Professor Wilton Catford


Professor, Research Group Leader of Experimental Nuclear Physics
+44 (0)1483 686804
04 BC 04

Academic and research departments

Experimental Nuclear Physics Group.

Biography

Research

Research interests

My publications

Publications

WN Catford, CN Timis, RC Lemmon, M Labiche, NA Orr, L Caballero, R Chapman, M Chartier, M Rejmund, H Savajols, TIARA Collaboration (2009)Neutron Transfer Studied with a Radioactive beam of 24Ne, using TIARA at SPIRAL
A general experimental technique for high resolution studies of nucleon transfer reactions using radioactive beams is briefly described, together with the first new physics results that have been obtained with the new TIARA array. These first results from TIARA are for the reaction 24Ne(d,p)25Ne, studied in inverse kinematics with a pure radioactive beam of 100,000 pps from the SPIRAL facility at GANIL. The reaction probes the energies of neutron orbitals relevant to very neutron rich nuclei in this mass region and the results highlight the emergence of the N=16 magic number for neutrons and the associated disappearance of the N=20 neutron magic number for the very neutron rich neon isotopes.
GJ Lotay, G Christian, C Ruiz, C Akers, DS Burke, WN Catford, AA Chen, D Connolly, B Davids, J Fallis, U Hager, DA Hutcheon, A Mahl, A Rojas, X Sun (2016)Direct Measurement of the Astrophysical 38Kðp;γÞ39Ca Reaction and Its Influence on theproduction of Nuclides toward the End Point of Nova Nucleosynthesis, In: Physical Review Letters116(13) American Physical Society
We have performed the first direct measurement of the 38Kðp; γÞ39Ca reaction using a beam of radioactive 38K. A proposed l ¼ 0 resonance in the 38K þ p system has been identified at 679(2) keV with an associated strength of 120 þ50 −30 meV. Upper limits of 1.16 (3.5) and 8.6 (26) meV at the 68% (95%) confidence level were also established for two further expected l ¼ 0 resonances at 386 and 515 keV, respectively. The present results have reduced uncertainties in the 38Kðp; γÞ39Ca reaction rate at temperatures of 0.4 GK by more than 2 orders of magnitude and indicate that Ar and Ca may be ejected in observable quantities by oxygen-neon novae. However, based on the newly evaluated rate, the 38Kðp; γÞ39Ca path is unlikely to be responsible for the production of Ar and Ca in significantly enhanced quantities relative to solar abundances.
G Christian, Gavin Lotay, C Ruiz, C Akers, D Burke, Wilton Catford, A Chen, D Connolly, B Davids, J Fallis, U Hager, D Hutcheon, A Mahl, A Rojas, X Sun (2018)Direct measurement of astrophysically important resonances in 38K( p,γ )39Ca, In: Physical Review C97(2)025802 American Physical Society
Background:

Classical novae are cataclysmic nuclear explosions occurring when a white dwarf in a binary system accretes hydrogen-rich material from its companion star. Novae are partially responsible for the galactic synthesis of a variety of nuclides up to the calcium ( A ∼ 40 ) region of the nuclear chart. Although the structure and dynamics of novae are thought to be relatively well understood, the predicted abundances of elements near the nucleosynthesis endpoint, in particular Ar and Ca, appear to sometimes be in disagreement with astronomical observations of the spectra of nova ejecta.

Purpose:

One possible source of the discrepancies between model predictions and astronomical observations is nuclear reaction data. Most reaction rates near the nova endpoint are estimated only from statistical model calculations, which carry large uncertainties. For certain key reactions, these rate uncertainties translate into large uncertainties in nucleosynthesis predictions. In particular, the 38 K ( p , γ ) 39 Ca reaction has been identified as having a significant influence on Ar, K, and Ca production. In order to constrain the rate of this reaction, we have performed a direct measurement of the strengths of three candidate ℓ = 0 resonances within the Gamow window for nova burning, at 386 ± 10 keV, 515 ± 10 keV, and 689 ± 10 keV.

Method:

The experiment was performed in inverse kinematics using a beam of unstable 38 K impinged on a windowless hydrogen gas target. The 39 Ca recoils and prompt γ rays from 38 K ( p , γ ) 39 Ca reactions were detected in coincidence using a recoil mass separator and a bismuth-germanate scintillator array, respectively.

Results:

For the 689 keV resonance, we observed a clear recoil- γ coincidence signal and extracted resonance strength and energy values of 120 + 50 − 30 ( stat . ) + 20 − 60 ( sys . ) meV and 679 + 2 − 1 ( stat . ) ± 1 ( sys . ) keV , respectively. We also performed a singles analysis of the recoil data alone, extracting a resonance strength of 120 ± 20 ( stat . ) ± 15 ( sys . ) meV, consistent with the coincidence result. For the 386 keV and 515 keV resonances, we extract 90 % confidence level upper limits of 2.54 meV and 18.4 meV, respectively.

Conclusions:

We have established a new recommended 38 K ( p , γ ) 39 Ca rate based on experimental information, which reduces overall uncertainties near the peak temperatures of nova burning by a factor of ∼ 250 . Using the rate obtained in this work in model calculations of the hottest oxygen-neon novae reduces overall uncertainties on Ar, K, and Ca synthesis to factors of 15 or less in all cases.

