2(1)(+) state of Hf-172, PHYSICAL REVIEW C80(5)ARTN 057303 AMER PHYSICAL SOC
Gottardo A, Valiente-Dobón JJ, Benzoni G, Lunardi S, Gadea A, Algora A, Al-Dahan N, De Angelis G, Ayyad Y, Bazzacco D, Benlliure J, Boutachkov P, Bowry M, Bracco A, Bruce AM, Bunce M, Camera F, Casarejos E, Cortes ML, Crespi FCL, Corsi A, Denis Bacelar AM, Deo AY, Domingo-Pardo C, Doncel M, Engert T, Eppinger K, Farrelly GF, Farinon F, Farnea E, Geissel H, Gerl J, Goel N, Górska M, Grebosz J, Gregor E, Habermann T, Hoischen R, Janik R, John PR, Klupp S, Kojouharov I, Kurz N, Lenzi SM, Leoni S, Mandal S, Menegazzo R, Mengoni D, Million B, Modamio V, Morales AI, Napoli DR, Naqvi F, Nicolini R, Nociforo C, Pfützner M, Pietri S, Podolyák Z, Prochazka A, Prokopowicz W, Recchia F, Regan PH, Reed MW, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steiger K, Strmen P, Swan TPD, Szarka I, Ur CA, Walker PM, Weick H, Wieland O, Wollersheim HJ (2014) Isomeric decay spectroscopy of the Bi 217 isotope,Physical Review C - Nuclear Physics90(3)
© 2014 American Physical Society.The structure of the neutron-rich bismuth isotope Bi217 has been studied for the first time. The fragmentation of a primary U238 beam at the FRS-RISING setup at GSI was exploited to perform ³-decay spectroscopy, since ¼s isomeric states were expected in this nucleus. Gamma rays following the decay of a t1/2=3 ¼s isomer were observed, allowing one to establish the low-lying structure of Bi217. The level energies and the reduced electric quadrupole transition probability B(E2) from the isomeric state are compared to large-scale shell-model calculations.
Britton R, Burnett JL, Davies AV, Regan PH (2014) Maximising the sensitivity of a ³ spectrometer for low-energy, low-activity radionuclides using Monte Carlo simulations., J Environ Radioact134pp. 1-5
Monte-Carlo simulations have been utilised to determine the optimum material and thickness for a ³ spectrometer to be used for the assay of radionuclides that emit radiation in the 50-300 keV energy range. Both HPGe and LaBr3(Ce) materials were initially considered for use, however the additional background radiation and lack of resolution in the latter drove the selection of HPGe for further optimisation. Multiple thicknesses were considered for the HPGe detector, with the aim of improving the sensitivity of the system by maximising the efficiency for low energy emissions, and reducing the probability of interaction with (and therefore the continuum from) higher energy photons. The minimum amount of material needed to achieve this was found to be 15 mm for a source that is dominated by high energy (>2.614 MeV) photons, and 20-30 mm for a typical reference source (with photons of energy 59.54 keV-2.614 MeV).
Jones GA, Regan PH, Podolyak Z, Yoshinaga N, Higashiyama K, de Angelis G, Zhang YH, Gadea A, Ur CA, Axiotis M, Bazzacco D, Bucurescu D, Farnea E, Gelletly W, Ionescu-Bujor M, Iordachescu A, Kroell T, Langdown SD, Lenzi S, Lunardi S, Marginean N, Martinez T, Medina NH, Menegazzo R, Napoli DR, Quintana B, Rubio B, Rusu C, Schwenger R, Tonev D, Doban JJV, von Oertzen W (2007) Yrast studies of (80,82)Se using deep-inelastic reactions, PHYSICAL REVIEW C76(5)ARTN 054317 AMER PHYSICAL SOC
Regan PH, Shearman R, Judge SM, Lorusso G, Main P, Bell S, Collins SM, Ivanov P, Jerome SM, Keightley JD, Larijani C, Lotay G, Pearce AK (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, APPLICATIONS OF NOVEL SCINTILLATORS FOR RESEARCH AND INDUSTRY (ANSRI 2015)620 IOP PUBLISHING LTD
Regan PH, Thompson NJ, Garnsworthy AB, Ai HC, Amon L, Cakirli RB, Casten RF, Fitzpatrick CR, Freeman SJ, Gurdal G, Heinz A, Jones GA, McCutchan EA, Qian J, Werner V, Williams SJ, Winkler R (2006) Isomer and in-beam spectroscopy of medium-spin states in Zr-91,Zr-92, Capture Gamma-Ray Spectroscopy and Related Topics819pp. 35-39 AMER INST PHYSICS
Caprio MA, Zamfir NV, McCutchan EA, Casten RF, Berant Z, Amro H, Barton CJ, Beausang CW, Brenner DS, Cooper JR, Gill RL, Gurdal G, Hecht AA, Hutter C, Krucken R, Meyer DA, Novak JR, Pietralla N, Regan PH, Ressler JJ (2003) Measurement of 2(1)(+) level lifetimes in Yb-162 and Er-162 by fast electronic scintillation timing, EUROPEAN PHYSICAL JOURNAL A16(2)pp. 177-180 SPRINGER-VERLAG
Narro JG, Longour C, Regan PH, Blank B, Pearson CJ, Lewitowicz M, Miehe C, Gelletly W, Appelbe D, Axelsson L, Bruce AM, Catford WN, Chandler C, Clark RM, Cullen DM, Czajkowski S, Daugas JM, Dessagne P, Fleury A, Frankland L, Giovinazzo J, Greenhalg B, Grzywacz R, Harder M, Jones KL, Kelsall N, Kszczot T, Page RD, Reed AT, Sorlin O, Wadsworth R (2001) Fermi superallowed beta(+) decays and T=1 ground states of heavy odd-odd N=Z nuclei, PHYSICAL REVIEW C63(4)ARTN 044307 AMERICAN PHYSICAL SOC
O'Leary CD, Bentley MA, Lenzi SM, Martinez-Pinedo G, Warner DD, Bruce AM, Cameron JA, Carpenter MP, Davids CN, Fallon P, Frankland L, Gelletly W, Janssens RVF, Joss DT, Lister CJ, Regan PH, Reiter P, Rubio B, Seweryniak D, Svensson CE, Vincent SM, Williams SJ (2002) Isovector pairing in odd-odd N=Z Mn-50, PHYSICS LETTERS B525(1-2)pp. 49-55 ELSEVIER SCIENCE BV
Vincent SM, Regan PH, Warner DD, Bark RA, Blumenthal D, Carpenter MP, Davids CN, Gelletly W, Janssens RVF, O'Leary CD, Lister CJ, Simpson J, Seweryniak D, Saitoh T, Schwartz J, Tormanen S, Juillet O, Nowacki F, Van Isacker P (1998) Competing T=0 and T=1 structures in the N=Z nucleus Ga-62(31), PHYSICS LETTERS B437(3-4)pp. 264-272 ELSEVIER SCIENCE BV
Saitoh TR, Saitoh-Hashimoto N, Sletten G, Bark RA, Bergström M, Regan P, Törmänen S, Varmette PG, Walker PM, Wheldon C (2000) Erratum to "collective and intrinsic structures in 183W" [nucl. Phys. A 660 (1999) 171-196] *, Nuclear Physics A669(3-4)pp. 381-406
The structure of 183W has been studied by employing the 176Yb(14C,± 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 ³-vibration of a one-quasiparticle structure have been newly identified. In the ½7/2-[503] and ½11/2+[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 g factors. In the À = 19-M rotational band, a Coriolis effect on the ½1/2-[510] neutron has been identified. In all, 17 -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.
Purry CS, Walker PM, Dracoulis GD, Kibedi T, Kondev FG, Bayer S, Bruce AM, Byrne AP, Gelletly W, Regan PH, Thwaites C, Burglin O, Rowley N (1998) Multi-quasiparticle isomers and rotational bands in W-178, NUCLEAR PHYSICS A632(2)pp. 229-274 ELSEVIER SCIENCE BV
CHAPPELL SPG, WATSON DL, FOX SP, JONES CD, RAE WDM, SIMMONS PM, FREER M, FULTON BR, CLARKE NM, CURTIS N, LEDDY MJ, POPLE JS, HALL SJ, WARD RP, TUNGATE G, CATFORD WN, GYAPONG GJ, SINGER SM, REGAN PH (1995) C-12+C-12 6-ALPHA-CHAIN STATE RESONANCE, PHYSICAL REVIEW C51(2)pp. 695-700 AMERICAN PHYSICAL SOC
Valencia E, Algora A, Tain JL, Rice S, Agramunt J, Zakari-Issoufou AA, Porta A, Fallot M, Jordan MD, Molina F, Estevez E, Bowry M, Bui VM, Caballero-Folch R, Cano-Ott D, Eloma V, Eronen T, Garcia A, Gomez-Hornillos MB, Gorlychev V, Hakala J, Jokinen A, Kondev FG, Martinez T, Moore I, Rissanen J, Äystö J, Penttilä H, Kankainen A, Rubio B, Gelletly W, Perez A, Podolyak Z, Regan PH, Farrelly GF, Weber C, Mendoza E (2013) Total absorption ³-ray spectroscopy of beta delayed neutron emitters, 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.
Boutachkov P, Górska M, Grawe H, Blazhev A, Braun N, Brock TS, Liu Z, Nara Singh BS, Wadsworth R, Pietri S (2011) High-spin isomers in 96Ag: Excitations across the Z=38 and Z=50, N=50 closed shells,Physical Review C - Nuclear Physics84(4)044311 American Physical Society
Alharbi T, Regan PH, Mason PJR, MÎrginean N, Podolyák Z, Bruce AM, Simpson EC, Algora A, Alazemi N, Britton R, Bunce MR, Bucurescu D, Cooper N, Deleanu D, Filipescu D, Gelletly W, GhitÎ D, Glodariu T, Ilie G, Kisyov S, Lintott J, Lalkovski S, Liddick S, Mihai C, Mulholland K, MÎrginean R, Negret A, Nakhostin M, Nita CR, Roberts OJ, Rice S, Smith JF, Stroe L, Sava T, Townsley C, Wilson E, Werner V, Zhekova M, Zamfir NV (2013) Electromagnetic transition rates in the N=80 nucleus 58138Ce, Physical Review C - Nuclear Physics87(1)
The half-life of the IÀ=6+ yrast state at Ex=2294 keV in 138Ce has been measured as T1/2=880(19) ps using the fast-timing ³-ray coincidence method with a mixed LaBr3(Ce)- HPGe array. The excited states in 138Ce have been populated by the 130Te(12C,4n) fusion-evaporation reaction at an incident beam energy of 56 MeV. The extracted B(E2;61+41+)=0.101(24) W.u. value is compared with the predictions of truncated basis shell model calculations and with the systematics of the region. This shows an anomalous behavior compared to the neighboring isotonic and isotopic chains. Half-lives for the yrast 5-, 11+ and 14+ states in 138Ce have also been determined in this work. © 2013 American Physical Society.
PURRY CS, WALKER PM, DRACOULIS GD, KIBEDI T, BAYER S, BRUCE AM, BYRNE AP, DASGUPTA M, GELLETLY W, KONDEV F, REGAN PH, THWAITES C (1995) ROTATION OF AN 8-QUASI-PARTICLE ISOMER,PHYSICAL REVIEW LETTERS75(3)pp. 406-409 AMERICAN PHYSICAL SOC
Nara Singh BS, Liu Z, Wadsworth R, Grawe H, Brock TS, Boutachkov P, Braun N, Blazhev A, Górska M, Pietri S, Rudolph D, Domingo-Pardo C, Steer SJ, Ataç A, Bettermann L, Cáceres L, Eppinger K, Engert T, Faestermann T, Farinon F, Finke F, Geibel K, Gerl J, Gernhäuser R, Goel N, Gottardo A, Grabosz J, Hinke C, Hoischen R, Ilie G, Iwasaki H, Jolie J, Ka_ka_ A, Kojouharov I, Krücken R, Kurz N, Merchán E, Nociforo C, Nyberg J, Pfützner M, Prochazka A, Podolyák Z, Regan PH, Reiter P, Rinta-Antila S, Scholl C, Schaffner H, Söderström P-A, Warr N, Weick H, Wollersheim H-J, Woods PJ, Nowacki F, Sieja K (2011) 16+ spin-gap isomer in Cd96,Physical Review Letters107(17)172502 American Physical Society
Pietri S, Regan PH, Podolyak Z, Rudolph D, Gorska M, Jungclaus A, Pfuetzner M, Garnsworthy AB, Steer SJ, Caceres L, Werner-Malento E, Hoischen R, Gerl J, Kojouharov I, Schaffner H, Wollersheim HJ, Becker F, Bednarczyk P, Doornenbal P, Geissel H, Grebosz J, Kelic A, Kurz N, Montes F, Prokopowicz W, Saito T, Tashenov S, Heinz A, Kurtukian-Nieto T, Benzoni G, Hellstrom M, Andersson L-L, Atanasova L, Balabanski DL, Bentley MA, Blank B, Blazhev A, Brandau C, Brown JR, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Fahlander C, Gelletly W, Ilie G, Johansson EK, Jolie J, Jones GA, Kmiecik M, Kondev FG, Lalkovski S, Liu Z, Maj A, Myalski S, Shizuma T, Simons AJ, Schwertel S, Walker PM, Wieland O (2007) First results from the stopped beam isomer rising campaign at GSI, ACTA PHYSICA POLONICA B38(4)pp. 1255-1264 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Hinke CB, Boehmer M, Boutachkov P, Faestermann T, Geissel H, Gerl J, Gernhaeuser R, Gorska M, Gottardo A, Grawe H, Grebosz JL, Kruecken R, Kurz N, Liu Z, Maier L, Nowacki F, Pietri S, Podolyak Z, Sieja K, Steiger K, Straub K, Weick H, Wollersheim H-J, Woods PJ, Al-Dahan N, Alkhomashi N, Atac A, Blazhev A, Braun NF, Celikovic IT, Davinson T, Dillmann I, Domingo-Pardo C, Doornenbal PC, de France G, Farrelly GF, Farinon F, Goel N, Habermann TC, Hoischen R, Janik R, Karny M, Kaskas A, Kojouharov IM, Kroell T, Litvinov Y, Myalski S, Nebel F, Nishimura S, Nociforo C, Nyberg J, Parikh AR, Prochazka A, Regan PH, Rigollet C, Schaffner H, Scheidenberger C, Schwertel S, Soederstroem P-A, Steer SJ, Stolz A, Strmen P (2012) Superallowed Gamow-Teller decay of the doubly magic nucleus Sn-100,NATURE486(7403)pp. 341-345 NATURE PUBLISHING GROUP
Denis Bacelar AM, Bruce AM, Podolyák Z, Al-Dahan N, Górska M, Lalkovski S, Pietri S, Ricciardi MV, Algora A, Alkhomashi N, Benlliure J, Boutachkov P, Bracco A, Calore E, Casarejos E, Cullen IJ, Deo AY, Detistov P, Dombradi Z, Domingo-Pardo C, Doncel M, Farinon F, Farrelly GF, Geissel H, Gelletly W, Gerl J, Goel N, Gr)bosz J, Hoischen R, Kojouharov I, Kurz N, Leoni S, Molina F, Montanari D, Morales AI, Musumarra A, Napoli DR, Nicolini R, Nociforo C, Prochazka A, Prokopowicz W, Regan PH, Rubio B, Rudolph D, Schmidt KH, Schaffner H, Steer SJ, Steiger K, Strmen P, Swan TPD, Szarka I, Valiente-Dobón JJ, Verma S, Walker PM, Weick H, Wollersheim HJ (2013) The population of metastable states as a probe of relativistic-energy fragmentation reactions,Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics723(4-5)pp. 302-306
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 238U beam by a 9Be 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 ¼s and spin values up to 55/2? 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.
Regan P, Blank B (2000) Exploring nuclear frontiers, PHYSICS WORLD13(1)pp. 29-34 IOP PUBLISHING LTD
Britton R, Burnett JL, Davies AV, Regan PH (2014) Monte-Carlo optimisation of a Compton suppression system for use with a broad-energy HPGe detector, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment762pp. 42-53
Monte-Carlo simulations are used to evaluate and optimise multiple components of a Compton Suppression System based upon a Broad-energy HPGe primary detector. Several materials for the secondary crystal are evaluated, including NaI(Tl), BGO and LaBr3(Ce). BGO was found to be the most effective across the required energy range, with the sizes of the proposed veto detector then optimised to extract the maximum performance for a given volume of material. Suppression factors are calculated for a range of nuclides (both single and cascade emitters) with improvements of 2 for the Compton Suppression Factors, and 10 for the continuum reduction when compared to the Compton suppression system currently in use. This equates to a reduction in the continuum by up to a factor of <240 for radionuclides such as 60Co, which is crucial for the detection of low-energy, low-activity ³ emitters typically swamped by such a continuum. © 2014 Published by Elsevier B.V. All rights reserved.
Nara Singh BS, Wadsworth R, Boutachkov P, Blazhev A, Liu Z, Grawe H, Brock TS, Braun N, Go M, Pietri S, Rudolph D, Domingo-Pardo C, Steer SJ, Atac A, Bettermann L, Cáceres L, Eppinger K, Engert T, Faestermann T, Farinon F, Finke F, Geibel K, Gerl J, Gernhäuser R, Goel N, Gottardo A, Gr)bosz J, Hinke C, Hoischen R, Llie G, Iwasaki H, Jolie J, Ka_ka_ A, Kojouharov I, Krücken R, Kurz N, Merchánt E, Nociforo C, Nyberg J, Pfützner M, Prochazka A, Podolyák Z, Regan PH, Reiter P, Rinta-Antila S, Scholl C, Schaffner H, Söderström P-A, Warr N, Weick H, Wollersheim H-J, Woods PJ, Nowacki F, Sieja K (2011) Exotic nuclear studies around and below A=100, AIP Conference Proceedings1409pp. 19-24 American Institute of Physics
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 ² 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.