A.  R. L Kennington, G Lotay, D. T Doherty, D Seweryniak, C Andreoiu, K Auranen, M. P Carpenter, W. N Catford, C. M Deibel, K Hadyńska-Klęk, S Hallam, D. E. M Hoff, T Huang, R. V. F Janssens, S Jazrawi, J José, F. G Kondev, T Lauritsen, J Li, A. M Rogers, J Saiz, G Savard, S Stolze, G. L Wilson, S Zhu (2020)Search for Nova Presolar Grains: $γ$-Ray Spectroscopy of 34Ar and its Relevance for the Astrophysical 33Cl($p,γ$) Reaction, In: Physical Review Letters124(25) American Physical Society (APS)
The discovery of presolar grains in primitive meteorites has launched a new era of research in the study of stellar nucleosynthesis. However, the accurate classification of presolar grains as being of specific stellar origins is particularly challenging. Recently, it has been suggested that sulfur isotopic abundances may hold the key to definitively identifying presolar grains with being of nova origins and, in this regard, the astrophysical Cl33 ( p,γ ) Ar34 reaction is expected to play a decisive role. As such, we have performed a detailed γ -ray spectroscopy study of Ar34 . Excitation energies have been measured with high precision and spin-parity assignments for resonant states, located above the proton threshold in Ar34 , have been made for the first time. Uncertainties in the Cl33 ( p,γ ) reaction have been dramatically reduced and the results indicate that a newly identified ℓ=0 resonance at Er=396.9 ( 13 ) keV dominates the entire rate for T=0.25–0.40 GK . Furthermore, nova hydrodynamic simulations based on the present work indicate an ejected S 32/ S 33 abundance ratio distinctive from type-II supernovae and potentially compatible with recent measurements of a presolar grain.
A. Matta, W. M. Catford, N. A. Orr, J. Henderson, P. Ruotsalainen, G. Hackman, A. B. Garnsworthy, F. Delaunay, R. Wilkinson, G. Lotay, Naofumi Tsunoda, Takaharu Otsuka, A. J. Knapton, G. C. Ball, N. Bernier, C. Burbadge, A. Chester, D. S. Cross, S. Cruz, C. Aa. Diget, T. Domingo, T. E. Drake, L. J. Evitts, F. H. Garcia, S. Hallam, E. MacConnachie, M. Moukaddam, D. Muecher, E. Padilla-Rodal, O. Paetkau, J. Park, J. L. Pore, U. Rizwan, J. Smallcombe, J. K. Smith, K. Starosta, C. E. Svensson, J. Williams, M. Williams (2019)Shell evolution approaching the N=20 island of inversion: Structure of ²⁹Mg, In: Physical Review C99044320 American Physical Society
The island of inversion for neutron-rich nuclei in the vicinity of N=20 has become the testing ground par excellence for our understanding and modeling of shell evolution with isospin. In this context, the structure of the transitional nucleus ²⁹Mg is critical. The first quantitative measurements of the single-particle structure of ²⁹Mg are reported, using data from the d(²⁸Mg, p γ)²⁹Mg reaction. Two key states carrying significant =3 (f-wave) strength were identified at 2.40±0.10 (Jπ=5/2¯) and 4.28±0.04 MeV (7/2¯). New state-of-the-art shell-model calculations have been performed and the predictions are compared in detail with the experimental results. While the two lowest 7/2¯ levels are well described, the sharing of single-particle strength disagrees with experiment for both the 3/2¯ and 5/2¯ levels and there appear to be general problems with configurations involving the p3/2 neutron orbital and core-excited components. These conclusions are supported by an analysis of the neutron occupancies in the shell-model calculations.
Ryan Wilkinson, Gavin Lotay, A. Lennarz, C. Ruiz, G. Christian, C. Akers, W. N. Catford, A. A. Chen, D. Connolly, B. Davids, D. A. Hutcheon, D. Jedrejcic, A. M. Laird, L. Martin, E. McNeice, J. Riley, M. Williams (2017)Direct Measurement of the Key Ec.m.=456 keV Resonance in the Astrophysical Ne19(p,γ)Na20 Reaction and Its Relevance for Explosive Binary Systems, In: Physical Review Letters119(24) American Physical Society
We have performed a direct measurement of the 19Ne(p,γ)20Na reaction in inverse kinematics using a beam of radioactive 19Ne. The key astrophysical resonance in the 19Ne+p system has been definitely measured for the first time at Ec.m.=456+5−2  keV with an associated strength of 17+7−5  meV. The present results are in agreement with resonance strength upper limits set by previous direct measurements, as well as resonance energies inferred from precision (3He, t) charge exchange reactions. However, both the energy and strength of the 456 keV resonance disagree with a recent indirect study of the 19Ne(d, n)20Na reaction. In particular, the new 19Ne(p,γ)20Na reaction rate is found to be factors of ∼8 and ∼5 lower than the most recent evaluation over the temperature range of oxygen-neon novae and astrophysical x-ray bursts, respectively. Nevertheless, we find that the 19Ne(p,γ)20Na reaction is likely to proceed fast enough to significantly reduce the flux of 19F in nova ejecta and does not create a bottleneck in the breakout from the hot CNO cycles into the rp process.
G. Fruet, S. Courtin, M. Heine, D. G. Jenkins, P. Adsley, A. Brown, R. Canavan, W. N. Catford, E. Charon, D. Curien, S. Della Negra, J. Duprat, F. Hammache, J. Lesrel, G. Lotay, A. Meyer, D. Montanari, L. Morris, M. Moukaddam, J. Nippert, Zs. Podolyak, P. H. Regan, I. Ribaud, M. Richer, M. Rudigier, R. Shearman, N. de Séréville, C. Stodel (2020)Advances in the Direct Study of Carbon Burning in Massive Stars, In: Physical Review Letters124192701 American Physical Society
The 12C + 12C fusion reaction plays a critical role in the evolution of massive stars and also strongly impacts various explosive astrophysical scenarios. The presence of resonances in this reaction at energies around and below the Coulomb barrier makes it impossible to carry out a simple extrapolation down to the Gamow window—the energy regime relevant to carbon burning in massive stars. The 12C + 12C system forms a unique laboratory for challenging the contemporary picture of deep sub-barrier fusion (possible sub-barrier hindrance) and its interplay with nuclear structure (sub-barrier resonances). Here, we show that direct measurements of the 12C + 12C fusion cross section may be made into the Gamow window using an advanced particle-gamma coincidence technique. The sensitivity of this technique effectively removes ambiguities in existing measurements made with gamma ray or charged-particle detection alone. The present cross-section data span over 8 orders of magnitude and support the fusion-hindrance model at deep sub-barrier energies.
SHAHEEN JAZRAWI, DANIEL THOMAS DOHERTY, J.M Allmond, PATRICK HENRY REGAN, R.V.F Janssens, W Korten, S Zhu, M Zielińska, D Radford, S Ansari, K Auranen, B Bucher, M.P Carpenter, WILTON NEIL CATFORD, K Hadyńska-Klek, JACK HENDERSON, M Hendricks, M Komorowska, F.G Kondev, T Lauritsen, JUERONG LI, GAVIN JAMES LOTAY, P.J Napiorkowski, E Padilla-Rodal, R.C Pardo, B.C Rasco, W Reviol, D.G Sarantites, D Seweryniak, D Santiago-Gonzalez, G Savard, P Singh, S.M Stolze, R Vondrasek, G Wilson, CHUAN-YU WU, J Wu (2020)A High-Resolution Study of the 110Tc → 110Ru → 110Rh → 110Pd Decay Chain with the GRETINA Array, In: Journal of Physics. Conference Series1643(1) IOP Publishing
Spectroscopic data, such as precise γ-ray branching and E2/M1 multipole-mixing ratios, provide vital constraints when performing multi-dimensional Coulomb-excitation analyses. Consequently, as part of our new Coulomb-excitation campaign aimed at investigating the role of exotic non-axial (triaxial) deformations in the unstable refractory Ru-Mo isotopes, additional beta-decay data was obtained. These measurements make use of ANL's CARIBU facility, which provides intense beams of radioactive refractory isotopes along with the excellent efficiency and angular resolution of the GRETINA γ-ray tracking array. In this article, we report on the analysis of the A = 110 decay chain, focussing on the identification of previously unreported states in 110Ru following the decay of 110Tc.
P-A Soderstrom, J Nyberg, PH Regan, A Algora, G de Angelis, SF Ashley, S Aydin, D Bazzacco, RJ Casperson, WN Catford, J Cederkall, R Chapman, L Corradi, C Fahlander, E Farnea, E Fioretto, SJ Freeman, A Gadea, W Gelletly, A Gottardo, E Grodner, CY He, GA Jones, K Keyes, M Labiche, X Liang, Z Liu, S Lunardi, N Marginean, P Mason, R Menegazzo, D Mengoni, G Montagnoli, D Napoli, J Ollier, S Pietri, Z Podolyak, G Pollarolo, F Recchia, E Sahin, F Scarlassara, R Silvestri, JF Smith, K-M Spohr, SJ Steer, AM Stefanini, S Szilner, NJ Thompson, GM Tveten, CA Ur, JJ Valiente-Dobon, V Werner, SJ Williams, FR Xu, JY Zhu (2010)Spectroscopy of neutron-rich Dy-168,Dy-170: Yrast band evolution close to the NpNn valence maximum, In: PHYSICAL REVIEW C81(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
M Labiche, WN Catford, RC Lemmon, CN Timis, R Chapman, NA Orr, B Fernandez-Dominguez, G Moores, NL Achouri, N Amzal, S Appleton, NI Ashwood, TD Baldwin, M Burns, L Caballero, J Cacitti, JM Casadjian, M Chartier, N Curtis, K Faiz, G de France, M Freer, JM Gautier, W Gelletly, G Iltis, B Lecornu, X Liang, C Marry, Y Merrer, L Olivier, SD Pain, VFE Pucknell, B Raine, M Rejmund, B Rubio, F Saillant, H Savajols, O Sorlin, K Spohr, C Theisen, G Voltolini, DD Warner (2010)TIARA: A large solid angle silicon array for direct reaction studies with radioactive beams, In: NUCL INSTRUM METH A614(3)pp. 439-448 ELSEVIER SCIENCE BV
A compact, quasi-4π position sensitive silicon array, TIARA, designed to study direct reactions induced by radioactive beams in inverse kinematics is described here. The Transfer and Inelastic All-angle Reaction Array (TIARA) consists of 8 resistive charge division detectors forming an octagonal barrel around the target and a set of double-sided silicon-strip annular detectors positioned at each end of the barrel. The detector was coupled to the γ-ray array EXOGAM and the spectrometer VAMOS at the GANIL Laboratory to demonstrate the potential of such an apparatus with radioactive beams. The reaction, well known in direct kinematics, has been carried out in inverse kinematics for that purpose. The observation of the ground state and excited states at 7.16 and 7.86 MeV is presented here as well as the comparison of the measured proton angular distributions with DWBA calculations. Transferred l-values are in very good agreement with both theoretical calculations and previous experimental results obtained in direct kinematics.
WN Catford, CN Timis, RC Lemmon, M Labiche, NA Orr, B Fernandez-Dominguez, R Chapman, M Freer, M Chartier, H Savajols, M Rejmund, NL Achouri, N Amzal, NI Ashwood, TD Baldwin, M Burns, L Caballero, JM Casadjian, N Curtis, G de France, W Gelletly, X Liang, SD Pain, VPE Pucknell, B Rubio, O Sorlin, K Spohr, C Theisen, DD Warner (2010)Migration of Nuclear Shell Gaps Studied in the d(Ne-24, p gamma)Ne-25 Reaction, In: PHYSICAL REVIEW LETTERS104(19)ARTN 1pp. ?-? AMER PHYSICAL SOC
S Myalski, M Kmiecik, A Maj, PH Regan, AB Garnsworthy, S Pietri, D Rudolph, Z Podolyak, SJ Steer, F Becker, P Bednarczyk, J Gerl, M Gorska, H Grawe, I Kojouharov, H Schaffner, HJ Wollersheim, W Prokopowicz, J Grebosz, G Benzoni, B Blank, C Brandau, AM Bruce, L Caceres, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbal, E Estevez, H Geissel, W Gelletly, A Heinz, R Hoischen, G Ilie, GA Jones, A Jungclaus, A Kelic, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkovski, Z Liu, F Montes, M Pfutzner, T Saito, T Shizuma, AJ Simons, S Schwertel, S Tachenov, PM Walker, E Werner-Malento, O Wieland (2007)Isomeric ratio for the I-pi=8(+) yrast state in Pd-96 produced in the relativistic fragmentation of Ag-107, In: ACTA PHYSICA POLONICA B38(4)pp. 1277-1282 ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS
We report on the preliminary results from a study of the decay of the I-pi = 8(+) T-1/2 = 2 mu s isomer in Pd-96 performed as part of the Stopped-Beam RISING campaign within the Rare Isotope Investigation at GSI (RISING). The Pd-96 ions were produced following the projectile fragmentation of a 750 MeV per nucleon Ag-107 primary beam. The reaction products were separated and identified by the in-flight method using the GSI Fragment Separator. The residues of interest were stopped in a perspex stopper surrounded by an array of 15, seven-element germanium Cluster detectors. One of the goals of the current work is to investigate the population of high-spin states produced projectile fragmentation reactions using isomeric ratio measurements to infer information on the angular momentum population distribution. In this short contribution the method and results of determining the isomeric ratio for the I-pi = 8(+) microsecond isomer in Pd-96 nucleus are presented.
GF Farrelly, Z Podolyak, SJ Steer, S Pietri, FR Xu, E Werner-Malento, T Shizuma, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, T Kurtukian-Nieto, G Benzoni, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geisserl, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfuezner, A Jungclaus, DL Balabanski, C Brandau, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, HL Liu, Z Liu, A Maj, S Myalski, S Schwerrel, PM Walker, O Wieland (2009)REVISION OF THE K-ISOMER IN W-190(116), In: ACTA PHYSICA POLONICA B40(3)pp. 885-888
Z Podolyak, SJ Steer, S Pietri, E Werner-Malento, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, T Kurtukian-Nieto, G Benzoni, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfutzner, M Hellstrom, A Jungclaus, LL Andersson, L Atanasova, DL Balabanski, A Bentley, B Blank, A Blazhev, C Brandau, J Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland, BA Brown (2007)Isomeric decay studies around Pt-204 and Tb-148, In: EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 165-168 EDP SCIENCES S A
Relativistic energy projectile fragmentation of Pb-208 has been used to produce a range of exotic nuclei. The nuclei of interest were studied by detecting delayed gamma rays following the decay of isomeric states. Experimental information on the excited states of the neutron-rich N = 126 nucleus, Pt-204, following internal decay of two isomeric states, was obtained for the first time. In addition, decays from the previously reported isomeric I=27h and I=(49/2)h states in Tb-148 and Gd-147, respectively, have been observed. These isomeric decays represent the highest spin discrete states observed to date following a projectile fragmentation reaction, and opens further the possibility of doing 'high-spin physics' using this technique.
Z Podolyak, SJ Steer, S Pietri, FR Xu, HL Liu, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, T Kurtukian-Nieto, G Benzoni, T Shizuma, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfutzner, A Jungclaus, DL Balabanski, C Brandau, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, PM Walker, E Werner-Malento, O Wieland (2009)Weakly deformed oblate structures in Os-198(76)122, In: PHYSICAL REVIEW C79(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
AB Garnsworthy, PH Regan, S Pietri, Y Sun, FR Xu, D Rudolph, M Gorska, L Caceres, Z Podolyak, SJ Steer, R Hoischen, A Heinz, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, H Grawe, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopwicz, T Saito, H Schaffner, S Tachenov, E Werner-Malento, HJ Wollersheim, G Benzoni, B Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfuetzner, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wieland (2009)Isomeric states in neutron-deficient A similar to 80-90 nuclei populated in the fragmentation of Ag-107, In: PHYSICAL REVIEW C80(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
C Longour, JG Narro, B Blank, M Lewitowicz, C Miehe, PH Regan, D Applebe, L Axelsson, AM Bruce, WN Catford, C Chandler, RM Clark, DM Cullen, S Czajkowski, JM Daugas, P Dessagne, A Fleury, L Frankland, W Gelletly, J Giovinazzo, B Greenhalgh, R Grzywacz, M Harder, KL Jones, N Kelsall, T Kszczot, RD Page, CJ Pearson, AT Reed, O Sorlin, R Wadsworth (1999)Half-lives of the odd-odd N=Z nuclei Y-78, Nb-82, Tc-86, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS25(4)pp. 759-762
PH Regan, AB Gamsworthy, SJ Steer, S Pletri, Z Podolyak, D Rudolph, M Gorska, L Caceres, E Wemer-Malento, J Gerl, HJ Wollersheim, F Becker, P Bednarczyk, PD Doornenbal, H Geissel, H Grawe, J Grebosz, R Hoischen, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, M Hellstroem, A Jungclaus, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, B Blank, A Blazhev, C Brandau, J Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, G Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wieland (2007)First results from the stopped RISING campaign at GSI: The mapping of isomeric decays in highly exotic nuclei, In: Six International Conference of the Balkan Physical Union899pp. 19-22