Schunck N, Dudek J, Gozdz A, Regan PH (2004) Tetrahedral symmetry in ground and low-lying states of exotic A similar to 110 nuclei, PHYSICAL REVIEW C69(6)ARTN 061305 AMERICAN PHYSICAL SOC
Podolyak Z, Regan PH, Pfutzner M, Gerl J, Hellstrom M, Caamano M, Mayet P, Schlegel C, Aprahamian A, Benlliure J, Bruce AM, Butler PA, Gil DC, Cullen DM, Doring J, Enqvist T, Rejmund F, Fox C, Narro JG, Geissel H, Gelletly W, Giovinazzo J, Gorska M, Grawe H, Grzywacz R, Kleinbohl A, Korten W, Lewitowicz M, Lucas R, Mach H, Mineva M, O'Leary CD, De Oliveira F, Pearson CJ, Rejmund M, Sawicka M, Schaffner H, Schmidt K, Theisen C, Walker PM, Warner DD, Wheldon C, Wollersheim HJ, Wooding SC, Xu FR (2000) Isomer spectroscopy of neutron rich W-190(116), PHYSICS LETTERS B491(3-4)pp. 225-231 ELSEVIER SCIENCE BV
Steer SJ, Podolyak Z, Pietri S, Gorska M, Regan PH, Rudolph D, Werner-Malento E, Garnsworthy AB, Hoischen R, Gerl J, Wollersheim HJ, Maier KH, Grawe H, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geissel H, Greabosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Heinz A, Pfuetzner M, Kurtukian-Nieto T, Benzoni G, Jungclaus A, Balabanski DL, Brandau C, Brown BA, Bruce AM, Catford WN, Cullen IJ, Dombradi Z, Estevez ME, Gelletly W, Ilie G, Jolie J, Jones GA, Kmiecik M, Kondev FG, Kruecken R, Lalkovski S, Liu Z, Maj A, Myalski S, Schwertel S, Shizuma T, Walker PM, Wieland O (2008) Single-particle behavior at N=126: Isomeric decays in neutron-rich Pt-204,PHYSICAL REVIEW C78(6)ARTN 061302 AMER PHYSICAL SOC
Rudolph D, Hoischen R, Hellstrom M, Pietri S, Podolyak Z, Regan PH, Garnsworthy AB, Steer SJ, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Gerl J, Gorska M, Grebosz J, Kojouharov I, Kurz N, Prokopowicz W, Schaffner H, Wollersheim HJ, Andersson L-L, Atanasova L, Balabanski DL, Bentley MA, Blazhev A, Brandau C, Brown JR, Fahlander C, Johansson EK, Jungclaus A (2008) Evidence for an isomeric 3/2(-) state in (53)Co, EUROPEAN PHYSICAL JOURNAL A36(2)pp. 131-138 SPRINGER
Garnsworthy AB, Regan PH, Caceres L, Pietri Y, Sun Y, Rudolph D, Gorska M, Podolyak Z, Steer SJ, Hoischen R, Heinz A, Becker F, Bednarczyk R, Doornenbal P, Geissel H, Gerl J, Grawe H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tachenov S, Werner-Malento E, Wollersheim HJ, Benzoni G, Blank BB, Brandau C, Bruce AM, Camera F, Catford WN, Cullen IJ, Dornbradi Z, Estevez E, Gelletly W, Ilie G, Jolie J, Jones GA, Jungclaus A, Kmiecik M, Kondev FG, Kurtukian-Nieto T, Lalkovski S, Liu Z, Maj A, Myalski S, Pfutzner M, Schwertel S, Shizuma T, Simons AJ, Walker PM, Wieland O, Xu FR (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), PHYSICS LETTERS B668(5)pp. 460-460 ELSEVIER SCIENCE BV
Wheldon C, Valiente-Dobon JJ, Regan PH, Pearson CJ, Wu CY, Smith JF, Macchiavelli AO, Cline D, Chakrawarthy RS, Chapman R, Cromaz M, Fallon P, Freeman SJ, Gorgen A, Gelletly W, Hayes A, Hua H, Langdown SD, Lee IY, Liang X, Podolyak Z, Sletten G, Teng R, Ward D, Warner DD, Yamamoto AD (2004) Multi-quasi particle states in W-184 via multi-nucleon transfer, EUROPEAN PHYSICAL JOURNAL A20(3)pp. 365-369 SPRINGER
Boutachkov P, Braun N, Brock T, Singh BSN, Blazhev A, Liu Z, Wadsworth R, Górska M, Grawe H, Pietri S, Domingo-Pardo C, Faestermann T, Farinon F, Grebosz J, Kojuharov I, Kurz N, Nociforo C, Podolyák Z, Prochazka A, Steer S, Cáceres L, Engert T, Gerl J, Goel N, Hoischen R, Schaffner H, Weick H, Wollersheim HJ, Bettermann L, Finke F, Geibel K, Ilie G, Iwasaki H, Jolie J, Nyberg J, Reiter P, Scholl C, Söderström PA, Warr N, Eppinger K, Gottardo A, Hinke C, Krücken R, Pfützner M, Regan P, Rinta-Antila S, Rudolph D, Woods P, Ataç A, Merchán E (2011) Isomer and ²-decay spectroscopy of Tz=1 isotopes below the N=Z=50 shell gap, Journal of Physics: Conference Series312(SECTION 9)
The RISING setup at the GSI-FRS facility was used to investigate the isomer and beta decays in N
Mohammadi S, De Angrlis G, Axiotis M, Bazzacco D, Bizzeti PG, Brandolini F, Broda R, Bucurescu D, Farnea E, Gelletly W, Gadea A, Ionescu-Bujor M, Iordachescu A, Kröll T, Longdown S, Lunardi S, Marginean N, Martinez T, Medina N, Podolyák Z, Quintana B, Regan PH, Rubio B, Ur CA, Valiente Dobon JJ, Walker PM, Zhang YH (2006) Yrast states in 188,190 Os nuclei, International Journal of Modern Physics E15(8)pp. 1797-1802
Yrast states in neutron rich nuclei 188Os and 190Os have been populated using the deep-inelastic reaction 82Se + 192Os at 460 MeV beam bombarding energy. A thick 192Os target (>50 mg/cm2) with 0.2 mm Ta backing was used to stop all of the recoils in the target, minimising the broadening of the lines due to Doppler shift. High fold ³-³ coincidences were aquired with the 4À spectrometer GASP detector array. Three and two dimensional gamma-ray matrices were used to construct level schemes of the nuclei of interest up to an yrast state of 22. © World Scientific Publishing Company.
Bruce AM, Byrne AP, Dracoulis GD, Gelletly W, Kibedi T, Kondev FG, Purry CS, Regan PH, Thwaites C, Walker PM (1997) Systematics of K-pi=8(-) isomers in N=74 nuclei, PHYSICAL REVIEW C55(2)pp. 620-624 AMERICAN PHYSICAL SOC
Nasir T, Al-Sulaiti H, Regan PH (2012) Assessment of radioactivity in some soil samples of qatar by gamma-ray spectroscopy and the derived dose rates, 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.
Regan PH, Gamsworthy AB, Steer SJ, Pletri S, Podolyak Z, Rudolph D, Gorska M, Caceres L, Wemer-Malento E, Gerl J, Wollersheim HJ, Becker F, Bednarczyk P, Doornenbal PD, Geissel H, Grawe H, Grebosz J, Hoischen R, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Heinz A, Pfuetzner M, Kurtukian-Nieto T, Benzoni G, Hellstroem M, Jungclaus A, Andersson L-L, Atanasova L, Balabanski DL, Bentley MA, Blank B, Blazhev A, Brandau C, Brown J, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Fahlander C, Gelletly W, Ilie G, Johansson EK, Jolie J, Jones GA, Kmiecik M, Kondev G, Lalkovski S, Liu Z, Maj A, Myalski S, Schwertel S, Shizuma T, Simons AJ, Walker PM, Wieland O (2007) First results from the stopped RISING campaign at GSI: The mapping of isomeric decays in highly exotic nuclei, Six International Conference of the Balkan Physical Union899pp. 19-22 AMER INST PHYSICS
Williams SJ, Jenneson PM, Garrett PE, Regan PH, Andreoiu C, Ball GC, Chakrawarthy RS, Daoud JJ, Grinyer GF, Hackman G, Hyland B, Mlwilo NA, Morton AC, Pearson CJ, Ressler JJ, Schumaker MA, Smith MB, Svensson CE, Dobon JJV (2005) Testing the integration of BaF2 detectors into the 8 pi array: fast-timing measurements at TRIUMF, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1979-S1984 IOP PUBLISHING LTD
Pfutzner M, Armbruster P, Baumann T, Benlliure J, Bernas M, Catford WN, Cortina-Gil D, Daugas JM, Geissel H, Gorska M, Grawe H, Grzywacz R, Hellstrom M, Iwasa N, Janas Z, Junghans AR, Karny M, Leenhardt S, Lewitowicz M, Mueller AC, de Oliviera F, Regan PH, Rejmund M, Rykaczewski K, Summerer K (1998) New isotopes and isomers produced by the fragmentation of U-238 at 1000 MeV/nucleon, PHYSICS LETTERS B444(1-2)pp. 32-37 ELSEVIER SCIENCE BV
Regan PH (2012) From RISING to the DESPEC fast-timing project within NUSTAR at FAIR: sub-nanosecond nuclear timing spectroscopy with LaBr3 scintillators., 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 ²--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.
Malain D, Regan PH, Bradley DA, Matthews M, Al-Sulaiti HA, Santawamaitre T (2012) An evaluation of the natural radioactivity in Andaman beach sand samples of Thailand after the 2004 tsunami., 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 ¼Sv/y with a mean value of 59.1 ± 0.3 ¼Sv/y, significantly lower than the worldwide average as reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) (2000).
Malain D, Regan PH, Bradley DA, Matthews M, Santawamaitre T, Al-Sulaiti HA (2010) Measurements of NORM in beach sand samples along the Andaman coast of Thailand after the 2004 tsunami,NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 441-445 ELSEVIER SCIENCE BV
Zhang YH, Podolyak Z, de Angelis G, Gadea A, Ur C, Lunardi S, Marginean N, Rusu C, Schwengner R, Kroll T, Napoli DR, Menegazzo R, Bazzacco D, Farnea E, Lenzi S, Martinez T, Axiotis M, Tonev D, Gelletly W, Langdown S, Regan PH, Dobon JJV, von Oertzen W, Rubio B, Quintana B, Medina N, Broda R, Bucurescu D, Ionescu-Bujor M, Iordachescu A (2004) Stability of the N=50 shell gap in the neutron-rich Rb, Br, Se, and Ge isotones,PHYSICAL REVIEW C70(2)ARTN 024301 AMERICAN PHYSICAL SOC
Descovich M, Nolan PJ, Boston AJ, Dobson J, Gros S, Cresswell JR, Simpson J, Lazarus I, Regan PH, Valiente-Dobon JJ, Sellin P, Pearson CJ (2005) The position response of a large-volume segmented germanium detector, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT553(3)pp. 512-521 ELSEVIER SCIENCE BV
Andgren K, Ashley SF, Regan PH, McCutchan EA, Zamfir NV, Amon L, Cakirli RB, Casten RF, Clark RM, Gurdal G, Keyes KL, Meyer DA, Erduran MN, Papenberg A, Pietralla N, Plettner C, Rainovski G, Ribas RV, Thomas NJ, Vinson J, Warner DD, Werner V, Williams E (2005) RDM lifetime measurements in Cd-107, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1563-S1568 IOP PUBLISHING LTD
Williams SJ, Bentley MA, Warner DD, Bruce AM, Cameron JA, Carpenter MP, Fallon P, Frankland L, Gelletly W, Janssens RVF, Joss DT, O'Leary CD, Lister CJ, Poves A, Regan PH, Reiter P, Rubio B, Seweryniak D, Svensson CE, Vincent SM (2003) Anomalous Coulomb matrix elements in the f(7/2) shell, PHYSICAL REVIEW C68(1)ARTN 011301 AMERICAN PHYSICAL SOC
Janas Z, Chandler C, Blank B, Regan PH, Bruce AM, Catford WN, Curtis N, Czajkowski S, Dessagne P, Fleury A, Gelletly W, Giovinazzo J, Grzywacz R, Lewitowicz M, Longour C, Marchand C, Miehe C, Orr NA, Page RD, Pearson CJ, Pravikoff MS, Reed AT, Saint-Laurent MG, Sheikh JA, Vincent SM, Wadsworth R, Warner DD, Winfield JS (1999) Observation of the Z=N+1 nuclei Y-77(39), Zr-79(40), and Mo-83(42), PHYSICAL REVIEW LETTERS82(2)pp. 295-298 AMERICAN PHYSICAL SOC
Britton R, Burnett JL, Davies AV, Regan PH (2014) Monte Carlo characterisation of a Compton suppressed broad-energy HPGe detector, Journal of Radioanalytical and Nuclear Chemistry300(3)pp. 1253-1259
GEANT4 Monte Carlo simulations have been successfully utilised to characterise a Compton suppressed broad-energy HPGe detector. The detector setup has been fully recreated in the simulation, which has been optimised to consistently reproduce the detector response. The peak efficiencies for both the primary BEGe detector and NaI(Tl) guard detectors agree with the simulated values for multiple test sources within 3 %. Compton suppression has also been simulated, with good agreement seen between the simulated and actual CSF values (<10 %) for multiple radionuclides. A secondary reference source was also simulated, which contained up to 30 radionuclides in a different geometry to that of the previous source. This showed excellent agreement with experimental data in both unsuppressed and suppressed modes of operation. © 2014 Akadémiai Kiadó.
Vincent SM, Regan PH, Mohammadi S, Blumenthal D, Carpenter M, Davids CN, Gelletly W, Ghugre SS, Henderson DJ, Janssens RVF, Hjorth-Jensen M, Kharraja B, Lister CJ, Pearson CJ, Seweryniak D, Schwartz J, Simpson J, Warner DD (1999) Near yrast study of the fpg shell nuclei Ni-58, Cu-61, and Zn-61, PHYSICAL REVIEW C60(6)ARTN 064308 AMER PHYSICAL SOC
Pietri S, Jungclaus A, Gorska M, Grawe H, Pfuetzner M, Caceres L, Detistov P, Lalkovski S, Modamio V, Podolyak Z, Regan PH, Rudolph D, Walker J, Werner-Malento E, Bednarczyk P, Doornenbal P, Geissel H, Gerl J, Grebosz J, Kojouharov I, Kurz N, Prokopowicz W, Schaffner H, Wollersheim HJ, Andgren K, Benlliure J, Benzoni G, Bruce AM, Casarejos E, Cederwall B, Crespi FCL, Hadinia B, Hellstrom M, Hoischen R, Ilie G, Khaplanov A, Kmiecik M, Kumar R, Maj A, Mandal S, Montes F, Myalski S, Simpson G, Steer SJ, Tashenov S, Wieland O (2011) First observation of the decay of a 15(-) seniority v=4 isomer in Sn-128,PHYSICAL REVIEW C83(4)ARTN 044328 AMER PHYSICAL SOC
Regan PH, Yamamoto AD, Xu FR, Wu CY, Macchiavelli AO, Cline D, Smith JF, Freeman SJ, Valiente-Dobon JJ, Andgren K, Chakrawarthy RS, Cromaz M, Fallon P, Gelletly W, Gorgen A, Hayes A, Hua H, Langdown SD, Lee IY, Pearson CJ, Podolyak Z, Teng R, Wheldon C (2003) Binary-reaction spectroscopy of Mo-99,Mo-100: Intruder alignment systematics in N=57 and N=58 isotones,PHYSICAL REVIEW C68(4)ARTN 044313 AMERICAN PHYSICAL SOC
Hoischen R, Rudolph D, Ma HL, Montuenga P, Hellstrom M, Pietri S, Podolyak Z, Regan PH, Garnsworthy AB, Steer SJ, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Gerl J, Gorska M, Grebosz J, Kojouharov I, Kurz N, Prokopowicz W, Schaffner H, Wollersheim HJ, Andersson L-L, Atanasova L, Balabanski DL, Bentley MA, Blazhev A, Brandau C, Brown JR, Fahlander C, Johansson EK, Jungclaus A (2011) Isomeric mirror states as probes for effective charges in the lower pf shell, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS38(3)ARTN 035104 IOP PUBLISHING LTD
Benzoni G, Azaiez F, Leoni S, Battacharyya S, Borcea R, Bracco A, Corradi L, Curien D, De France G, Dombradi Z, Fioretto E, Franchoo S, Grevy S, Ibrahim F, Iulian S, Mukherjee G, Navin A, Pollarolo G, Redon N, Regan PH, Rejmund M, Schmitt C, Sletten G, Sohler D, Stanoiu M, Szilner S, Verney D (2006) In-beam ³ spectroscopy using DIC with a radioactive Ne beam, 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.
Neyens G, Georgiev G, Grzywacz R, Hass M, Santos FD, Lewitowicz M, Balabanski DL, Bingham C, Borcea C, Coulier N, Coussement R, Daugas JM, Defrance G, Goldring G, Gorska M, Grawe H, O'Leary C, Macovei I, Mach H, Page R, Pfutzner M, Penionzkevich YE, Podolyak Z, Regan PH, Rykaczewski K, Sawicka M, Smirnova NA, Sobolev Y, Teughels S, Vyvey K (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, NUCLEAR PHYSICS A701pp. 403C-409C ELSEVIER SCIENCE BV
Gottardo A, Valiente-Dobón JJ, Benzoni G, Gadea A, Lunardi S, Boutachkov P, Bruce AM, Górska M, Grebosz J, Pietri S, Podolyák Z, Pfützner M, Regan PH, Weick H, Alcántara Núñez J, Algora A, Al-Dahan N, de Angelis G, Ayyad Y, Alkhomashi N, Allegro PRP, Bazzacco D, Benlliure J, Bowry M, Bracco A, Bunce M, Camera F, Casarejos E, Cortes ML, Crespi FCL, Corsi A, Denis Bacelar AM, Deo AY, Domingo-Pardo C, Doncel M, Dombradi Z, Engert T, Eppinger K, Farrelly GF, Farinon F, Farnea E, Geissel H, Gerl J, Goel N, Gregor E, Habermann T, Hoischen R, Janik R, John PR, Klupp S, Kojouharov I, Kurz N, Lenzi SM, Leoni S, Mandal S, Menegazzo R, Mengoni D, Million B, Modamio V, Morales AI, Napoli DR, Naqvi F, Nicolini R, Nociforo C, Prochazka A, Prokopowicz W, Recchia F, Ribas RV, Reed MW, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steiger K, Strmen P, Swan TPD, Szarka I, Ur CA, Walker PM, Wieland O, Wollersheim HJ (2013) New ¼s isomers in the neutron-rich 210Hg nucleus,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 210Hg: the 8+ isomer expected from the seniority scheme in the ½g9/2 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..
Valencia E, Algora A, Tain JL, Rice S, Agramunt J, Zakari-Issoufou AA, Äystö J, Bowry M, Bui VM, Caballero-Folch R, Cano-Ott D, Eloma V, Eronen T, Estevez E, Farrelly GF, Fallot M, Garcia A, Gelletly W, Gomez-Hornillos MB, Gorlychev V, Hakala J, Jokinen A, Jordan MD, Kankainen A, Kondev FG, Martinez T, Mendoza E, Molina F, Moore I, Perez A, Podolyak Z, Penttilä H, Porta A, Regan PH, Rissanen J, Rubio B, Weber C (2014) Gamma/neutron competition above the neutron separation energy in delayed neutron emitters, EPJ Web of Conferences66
To study the ²-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 ²-strength distribution below the neutron separation energy (Sn) and the ³/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 ³-branching ratio above Sn. © Owned by the authors, published by EDP Sciences, 2014.
Caamano M, Walker PM, Regan PH, Pfutzner M, Podolyak Z, Gerl J, Hellstrom M, Mayet P, Mineva MN, Aprahamian A, Benlliure J, Bruce AM, Butler PA, Gil DC, Cullen DM, Doring J, Enqvist T, Fox C, Narro JG, Geissel H, Gelletly W, Giovinazzo J, Gorska M, Grawe H, Grzywacz R, Kleinbohl A, Korten W, Lewitowicz M, Lucas R, Mach H, O'Leary CD, De Oliveira F, Pearson CJ, Rejmund F, Rejmund M, Sawicka M, Schaffner H, Schlegel C, Schmidt K, Schmidt KH, Stevenson PD, Theisen C, Vives F, Warner DD, Wheldon C, Wollersheim HJ, Wooding S, Xu F, Yordanov O (2005) Isomers in neutron-rich A approximate to 190 nuclides from Pb-208 fragmentation, EUROPEAN PHYSICAL JOURNAL A23(2)pp. 201-215 SPRINGER
Georgiev G, Balabanski DL, Bingham C, Borcea C, Coulier N, Coussement R, Daugas JM, Defrance G, De Oliveira Santos F, Goldring G, Górska M, Grawe H, Grzywacz R, Hass M, O'Leary C, Lewitowicz M, Mach H, Macovei I, Page R, Pfützner M, Penionzkevich YE, Podolyák Z, Regan PH, Rykaczewski K, Sawicka M, Smirnova NA, Sobolev YG, Stanoiu M, Teughels S, Vyvey K, Neyens G (2001) Measurement of the g factors of isomers near the proposed N H 40 subshell closure, 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 ² stability. For the first time, the time-dependent perturbed angular distribution method was applied in combination with the heavy-ion-³ 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".