S Pietri, PH Regan, Z Podolyak, D Rudolph, S Steer, AB Garnsworthy, E Werner-Malento, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, I Kojouharov, H Schaffner, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, N Kurz, F Montes, W Prokopowicz, T Saito, S Tashenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, M Hellstrom, A Jungclaus, J Simpson, L-L Andersson, L Atanasova, D Balabanski, MA Bentley, B Blank, A Blazhev, C Brandau, JR Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)Recent results in fragmentation isomer spectroscopy with rising, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS261(1-2)pp. 1079-1083
D Rudolph, S Pietri, Z Podolyak, PH Regan, AB Garnsworthy, R Hoischen, SJ Steer, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Gerl, M Gorska, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, E Werner-Malento, HJ Wollersheim, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, G Benzoni, B Blank, A Blazhev, C Brandau, JR Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, A Heinz, M Hellstrom, G Ilie, EK Johansson, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfutzner, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)Exciting isomers from the first stopped-beam RISING campaign, In: EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 173-176
S Pietri, PH Regan, Z Podolyak, D Rudolph, M Gorska, A Jungclaus, M Pfuetzner, AB Garnsworthy, SJ Steer, L Caceres, E Werner-Malento, R Hoischen, J Gerl, I Kojouharov, H Schaffner, HJ Wollersheim, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Grebosz, A Kelic, N Kurz, F Montes, W Prokopowicz, T Saito, S Tashenov, A Heinz, T Kurtukian-Nieto, G Benzoni, M Hellstrom, L-L Andersson, L Atanasova, DL Balabanski, MA Bentley, B Blank, A Blazhev, C Brandau, JR Brown, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, C Fahlander, W Gelletly, G Ilie, EK Johansson, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)First results from the stopped beam isomer rising campaign at GSI, In: ACTA PHYSICA POLONICA B38(4)pp. 1255-1264
WN Catford, S Mohammadi, PH Regan, CS Purry, W Gelletly, PM Walker, GJ Gyapong, J Simpson, DD Warner, T Davinson, R Neal, RD Page, AC Shotter, IM Hibbert, R Wadsworth, SA Forbes, AM Bruce, C Thwaites, P Thirolf, P VanDuppen, W Galster, A Ninane, J Vervier, P Decrock, M Huyse, J Szerypo, J Wauters (1997)High resolution gamma-ray spectroscopy with a radioactive beam, In: NUCLEAR PHYSICS A616(1-2)pp. C303-C310
AB Garnsworthy, PH Regan, S Pietri, D Rudolph, L Caceres, M Gorska, Z Podolyak, SJ Steer, A Heinz, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, H Grawe, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopwicz, T Saito, H Schaffner, S Tachenov, E Werner-Malento, HJ Wollersheim, G Benzoni, B Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, R Hoischen, G Ilie, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfutzner, T Shizuma, AJ Simons, S Schwertel, PM Walker, O Wieland (2007)Isomeric states in the light Tc isotopes, In: ACTA PHYSICA POLONICA B38(4)pp. 1265-1269
AB Garnsworthy, PH Regan, L Caceres, S Pietri, Y Sun, D Rudolph, M Gorska, Z Podolyak, SJ Steer, R Hoischen, A Heinz, F Becker, P Bednarczyk, P Doornenbal, H Geissel, J Gerl, H Grawe, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tachenov, E Werner-Malento, HJ Wollersheim, G Benzoni, BB Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, A Jungclaus, M Kmiecik, FG Kondev, T Kurtukian-Nieto, S Lalkovski, Z Liu, A Maj, S Myalski, M Pfutzner, S Schwertel, T Shizuma, AJ Simons, PM Walker, O Wielandi, FR Xu (2008)Neutron-proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei Nb-82(41) and Tc-86(43), In: PHYSICS LETTERS B660(4)pp. 326-330 ELSEVIER SCIENCE BV
WN Catford, S Mohammadi, PH Regan, CS Purry, W Gelletly, PM Walker, GJ Gyapong, J Simpson, DD Warner, T Davinson, R Neal, RD Page, AC Shotter, IM Hibbert, R Wadsworth, SA Forbes, AM Bruce, C Thwaites, P Thirolf, P VanDuppen, W Galster, A Ninane, J Vervier, P Decrock, M Huyse, J Szerypo, J Wauters (1996)High resolution gamma-ray spectroscopy with a radioactive beam, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT371(3)pp. 449-459 ELSEVIER SCIENCE BV
S Myalski, A Maj, Z Podolyak, F Becker, P Bednarczyk, G Benzoni, B Blank, C Brandau, AM Bruce, L Caceres, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbal, E Estevez, AB Garnsworthy, H Geissel, W Gelletly, J Gerl, M Corska, H Grawe, J Grebosz, A Heinz, R Hoischen, G Ilie, GA Jones, A Jungclaus, A Kelic, M Kmiecik, I Kojouharov, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkovski, Z Liu, F Montes, M Pfuetzner, S Pietri, W Prokopowicz, PH Regan, D Rudolph, T Saito, H Schaffner, S Schwertel, T Shizuma, AJ Simon, SJ Steer, S Tashenov, PM Walker, E Werner-Malento, O Wieland, HJ Wollersheim (2009)ISOMERIC RATIOS FOR NUCLEI WITH Z=62-67 AND A=142-152 PRODUCED IN THE RELATIVISTIC FRAGMENTATION OF Pb-208, In: ACTA PHYSICA POLONICA B40(3)pp. 879-883
Z Podolyak, SJ Steer, S Pietri, M Gorska, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, J Gerl, HJ Wollersheim, H Grawe, KH Maier, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, T Kurtukian-Nieto, G Benzoni, M Pfuetzner, A Jungclaus, DL Balabanski, C Brandau, BA Brown, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, ME Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, PM Walker, E Werner-Malento, O Wieland (2009)Structure of neutron-rich nuclei around the N=126 closed shell; the yrast structure of Au-205(126) up to spin-parity I-pi = (19/2(+)), In: EUROPEAN PHYSICAL JOURNAL A42(3)pp. 489-493
C Longour, JG Narro, B Blank, M Lewitowicz, C Miehe, PH Regan, D Applebe, L Axelsson, AM Bruce, WN Catford, C Chandler, RM Clark, DM Cullen, S Czajkowski, JM Daugas, P Dessagne, A Fleury, L Frankland, W Gelletly, J Giovinazzo, B Greenhalgh, R Grzywacz, M Harder, KL Jones, N Kelsall, T Kszczot, RD Page, CJ Pearson, AT Reed, O Sorlin, R Wadsworth (1998)Observation of Fermi superallowed beta(+) decays in heavy odd-odd, N = Z nuclei: Evidence for 0(+) ground states in Y-78, Nb-82, and Tc-86, In: PHYSICAL REVIEW LETTERS81(16)pp. 3337-3340 AMERICAN PHYSICAL SOC