Roberts OJ, Bruce AM, Browne F, Marginean N, Alexander T, Alharbi T, Bucurescu D, Deleanu D, Delion D, Filipescu D, Fraile L, Gheorghe I, Ghia D, Glodariu T, Ivanova D, Kisyov S, Marginean R, Mason PJR, Mihai C, Mulholland K, Negret A, Nia C, Olaizola B, Pascu S, Söderström PA, Regan PH, Sava T, Stroe L, Toma S, Townsley C (2013) Half-life measurements of excited states in 132Te, 134Xe, Acta Physica Polonica B44(3)pp. 403-406
The 7Li+130Te reaction was used to populate excited states in 132Te and 134Xe. The experiment at the Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania, used an array of high-purity germanium (HPGe) and cerium-doped lanthanum bromide (LaBr3(Ce)) detectors to measure sub-nanosecond half-lives using fast-timing techniques. The half-lives of the yrast 4+ and 6+ levels were measured in the N = 80 nuclei 132Te and 132Xe, respectively. An upper limit of T1=2d 40 ps was assigned to the 4+ level in 132Te and T1=2 = 1075(155) ps was assigned to the 6+ level in 132Xe. The systematics of the B(E2) strengths around the N = 82 shell closure are discussed.
Zakari-Issoufou AA, Porta A, Fallot M, Algora A, Tain JL, Valencia E, Rice S, Agramunt J, Äystö J, Bowry M, Bui VM, Caballero-Folch R, Cano-Ott D, Eloma V, Estévez E, Farrelly GF, Garcia A, Gelletly W, Gomez-Hornillos MB, Gorlychev V, Hakala J, Jokinen A, Jordan MD, Kankainen A, Kondev FG, Martinez T, Mendoza E, Molina F, Moore I, Perez A, Podolyak Z, Penttilä H, Regan PH, Rissanen J, Rubio B, Weber C (2014) Results of fission products ² decay properties measurement performed with a total absorption spectrometer, EPJ Web of Conferences66
²-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 ½ flux emitted. An accurate estimation of the decay heat and the ½ 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 ²-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.
Jones GA, Podolyak Z, Walker PM, Regan PH, de Angelis G, Axiotis M, Bazzacco D, Bizzeti PG, Brandolini F, Broda R, Bucurescu D, Farnea E, Gelletly W, Gadea A, Ionescu-Bujor M, Iordachescu A, Kroll T, Langdown SD, Lunardi S, Marginean N, Martinez T, Medina NH, Quintana B, Rubio B, Ur CA, Valiente-Dobon JJ, Williams SJ, Zhang YH (2005) Population of yrast states in Os-191 using deep-inelastic reactions, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1891-S1894 IOP PUBLISHING LTD
Garnsworthy AB, Lister CJ, Regan PH, Blank BB, Cullen IJ, Gros S, Henderson DJ, Jones GA, Liu Z, Seweryniak D, Shumard BR, Thompson NJ, Williams SJ, Zhu S (2008) Optimizing recoil-isomer tagging with the Argonne fragment mass analyzer, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT594(2)pp. 184-187 ELSEVIER SCIENCE BV
Nomura K, Otsuka T, Rodriguez-Guzman R, Robledo LM, Sarriguren P, Regan PH, Stevenson PD, Podolyak Z (2011) Spectroscopic calculations of the low-lying structure in exotic Os and W isotopes,PHYSICAL REVIEW C83(5)ARTN 054303 AMER PHYSICAL SOC
Lalkovski S, Bruce AM, Bacelar AMD, Górska M, Pietri S, Podolyák Z, Bednarczyk P, Caceres L, Casarejos E, Cullen IJ, Doornenbal P, Farrelly GF, Garnsworthy AB, Geissel H, Gelletly W, Gerl J, Gr)bosz J, Hinke C, Ilie G, Jaworski G, Kisyov S, Kojouharov I, Kurz N, Myalski S, Palacz M, Prokopowicz W, Regan PH, Schaffner H, Steer S, Tashenov S, Walker PM, Wollersheim HJ, Zhekova M (2012) Single-particle isomeric states in 121Pd and 117Ru,Journal of Physics: Conference Series366(1)
Neutron-rich nuclei were populated in a relativistic fission of 238U. Gamma-rays with energies of 135 keV and 184 keV were associated with two isomeric states in 121Pd and 117Ru. Half-lives of 0.63(5) ¼s and 2.0(3) ¼s were deduced and the isomeric states were interpreted in terms of prolate deformed single-particle states.
Alharbi T, Regan PH, MÎrginean N, Podolyák Z, Bajoga A, Britton R, Bucurescu D, Deleanu D, Filipescu D, GhitÎ D, Glodariu T, Mihai C, Mulholland K, MÎrginean R, Negret A, Nita CR, Patel Z, Roberts OJ, Stroe L, Sava T, Townsley C, Zamfir NV (2014) Sub-nanosecond Half-life Measurement of the Yrast IÀ=5- State in the N=78 Nucleus Ce58136 using Fast-timing Coincident Gamma-ray Spectroscopy, Nuclear Data Sheets120pp. 59-61
We report on the measurement of the half-life of the yrast IÀ=5- state in the transitional nucleus 136Ce using a combined HPGe-LaBr3(Ce) scintillator gamma-ray detection array. The measured value for the E1 decay is approximately half a nanosecond, which corresponds to an E1 decay strength of approximately 2×10-6 Wu. This value is in line with single-particle type E1 decays in this mass region and suggests no sign of additional K-hindrance associated with axially symmetric quadrupole deformations observed for lighter cerium isotopes. © 2014 Elsevier Inc.
Ressler JJ, Beausang CW, Casten RF, Zamfir NV, Ai H, Amro H, Babilon M, Cakirli RB, Caggiano JA, Gurdal G, Heinz A, Hughes RO, Langdown SD, McCutchan EA, Meyer DA, Plettner C, Qian J, Regan PH, Sciacchitano MJS, Thomas NJ, Williams E, Yamamoto A (2005) Isomers and seniority in the trans-Pb nuclei, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1605-S1610 IOP PUBLISHING LTD
Cieplicka N, Fornal B, Maier KH, Szpak B, Broda R, Krolas W, Pawlat T, Wrzesinski J, Janssens RVF, Carpenter MP, Chiara CJ, Hoffman CR, Kondev FG, Lauritsen T, Zhu S, Podolyak Z, Bowry M, Bunce M, Gelletly W, Kempley R, Reed M, Regan P, Walker P, Wilson E, Deo AY, Dracoulis G, Lane G, Rodriguez-Triguero C (2014) ANGULAR DISTRIBUTIONS OF gamma RAYS FROM Bi-210 PRODUCED IN Pb-208+Pb-208 DEEP-INELASTIC REACTIONS,ACTA PHYSICA POLONICA B45(2)pp. 205-210 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Lorusso G, Shearman R, Regan PH, Judge SM, Bell S, Collins SM, Larijani C, Ivanov P, Jerome SM, Keightley JD, Lalkovski S, Pearce AK, Podolyak Z (2016) Development of the NPL gamma-ray spectrometer NANA for traceable nuclear decay and structure studies,APPLIED RADIATION AND ISOTOPES109pp. 507-511 PERGAMON-ELSEVIER SCIENCE LTD
Jimenez MJL, Blank B, Chartier M, Czajkowski S, Dessagne P, de France G, Giovinazzo J, Karamanis D, Lewitowicz M, Maslov V, Miehe C, Regan PH, Stanoiu M, Wiescher M (2002) Half-life measurements of proton-rich Kr-78 fragments, PHYSICAL REVIEW C66(2)ARTN 025803 AMERICAN PHYSICAL SOC
REGAN PH, STUCHBERY AE, ANDERSSEN SS (1995) MEASUREMENT OF THE G-FACTOR OF THE YRAST-10(+)-STATE IN CD-11O, NUCLEAR PHYSICS A591(3)pp. 533-547 ELSEVIER SCIENCE BV
Wolf A, Berant Z, Zamfir NV, Brenner DS, McCutchan EA, Ai H, Casten RF, Dusling K, Heinz A, Meyer DA, Millman EA, Pietralla N, Plettner C, Qian J, Regan PH, Swanson D, Vinson J, Williams E, Winkler R (2005) g factor of the 2(1)(+) state of Er-160, PHYSICAL REVIEW C72(2)ARTN 027301 AMERICAN PHYSICAL SOC
Collins SM, Harms AV, Regan PH (2016) Half-life determination of the ground state decay of Ag-111,APPLIED RADIATION AND ISOTOPES108pp. 143-147 PERGAMON-ELSEVIER SCIENCE LTD
Mason PJR, Alharbi T, Regan PH, Marginean N, Podolyak Z, Simpson EC, Alkhomashi N, Bender PC, Bowry M, Bostan M, Bucurescu D, Bruce AM, Cata-Danil G, Cata-Danil I, Chakrabarti R, Deleanu D, Detistov P, Erduran MN, Filipescu D, Garg U, Glodariu T, Ghita D, Ghugre SS, Kusoglu A, Marginean R, Mihai C, Nakhostin M, Negret A, Pascu S, Triguero CR, Sava T, Sinha AK, Stroe L, Suliman G, Zamfir NV (2012) Half-life of the I-pi=4(-) intruder state in P-34: M2 transition strengths approaching the island of inversion,PHYSICAL REVIEW C85(6)ARTN 064303 AMER PHYSICAL SOC
Lewitowicz M, Blank B, Daugas JM, Grawe H, Grzywacz R, Neyens G, Pfutzner M, Regan PH, Rykaczewski K (2001) Nuclear structure studies by means of short-lived isomers at intermediate energies, NUCLEAR PHYSICS A682pp. 175C-182C ELSEVIER SCIENCE BV
Grodner E, Gadea A, Sarriguren P, Lenzi SM, Grebosz J, Valiente-Dobón JJ, Algora A, Górska M, Regan PH, Rudolph D, de Angelis G, Agramunt J, Alkhomashi N, Amon Susam L, Bazzacco D, Benlliure J, Benzoni G, Boutachkov P, Bracco A, Caceres L, Cakirli RB, Crespi FC, Domingo-Pardo C, Doncel M, Dombrádi Z, Doornenbal P, Farnea E, Ganio?lu E, Gelletly W, Gerl J, Gottardo A, Hüyük T, Kurz N, Leoni S, Mengoni D, Molina F, Morales AI, Orlandi R, Oktem Y, Page RD, Perez D, Pietri S, Podolyák Z, Poves A, Quintana B, Rinta-Antila S, Rubio B, Nara Singh BS, Steer AN, Verma S, Wadsworth R, Wieland O, Wollersheim HJ (2014) Hindered Gamow-Teller decay to the odd-odd N=Z (62)Ga: absence of proton-neutron T=0 condensate in A=62., Phys Rev Lett113(9)
Search for a new kind of superfluidity built on collective proton-neutron pairs with aligned spin is performed studying the Gamow-Teller decay of the T=1, J(À)=0+ ground state of (62)Ge into excited states of the odd-odd N=Z nucleus (62)Ga. The experiment is performed at GSI Helmholtzzentrum für Shwerionenforshung with the (62)Ge ions selected by the fragment separator and implanted in a stack of Si-strip detectors, surrounded by the RISING Ge array. A half-life of T1/2=82.9(14) ms is measured for the (62)Ge ground state. Six excited states of (62)Ga, populated below 2.5 MeV through Gamow-Teller transitions, are identified. Individual Gamow-Teller transition strengths agree well with theoretical predictions of the interacting shell model and the quasiparticle random phase approximation. The absence of any sizable low-lying Gamow-Teller strength in the reported beta-decay experiment supports the hypothesis of a negligible role of coherent T=0 proton-neutron correlations in (62)Ga.
Caamano M, Walker PM, Regan PH, Pearson CJ, Podolyak Z, Mayet P, Gerl J, Schlegel C, Hellstrom M, Mineva M, Pfutzner M (2001) Isomeric decays in Pt-200, ACTA PHYSICA POLONICA B32(3)pp. 763-766 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Al-Dahan N, Podolyak Z, Regan PH, Steer SJ, Alkhomashi N, Bacelar AMD, Gorska M, Pietri SB, Gelletly W, Walker PM, Farrelly G, Morales AI, Deo AY, Cullen IJ, Gerl J, Domingo-Pardo C, Verma S, Swan T, Wollersheim HJ, Bruce AM, Lalkovski S, Benlliure J, Algora A, Boutachkov P, Bracco A, Calore E, Casarejos E, Detistov P, Dombradi Z, Doncel M, Farinon F, Geissel H, Goel N, Grebosz J, Hoischen R, Kojouharov I, Leoni S, Molina F, Montanari D, Musumarra A, Nicolini R, Napoli DR, Nociforo C, Rubio B, Prochazka A, Rudolph D, Strmen P, Szarka I, Valiente-Dobon JJ, Weick H (2009) Structure of N >= 126 nuclei produced in fragmentation of (238)U,CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS1090pp. 145-148 AMER INST PHYSICS
Lalkovski S, Bruce AM, Jungclaus A, Górska M, Pfützner M, Cáceres L, Naqvi F, Pietri S, Podolyák Z, Simpson GS, Andgren K, Bednarczyk P, Beck T, Benlliure J, Benzoni G, Casarejos E, Cederwall B, Crespi FCL, Cuenca-García JJ, Cullen IJ, Denis Bacelar AM, Detistov P, Doornenbal P, Farrelly GF, Garnsworthy AB, Geissel H, Gelletly W, Gerl J, Grebosz J, Hadinia B, Hellström M, Hinke C, Hoischen R, Ilie G, Jaworski G, Jolie J, Khaplanov A, Kisyov S, Kmiecik M, Kojouharov I, Kumar R, Kurz N, Maj A, Mandal S, Modamio V, Montes F, Myalski S, Palacz M, Prokopowicz W, Reiter P, Regan PH, Rudolph D, Schaffner H, Sohler D, Steer SJ, Tashenov S, Walker J, Walker PM, Weick H, Werner-Malento E, Wieland O, Wollersheim HJ, Zhekova M (2013) Core-coupled states and split proton-neutron quasiparticle multiplets in 122-126Ag,Physical Review C - Nuclear Physics87(3)
Neutron-rich silver isotopes were populated in the fragmentation of a 136Xe beam and the relativistic fission of 238U. The fragments were mass analyzed with the GSI Fragment Separator and subsequently implanted into a passive stopper. Isomeric transitions were detected by 105 high-purity germanium detectors. Eight isomeric states were observed in 122-126Ag nuclei. The level schemes of 122,123,125Ag were revised and extended with isomeric transitions being observed for the first time. The excited states in the odd-mass silver isotopes are interpreted as core-coupled states. The isomeric states in the even-mass silver isotopes are discussed in the framework of the proton-neutron split multiplets. The results of shell-model calculations, performed for the most neutron-rich silver nuclei are compared to the experimental data. © 2013 American Physical Society.
Bucurescu D, Podolyak Z, Rusu C, de Angelis G, Zhang YH, Cata-Danil G, Cata-Danil I, Ivascu M, Marginean N, Marginean R, Mihailescu LC, Suliman GA, Regan PH, Gelletly W, Langdown SD, Dobon JJV, Bazzacco D, Lunardi S, Ur CA, Axiotis M, Gadea A, Farnea E, Ionescu-Bujor M, Iordachescu A, Kroll T, Martinez T, Bizzetti PG, Broda R, Medina NH, Quintana B, Rubio B (2005) High-spin states in the nuclei Y-91 and Nb-95,PHYSICAL REVIEW C71(3)ARTN 034315 AMERICAN PHYSICAL SOC
Podolyak Z, Mohammadi S, De Angelis G, Zhang YH, Axiotis M, Bazzacco D, Bizzeti PG, Brandolini F, Broda R, Bucurescu D, Farnea E, Gelletly W, Gadea A, Ionescu-Bujor M, Iordachescu A, Kroll T, Langdown SD, Lunardi S, Marginean N, Martinez T, Medina NH, Quintana B, Regan PH, Rubio B, Ur CA, Valiente-Dobon JJ, Walker PM (2004) Structure of neutron-rich nuclei from deep-inelastic reactions, INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS13(1)pp. 123-126 WORLD SCIENTIFIC PUBL CO PTE LTD
Jungclaus A, Caceres L, Gorska M, Pfutzner M, Pietri S, Werner-Malento E, Grawe H, Langanke K, Martinez-Pinedo G, Nowacki F, Poves A, Cuenca-Garcia JJ, Rudolph D, Podolyak Z, Regan PH, Detistov P, Lalkovski S, Modamio V, Walker J, Bednarczyk P, Doornenbal P, Geissel H, Gerl J, Grebosz J, Kojouharov I, Kurz N, Prokopowicz W, Schaffner H, Wollersheim HJ, Andgren K, Benlliure J, Benzoni G, Bruce AM, Casarejos E, Cederwall B, Crespi FCL, Hadinia B, Hellstrom M, Hoischen R, Ilie G, Jolie J, Khaplanov A, Kmiecik M, Kumar R, Maj A, Mandal S, Montes F, Myalski S, Simpson GS, Steer SJ, Tashenov S, Wieland O (2007) Observation of isomeric decays in the r-process waiting-point nucleus Cd-130(82),PHYSICAL REVIEW LETTERS99(13)ARTN 132501 AMER PHYSICAL SOC
Jones GA, Regan PH, Walker PM, Podolyak Z, Stevenson PD, Carpenter MP, Carroll JJ, Chakrawarthy RS, Chowdhury P, Garnsworthy AB, Janssens RVF, Khoo TL, Kondev FG, Lane GJ, Liu Z, Seweryniak D, Thompson NJ, Zhu S, Williams SJ (2007) Identification of a high-spin isomer in (99)Mo,PHYSICAL REVIEW C76(4)ARTN 047303 AMER PHYSICAL SOC
Britton R, Burnett J, Davies A, Regan PH (2012) Preliminary simulations of NaI(Tl) detectors, and coincidence analysis using event stamping, 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.
Mineva MN, Hellström M, Bernas M, Gerl J, Grawe H, Pfützner M, Regan PH, Rejmund M, Rudolph D, Becker F, Bingham CR, Enqvist T, Fogelberg B, Gausemel H, Geissel H, Genevey J, Górska M, Grzywacz R, Hauschild K, Janas Z, Kojouharov I, Kopatch Y, Korgul A, Korten W, Kurcewicz J, Lewitowicz M, Lucas R, Mach H, Mandal S, Mayet P, Mazzocchi C, Pinston JA, Podolyàk Z, Schaffner H, Schlegel C, Schmidt K, Sümmerer K, Wollersheim HJ (2001) A new ¼s isomer in 136Sb produced in the projectile fission of 238U, 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 ³-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.
Bell SJ, Judge SM, Regan PH (2012) An investigation of HPGe gamma efficiency calibration software (ANGLE V.3) for applications in nuclear decommissioning., 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%.
Gorska M, Grawe H, Caceres L, Algora A, Boehmer M, Boutachkov P, Eppinger K, Faestermann T, Fujita Y, Gadea A, Garnsworthy A, Gelletly W, Gerl J, Gernhaeuser R, Hinke C, Jungclaus A, Kojouharov I, Kruecken R, Maier L, Molina P, Pfuetzner M, Pietri S, Podolyak Z, Regan PH, Rubio B, Rudolph D, Wollersheim HJ (2009) NUCLEAR STRUCTURE ADDRESSED AT GSI/RISING, INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS18(4)pp. 759-766 WORLD SCIENTIFIC PUBL CO PTE LTD
Regan PH (2015) Precision measurement of sub-nanosecond lifetimes of excited nuclear states using fast-timing coincidences with LaBr3(Ce) detectors,RADIATION PHYSICS AND CHEMISTRY116pp. 38-42 PERGAMON-ELSEVIER SCIENCE LTD
© 2015 Elsevier Ltd. Precision measurements of electromagnetic (EM) transition rates enable tests of models of internal nuclear structure. Measurements of transition rates can be used to infer the spin and parity differences between the initial and final discrete nuclear excited states via which the EM transition takes place. This short conference paper reports on developments of detection systems for the identification of discrete energy gamma-ray decays using arrays of halide-scintillation detectors acting in coincidence mode, which can be used to determine electromagnetic transition rates between excited nuclear states in the sub-nanosecond temporal regime. Ongoing development of a new multi-detector LaBr3(Ce) array for studies of exotic nuclei produced at the upcoming Facility for Anti-Proton and Ion Research (FAIR) as part of the NUSTAR-DESPEC project are presented, together with initial results from pre-NUSTAR implementations of this array for nuclear structure studies of neutron-rich fission fragment radionuclides at ILL-Grenoble, France and RIBF at RIKEN, Japan.
Steer SJ, Podolyak Z, Pietri S, Regan PH, Rudolph D, Werner-Malento E, Garnsworthy AB, Hoischen R, Gorska M, Gerl J, Wollersheim HJ, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geissel H, Grebosz J, Kelic A, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tachenov S, Heinz A, Pfuetzner M, Kurtukian-Nieto T, Benzoni G, Jungclaus A, Balabanski DL, Brandau C, Bruce AM, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Gelletly W, Ilie G, Jolie J, Jones GA, Kmiecik M, Kondev FG, Lalkovski S, Liu Z, Maj A, Myalski S, Shizuma T, Schwertel S, Walker PM, Wieland O (2007) Identification of isomeric states 'south' of Pb-208 via projectile fragmentation, ACTA PHYSICA POLONICA B38(4)pp. 1283-1286 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Myalski S, Kmiecik M, Maj A, Regan PH, Garnsworthy AB, Pietri S, Rudolph D, Podolyak Z, Steer SJ, Becker F, Bednarczyk P, Gerl J, Gorska M, Grawe H, Kojouharov I, Schaffner H, Wollersheim HJ, Prokopowicz W, Grebosz J, Benzoni G, Blank B, Brandau C, Bruce AM, Caceres L, Camera F, Catford WN, Cullen IJ, Dombradi Z, Doornenbal P, Estevez E, Geissel H, Gelletly W, Heinz A, Hoischen R, Ilie G, Jones GA, Jungclaus A, Kelic A, Kondev FG, Kurtukian-Nieto T, Kurz N, Lalkovski S, Liu Z, Montes F, Pfuetzner M, Saito T, Shizuma T, Simons AJ, Schwertel S, Tachenov S, Walker PM, Werner-Malento E, Wieland O (2007) Isomeric ratio for the I-pi=8(+) yrast state in Pd-96 produced in the relativistic fragmentation of Ag-107, ACTA PHYSICA POLONICA B38(4)pp. 1277-1282 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Podolyak Z, Gerl J, Hellstroem M, Becker F, Gladnishki KA, Gorska M, Kelic A, Kopatch Y, Mandal S, Regan PH, Schmidt K-H, Walker PM, Wollersheim HJ, Banu A, Benzoni G, Boardman H, Casarejos E, Ekman J, Geissel H, Grawe H, Hohn D, Kojouharov I, Leske J, Lozeva R, Mineva MN, Neyens G, Page RD, Pearson CJ, Portillo M, Rudolph D, Saito N, Schaffner H, Sohler D, Summerer K, Valiente-Dobon JJ, Wheldon C, Weick H, Winkler M (2006) Neutron-deficient N approximate to 126 nuclei produced in U-238 fragmentation: Population of high-spin states,Frontiers in Nuclear Structure Astrophysics, and Reactions: FINUSTAR831pp. 114-118 AMER INST PHYSICS
Al-Sulaiti H, Regan PH, Bradley DA, Malain D, Santawamaitre T, Habib A, Matthews M, Bukhari S, Al-Dosari M (2010) A preliminary report on the determination of natural radioactivity levels of the State of Qatar using high-resolution gamma-ray spectrometry, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 427-431 ELSEVIER SCIENCE BV
Walker PM, Cullen DM, Purry CS, Appelbe DE, Byrne AP, Dracoulis GD, Kibedi T, Kondev FG, Lee LY, Macchiavelli AO, Reed AT, Regan PH, Xu F (1997) K-forbidden transitions from multi-quasiparticle states, PHYSICS LETTERS B408(1-4)pp. 42-46 ELSEVIER SCIENCE BV
Mason PJR, Alharbi T, Regan PH, Marginean N, Podolyak Z, Alkhomashi N, Bender PC, Bowry M, Bostan M, Bucurescu D, Bruce AM, Cata-Danil G, Cata-Danil I, Chakrabarti R, Deleanu D, Detistov P, Erduran MN, Filipescu D, Garg U, Glodariu T, Ghita D, Ghugre SS, Kusoglu A, Marginean R, Mihai C, Nakhostin M, Negret A, Pascu S, Triguero CR, Sava T, Simpson EC, Sinha AK, Stroe L, Suliman G, Zamfir NV (2012) Half-life of the I-pi=4(-) Intruder State in P-34 Using LaBr3:Ce Fast Timing, RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011381 IOP PUBLISHING LTD
Bentley MA, Williams SJ, Joss DT, O'Leary CD, Bruce AM, Frankland L, Cameron JA, Svensson CE, Carpenter MP, Lister CJ, Reiter R, Seweryniak D, Fallon P, Gelletly W, Regan PH, Martinez-Pinedo G, Poves A, Solano JS, Rubio B, Warner DD (2002) Mirror symmetry and coulomb energies at high angular momentum, REVISTA MEXICANA DE FISICA48pp. 123-128 SOCIEDAD MEXICANA DE FISICA
Al-Garni S, Walker PM, Regan PH, Narro JG, El-Masri HM, Roeckl E, Kirchner R, La Commara M, Mazzocchi C, Grawe H, Borcea R, Doring J, Wooding SC, Schmidt K, Wheldon C, Cullen DM, Schmidt-Ott WD (2002) Evidence for a K approximate to.139/2 beta-decaying isomer in Lu-177, NUCLEAR PHYSICS IN THE 21ST CENTURY610pp. 854-858 AMER INST PHYSICS
Gottardo A, Valiente-Dobón JJ, Benzoni G, Nicolini R, Núñez JA, Algora A, Al-Dahan N, Angelis GD, Ayyad Y, Alkhomashi N, Allegro PRP, Benlliure J, Boutachkov P, Bowry M, Bracco A, Bruce AM, Bunce M, Casarejos E, Cortes L, Crespi FCL, Camera F, Corsi A, Bacelar AMD, Deo A, Domingo-Pardo C, Doncel M, Dombradi Z, Engert T, Eppinger K, Farrelly GF, Farinon F, Gadea A, Geissel H, Gerl J, Goel N, Górska M, Grebosz J, Gregor E, Haberman T, Hoischen R, Janik R, Klupp S, Kojouharov I, Kurz N, Leoni S, Lunardi S, Mandal S, Menegazzo R, Mengoni D, Million B, Napoli DR, Naqvi F, Nociforo C, Pfützner M, Pietri S, Podolyak Z, Prochazka A, Prokopowicz W, Recchia F, Ribas RV, Reed MW, Regan PH, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steger K, Strmen P, Swan TPD, Szarka I, Walker PM, Wieland O, Weick H, Wollersheim H-J (2011) Isomers in neutron-rich lead isotopes populated via the fragmentation of 238U at 1 GeV A,Journal of Physics: Conference Series: International Nuclear Physics Conference312(Section 9) Institute of Physics
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.
Oi M, Regan PH, Xu FR, Walker PM, Rath AK, Stevenson PD (2002) Cranked-Hartree-Fock-Bogoliubov analysis at the valence maximum: Yrast behaviour of Dy-170(66)104, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT(146)pp. 609-610 PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE
Grieser M, Litvinov YA, Raabe R, Blaum K, Blumenfeld Y, Butler PA, Wenander F, Woods PJ, Aliotta M, Andreyev A, Artemyev A, Atanasov D, Aumann T, Balabanski D, Barzakh A, Batist L, Bernardes AP, Bernhardt D, Billowes J, Bishop S, Borge M, Borzov I, Bosch F, Boston AJ, Brandau C, Catford W, Catherall R, Cederkäll J, Cullen D, Davinson T, Dillmann I, Dimopoulou C, Dracoulis G, Düllmann CE, Egelhof P, Estrade A, Fischer D, Flanagan K, Fraile L, Fraser MA, Freeman SJ, Geissel H, Gerl J, Greenlees P, Grisenti RE, Habs D, von Hahn R, Hagmann S, Hausmann M, He JJ, Heil M, Huyse M, Jenkins D, Jokinen A, Jonson B, Joss DT, Kadi Y, Kalantar-Nayestanaki N, Kay BP, Kiselev O, Kluge HJ, Kowalska M, Kozhuharov C, Kreim S, Kröll T, Kurcewicz J, Labiche M, Lemmon RC, Lestinsky M, Lotay G, Ma XW, Marta M, Meng J, Mücher D, Mukha I, Müller A, Murphy AS, Neyens G, Nilsson T, Nociforo C, Nörtershäuser W, Page RD, Pasini M, Petridis N, Pietralla N, Pfützner M (2012) Storage ring at HIE-ISOLDE: Technical design report: Technical design report,European Physical Journal: Special Topics207(1)pp. 1-117
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. © 2012 EDP Sciences and Springer.
Chandler C, Regan PH, Blank B, Pearson CJ, Bruce AM, Catford WN, Curtis N, Czajkowski S, Dessagne P, Fleury A, Gelletly W, Giovinazzo J, Grzywacz R, Janas Z, Lewitowicz M, Marchand C, Miehe C, Orr NA, Page RD, Pravikoff MS, Reed AT, Saint-Laurent MG, Vincent SM, Wadsworth R, Warner DD, Winfield JS, Xu F (2000) Observation of isomeric states in neutron deficient A similar to 80 nuclei following the projectile fragmentation of Mo-92, PHYSICAL REVIEW C61(4)ARTN 044309 AMERICAN PHYSICAL SOC
Al-Sulaiti L, Shipley D, Thomas R, Owen P, Kacperek A, Regan PH, Palmans H (2012) Water equivalence of some plastic-water phantom materials for clinical proton beam dosimetry, Applied Radiation and Isotopes70(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 60MeV and 200MeV. 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 60MeV and less than 1% at 200MeV up to 20cm depth for PWDT, PW and WT1. With respect to graphite the fluence correction was about 0.5% for 60MeV and about 4% for 200MeV. The experimental results for modulated and un-modulated 60MeV 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. © 2012 Elsevier Ltd.
Goerska M, Banu A, Bednarczyk P, Bracco A, Buerger A, Camera F, Caurier E, Doornenbal P, Gerl J, Grawe H, Honma M, Huebel H, Jungclaus A, Maj A, Neyens G, Nowacki F, Otsuka T, Pfutzner T, Pietri S, Podolyak Z, Poves A, Regan PH, Reiter P, Rudolph D, Wollersheim HJ (2007) Nuclear structure far off stability - Rising campaigns, ACTA PHYSICA POLONICA B38(4)pp. 1219-1228 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Kumar R, Molina FG, Pietri S, Casarejos E, Algora A, Benlliure J, Doornenbal P, Gerl J, Gorska M, Kojouharov I, Podolyak Z, Prokopowicz W, Regan PH, Rubio B, Schaffner H, Tashenov S, Wollersheim H-J (2009) Testing of a DSSSD detector for the stopped RISING project, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT598(3)pp. 754-758 ELSEVIER SCIENCE BV
Mohammadi S, De Angelis G, Axiotis M, Bazzacco D, Bizzeti PG, Brandolini F, Broda R, Bucurescu D, Farnea E, Gelletly W, Gadea A, Ionescu-Bujor M, Iordachescu A, Kroll T, Longdown S, Lunardi S, Marginean N, Martinez T, Medina N, Podolyak Z, Quintana B, Regan PH, Rubio B, Ur CA, Dobon J-JV, Walker PM, Zhang YH (2006) Yrast states in Os-188,Os-190 nuclei, INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS15(8)pp. 1797-1802 WORLD SCIENTIFIC PUBL CO PTE LTD
Garnsworthy AB, Regan PH, Cáceres L, Pietri S, Sun Y, Rudolph D, Górska M, Podolyák Z, Steer SJ, Hoischen R, Heinz A, Becker F, Bednarczyk P, Doornenbal P, Geissel H, Gerl J, Grawe H, Gr)bosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tachenov S, Werner-Malento E, Wollersheim HJ, Benzoni G, Blank BB, Brandau C, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombrádi Z, Estevez E, Gelletly W, Ilie G, Jolie J, Jones GA, Jungclaus A, Kmiecik M, Kondev FG, Kurtukian-Nieto T, Lalkovski S, Liu Z, Maj A, Myalski S, Pfützner M, Schwertel S, Shizuma T, Simons AJ, Walker PM, Wieland O, Xu FR (2008) Erratum to: "Neutron-proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei 82 41Nb and 86 43Tc", Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics668(5)pp. 460-460
Saitoh TR, Saitoh-Hashimoto N, Sletten G, Bark RA, Bergstrom M, Regan P, Tormanen S, Varmette PG, Walker PM (1999) Collective and intrinsic structures in W-183, NUCLEAR PHYSICS A660(2)pp. 171-196 ELSEVIER SCIENCE BV
Georgiev G, Neyens G, Hass M, Balabanski DL, Bingham C, Borcea C, Coulier N, Coussement R, Daugas JM, De France G, Santos FD, Gorska M, Grawe H, Grzywacz R, Lewitowicz M, Mach H, Matea I, Page RD, Pfutzner M, Penionzhkevich YE, Podolyak Z, Regan PH, Rykaczewski K, Sawicka M, Smirnova NA, Sobolev YG, Stanoiu M, Teughels S, Vyvey K (2002) g factor measurements of mu s isomeric states in neutron-rich nuclei around Ni-68 produced in projectile-fragmentation reactions, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS28(12)PII S0954-3899(02)54753-8pp. 2993-3006 IOP PUBLISHING LTD
Shand CM, Wilson E, Podolyák Z, Grawe H, Brown BA, Fornal B, Janssens RVF, Bowry M, Bunce M, Carpenter MP, Carroll RJ, Chiara CJ, Cieplicka-OryDczak N, Deo AY, Dracoulis GD, Hoffman CR, Kempley RS, Kondev FG, Lane GJ, Lauritsen T, Lotay G, Reed MW, Regan PH, Rodriguez-Triguero C, Seweryniak D, Szpak B, Walker PM, Zhu S (2015) Structure of <sup>207</sup>Pb populated in <sup>208</sup>Pb + <sup>208</sup>Pb deep-inelastic collisions, Acta Physica Polonica B46(3)pp. 619-622
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 ³-ray intensity analyses. Spin and parity assignments of states were made, based on angular distributions and comparisons to shell model calculations.
Rice S, Valencia E, Algora A, Tain JL, Regan PH, Podolyak Z, Agramunt J, Gelletly W, Nichols AL (2012) Decay Heat Measurements Using Total Absorption Gamma-ray Spectroscopy, RUTHERFORD CENTENNIAL CONFERENCE ON NUCLEAR PHYSICS, 2011381 IOP PUBLISHING LTD
Jones GA, Walker PM, Podoydk Z, Regan PH, Williams SJ, Carpentert MP, Carroll JJ, Chakrawarthy RS, Chowdhury P, Cullen IJ, Dracoulis GD, Gamsworthy AB, Hackman G, Janssens RVF, Khoo TL, Kondev FG, Lane GJ, Liu Z, Seweryniak D, Thompson NJ, Zhu S (2006) Microsecond and nanosecond isomers populated in fission reactions, FUSION06: Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier853pp. 342-349 AMER INST PHYSICS
Al-Sulaiti H, Nasir T, Regan PH, Bradley D, Al-Mugren K, Alkhomashi N, Al-Dahan N, Al-Dosari M, Bukhari SJ, Matthews M, Santawamaitre T, Malain D, Habib A (2014) Effect of the grain size of the soil on the measured activity and variation in activity in surface and subsurface soil samples,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).
Tarifeno-Saldivia A, Tain J, Domingo-Pardo C, Calvino F, Cortes G, Phong V, Riego A, Agramunt J, Algora A, Brewer N, Caballero-Folch R, Coleman-Smith P, Davinson T, Dillmann I, Estrade A, Griffin C, Grzywacz R, Harkness-Brennan L, Kiss G, Kogimtzis M, Lazarus I, Lorusso G, Matsui K, Miernik K, Montes F, Morales A, Nishimura S, Page R, Podolyak Z, Pucknell V, Rasco B, Regan P, Rubio P, Rykaczewski K, Sakurai H, Simpson J, Sokol E, Surman R, Svirkhin A, Thomas S, Tolosa A, Woods P (2017) Conceptual design of a hybrid neutron-gamma detector for study of -delayed neutrons at the RIB facility of RIKEN,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, ² particles, ³ rays and ²-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 ³ 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.
Wheldon C, Narro JG, Pearson CJ, Regan PH, Podolyak Z, Warner DD, Fallon P, Macchiavelli AO, Cromaz M (2001) Yrast states in Os-194: The prolate-oblate transition region, PHYSICAL REVIEW C63(1)ARTN 011304 AMERICAN PHYSICAL SOC
Andgren K, Ashley SF, Regan PH, McCutchan EA, Zamfir NV, Amon L, Cakirli RB, Casten RF, Clark RM, Erduran MN, Gürdal G, Keyes KL, Meyer DA, Papenberg A, Pietralla N, Plettner C, Rainovski G, Ribas RV, Thomas NJ, Vinson J, Warner DD, Werner V, Williams E (2006) Recoil distance method lifetime measurements in 107Cd and 103Pd, 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,3nx±)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, ½ 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.
Bunce M, Regan PH, Werner V, Beausang CW, Anagnostatou V, Bowry M, Casperson RJ, Chen D, Cooper N, Goddard PM, Hughes RO, Ilie G, Mason PJR, Pauerstein B, Reed MW, Ross TJ, Simpson EC (2013) High-spin study of the shell model nucleus 88Y49, Physical Review C - Nuclear Physics87(4)
The near-yrast structure of the near-magic, odd-odd nucleus, 3988Y 49, has been studied into the high-spin regime. Investigations were performed at the Wright Nuclear Structure Laboratory, Yale University, using the 74Ge(18O,p3n) and 76Ge(18O,p5n) fusion-evaporation reactions at beam energies of 60 and 90 MeV, respectively. Gamma-ray energy coincidence analyses using both double (³2) and triple (³3) fold coincidences, together with angular correlation measurements, have been used to extend the previously reported level scheme to an excitation energy of 8.6 MeV and a spin and parity of 19(-). The presented level scheme is compared with predictions of a truncated valence space shell-model calculation, which assumes an inert 56Ni core with proton and neutron excitations allowed within the f5/2, p3/2, p1/2, and g 9/2 single-particle states. The shell-model calculations show a reasonable comparison with the experimental data for the yrast, positive-parity states up to spin 18 â, with larger variations evident for negative-parity states with spins greater than 16. In spite of a significant increase in angular momentum input associated with the thin target 76Ge(18O,p5n) reaction channel, as compared to the backed target data using the 74Ge target, no additional discrete states were identified in the former data set, suggesting that the level scheme for this nucleus fragments significantly above the observed states, possibly indicating cross-shell excitations becoming dominant for I>19. © 2013 American Physical Society.