SJ Steer, Z Podolyak, S Pietri, PH Regan, D Rudolph, E Werner-Malento, AB Garnsworthy, R Hoischen, M Gorska, J Gerl, HJ Wollersheim, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Grebosz, A Kelic, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tachenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, A Jungclaus, DL Balabanski, C Brandau, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, E Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, S Lalkovski, Z Liu, A Maj, S Myalski, T Shizuma, S Schwertel, PM Walker, O Wieland (2007)Identification of isomeric states 'south' of Pb-208 via projectile fragmentation, In: ACTA PHYSICA POLONICA B38(4)pp. 1283-1286
B Fernández-Domínguez, RC Lemmon, C Timis, M Labiche, WN Catford, M Chartier, NI Ashwood, N Amzal, TD Baldwin, M Burns, L Caballero, R Chapman, N Curtis, G de France, M Freer, W Gelletly, X Liang, NA Orr, SD Pain, VPE Pucknell, M Rejmund, B Rubio, H Savajols, O Sorlin, K Spohr, C Thiesen, DD Warner (2007)Single particle structure of exotic nuclei with transfer reactions, In: Progress in Particle and Nuclear Physics59(1)pp. 389-391
We report here on the first results obtained from the study of the 24Ne(d, p)25Ne reaction performed with SPIRAL beam at GANIL using the new TIARA+V AMOS+EXOGAM setup. © 2007.
RC Lemmon, B Fernandez-Dominguez, C Timis, M Labiche, WN Catford, M Chartier, N Ashwood, N Amzal, TD Baldwin, M Burns, L Caballero, R Chapman, N Curtis, G De France, M Freer, W Gelletly, X Liang, NA Orr, SD Pain, VPE Pucknell, M Rejmund, B Rubio, H Savajols, O Sorlin, K Spohr, C Thiesen, DD Warner (2006)Studies of single-particle structure in the N=16 region using transfer reactions, In: AIP Conference Proceedings853pp. 285-290
We have developed a new experimental setup based at the GANIL/SPIRAL facility in Caen, France to measure one-nucleon transfer reactions in inverse kinematics in order to study the evolution of the single particle structure of exotic nuclei. The setup couples together three state-of-the-art detection systems: the TIARA Si array, the large-acceptance magnetic spectrometer VAMOS and the high-efficiency segmented Ge γ-ray array EXOGAM. In a first experiment, the 24Ne(d,p)25Ne reaction has been studied to probe the N=16 shell closure. Details of the setup, data analysis and preliminary results are presented. © 2006 American Institute of Physics.
B Fernández-Domínguez, RC Lemmon, C Timis, M Labiche, WN Catford, M Chartier, N Ashwood, N Amzal, TD Baldwin, M Burns, L Caballero, R Chapman, N Curtis, G De France, M Freer, W Gelletly, X Liang, NA Orr, SD Pain, VPE Pucknell, M Rejmund, B Rubio, H Savajols, O Sorlin, K Spohr, C Thiesen, DD Warner (2006)Studies of the single particle structure of exotic nuclei using transfer reactions, In: AIP Conference Proceedings831pp. 347-351
The TIARA+VAMOS+EXOGAM set-up has recently been installed at GANIL to study the single-particle structure of exotic nuclei. The unique characteristics of the TIARA array, combined with the large acceptance spectrometer VAMOS and the high efficiency Germanium detector array EXOGAM, has allowed high-resolution measurements of transfer reactions in inverse kinematics using low intensity exotic beams. We will describe the experimental set-up, data analysis and preliminary results of the first experiments using a 24Ne beam from SPIRAL, concentrating in particular on the performance of VAMOS that has been used to detect the heavy fragments after the (d,p), (d,d) and (d,t) reactions. © 2006 American Institute of Physics.
LS Caceres, M Gorska, A Jungclaus, PH Regan, AB Garnsworthy, S Pietri, Z Podolyak, D Rudolph, SJ Steer, H Grawe, DL Balabanski, F Becker, P Bednarczyk, G Benzoni, B Blank, C Brandau, AM Bruce, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbalal, E Estevez, H Geissel, W Gelletly, J Gerl, J Grebosz, A Heinz, R Hoischen, G Ilie, J Jolie, GA Jones, M Kmiecik, I Kojouharov, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkowski, L Liu, A Maj, S Myalsk, F Montes, M Pfuetzner, W Prokopowicz, T Saito, H Schatfner, S Schwertel, T Shizuma, AJ Simons, S Tashenov, PM Walker, E Werner-Malento, O Wielandh, HJ Wollersheim (2007)Identification of excited states in the N = Z nucleus Nb-82, In: ACTA PHYSICA POLONICA B38(4)pp. 1271-1275
S Myalski, A Maj, Z Podolyak, M Kmiecik, P Bednarczyk, J Grebosz, PH Regan, AB Garnsworthy, S Pietri, D Rudolph, SJ Steer, F Becker, J Gerl, M Gorska, H Grawe, I Kojouharov, H Schaffner, HJ Wollersheim, W Prokopowicz, G Benzoni, B Blank, C Brandau, AM Bruce, L Caceres, F Camera, WN Catford, IJ Cullen, Z Dombradi, P Doornenbal, E Estevez, H Geissel, W Gelletly, A Heinz, R Hoischen, G Ilie, GA Jones, A Jungclaus, A Kelic, FG Kondev, T Kurtukian-Nieto, N Kurz, S Lalkovski, Z Liu, F Montes, M Pfuetzner, T Saito, T Shizuma, AJ Simons, S Schwertel, S Tachenov, PM Walker, E Werner-Malento, O Wieland (2012)STUDY OF ISOMER PRODUCTION RATES FOR A=142-152 AND Z=62-67 IN FRAGMENTATION OF A RELATIVISTIC Pb-208 BEAM, In: ACTA PHYSICA POLONICA B43(2)pp. 253-259 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
JG Narro, C Longour, PH Regan, B Blank, CJ Pearson, M Lewitowicz, C Miehe, W Gelletly, D Appelbe, L Axelsson, AM Bruce, WN Catford, C Chandler, RM Clark, DM Cullen, S Czajkowski, JM Daugas, P Dessagne, A Fleury, L Frankland, J Giovinazzo, B Greenhalg, R Grzywacz, M Harder, KL Jones, N Kelsall, T Kszczot, RD Page, AT Reed, O Sorlin, R Wadsworth (2001)Fermi superallowed beta(+) decays and T=1 ground states of heavy odd-odd N=Z nuclei, In: PHYSICAL REVIEW C63(4)ARTN 04430 AMERICAN PHYSICAL SOC