Bruce AM, Lalkovski S, Bacelar AMD, Gorska M, Pietri S, Podolyak Z, Shi Y, Walker PM, Xu FR, Bednarczyk P, Caceres L, Casarejos E, Cullen IJ, Doornenbal P, Farrelly GF, Garnsworthy AB, Geissel H, Gelletly W, Gerl J, Grebosz J, Hinke C, Ilie G, Jaworski G, Kojouharov I, Kurz N, Myalski S, Palacz M, Prokopowicz W, Regan PH, Schaffner H, Steer S, Tashenov S, Wollersheim HJ (2010) Shape coexistence and isomeric states in neutron-rich Tc-112 and Tc-113,PHYSICAL REVIEW C82(4)ARTN 044312 AMER PHYSICAL SOC
Caamãno M, Walker PM, Regan PH, Pearson CJ, Podolyak ZS, Mayet P, Gerl J, Schlegel C, Hellström M, Mlneva M, Pfützner M (2001) Isomeric decays in200Pt, 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 ³-³ coincidences.
Britton R, Regan PH, Burnett JL, Davies AV (2014) Next Generation Detection Systems for Radioactive Material Analysis, NUCLEAR DATA SHEETS119pp. E410-E412 ACADEMIC PRESS INC ELSEVIER SCIENCE
Reed AT, Tarasov O, Page RD, Guillemaud-Mueller D, Penionzhkevich YE, Allatt RG, Angelique JC, Anne R, Borcea C, Burjan V, Catford WN, Dlouhy Z, Donzaud C, Grevy S, Lewitowicz M, Lukyanov SM, Marques FM, Martinez G, Mueller AC, Nolan PJ, Novak J, Orr NA, Pougheon F, Regan PH, Saint-Laurent MG, Siiskonen T, Sokol E, Sorlin O, Suhonen J, Trinder W, Vincent SM (1999) Radioactivity of neutron-rich oxygen, fluorine, and neon isotopes, PHYSICAL REVIEW C60(2)ARTN 024311 AMERICAN PHYSICAL SOC
Pearson CJ, Dobon JJV, Regan PH, Sellin PJ, Morton E, Nolan PJ, Boston A, Descovich M, Thornhill J, Cresswell J, Lazarus I, Simpson J (2002) Digital gamma-ray tracking algorithms in segmented germanium detectors, IEEE TRANSACTIONS ON NUCLEAR SCIENCE49(3)pp. 1209-1215 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Morales AI, Benzoni G, Gottardo A, Valiente-Dobón JJ, Blasi N, Bracco A, Camera F, Crespi FCL, Corsi A, Leoni S, Million B, Nicolini R, Wieland O, Gadea A, Lunardi S, Górska M, Regan PH, Podolyák Z, Pfützner M, Pietri S, Boutachkov P, Weick H, Grebosz J, Bruce AM, Núñez JA, Algora A, Al-Dahan N, Ayyad Y, Alkhomashi N, Allegro PRP, Bazzacco D, Benlliure J, Bowry M, Bunce M, Casarejos E, Cortes ML, Bacelar AMD, Deo AY, De Angelis G, Domingo-Pardo C, Doncel M, Dombradi Z, Engert T, Eppinger K, Farrelly GF, Farinon F, Farnea E, Geissel H, Gerl J, Goel N, Gregor E, Habermann T, Hoischen R, Janik R, Klupp S, Kojouharov I, Kurz N, Mandal S, Menegazzo R, Mengoni D, Napoli DR, Naqvi F, Nociforo C, Prochazka A, Prokopowicz W, Recchia F, Ribas RV, Reed MW, Rudolph D, Sahin E, Schaffner H, Sharma A, Sitar B, Siwal D, Steiger K, Strmen P, Swan TPD, Szarka I, Ur CA, Walker PM, Wollersheim HJ (2014) ² -decay studies of neutron-rich Tl, Pb, and Bi isotopes,Physical Review C - Nuclear Physics89(1)
The fragmentation of relativistic uranium projectiles has been exploited at the Gesellschaft für Schwerionenforschung laboratory to investigate the ² decay of neutron-rich nuclei just beyond 208Pb. This paper reports on ²-delayed ³ decays of 211-213Tl, 215Pb, and 215-219Bi de-exciting states in the daughters 211-213Pb, 215Bi, and 215-219Po. The resulting partial level schemes, proposed with the help of systematics and shell-model calculations, are presented. The role of allowed Gamow-Teller and first-forbidden ² transitions in this mass region is discussed. © 2014 American Physical Society.
Morales AI, Benlliure J, Regan PH, Podolyak Z, Gorska M, Alkhomashi N, Pietri S, Kumar R, Casarejos E, Agramunt J, Algora A, Alvarez-Pol H, Benzoni G, Blazhev A, Boutachkov P, Bruce AM, Caceres LS, Cullen IJ, Bacelar AMD, Doornenbal P, Dragosavac D, Estevez ME, Farrelly G, Fujita Y, Garnsworthy AB, Gelletly W, Gerl J, Grebosz J, Hoischen R, Kojouharov I, Kurz N, Lalkovski S, Liu Z, Perez-Loureiro D, Prokopowicz W, Mihai C, Molina F, Muecher D, Rubio B, Schapffner H, Steer SJ, Tamii A, Tashenov S, Dobon JJV, Verma S, Walker PM, Wollersheim HJ, Woods PJ (2009) beta-DELAYED gamma-RAY SPECTROSCOPY OF HEAVY NEUTRON RICH NUCLEI "SOUTH" OF LEAD,ACTA PHYSICA POLONICA B40(3)pp. 867-870 POLISH ACAD SCIENCES INST PHYSICS
Regis J-M, Jolie J, Saed-Samii N, Warr N, Pfeiffer M, Blanc A, Jentschel M, Koester U, Mutti P, Soldner T, Simpson GS, Drouet F, Vancraeyenest A, de France G, Clement E, Stezowski O, Ur CA, Urban W, Regan PH, Podolyak Z, Larijani C, Townsley C, Carroll R, Wilson E, Fraile LM, Mach H, Paziy V, Olaizola B, Vedia V, Bruce AM, Roberts OJ, Smith JF, Kroell T, Hartig A-L, Ignatov A, Ilieva S, Thuerauf M, Lalkovski S, Ivanova D, Kisyov S, Korten W, Salsac M-D, Zielinska M, Marginean N, Ghita DG, Lica R, Petrache CM, Astier A, Leguillon R (2014) B(E2; 2(1)(+) -> 0(1)(+)) value in Kr-90,PHYSICAL REVIEW C90(6)ARTN 06730 AMER PHYSICAL SOC
© 2014 American Physical Society.A smooth onset of collectivity in 88,92,94,96Kr has been determined from reported B(E2;21+01+) and E(21+) values. This is in contrast to the sudden onset in even-even Zr, Mo, and Sr isotopes. Our objective was to complete the systematics by determining the B(E2;21+01+) value in Kr90, which was produced by cold-neutron-induced fission of 235U. The lifetime of the 21+ state in Kr90 was measured via the electronic ³-³ timing technique using the EXILL and FATIMA spectrometers. Based on the measured mean lifetime of Ä = 15(10) ps, the B(E2;21+01+) value of 13-5+26 W.u. in Kr90 is determined for the first time and the smooth onset of deformation in the even-even Kr isotopes beyond neutron number N=50 is confirmed.
Jolie J, Régis JM, Wilmsen D, Ahmed S, Pfeiffer M, Saed-Samii N, Warr N, Blanc A, Jentschel M, Köster U, Mutti P, Soldner T, Simpson G, De France G, Urban W, Bruce AM, Roberts OJ, Fraile LM, Paziy V, Ignatov A, Ilieva S, Kröll T, Scheck M, Thürauf M, Ivanova D, Kisyov S, Lalkovski S, Podolyak Z, Regan PH, Korten W, Habs D, Thirolf PG, Ur CA (2014) First results of the (n,³) EXILL campaigns at the Institut Laue Langevin using EXOGAM and FATIMA,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,³) 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.
Mandal S, Gerl J, Geissel H, Hauschild K, Hellstrom M, Janas Z, Kojouharov I, Kopatch Y, Lemmon RC, Mayet P, Podolyak Z, Regan PH, Schaffner H, Schlegel C, Simpson J, Wollersheim HJ (2001) Gamma-ray spectroscopy with relativistic exotic heavy-ions, PRAMANA-JOURNAL OF PHYSICS57(1)pp. 161-164 INDIAN ACADEMY SCIENCES
Pfutzner M, Regan PH, Walker PM, Podolyak Z, Caamano M, Gerl J, Hellstrom M, Mayet P, Mineva MN (2001) Population of high spin states in relativistic fragmentation, ACTA PHYSICA POLONICA B32(9)pp. 2507-2518 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
Zakari-Issoufou A-A, Fallot M, Porta A, Algora A, Tain JL, Valencia E, Rice S, Bui VM, Cormon S, Estienne M, Agramunt J, Aysto J, Bowry M, Briz JA, Caballero-Folch R, Cano-Ott D, Cucoanes A, Elomaa V-V, Eronen T, Estevez E, Farrelly GF, Garcia AR, Gelletly W, Gomez-Hornillos MB, Gorlychev V, Hakala J, Jokinen A, Jordan MD, Kankainen A, Karvonen P, Kolhinen VS, Kondev FG, Martinez T, Mendoza E, Molina F, Moore I, Perez-Cerdan AB, Podolyak Z, Penttila H, Regan PH, Reponen M, Rissanen J, Rubio B, Shiba T, Sonzogni AA, Weber C (2015) Total Absorption Spectroscopy Study of Rb-92 Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape,PHYSICAL REVIEW LETTERS115(10)ARTN 10250 AMER PHYSICAL SOC
Podolyak Z, Gerl J, Hellstrom M, Becker F, Gladnishki KA, Gorska M, Kelic A, Kopatch Y, Mandal S, Regan PH, Schmidt KH, Walker PM, Wollersheim HJ, Banu A, Benzoni G, Boardman H, Casarejos E, Ekman J, Geissel H, Grawe H, Hohn D, Kojouharov I, Leske J, Lozeva R, Mineva MN, Neyens G, Page RD, Pearson CJ, Portillo M, Rudolph D, Saito N, Schaffner H, Sohler D, Summerer K, Valiente-Dobon JJ, Wheldon C, Weick H, Winkler M (2006) High angular momentum states populated in fragmentation reactions, PHYSICS LETTERS B632(2-3)pp. 203-206 ELSEVIER SCIENCE BV
Wheldon C, Walker PM, Regan PH, Saitoh T, Hashimoto N, Sletten G, Xu FR (1999) Triaxial nuclear shapes at high angular momentum,PHYSICAL REVIEW C59(5)pp. R2334-R2338 AMERICAN PHYSICAL SOC
Jerome SM, Ivanov P, Larijani C, Parker DJ, Regan PH (2014) The production of Neptunium-236g, Journal of Environmental Radioactivity138pp. 315-322
© 2014 Elsevier Ltd.Radiochemical analysis of 237Np is important in a number of fields, such as nuclear forensics, environmental analysis and measurements throughout the nuclear fuel cycle. However analysis is complicated by the lack of a stable isotope of neptunium. Although various tracers have been used, including 235Np, 239Np and even 236Pu, none are entirely satisfactory. However, 236gNp would be a better candidate for a neptunium yield tracer, as its long half-life means that it is useable as both a radiometric and mass spectrometric measurements. This radionuclide is notoriously difficult to prepare, and limited in scope. In this paper, we examine the options for the production of 236gNp, based on work carried out at NPL since 2011. However, this work was primarily aimed at the production of 236Pu, and not 236gNp and therefore the rate of production are based on the levels of 236Pu generated in the irradiation of (i) 238U with protons, (ii) 235U with deuterons, (iii) 236U with protons and (iv) 236U with deuterons. The derivation of a well-defined cross section is complicated by the relevant paucity of information on the variation of the 236mNp:236gNp production ratio with incident particle energy. Furthermore, information on the purity of 236gNp so produced is similarly sparse. Accordingly, the existing data is assessed and a plan for future work is presented.
Podolyak Z, Caamano M, Regan PH, Walker PM, Mayet P, Gerl J, Schlegel C, Hellstrom M, Mineva M, Pfutzner M (2002) Isomeric decays in neutron-rich W, Os and Pt nuclei, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT(146)pp. 467-472 PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE
Collins SM, Pomme S, Jerome SM, Ferreira KM, Regan PH, Pearce AK (2015) The half-life of Th-227 by direct and indirect measurements,APPLIED RADIATION AND ISOTOPES104pp. 203-211 PERGAMON-ELSEVIER SCIENCE LTD
Régis JM, Simpson GS, Blanc A, De France G, Jentschel M, Köster U, Mutti P, Paziy V, Saed-Samii N, Soldner T, Ur CA, Urban W, Bruce AM, Drouet F, Fraile LM, Ilieva S, Jolie J, Korten W, Kröll T, Lalkovski S, Mach H, MÎrginean N, Pascovici G, Podolyak Z, Regan PH, Roberts OJ, Smith JF, Townsley C, Vancraeyenest A, Warr N (2014) Germanium-gated ³-³ Fast timing of excited states in fission fragments using the EXILL&FATIMA spectrometer, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment763pp. 210-220
A high-granularity mixed spectrometer consisting of high-resolution Ge and very fast LaBr3(Ce)-scintillator detectors has been installed around a fission target at the cold-neutron guide PF1B of the high-flux reactor of the Institut Laue-Langevin. Lifetimes of excited states in the range of 10 ps to 10 ns can be measured in around 100 exotic neutron-rich fission fragments using Ge-gated LaBr3(Ce)-LaBr3(Ce) or Ge-Ge-LaBr 3(Ce)-LaBr3(Ce) coincidences. We report on various characteristics of the EXILL&FATIMA spectrometer for the energy range of 40 keV up to 6.8 MeV and present results of ps-lifetime test measurements in a fission fragment. The results are discussed with respect to possible systematic errors induced by background contributions. © 2014 Published by Elsevier B.V.
Naqvi F, Gorska M, Caceres L, Jungclaus A, Pfuetzner M, Grawe H, Nowacki F, Sieja K, Pietri S, Werner-Malento E, Regan PH, Rudolf D, Podolyak Z, Jolie J, Andgren K, Beck T, Bednarczyk P, Benlliure J, Benzoni G, Bruce AM, Casarejos E, Cederwall B, Crespi FCL, Detistov P, Dombradi Z, Doornenbal P, Geissel H, Gerl J, Grebosz J, Hadinia B, Hellstrom M, Hoischen R, Ilie G, Khaplanov A, Kojouharov I, Kmiecik M, Kurz N, Lalkovski S, Maj A, Mandal S, Modamio V, Montes F, Myalski S, Prokopowicz W, Reiter P, Schaffner H, Simpson G, Sohler D, Steer SJ, Tashenov S, Walker J, Wieland O, Wollersheim HJ (2010) Isomer spectroscopy of Cd-127,PHYSICAL REVIEW C82(3)ARTN 034323 AMER PHYSICAL SOC
Rice S, Valencia E, Algora A, Taín JL, Regan PH, Podolyák Z, Agramunt J, Gelletly W, Nichols AL (2012) Decay heat measurements using total absorption gamma-ray spectroscopy, Journal of Physics: Conference Series381(1)
A knowledge of the decay heat emitted by thermal neutron-irradiated nuclear fuel is an important factor in ensuring safe reactor design and operation, spent fuel removal from the core, and subsequent storage prior to and after reprocessing, and waste disposal. Decay heat can be readily calculated from the nuclear decay properties of the fission products, actinides and their decay products as generated within the irradiated fuel. Much of the information comes from experiments performed with HPGe detectors, which often underestimate the beta feeding to states at high excitation energies. This inability to detect high-energy gamma emissions effectively results in the derivation of decay schemes that suffer from the pandemonium effect, although such a serious problem can be avoided through application of total absorption ³-ray spectroscopy (TAS). The beta decay of key radionuclei produced as a consequence of the neutron-induced fission of 235U and 239Pu are being re-assessed by means of this spectroscopic technique. A brief synopsis is given of the Valencia-Surrey (BaF 2) TAS detector, and their method of operation, calibration and spectral analysis. © Published under licence by IOP Publishing Ltd.
Bajoga AD, Alazemi N, Regan PH, Bradley DA (2015) Radioactive investigation of NORM samples from Southern Kuwait soil using high-resolution gamma-ray spectroscopy,RADIATION PHYSICS AND CHEMISTRY116pp. 305-311 PERGAMON-ELSEVIER SCIENCE LTD
Nara Singh BS, Brock TS, Wadsworth R, Grawe H, Boutachkov P, Braun N, Blazhev A, Liu Z, Górska M, Pietri S, Rudolph D, Domingo-Pardo C, Steer SJ, Ataç A, Bettermann L, Cáceres L, Engert T, Faestermann T, Farinon F, Finke F, Geibel K, Gerl J, Gernhäuser R, Goel N, Gottardo A, Gr)bosz J, Hinke C, Hoischen R, Ilie G, Iwasaki H, Jolie J, Ka_ka_ A, Kojouharov I, Krücken R, Kurz N, Merchán E, Nociforo C, Nyberg J, Pfützner M, Prochazka A, Podolyák Z, Regan PH, Reiter P, Rinta-Antila S, Scholl C, Schaffner H, Söderström PA, Warr N, Weick H, Wollersheim HJ, Woods PJ, Nowacki F (2012) Influence of the np interaction on the ² decay of 94Pd, Physical Review C - Nuclear Physics86(4)
We present results from stopped beam rare isotope spectroscopic investigations at the GSI (RISING) experiment based on the detection of ³-ray transitions following the ² decay of 94Pd. A comparison between the measured low-lying level scheme of 94Rh and the prediction from shell-model calculations reveals the important roles of the g 7/2 and g 9/2 orbitals in explaining the structural features. The low values of the Gamow-Teller strengths B(GT) can be attributed to the influence of the neutron-proton interaction, which gives rise to an increased seniority mixing for the nuclear states, thereby leading to a fragmentation of the strength to several daughter levels. These results provide further strong indications that 94Pd resides in the middle of a structural transition region in the Pd isotopes as the N=Z line is approached. © 2012 American Physical Society.
Lazarus IH, Appelbe DE, Butler PA, Coleman-Smith PJ, Cresswell JR, Freeman SJ, Herzberg RD, Hibbert I, Joss DT, Letts SC, Page RD, Pucknell VFE, Regan PH, Sampson J, Simpson J, Thornhill J, Wadsworth R (2001) The GREAT triggerless total data readout method,IEEE TRANSACTIONS ON NUCLEAR SCIENCE48(3)pp. 567-569 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Bentley MA, Williams SJ, Joss DT, O'Leary CD, Bruce AM, Cameron JA, Carpenter MP, Fallon P, Frankland L, Gelletly W, Lister CJ, Martinez-Pinedo G, Poves A, Regan PH, Reiter P, Rubio B, Sanchez-Solano J, Seweryniak D, Svensson CE, Vincent SM, Warner DD (2002) Mirror symmetry and Coulomb effects in light N approximate to Z nuclei, CZECHOSLOVAK JOURNAL OF PHYSICS52pp. C597-C606 INST PHYSICS ACAD SCI CZECH REPUBLIC
Alharbi T, Mason PJR, Regan PH, Mrginean N, Podolyák Z, Algora A, Alazemi N, Bruce AM, Britton R, Bunce MR, Bucurescu D, Cooper N, Deleanu D, Filipescu D, Gelletly W, Ghit D, Glodariu T, Ilie G, Kisyov S, Lintott J, Lalkovski S, Liddick S, Mihai C, Mulholland K, Mrginean R, Negret A, Nakhostin M, Roberts OJ, Rice S, Smith JF, Stroe L, Sava T, Townsley C, Wilson E, Werner V, Zhekova M, Zamfir NV (2012) Electromagnetic transition rate measurements in the N=80 isotone, 138Ce, Journal of Physics: Conference Series381(1)
A study of intrinsic state halflife measurements in the N=80 nucleus 138Ce has been made using the 130Te( 12C,4n) 138Ce fusion evaporation reaction at beam energy of 56 MeV. The fast-timing gamma-ray coincidence method was used with a mixed LaBr 3(Ce)-HPGe array to establish the lifetimes of the yrast 6 + state at 2294 keV, the I À=5 - state at 2218 keV, the I À=11 + state at 3943 keV and the 14 + state at that at 5312 keV, all of which are in the sub nanosecond regime. Reduced transition probabilities have been calculated for the electromagnetic decays from these states. © Published under licence by IOP Publishing Ltd.
Daugas JM, Grzywacz R, Lewitowicz M, Achouri L, Angelique JC, Baiborodin D, Bennaceur K, Bentida R, Beraud R, Borcea C, Bingham C, Catford WN, Emsallem A, de France G, Grawe H, Jones KL, Lemmon RC, Jimenez MJL, Nowacki F, Santos FD, Pfutzner M, Regan PH, Rykaczewski K, Sauvestre JE, Sawicka M, Sletten G, Stanoiu M (2000) The 8(+) isomer in Zn-78 and the doubly magic character of Ni-78, PHYSICS LETTERS B476(3-4)pp. 213-218 ELSEVIER SCIENCE BV
Habib AS, Bradley DA, Regan PH, Shutt AL (2010) The use of MCNP and gamma spectrometry in supporting the evaluation of NORM in Libyan oil pipeline scale, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT619(1-3)pp. 245-251 ELSEVIER SCIENCE BV
Farrelly GF, Podolyak Z, Steer SJ, Pietri S, Xu FR, Werner-Malento E, Shizuma T, Regan PH, Rudolph D, Garnsworthy AB, Hoischen R, Gorska M, Gerl J, Wollersheim HJ, Kurtukian-Nieto T, Benzoni G, Becker F, Bednarczyk P, Caceres L, Doornenbal P, Geisserl H, Grebosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Heinz A, Pfuezner M, Jungclaus A, Balabanski DL, Brandau C, Bruce AM, Catford WN, Cullen IJ, Dombradi Z, Estevez E, Gelletly W, Ilie G, Jolie J, Jones GA, Kmiecik M, Kondev FG, Kruecken R, Lalkovski S, Liu HL, Liu Z, Maj A, Myalski S, Schwerrel S, Walker PM, Wieland O (2009) REVISION OF THE K-ISOMER IN W-190(116),ACTA PHYSICA POLONICA B40(3)pp. 885-888 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
Soderstrom P-A, Recchia F, Nyberg J, Gadea A, Lenzi SM, Poves A, Atac A, Aydin S, Bazzacco D, Bednarczyk P, Bellato M, Birkenbach B, Bortolato D, Boston AJ, Boston HC, Bruyneel B, Bucurescu D, Calore E, Cederwall B, Charles L, Chavas J, Colosimo S, Crespi FCL, Cullen DM, de Angelis G, Desesquelles P, Dosme N, Duchene G, Eberth J, Farnea E, Filmer F, Gorgen A, Gottardo A, Grebosz J, Gulmini M, Hess H, Hughes TA, Jaworski G, Jolie J, Joshi P, Judson DS, Jungclaus A, Karkour N, Karolak M, Kempley RS, Khaplanov A, Korten W, Ljungvall J, Lunardi S, Maj A, Maron G, Meczynski W, Menegazzo R, Mengoni D, Michelagnoli C, Molini P, Napoli DR, Nolan PJ, Norman M, Obertelli A, Podolyak Z, Pullia A, Quintana B, Redon N, Regan PH, Reiter P, Robinson AP, Sahin E, Simpson J, Salsac MD, Smith JF, Stezowski O, Theisen C, Tonev D, Unsworth C, Ur CA, Valiente-Dobon JJ, Wiens A (2012) High-spin structure in K-40, PHYSICAL REVIEW C86(5)ARTN 054320 AMER PHYSICAL SOC
Parry CM, Boston AJ, Chandler C, Galindo-Uribarri A, Hibbert IM, Janzen VP, Joss DT, Mullins SM, Nolan PJ, Paul ES, Regan PH, Vincent SM, Wadsworth R, Ward D, Wyss R (1998) Yrast structures in the neutron-deficient 12759 Pr68 and 13161 Pm70 nuclei, 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,±p)/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 Àh11/2 bands of the odd mass Pr and Pm isotopes are discussed and compared with extended total Routhian surface calculations.
Lewitowicz M, Daugas JM, Grzywacz R, Achouri L, Angélique JC, Baiborodin D, Bentida R, Béraud R, Bingham C, Borcea C, Catford W, Emsallem A, De France G, Glogowski M, Grawe H, Guillemaud-Mueller D, Houry M, Hurskanen S, Jones KL, Lemmon RC, Mueller AC, Nowak A, De Oliveira-Santos F, PBochocki A, Pfützner M, Regan PH, Rykaczewski K, Saint-Laurent MG, Sauvestre JE, Sawicka M, Schaefer M, Sletten G, Sorlin O, Stanoiu M, Szerypo J, Trinder W, Viteritti S, Winfield J (1999) Study of ¼s-isomers in neutron-rich nuclei around Z=28 and N=40 shell closures, Nuclear Physics A654(1 SUPPL. 1)
Caceres LS, Gorska M, Jungclaus A, Regan PH, Garnsworthy AB, Pietri S, Podolyak Z, Rudolph D, Steer SJ, Grawe H, Balabanski DL, Becker F, Bednarczyk P, Benzoni G, Blank B, Brandau C, Bruce AM, Camera F, Catford WN, Cullen IJ, Dombradi Z, Doornenbalal P, Estevez E, Geissel H, Gelletly W, Gerl J, Grebosz J, Heinz A, Hoischen R, Ilie G, Jolie J, Jones GA, Kmiecik M, Kojouharov I, Kondev FG, Kurtukian-Nieto T, Kurz N, Lalkowski S, Liu L, Maj A, Myalsk S, Montes F, Pfuetzner M, Prokopowicz W, Saito T, Schatfner H, Schwertel S, Shizuma T, Simons AJ, Tashenov S, Walker PM, Werner-Malento E, Wielandh O, Wollersheim HJ (2007) Identification of excited states in the N = Z nucleus Nb-82, ACTA PHYSICA POLONICA B38(4)pp. 1271-1275 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
SIMMONS PM, RAE WDM, CHAPPELL SPG, FOX SP, JONES CD, WATSON DL, FREER M, FULTON BR, CLARKE NM, CURTIS N, LEDDY MJ, POPLE JS, HALL SJ, WARD RP, TUNGATE G, CATFORD WN, GYAPONG GJ, SINGER SM, REGAN PH (1995) SEARCH FOR A 7-ALPHA CHAIN STATE, PHYSICAL REVIEW C51(6)pp. 3500-3503 AMERICAN PHYSICAL SOC
Steer SJ, PodolyÁk ZS, Pietri S, GÓrska M, Farrelly GF, Regan PH, Rudolph D, Garnsworthy AB, Hoischen R, Gerl J, Wollersheim HJ, Grawe H, Maier KH, Becker F, Bednarczyk P, CÁceres L, Doornenbal P, Geissel H, Grbosz J, Kelic A, Kojouharov I, Kurz N, Montes F, Prokopowicz W, Saito T, Schaffner H, Tashenov S, Heinz A, Kurtukian-Nieto T, Benzoni G, PfÜtzner M, Jungclaus A, Balabanski DL, Brandau C, Brown A, Bruce AM, Catford WN, Cullen IJ, DombrÁdi Z, Estevez ME, Gelletly W, Ilie G, Jolie J, Jones GA, Kmiecik M, Kondev FG, KrÜcken R, Lalkovski S, Liu Z, Maj A, Myalski S, Schwertel S, Shizuma T, Walker PM, Werner-Malento E, Wieland O (2009) Isomeric decay studies in neutron-rich N H 126 nuclei,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.
Myalski S, Maj A, Podolyák Z, Kmiecik M, Bednarczyk P, Grebosz J, Regan PH, Garnsworthy AB, Pietri S, Rudolph D, Steer SJ, Becker F, Gerl J, Górska M, Grawe H, Kojouharov I, Schaffner H, Wollersheim HJ, Prokopowicz W, Benzoni G, Blank B, Brandau C, Bruce AM, Cáceres L, Camera F, Catford WN, Cullen IJ, Dombradi Z, Doornenbal P, Estevez E, Geissel H, Gelletly W, Heinz A, Hoischen R, Ilie G, Jones GA, Jungclaus A, Kelic A, Kondev FG, Kurtukian-Nieto T, Kurz N, Lalkovski S, Liu Z, Montes F, Pfützner M, Saito T, Shizuma T, Simons AJ, Schwertel S, Tachenov S, Walker PM, Werner-Malento E, Wieland O (2012) Study of isomer production rates for A = 142-152 and Z = 62-67 in fragmentation of a relativistic 208Pb beam, Acta Physica Polonica B43(2)pp. 253-259
We have investigated nuclear fragmentation reactions of a relativistic 208Pb beam.Ten isomeric states for nuclei with A = 142-152 and Z = 62-67 were observed. Measured isomeric ratios were compared, together with values from other experiments, with prediction of theoretical models. The discrepancies between the experimental and theoretical values were discussed in terms of transitions by-passing the isomer that are not included in the models.
Lazarus IH, Appelbe DE, Butler PA, Coleman-Smith PJ, Cresswell JR, Freeman SJ, Herzberg RD, Hibbert I, Joss DT, Letts SC, Page RD, Pucknell VFE, Regan PH, Sampson J, Simpson J, Thornhill J, Wadsworth R (2000) The GREAT triggerless total data readout method,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.
Bunce M, Regan PH, Werner V, Anagnostatou V, Beausang CW, Bowry M, Casperson RJ, Chen D, Cooper N, Goddard P, Hughes RO, Ilie G, Mason PJR, Pauerstein B, Reed MW, Ross TJ (2012) A shell model study of the high spin states of 88Y, Journal of Physics: Conference Series381(1)
Experiments were carried out at the Wright Nuclear Structure Laboratory at Yale University using the 21MV ESTU Tandem Van de Graaff accelerator with the purpose of studying 88Y. A beam of 18O impinged at laboratory energies of 60, 65 and 70 MeV on a 600 ¼g/cm 274Ge target with a thick (10mg/cm 2) 197Au backing. This experiment was performed with the specific aim of accessing medium spin states of the nucleus of interest. A second experiment was undertaken to populate the nucleus of interest in higher spin states by impinging the same 18O beam on a thin 62 ¼g/cm 276Ge target with a 20 ¼g/cm 2 carbon backing at a laboratory beam energy of 90 MeV. Gamma rays emitted following the decay of excited states in 88Y and other nuclei populated in the reactions were measured using the YRAST ball detector array, consisting of 10 Compton suppressed HPGe clover detectors. In conjunction with the experimental study presented here, nuclear shell model calculations using a truncated valence space have also been performed in an attempt to describe the single-particle make-up of the states observed. Preliminary results from these experiments and theoretical calculations are presented. © Published under licence by IOP Publishing Ltd.
Mineva AN, Hellstrom M, Bernas M, Gerl J, Grawe H, Pfutzner M, Regan PH, Rejmund M, Rudolph D, Becker F, Bingham CR, Enqvist T, Fogelberg B, Gausemel H, Geissel H, Genevey J, Gorska M, Grzywacz R, Hauschild K, Janas Z, Kojouharov I, Kopatch Y, Korgul A, Korten W, Kurcewicz J, Lewitowicz M, Lucas R, Mach H, Mandal S, Mayet P, Mazzocchi C, Pinston JA, Podolyak Z, Schaffner H, Schlegel C, Schmidt K, Summerer K, Wollersheim HJ (2001) A new mu s isomer in Sb-136 produced in the projectile fission of U-238, EUROPEAN PHYSICAL JOURNAL A11(1)pp. 9-13 SPRINGER-VERLAG
Britton R, Regan PH, Burnett J, Davies A (2012) Determining the efficiency of a broad-energy HPGe detector using Monte Carlo simulations, Journal of Radioanalytical and Nuclear Chemistrypp. 1-7
Broad-energy HPGe detectors have a useful range of 3 keV to 3 MeV, making them ideal for the assay of environmental samples. Such measurements however, are hindered by variations in the sample matrix, summing effects, and the Compton continuum. Detectors may be characterised by proprietary software in such a situation, however Monte-Carlo modelling is a useful, inexpensive alternative that also provides greater flexibility when determining the detector response and efficiency during a measurement. In the current work, a full GEANT4 model of a broad-energy HPGe detector is presented, and simulations of various samples are compared to experimental data. These are found to be accurate within 3 % at a confidence level of 95 % for energies from 30 to 3,000 keV, with greater variations below 100 keV due to an increased sensitivity to geometrical inaccuracies. © 2012 Akadémiai Kiadó, Budapest, Hungary.
Benzoni G, Azaiez F, Stefan GI, Franchoo S, Battacharyya S, Borcea R, Bracco A, Corradi L, Curien D, De France G, Dombradi Z, Fioretto E, Grevy S, Ibrahim F, Leoni S, Montanari D, Mukherjee G, Pollarolo G, Redon N, Regan PH, Schmitt C, Sletten G, Sohlers D, Stanoiu M, Szilner S, Verney D (2010) Study of collisions of the radioactive Ne-24 beam at 7.9 MeV/u on Pb-208, EUROPEAN PHYSICAL JOURNAL A45(3)pp. 287-292 SPRINGER
Valencia E, Tain JL, Algora A, Agramunt J, Estevez E, Jordan MD, Rubio B, Rice S, Regan Patrick, Gelletly William, Podolyak Zsolt, Bowry M, Mason P, Farrelly GF, Zakari-Issoufou A, Fallot M, Porta A, Bui VM (2017) Total absorption ³ -ray spectroscopy of the ²-delayed neutron emitters 87Br, 88Br, and 94Rb,Physical Review C: Nuclear Physics024320 American Physical Society
We investigate the decay of 87,88Br and 94Rb using total absorption ³ -ray spectroscopy. These important fission products are ²-delayed neutron emitters. Our data show considerable ²³ intensity, so far unobserved in high-resolution ³ -ray spectroscopy, from states at high excitation energy. We also find significant differences with the ² intensity that can be deduced from existing measurements of the ² 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 ³ emission from neutron unbound states populated in the daughter nucleus. The ³ 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 ³ by one order of magnitude. This increase in ³ would lead to a similar increase in the calculated (n,³ ) cross section for this very neutron-rich nucleus with a potential impact on r process abundance calculations.
Britton R, Burnett JL, Davies AV, Regan PH (2014) Characterisation of cascade summing effects in gamma spectroscopy using Monte Carlo simulations, Journal of Radioanalytical and Nuclear Chemistry299(1)pp. 447-452
A GEANT4 based Monte Carlo simulation has been successfully utilised to calculate peak efficiency characterisations and cascade summing (true coincidence summing) corrections in two source geometries commonly used for environmental monitoring. The cascade summing corrections are compared with values generated using an existing (validated) system, and found to be in excellent agreement for all radionuclides simulated. The calculated correction factors and peak efficiencies were also tested by analysing well defined sources used in the operation of the International Monitoring System, which undertakes radionuclide monitoring for verification of the Comprehensive Nuclear-Test-Ban Treaty. All abundances of the radionuclides measured matched the values that were previously determined using proprietary software. Using GEANT4 in this way, cascade summing corrections can now be extended to complex detector models and source matrices, such as Compton Suppression systems. © 2013 Akadémiai Kiadó, Budapest, Hungary.
Singh BSN, Liu Z, Wadsworth R, Grawe H, Brock TS, Boutachkov P, Braun N, Blazhev A, Gorska M, Pietri S, Rudolph D, Domingo-Pardo C, Steer SJ, Atac A, Bettermann L, Caceres L, Eppinger K, Engert T, Faestermann T, Farinon F, Finke F, Geibel K, Gerl J, Gernhaeuser R, Goel N, Gottardo A, Grebosz J, Hinke C, Hoischen R, Ilie G, Iwasaki H, Jolie J, Kaskas A, Kojouharov I, Kruecken R, Kurz N, Merchan E, Nociforo C, Nyberg J, Pfuetzner M, Prochazka A, Podolyak Z, Regan PH, Reiter P, Rinta-Antila S, Scholl C, Schaffner H, Soderstrom P-A, Warr N, Weick H, Wollersheim H-J, Woods PJ, Nowacki F, Sieja K (2011) 16(+) Spin-Gap Isomer in Cd-96, PHYSICAL REVIEW LETTERS107(17)ARTN 172502
Santawamaitre T, Malain D, Al-Sulaiti HA, Bradley DA, Matthews MC, Regan PH (2014) Determination of (238)U, (232)Th and (40)K activity concentrations in riverbank soil along the Chao Phraya river basin in Thailand., J Environ Radioact138pp. 80-86
The activity concentrations of (238)U, (232)Th and (40)K in riverbank soil along the Chao Phraya river basin was determined through gamma-ray spectrometry measurements made using a hyper-pure germanium detector in a low background configuration. The ranges of activity concentrations of (238)U, (232)Th and (40)K were found to be 13.9 76.8, 12.9 142.9 and 178.4 810.7 Bq kg(-1), respectively. The anthropogenic radionuclide, (137)Cs, was not observed in statistically significant amounts above the background level in the current study. The absorbed gamma dose rate in air at 1 m above the ground surface, the outdoor annual effective dose equivalent, the values of the radium equivalent activity and the external hazard index associated with all the soil samples in the present work were evaluated. The results indicate that the radiation hazard from primordial radionuclides in all soil samples from the area studied in this current work is not significant.
Mohamud Hibaaq, Van Es Elsje, Sainsbury T, Ivanov P, Russell B, Regan Patrick, Ward Neil (2017) Progress towards the development of a rapid analytical approach for
separation of 226Ra using dibenzo-18-crown-6 ether functionalised silica
(SiO2) disks,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.