SJ Steer, ZS PodolyÁk, S Pietri, M GÓrska, GF Farrelly, PH Regan, D Rudolph, AB Garnsworthy, R Hoischen, J Gerl, HJ Wollersheim, H Grawe, KH Maier, F Becker, P Bednarczyk, L CÁceres, P Doornenbal, H Geissel, J Grbosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, T Kurtukian-Nieto, G Benzoni, M PfÜtzner, A Jungclaus, DL Balabanski, C Brandau, A Brown, AM Bruce, WN Catford, IJ Cullen, Z DombrÁdi, ME Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R KrÜcken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, PM Walker, E Werner-Malento, O Wieland (2009)Isomeric decay studies in neutron-rich N ≈ 126 nuclei, In: International Journal of Modern Physics E18(4)pp. 1002-1007
Heavy neutron-rich nuclei were populated via relativistic energy fragmentation of a E/A=1 GeV 208Pb beam. The nuclei of interest were selected and identified by a fragment separator and then implanted in a passive plastic stopper. Delayed rays following internal isomeric decays were detected by the RISING array. Experimental information was obtained on a number of nuclei with Z=73-80 (Ta-Hg), providing new information both on the prolate-oblate transitional region as well as on the N=126 closed shell nuclei.
SJ Steer, Z Podolyak, S Pietri, M Gorska, PH Regan, D Rudolph, E Werner-Malento, AB Garnsworthy, R Hoischen, J Gerl, HJ Wollersheim, KH Maier, H Grawe, F Becker, P Bednarczyk, L Caceres, P Doornenbal, H Geissel, J Greabosz, A Kelic, I Kojouharov, N Kurz, F Montes, W Prokopowicz, T Saito, H Schaffner, S Tashenov, A Heinz, M Pfuetzner, T Kurtukian-Nieto, G Benzoni, A Jungclaus, DL Balabanski, C Brandau, BA Brown, AM Bruce, WN Catford, IJ Cullen, Z Dombradi, ME Estevez, W Gelletly, G Ilie, J Jolie, GA Jones, M Kmiecik, FG Kondev, R Kruecken, S Lalkovski, Z Liu, A Maj, S Myalski, S Schwertel, T Shizuma, PM Walker, O Wieland (2008)Single-particle behavior at N=126: Isomeric decays in neutron-rich Pt-204, In: PHYSICAL REVIEW C78(6)ARTN 0pp. ?-? AMER PHYSICAL SOC
AN Antonov, MK Gaidarov, MV Ivanov, DN Kadrev, M Aïche, G Barreau, S Czajkowski, B Jurado, G Belier, A Chatillon, T Granier, J Taieb, D Doré, A Letourneau, D Ridikas, E Dupont, E Berthoumieux, S Panebianco, F Farget, C Schmitt, L Audouin, E Khan, L Tassan-Got, T Aumann, P Beller, K Boretzky, A Dolinskii, P Egelhof, H Emling, B Franzke, H Geissel, A Kelic-Heil, O Kester, N Kurz, Y Litvinov, G Münzenberg, F Nolden, K-H Schmidt, C Scheidenberger, H Simon, M Steck, H Weick, J Enders, N Pietralla, A Richter, G Schrieder, A Zilges, MO Distler, H Merkel, U Müller, AR Junghans, H Lenske, M Fujiwara, T Suda, S Kato, T Adachi, S Hamieh, MN Harakeh, N Kalantar-Nayestanaki, H Wörtche, GPA Berg, IA Koop, PV Logatchov, AV Otboev, VV Parkhomchuk, DN Shatilov, PY Shatunov, YM Shatunov, SV Shiyankov, DI Shvartz, AN Skrinsky, LV Chulkov, BV Danilin, AA Korsheninnikov, EA Kuzmin, AA Ogloblin, VA Volkov, Y Grishkin, VP Lisin, AN Mushkarenkov, V Nedorezov, AL Polonski, NV Rudnev, AA Turinge, A Artukh, V Avdeichikov, SN Ershov, A Fomichev, M Golovkov, AV Gorshkov, L Grigorenko, S Klygin, S Krupko, IN Meshkov, A Rodin, Y Sereda, I Seleznev, S Sidorchuk, E Syresin, S Stepantsov, G Ter-Akopian, Y Teterev, AN Vorontsov, SP Kamerdzhiev, EV Litvinova, S Karataglidis, R Alvarez Rodriguez, MJG Borge, C Fernandez Ramirez, E Garrido, P Sarriguren, JR Vignote, LM Fraile Prieto, J Lopez Herraiz, E Moya De Guerra, J Udias-Moinelo, JE Amaro Soriano, AM Lallena Rojo, JA Caballero, HT Johansson, B Jonson, T Nilsson, G Nyman, M Zhukov, P Golubev, D Rudolph, K Hencken, J Jourdan, B Krusche, T Rauscher, D Kiselev, D Trautmann, J Al-Khalili, W Catford, R Johnson, PD Stevenson, C Barton, D Jenkins, R Lemmon, M Chartier, D Cullen, CA Bertulani, A Heinz (2011)The electronion scattering experiment ELISe at the International Facility for Antiproton and Ion Research (FAIR) - A conceptual design study, In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment637(1)pp. 60-76
Since the industrial revolution pollution has typically been classified according to whether it concerns air, water or noise, the issue of light-pollution now joining these. Pollution, direct or otherwise, causes damage to the living environment. In the present study of moderate to high atomic number media, analysis of major, minor and trace elemental concentrations is shown to be effective via x-ray fluorescence and mass spectroscopy (MS) based methods. Particular choice has been made of two media of highly differing constitution, both of toxicological consequence and each with its own challenges. Metals are prevalent in the widespread environmental emissions that result from the use of motorised vehicles, not least in road dust. Conversely, the metals manifest in Kohl have been analysed as an example of how an absence of regulatory control can allow the unimpeded marketing of personal products of clear human health impact. In conducting such a study, comparison has been made of several sensitive yet convenient sample analysis techniques (XRF, SEM/EDX, ICP-MS and ICP-OES), their relative efficacy being examined. The ICP-based methods provide for quantitative sample analysis while XRF/EDX can provide quantitative and qualitative analysis. The XRF study of Kohl has involved analysis of Pb, Fe and Zn concentrations in 135 samples, obtained from nine randomly selected market outlets (15 aliquots of each brand being represented). Among the published physiological effects of exposure to Pb is replacement of Ca in bones and teeth, making them weak and fragile, other impacts including nephrotoxicity, linked with increased Pb blood levels. While