Régis J.-M., Jolie J., Saed-Samii N., Warr N., Pfeiffer M., Blanc A., Jentschel M., Köster U., Mutti P., Soldner T., Simpson G. S., Drouet F., Vancraeyenest A., de France G., Clément E., Stezowski O., Ur C. A., Urban W., Regan Patrick, Podolyak Zsolt, Larijani Cyrus Kouroush, Townsley C., Carroll R., Wilson E., Fraile L. M., Mach H., Paziy V., Olaizola B., Vedia V., Bruce A. M., Roberts O. J., Smith J. F., Scheck M., Kröll T., Hartig A.-L., Ignatov A., Ilieva S., Lalkovski S., Korten W., M?rginean N., Otsuka T., Shimizu N., Togashi T., Tsunoda Y. (2017) Abrupt shape transition at neutron number N=60 : B(E2) values in Sr94,96,98 from fast ³?³ timing,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 ³?³ 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.
Söderström P, Walker PM, Wu J, Liu H, Regan PH, Watanabe H, Doornenbal P, Korkulu Z, Lee P, Liu J, Lorusso G, Nishimura S, Phong V, Sumikama T, Xu F, Yagi A, Zhang G, Ahn D, Alharbi T, Baba H, Browne F, Bruce A, Carroll R, Chae K, Dombradi Z, Estrade A, Fukuda N, Griffin C, Ideguchi E, Inabe N, Isobe T, Kanaoka H, Kanaya S, Kojouharov I, Kondev F, Kubo T, Kubono S, Kurz N, Kuti I, Lalkovski S, Lane G, Lee E, Lee C, G. Lotay G, Moon C, Nishizuka I, Nita C, Odahara A, Patel Z, Podolyak Z, Roberts O, Sakurai H, Schaffner H, Shand C, Suzuki H, Takeda H, Terashima S, Vajta Z, Valiente-Dòbon J, Xui Z (2016) Collective And Single-particle Structures In The Neutron-rich Doubly Mid-shell Nucleus 170Dy,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.
Wu J, Nishimura S, Lorusso G, Moller P, Ideguchi E, Regan PH, Simpson G, Soderstrom P, Walker PM, Watanabe H, Xu Z, Baba H, Browne F, Daido R, Doornenbal P, Fang Y, Gey G, Isobe T, Lee P, Liu J, Li Z, Korkulu Z, Patel Z, Phong V, Rice S, Sakurai H, Sinclair L, Sumikama T, Tanaka M, Yagi A, Ye Y, Yokoyama R, Zhang G, Alharbi T, Aoi N, Bello Garrote F, Benzoni G, Bruce A, Carroll R, Chae K, Dombradi Z, Estrade A, Gottardo A, Griffin C, Kanaoka H, Kojouharov I, Kondev F, Kubono S, Kurz N, Kuti I, Lalkovski S, Lane G, Lee E, Lokotko T, Lotay GJ, Moon C, Nishibata H, Nishizuka I, Nita C, Odahara A, Podolyak Z, Roberts O, Schaffner H, Shand CM, Taprogge J, Terashima S, Vajta Z, Yoshida S (2017) 94 -Decay Half-lives of Neutron-Rich 55Cs to 67Ho: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation,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.
Da Silva F, Bradley DA, Regan PH, Siti Rozaila Z (2016) Measurement of the total activity concentrations of Libyan oil scale,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.
Gurgi LA, Regan PH, Daniel T, Podolyak Z, Bruce A, Mason P, MÎrginean N, MÎrginean R, Werner V, Alharbi T, Alkhomashi N, Bajoga A, Britton R, CÎta-Danil I, Carroll R, Deleanu D, Bucurescu D, Florea N, Gheorghe I, Ghita D, Lice R, Mihai C, Mulholland K, Negret A, Olacel A, Roberts O, Sava T, Söderström P, Stroe L, Suvaila R, Toma S, Wilson E, Wood R (2016) Nanosecond lifetime measurements of IÀ¼9/2- intrinsic excited states and low-lying B(E1)strengths in 183Re using combined HPGe-LaBr3 coincidence spectroscopy,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.
Rice S, Algora A, Tain J, Valencia E, Agramunt J, Rubio B, Gelletly W, Regan P, Zakari-Issoufou A, Fallot M, Porta A, Rissanen J, Eronen T, Aysto J, Batist L, Bowry M, Bui V, Caballero-Folch R, Cano-Ott D, Elomaa V, Estevez E, Farrelly G, Garcia A, Gomez-Hornillos B, Gorlychev V, Hakala J, Jordan M, Jokinen A, Kolhinen V, Kondev F, Martinez T, Mendoza E, Moore I, Penttila H, Podolyak Z, Reponen M, Sonnenschein V, Sonzogni A, Sarriguren P (2017) Total Absorption Spectroscopy Study of the Beta Decay of 86Br and 91 1 Rb,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.
Mason P, Podolyak Z, Marginean N, Regan PH, Stevenson PD, Werner V, Alexander T, Algora A, Alharbi T, Bowry M, Britton R, Bruce A, Bucurescu D, Bunce M, Cata-Danil G, Cata-Danil I, Cooper N, Deleanu D, Delion D, Filipescu D, Gelletly W, Ghita D, Gheorghe I, Glodariu T, Ilie G, Ivanova D, Kisyov S, Lalkovski S, Lica R, Liddick S, Marginean R, Mihai C, Mulholland K, Nita C, Negret A, Pascu S, Rice S, Roberts O, Sava T, Smith J, Soederstroem P, Stroe L, Suliman G, Suvaila R, Toma S, Townsley C, Wilson E, Wood RT, Zhekova M, Zhou C (2013) Half-life of the yrast 2(+) state in W-188: Evolution of deformation and collectivity in neutron-rich tungsten isotopes,PHYSICAL REVIEW C88(4)044301 AMER PHYSICAL SOC
The half-life of the yrast I À = 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 ³ softness for 184?192W and an oblate minimum for 194W.
Wilson J, Lebois M, Qi L, Amador-Celdran P, Bleuel D, Briz J, Carroll R, Catford WN, De Witte H, Doherty D, Eloirdi R, Georgiev G, Gottardo A, Goasduff A, Hadynska-Klek K, Hauschild K, Hess M, Ingeberg V, Konstantinopoulos T, Ljungvall J, Lopez-Martens A, Lorusso G, Lozeva R, Lutter R, Marini P, Matea I, Materna T, Mathieu L, Oberstedt A, Oberstedt S, Panebianco S, Podolyak Z, Porta D, Regan PH, Reiter P, Rezynkina K, Rose S, Sahin E, Seidlitz M, Shearman R, Siebeck B, Siem S, Smith A, Tveten G, Verney D, Warr N, Zeiser F, Zielinska M (2017) PRODUCTION AND STUDY OF NEUTRON-RICH NUCLEI USING THE LICORNE DIRECTIONAL NEUTRON SOURCE,Acta Physica Polonica B48(3)pp. 395-401 Pan?stwowe 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.
Courtin S, Fruet G, Jenkins D, Heine M, Montanari D, Morris L, Lotay GJ, Regan PH, Kirsebom O, Della Negra S, Hammache F, De Sereville N, Bastin B, de Oliveira F, Randisi G, Stodel C, Beck C, Haas F (2017) Fusion Cross Sections of Astrophysics Interest Within the STELLA Project.,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.
Spagnoletti P, Simpson G, Carroll R, Regis J, Blanc A, Jentschel M, Koster U, Mutti P, Soldner T, de France G, Ur C, Urban W, Bruce A, Drouet F, Fraile L, Gaffney L, GhitØa D, Ilieva S, Jolie J, Korten W, Kroll T, Larijarni C, Lalkovski S, Lica R, Mach H, Marginean N, Paziy V, Podolyak Z, Regan PH, Scheck M, Saed-Samii N, Thiamova G, Townsley C, Vancraeyenest A, Vedia V, Gargano A, Van Isacker P (2017) Half-life of the 15/2+ state of 135I: A test of E2 seniority relations,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.
Larijani Cyrus Kouroush, Jerome SM, Lorusso G, Ivanov P, Russell B, Pearce AK, Regan Patrick (2017) Progress on the chemical separation of fission fragments from 236Np produced by proton irradiation of natural uranium target,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 ¼A 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 ± particle and ³-ray spectrometry.
Regan P, Larijani C, Schwendner P, Cockell C, Ivanov P, Russell B, Aitken-Smith P (2017) Destructive and non-destructive measurements of NORM in monazite-rich sands of Brazil,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).
Rice S, Algora A, Tain J, Valencia E, Agramunt J, Rubio B, Gelletly W, Regan PH, Zakari-Issoufou A, Fallot M, Porta A, Rissanen J, Eronen T, Äystö J, Batist L, Bowry M, Bui V, Caballero-Folch R, Cano-Ott D, Elomaa V, Estevez E, Farrelly G, Garcia A, Gomez-Hornillos B, Gorlychev V, Hakala J, Jordan M, Jokinen A, Kolhinen V, Kondev F, Martínez T, Mason P, Mendoza E, Moore I, Penttilä H, Podolyak Z, Reponen M, Sonnenschein V, Sonzogni A, Sarriguren P (2017) Total absorption spectroscopy study of the ² decay of 86Br and 91Rb,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
Patel Z, Walker P, Podolyak Z, Regan P, Berry T, Söderström P, Watanabe H, Ideguchi E, Simpson G, Nishimura S, Wu Q, Xu F, Browne F, Doornenbal P, Lorusso G, Rice S, Sinclair L, Sumikama T, Wu J, Xu Z, Aoi N, Baba H, Bello Garrote F, Benzoni G, Daido R, Dombrádi Z, Fang Y, Fukuda N, Gey G, Go S, Gottardo A, Inabe N, Isobe T, Kameda D, Kobayashi K, Kobayashi M, Komatsubara T, Kojouharov I, Kubo T, Kurz N, Kuti I, Li Z, Matsushita M, Michimasa S, Moon C, Nishibata H, Nishizuka I, Odahara A, Sahin E, Sakurai H, Schaffner H, Suzuki H, Takeda H, Tanaka M, Taprogge J, Vajta Z, Yagi A, Yokoyama R (2017) Isomer-delayed
-ray spectroscopy of A = 159 - 164 midshell nuclei and the variation of
K-forbidden E1 transition hindrance factors,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.
Gurgi Laila, Regan Patrick, Söderström P-A, Watanabe H, Walker Philip, Podolyak Zsolt, Nishimura S, Berry Thomas, Doornenbal P, Lorusso G, Isobe T, Baba H, Xu ZY, Sakurai H, Sumikama T, Catford Wilton, Bruce AM, Browne F, Lane GJ, Kondev FG, Odahara A, Wu J, Liu HL, Xu FR, Korkulu Z, Lee P, Liu JJ, Phong VH, Yag A, Zhang GX, Alharbi T, Carroll RJ, Chae KY, Dombradi Zs, Estrade A, Fukuda N, Griffin C, Ideguchi E, Inabe N, Kanaoka H, Kojouharov I, Kubo T, Kubono S, Kurz N, Kuti I, Lalkovski S, Lee EJ, Lee CS, Lotay Gavin, Moon C-B, Nishizuka I, Nita CR, Patel Z, Roberts OJ, Schaffner H, Shand Callum, Suzuki H, Takeda H, Terashima S, Vajta Zs, Yoshida S, Valiente-Dòbon JJ (2016) Isomer spectroscopy of neutron-rich 168Tb103,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 ²-decay.
Discrete ³-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)
Judge S, Regan P (2017) Radionuclide metrology research for nuclear site decommissioning,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.
Jentschel M, Blanc A, de France G, Köster U, Leoni S, Mutti P, Simpson G, Soldner T, Ur C, Urban W, Ahmed S, Astier A, Augey L, Back T, Ba'czyk P, Bajoga A, Balabanski D, Belgya T, Benzoni G, Bernards C, Biswas D, Bocchi G, Bottoni S, Britton R, Bruyneel B, Burnett J, Cakirli R, Carroll R, Catford W, Cederwall B, Celikovic I, Cieplicka-OryDczak N, Clement E, Cooper N, Crespi F, Csatlos M, Curien D, CzerwiDski M, Danu L, Davies A, Didierjean F, Drouet F, Duchêne G, Ducoin C, Eberhardt K, Erturk S, Fraile L, Gottardo A, Grente L, Grocutt L, Guerrero C, Guinet D, Hartig A, Henrich C, Ignatov A, Ilieva S, Ivanova D, John B, John R, Jolie J, Kisyov S, Krticka M, Konstantinopoulos T, Korgul A, Krasznahorkay A, Kröll T, Kurpeta J, Kuti I, Lalkovski S, Larijani C, Leguillon R, Lica R, Litaize O, Lozeva R, Magron C, Mancuso C, Martinez E, Massarczyk R, Mazzocchi C, Melon B, Mengoni D, Michelagnoli C, Million B, Mokry C, Mukhopadhyay S, Mulholland K, Nannini A, Napoli D, Olaizola B, Orlandi R, Patel Z, Paziy V, Petrache C, Pfeiffer M, Pietralla N, Podolyak Z, Ramdhane M, Redon N, Regan P, Regis J, Regnier D, Oliver R, Rudigier M, Runke J, Rza'ca-Urban T, Saed-Samii N, Salsac M, Scheck M, Schwengner R, Sengele L, Singh P, Smith J, Stezowski O, Szpak B, Thomas T, Thürauf M, Timar J, Tom A, Tomandl I, Tornyi T, Townsley C, Tuerler A, Valenta S, Vancraeyenest A, Vandone V, Vanhoy J, Vedia V, Warr N, Werner V, Wilmsen D, Wilson E, Zerrouki T, Zielinska M (2017) EXILL?a high-efficiency, high-resolution setup for ³-spectroscopy at an intense cold neutron beam facility,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 ³-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,³)28Al and 35Cl(n,³)36Cl in the energy range from 30 keV up to 10 MeV.
Lalovic Natasa, Rudolph Dirk, Podolyak Zsolt, Sarmiento Luis, Simpson Edward C, Alexander Tom, Cortes Sua Martha Liliana, Gerl Juergen, Golubev Pavel, Ameil Frederic, Arici Tugba, Bauer Christopher, Bazzacco Dino, Bentley Michael A, Boutachkov Plamen, Bowry Michael, Fahlander Claes, Gadea Andres, Gellanki Jnaneswari, Givechev Angel, Goel Namita, Gorska M, Gottardo A., Gregor Eleonora, Guastalla Giulia, Habermann Tobias, Hackstein Mathias, Jungclaus A., Kojouharov Ivan, Kumar Rakesh, Kurz Nikolaus, Lettmann Marc, Lizarazo Cesar, Louchart-Henning Corinne, Merchan Edana, Michelagnoli Caterina, Moeller T, Moschner Kevin, Patel Zena, Pietralla Norbert, Pietri Stephane, Ralet Damian, Reese Michael, Regan Patrick, Reiter Peter, Schaffner Henning, Singh Pushpendra P, Stahl Christian, Stegmann Robert, Stézowski Olivier, Taprogge Jan, Thoele P, Wendt Andreas, Wieland Oliver, Wilson Emma, Wood Rachael, Wollersheim Hans-Juergen, Birkenbach Benedikt, Bruyneel Bart, Burrows Ian, Clement Emmanuel, Desesquelles Pierre, Domingo-Pardo Cesar, Eberth Juergen, Gonzales Millan Vicente, Hess Herbert, Jolie Jan, Judson Daniel, Menegazzo Roberto, Mengoni Daniele, Napoli Daniel, Pullia Alberto, Quintana Arnes Begona, Rainovski G I, Salsac Marie-Delphine, Sanchis Esteban, Simpson John, Valiente Dobón Jose Javier (2018) Study of Isomeric States in 198,200,202,206Pb and 206Hg Populated in Fragmentation Reactions,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 ³ 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.
Mohamud H, Ivanov P, Russell B, Regan P, Ward N (2018) Selective sorption of uranium from aqueous solution by graphene oxide-modified materials,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.
Tain J, Agramunt J, Ahn D, Algora A, Allmond J, Baba H, Bae S, Brewer N, Caballero Folch R, Calvino F, Coleman-Smith P, Cortes G, Davinson T, Dillmann I, Domingo-Pardo C, Estrade A, Fukuda N, Go S, Griffin C, Grzywacz R, Ha J, Hall O, Harkness-Brennan L, Isobe T, Kahl D, Karny M, Kiss G, Kogimtzis M, Korgul A, Kubono S, Labiche M, Lazarus I, Lee J, Liu J, Lorusso G, Matsui K, Miernik K, Montes F, Moon B, Morales A, Nepal N, Nishimura S, Page R, Podolyak Zsolt, Pucknell V, Rasco B, Regan Patrick, Riego A, Rubio B, Rykaczewski K, Saito Y, Sakurai H, Shimizu Y, Simpson J, Soderstrom P, Stracener D, Sumikama T, Surman R, Suzuki H, Takechi M, Takeda H, Tarifeno-Saldiva A, Thomas S, Tolosa-Delgado A, Phong V, Woods P (2018) The BRIKEN Project: Extensive Measurements of ²-delayed Neutron Emitters for the Astrophysical r Process,Acta Physica Polonica B49(3)pp. 417-428 Jagiellonian University
An ambitious program to measure decay properties, primarily ²-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.
Morales A.I., Benzoni G., Watanabe H., de Angelis G., Nishimura S., Coraggio L., Gargano A., Itaco N., Otsuka T., Tsunoda Y., Van Isacker P., Browne F., Daido R., Doornenbal P., Fang Y., Lorusso G., Patel Z., Rice S., Sinclair L., Söderström P.-A., Sumikama T., Valiente-Dobón J.J., Wu J., Xu Z.Y., Yagi A., Yokoyama R., Baba H., Avigo R., Bello Garrote F.L., Blasi N., Bracco A., Bruce A.M., Camera F., Ceruti S., Crespi F.C.L., Delattre M.-C., Dombradi Zs., Gottardo A., Isobe T., Kojouharov I., Kurz N., Kuti I., Lalkovski S, Matsui K., Melon B., Mengoni D., Miyazaki T., Modamio-Hoybjor V., Momiyama S., Napoli D.R., Niikura M., Orlandi R., Podolyak Zsolt, Regan Patrick, Sakurai H., Sahin E., Sohler D., Schaffner H., Taniuchi R., Taprogge J., Vajta Zs., Wieland O., Yalcinkaya M. (2018) Is seniority a partial dynamic symmetry in the first ½ g 9/2 shell?,Physics Letters B781pp. 706-712 Elsevier
The low-lying structures of the midshell ½g9/2 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 ² 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.
Koseoglou P., Werner V., Pietralla N., Ilieva S., Thürauf M., Bernards C., Blanc A., Bruce A. M., Cakirli R. B., Cooper N., Fraile L. M., de France G., Jentschel M., Jolie J., Koester U., Korten W., Kröll T., Lalkovski S., Mach H., M?rginean N., Mutti P., Patel Z., Paziy V., Podolyák Z., Regan P. H., Régis J.-M., Roberts O. J., Saed-Samii N., Simpson G. S., Soldner T., Ur C. A., Urban W., Wilmsen D., Wilson E. (2018) The boundary of the N=90 shape phase transition: 148Ce,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.
Sun Y, Zhang G, Watanabe H, Kondev F, Lane G, Regan P, Söderström P, Walker P, Kanaoka H, Korkulu Z, Lee P, Liu J, Nishimura S, Wu J, Yagi A, Ahn D, Alharbi T, Baba H, Browne F, Bruce A, Carroll R, Chae K, Dombradi Z, Doornenbal P, Estrade A, Fukuda N, Griffin C, Ideguchi E, Inabe N, Isobe T, Kanaya S, Kojouharov I, Kubo T, Kubono S, Kurz N, Kuti I, Lalkovski S, Lee C, Lee E, Lorusso G, Lotay G, Moon C, Nishizuka I, Nita C, Odahara A, Patel Z, Phong V, Podolyak Z, Roberts O, Sakurai H, Schaffner H, Shand C, Shimizu Y, Sumikama T, Suzuki H, Takeda H, Terashima S, Vajta Z, Valiente-Dóbon J, Xu Z (2018) ²-³ and isomeric decay spectroscopy of 168Dy,EPJ Web of Conferences178pp. 02023-1 - 02023-3 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 ² decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.
Heine M., Courtin S., Fruet G., Jenkins D.G., Morris L., Montanari D., Rudigier M., Adsley P., Curien D., Della Negra S., Lesrel J., Beck C., Charles L., Dené P., Haas F., Hammache F., Heitz G., Krauth M., Meyer A., Podolyak Zs., Regan P.H., Richer M., de Séréville N., Stodel C. (2018) The STELLA apparatus for particle-Gamma coincidence fusion measurements with nanosecond timing,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 10¼A, 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.
Shearman Robert (2018) Development of a novel gamma-ray detection system for decay data measurement and beta-delayed spectroscopy of primary fission fragments at N~82.,
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.
Regan Patrick H, Judge Steven M, Keightley John D, Pearce Andy K (2018) Radionuclide Metrology and Standards in Nuclear
Physics,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.-
Wiederhold J., Werner V., Kern R., Pietralla N., Bucurescu D., Carroll R., Cooper N, Daniel T., Filipescu D., Florea N., Gerst R-B., Ghita D., Gurgi Laila, Jolie J., Ilieva Ralitsa, Lica R., Marginean N., Marginean R., Mihai C., Mitu I. O., Naqvi F., Nita C., Rudigier Matthias, Stegemann S., Pascu S., Regan Patrick (2019) Evolution of E2 strength in the rare-earth isotopes Hf174,176,178,180,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 ² 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, Ä (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.
Berry T.A., Podolyak Zs., Carroll R.J., Lic? R., Grawe H., Timofeyuk N.K., Alexander T., Andreyev A.N., Ansari S., Borge M.J.G., Creswell J., Fahlander C., Fraile L.M., Fynbo H.O.U., Gelletly W., Gerst R.-B., Górska M., Gredley A., Greenlees P., Harkness-Brennan L.J., Huyse M., Judge S.M., Judson D.S., Konki J., Kurcewicz J., Kuti I., Lalkovski S., Lazarus I., Lund M., Madurga M., M?rginean N., M?rginean R., Marroquin I., Mihai C., Mihai R.E., Nácher E., Nae S., Negret A., Nic? C., Page R.D., Pascu S., Patel Z., Perea A., Pucknell V., Rahkila P., Rapisarda E., Regan P.H., Rotaru F., Shand C.M., Simpson E.C., Sotty Ch., Stegemann S., Stora T., Tengblad O., Turturica A., Van Duppen P., Vedia V., Wadsworth R., Walker P.M., Warr N., Wearing F., De Witte H. (2019) Investigation of the n = 0 selection rule in Gamow-Teller transitions: The ²-decay of 207Hg,Physics Letters B793pp. 271-275 Elsevier
Gamow-Teller ² decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This n=0 requirement plays a major role in the ² 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 à 82) and Z = 82 (for N à 126). The level of forbiddenness of the n=1v1g9/2 À0g7/2 transition has been investigated from the ² 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 ³-ray transitions depopulating the À0g-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 à 8.8 within a 95% confidence limit. This is the most stringent test of the n=0 selection rule to date.
Jovan
evi? N., Lebois M., Wilson J.N., Thisse D., Qi L., Matea I., Ibrahim F., Verney D., Babo M., Delafosse C., Adsley F., Tocabens G., Gottardo A., Popovitch Y., Nemer J., Canavan R., Rudigier M., Belvedere K., Boso A., Regan P., Podolyak Zs., Shearman R., Bunce M., Inavov P., Oberstedt S., Lopez-Martens A., Hauschild K., Ljungvall J., Chakma R., Lozeva R., Söderström P.-A., Oberstedt A., Etasse D., Ralet D., Blazhev A., Gerst R.-B., Hafner G., Cieplicka-OryDczak N., Iskra L., Fornal B., Benzoni G., Leoni S., Bottoni S., Henrich C., Koseoglou P., Wiederhold J., Homm I., Surder C., Kroll T., Knezevic D., Dragic A., Cortes L., Warr N., Miernik K., Adamska E., Piersa M., Rezynkina K., Fraile L., Benito Garcia J., Sanchez V., Algora A., Davies P., Guadilla-Gomez V., Fallot M., Kurtukian-Nieto T., Schmitt C., Heine M., Reygadas Tello D., Yavachova M., Diakaki M., Zeiser F., Paulson W., Gestvang D. (2019) Spectroscopy of neutron induced reactions with the -ball spectrometer,Acta Physica Polonica B50(3)pp. 297-304 Jagiellonian University
The -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 -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 -ball
experiments will be presented here.
Rudigier M., Canavan R.L., Regan P.H., Söderström P.-A., Lebois M., Wilson J.N., Jovancevic N., Bottoni S., Brunet M., Cieplicka-Orynczak N., Courtin S., Doherty D.T., Hadynska-Klek K., Heine M., Iskra W., Karayonchev V., Kennington A., Koseoglou P., Lotay G., Lorusso G., Nakhostin M., Nita C.R., S. Oberstedt S., Podolyak Zs., Qi L., Régis J.-M., Shearman R., Walker P.M., Witt W. (2019) Isomer spectroscopy and sub-nanosecond half-live determination in 178w using the NuBall array,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.
Gottardo A., Valiente-Dobón J. J., Benzoni G., Morales A. I., Gadea A., Lunardi S., Boutachkov P., Bruce A. M., Górska M., Grebosz J., Pietri S., Podolyak Zs., Pfützner M., Regan P. H., Rudolph D., Weick H., Alcántara Núñez J., Algora A., Al-Dahan N., de Angelis G., Ayyad Y., Alkhomashi N., Allegro P. R. P., Bazzacco D., Benlliure J., Bowry M., Bracco A., Bunce M., Camera F., Casarejos E., Cortes M. L., Crespi F. C. L., Corsi A., Denis Bacelar A. M., Deo A. Y., Domingo-Pardo C., Doncel M., Dombradi Zs., Engert T., Eppinger K., Farrelly G. F., Farinon F., Geissel H., Gerl J., Goel N., Gregor E., Habermann T., Hoischen R., Janik R., Klupp S., Kojouharov I., Kurz N., Lenzi S. M., Leoni S., Mandal S., Menegazzo R., Mengoni D., Million B., Napoli D. R., Naqvi F., Nociforo C., Prochazka A., Prokopowicz W., Recchia F., Ribas R. V., Reed M. W., Sahin E., Schaffner H., Sharma A., Sitar B., Siwal D., Steiger K., Strmen P., Swan T. P. D., Szarka I., Ur C. A., Walker P.M., Wieland O., Wollersheim H-J., Nowacki F., Maglione E. (2019) New spectroscopic information on 211;213Tl A changing structure beyond the N=126
shell closure,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 ³-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.
Mohamud Hibaaq (2019) The use of carbon-based nanomaterials for the removal of radionuclides from aqueous solution.,
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.
Spagnoletti P., Simpson G., Kisyov S., Bucurescu D., Régis J.-M., Saed-Samii N., Blanc A., Jentschel M., Köster U., Mutti P., Soldner T., de France G., Ur C. A., Urban W., Bruce A. M., Bernards C., Drouet F., Fraile L. M., Gaffney L. P., Ghit? D. G., Ilieva S., Jolie J., Korten W., Kröll T., Lalkovski S., Larijarni C., Lic? R., Mach H., M?rginean N., Paziy V., Podolyak Zs., Regan P. H., Scheck M., Smith J. F., Thiamova G., Townsley C., Vancraeyenest A., Vedia V., Warr N., Werner V., ZieliDska M. (2019) Lifetimes and shape-coexisting states of 99Zr,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 ½3/2[541] band allow quadrupole deformations of ²2=0.34(1) and 0.26(3) to be determined for the 821.6- and 1236.6-keV members, whereas ²2=0.32(3) was found for the 850.5-keV member of the ½3/2[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.
Phong V. H., Lorusso G., Davinson T., Estrade A., Hall O., Liu J., Matsui K., Montes F., Nishimura S., Boso A., Regan P. H., Shearman R., Xu Z. Y., Agramunt J., Allmond J. M., Ahn D. S., Algora A., Baba H., Brewer N. T., Bruno C. G., Caballero-Folch R., Calvino F., WoliDska-Cichocka M., Cortes G., Dillmann I., Domingo-Pardo C., Gargano A., Go S., Griffin C. J., Grzywacz R. K., Harkness-Brennan L., Isobe T., Jungclaus A., Kahl D., Khiem L. H., Kiss G., Korgul A., Kubono S., Miernik K., Morales A. I., Nepal N., Piersa M., Podolyak Zs., Rasco B. C., Rykaczewski K. P., Sakurai H., Shimizu Y., Stacener D. W., Sumikama T., Suzuki H., Takeda H., Tain J. L., Tarifeño-Saldivia A., Tolosa-Delgado A., Vaquero V., Woods P. J., Yokoyama R., Yuan C. (2019) Observation of a ¼s isomer in ¹³tIn
: Proton-neutron coupling "southeast" of ¹³²
Sn,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 ¹³tIn. The nuclei of interest were produced by in-flight fission of a ²³xU beam at the Radioactive Isotope Beam Factory at RIKEN. The isomer depopulates through a ³ ray of energy 56.7(1) keV and with a half-life of T1/2=3.5(4)¼s. Based on the comparison with shell-model calculations, we interpret the isomer as the IÀ=5? member of the À0g?19/2½1f37/2 multiplet, decaying to the IÀ=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 IÀ=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.
Gamba E. R., Bruce A. M., Lalkovski S., Rudigier M., Bottoni S., Carpenter M. P., Zhu S., Anderson J. T., Ayangeakaa A. D., Berry T. A., Burrows I., Gallardo M. Carmona, Carroll R. J., Copp P., Cullen D. M., Daniel T., Martínez G. Fernández, Greene J. P., Gurgi L. A., Hartley D. J., Ilieva R., Ilieva S., Kondev F. G., Kröll T., Lane G. J., Lauritsen T., Lazarus I., Lotay G., Nic? C. R., Podolyak Zs., Pucknell V., Reed M., Regan P. H., Rohrer J., Sethi J., Seweryniak D., Shand C. M., Simpson J., SmoleD M., Stefanova E. A., Vedia V., Yordanov O. (2019) Fast-timing measurements in the ground-state band of ¹¹tPd,Physical Review C100(4)044309pp. 044309-1 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 ¹¹tPd populated via ²u²Cf decay, have been measured. The measured lifetimes are Ä+=103(10)ps, Ä+=22(13)ps, and Ä+d10ps for the 2z, 4z, and 6z 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;JJ?2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio RB(E)=B(E2;4z2z)/B(E2;2z0z)=0.80(42) is measured for the first time in ¹¹tPd and compared with the known values RB(E) in the palladium isotopic chain: the systematics suggest that, for N=68, a transition from ³-unstable to a more rigid ³-deformed nuclear shape occurs.
Zhang G.X., Watanabe H., Dracoulis G.D., Kondev F.G., Lane G.J., Regan P.H., Söderström P.-A., Walker P.M., Yoshida K., Kanaoka H., Korkulu Z., Lee P.S., Liu J.J., Nishimura S., Wu J., Yagi A., Ahn D.S., Alharbi T., Baba H., Browne F., Bruce A.M., Carpenter M.P., Carroll R.J., Chae K.Y., Chiara C.J., Dombradi Zs., Doornenbal P., Estrade A., Fukuda N., Griffin C., Ideguchi E., Inabe N., Isobe T., Kanaya S., Kojouharov I., Kubo T., Kubono S., Kurz N., Kuti I., Lalkovski S., Lauritsen T., Lee C.S., Lee E.J., Lister C.J., Lorusso G., Lotay G., McCutchan E.A., Moon C.-B., Nishizuka I., Nita C.R., Odahara A., Patel Z., Phong V.H., Podolyak Zs., Roberts O.J., Sakurai H., Schaffner H., Seweryniak D., Shand C.M., Shimizu Y., Sumikama T., Suzuki H., Takeda H., Terashima S., Vajta Zs., Valiente-Dóbon J.J., Xu Z.Y., Zhu S. (2019) Interplay of quasiparticle and vibrational excitations: First observation of isomeric states in ¹vxDy and ¹vyDy,Physics Letters B799135036pp. 1-7 Elsevier
The neutron-rich dysprosium isotopes ¹vxDy and ¹vyDy have been investigated using the EURICA ³-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 ¹vxDy, a previously unreported isomer with a half-life of 0.57(7) ¼s has been identified at an excitation energy of 1378 keV, and its presence affirmed independently using ³-³-³ coincidence data taken with Gammasphere via two-proton transfer from an enriched ¹wpEr target performed at Argonne National Laboratory. This isomer is assigned JÀ = KÀ = (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 ¹vyDy, the B(E2) value for the transition de-exciting the previously unreported KÀ = (1/2{) isomeric state at 166 keV to the KÀ = (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 ¹w³Yb, suggesting the presence of a significant ³-vibrational admixture with a dominant neutron one-quasiparticle component in the isomeric state.
Rudigier M., Walker P. M., Canavan R.L., Podolyak Zs., Regan P. H., Söderström P.-A., Lebois M., Wilson J.N., Jovancevic N., Blazhev A., Benito J., Bottoni S., Brunet M., Cieplicka-Orynczak N., Courtin S., Doherty D. T., Fraile L.M., Hadynska-Klek K., Heine M., Iskra A.W., Jolie J., Karayonchev V., Kennington A. R., Koseoglou P., Lotay G., Lorusso G., Nakhostin M., Nita C.R., Oberstedt S., Qi L., Régis J.-M., Sánchez-Tembleque V., Shearman R., Witt W., Vedia V., Zell K.O. (2020) Multi-quasiparticle sub-nanosecond isomers in 178W,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.
Koseoglou P., Werner V., Pietralla N., Ilieva S., Nikai? T., Vretenar D., Alexa P., Thqrauf M., Bernards C., Blanc A., Bruce A. M., Cakirli R. B., Cooper N., Fraile L. M., de France G., Jentschel M., Jolie J., KQster U., Korten W., KrQll T., Lalkovski S., Mach H., M?rginean N., Mutti P., Patel Z., Paziy V., Podolyak Zs., Regan Patrick, Régis J.-M., Roberts O. J., Saed-Samii N., Simpson G. S., Soldner T., Ur C. A., Urban W., Wilmsen D., Wilson E. (2020) Low-Z boundary of the N = 88-90 shape phase transition: 148Ce near the critical point,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 ³-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.
Rudigier M., Podolyak Zs., Regan P.H., Bruce A.M., Lalkovski S., Canavan R.L., Gamba E.R., Roberts O., Burrows I., Cullen D.M., Fraile L.M., Gerhard L., Gerl J., Gorska M., Grant A., Jolie J., Karayonchev V., Kurz N., Korten W., Lazarus I.H., Nita C.R., Pucknell V.F.E., Régis J.-M., Schaffner H., Simpson J., Singh P., Townsley C.M., Smith J.F., Vesic J. (2020) FATIMA ? FAst TIMing Array for DESPEC at FAIR,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 ³-³ 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.
Ha J., Sumikama T., Browne F., Hinohara N., Bruce A. M., Choi S., Nishizuka I., Nishimura S., Doornenbal P., Lorusso G., Söderström P.-A., Watanabe H., Daido R., Patel Z., Rice S., Sinclair L., Wu J., Xu Z. Y., Yagi A., Baba H., Chiga N., Carroll R., Didierjean F., Fang Y., Fukuda N., Gey G., Ideguchi E., Inabe N., Isobe T., Kameda D., Kojouharov I., Kurz N., Kubo T., Lalkovski S., Li Z., Lozeva R., Nishibata H., Odahara A., Podolyak Zs., Regan P. H., Roberts O. J., Sakurai H., Schaffner H., Simpson G. S., Suzuki H., Takeda H., Tanaka M., Taprogge J., Werner V., Wieland O. (2020) Shape evolution of neutron-rich 106,108,110Mo isotopes in the triaxial degree of freedom,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, ³ vibration, or ³ -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 KÀ = 0+, 2+, and 4+.
Method: ² -delayed ³ -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 ³ -ray detection and lifetimes of the 2+1 states were determined using the UK fast-timing array of LaBr3(Ce) detectors.
Results: New ³ -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 ² -delayed neutron-emission probabilities of 108 Nb and 110 Nb were determined by examining the ³ rays of their respective daughter decays.
Conclusions: The even-odd energy staggering in the 2+2 band was compared with typical patterns of the ³ -vibrational band, rigid triaxial rotor, and ³ -soft rotor. The very small even-odd staggering of 106Mo, 108Mo, and 110Mo favors a ³ -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 ³ -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 ³ -vibrational band of the prolate shape. However, the staggering pattern observed in 110Mo differs from the one suggested in the calculations which predict a ³ -soft rotor. There was no experimental indication of the oblate shape or the ³ -soft rotor predicted in these Mo isotopes.
Berry T. A., Podolyak Zs., Carroll R. J., Lic? R., Brown B. A., Grawe H., Sotty Ch., Timofeyuk N. K., Alexander T., Andreyev A. N., Ansari S., Borge M. J. G., Brunet M., Cresswell J. R., Fahlander C., Fraile L. M., Fynbo H. O. U., Gamba E., Gelletly W., Gerst R.-B., Górska M., Gredley A., Greenlees P., Harkness-Brennan L. J., Huyse M., Judge S. M., Judson D. S., Konki J., Kowalska M., Kurcewicz J., Kuti I., Lalkovski S., Lazarus I., Lund M., Madurga M., M?rginean N., M?rginean R., Marroquin I., Mihai C., Mihai R. E., Nácher E., Negret A., Nae S., Nic? C., Pascu S., Page R. D., Patel Z., Perea A., Phrompao J., Piersa M., Pucknell V., Rahkila P., Rapisarda E., Regan P. H., Rotaru F., Rudigier M., Shand C. M., Shearman R., Simpson E. C., Stegemann S., Stora T., Tengblad O., Turturica A., Van Duppen P., Vedia V., Walker P. M., Warr N., Wearing F. P., De Witte H. (2020) Octupole states in 207Tl studied through ² decay,Physical Review C101(5)054311 American Physical Society
The ² decay of 207Hg into the single-proton-hole nucleus 207Tl has been studied through ³-ray spectroscopy at the ISOLDE Decay Station (IDS) with the aim of identifying states resulting from coupling of the Às?11/2, Àd?13/2, and Àh?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.
Fruet G., Courtin S., Heine M., Jenkins D. G., Adsley P., Brown A., Canavan R., Catford W. N., Charon E., Curien D., Della Negra S., Duprat J., Hammache F., Lesrel J., Lotay G., Meyer A., Montanari D., Morris L., Moukaddam M., Nippert J., Podolyak Zs., Regan P. H., Ribaud I., Richer M., Rudigier M., Shearman R., de Séréville N., Stodel C. (2020) Advances in the Direct Study of Carbon Burning in Massive Stars,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.
Goodwin M.A, Britton R., Davies A.V., Bell S.J., Collins S.M, Regan P.H (2020) A high-resolution ²?³ coincidence spectrometry system for radioxenon measurements,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.