in this study the work on Kohl formed an introduction to elemental analysis, one particular challenge, also one that quickly became apparent but yet notable in terms of its absence from discussion in the literature, was investigation of high concentrations of highly attenuating media. Sample dilution and account of it has been required in arriving at reliable quantification. One desire has been to draw regulator attention to the potentiality of convenient, compact instrumentation and associated methodology, allowing for product screening. For road dust, obtained from a total of 60 locations, analysis has been conducted on particle sizes ranging from < 45 m up to 125 m. Arid climate samples were collected from the campuses of King Saud University, the Kuwait Research Institute and Qatar University, while maritime climate samples were collected from the Surrey University campus. Ttropical climate samples were collected from the campus of the University of Malaya as well as surrounding roads to the Malaysian radiation consultancy company, Asia Lab (now Alypz Sdn. Bhd.). Roadside dirt has been sampled along busy campus roads of universities/research centres in Guildford, Riyadh, Kuwait City, Doha and Kuala Lumpur, satisfying interest in climatic influences as well as vehicle engine size (in the Gulf countries non-commercial vehicle engine capacities tend to be greater than those in the UK or Malaysia, a product of relatively cheap fuel prices). A total of 200 street dust samples have been analyzed, elemental concentrations being reported for Mg, Al, Ti, Mn, Fe, Co, Zr, Mo, Ba, Tl, V, Rd, Pb, Cu, Zn, Ni, Cr, Cd, As, Hg and Au. For all five urban centres, Al, Fe, Mg, and Si values were found to be well above background although concentrations of Ti, Cr and Ba were lower than values reported by others. The concentrations of Pb were relatively low, likely attributable to restrictions on lead in fuel. Au and Ag were detected in low quantities in both Arid and Maritime climates, use being made of the SEM/EDX, appearing at levels unlikely to make economic sense in terms of recovery. Note that elemental loadings are provided in terms of concentrations per unit mass of sample. In general, the elements found in elevated concentrations can all be linked to the wear and tear of motor parts as debris. For the Guildford samples, obtained at three different times of the year, the main SEM/EDX findings were for Mg, Al, Cr, Ti, Mn, Fe, Co, Cu, Zr, Mo, Ba, Tl, V, Rh, Au and Ag, values ranging from non-detectable (below detection limits), through to from as low as 34.7 E-6 mg/m2 up to as high as 6 E-2 mg/m2. Note that the output provides estimates of elemental loadings per unit area at the sampling site. Using ICP-MS, Guildford concentrations in mg/kg (ppm) have been found for Al, V, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Mo, Cd, Sb, Pb, and U, for samples of mean size < 45 micron. Respective values were 3081, 12.3, 40.2, 333, 14133, 3.5, 70.4, 288, 5.96, 0.400, 2.35, 0.567, 2.77, 78.0, 0.657, results showing particular elevations of Al, Fe, Cu, Zn and Pb. Other toxic metals found in the Guildford and Kuwait samples in different concentrations were V, Ti, Cr, and Ba. For Riyadh and Doha samples four elements have been observed to be particularly prominent: Al, Fe, Mg, and Si, notwithstanding that they all have natural abundance in desert sands. Elemental presence has been seen to be influenced by climatic conditions as well as vehicle engine size. In conclusion, the various techniques offer complementary information on vehicular emission elemental concentrations in urban environments.
In line with the rapid advances that are being made in medical and industrial applications of radiation at elevated doses, a need is seen for convenient detectors that also offer a favourable range of characteristics. Particular utilisations herein largely depend upon the sensitivity of the dosimetric medium and also upon spatial resolution. The work herein is novel, encompassing characterisation of defects and dosimetric studies of commercial low-cost borosilicate (Pyrex) microscope glass slides and glass-fibre filters, with a view to making use of these as thermoluminescent dosimeters (TLDs). The particular glass forms studied herein have a number of potentially favourable physical characteristics, including being small in thickness (from a few mm down to sub mm diameters), inexpensive, readily available, resistant to moisture/wetting and reusable. Having established the utility of both the glass slides and filter forms towards photon irradiations, the work makes a more detailed investigation of the microscope slide (coverslips), the high degree of optical performance of these being indicative of homogeneity. Dosimetric characterisation of borosilicate glass has been obtained by irradiating them in various radiotherapy and product-irradiator beams, including kilovoltage and megavoltage photons, and megavoltage electrons. The borosilicate glass is found to exhibit minimal fading, competitive with commercial LiF thermoluminescent (TLD-100) dosimeters, also demonstrating a large dynamic dose range over which they remain linear, from sub-Gy through to 250 kGy. Via computerised glow curve deconvolution, the broad overarching peak has been analysed, being best fit deconvolved at into five peaks, associated with silicon oxygen defect centres (Si-ODC), B-O centres and B structural defects. More definitively, the first, second and third peaks, with activation energies of less than 1.2 eV, can be related to the existence of O+ and O- in the silica network. Also shown is that the borosilicate glass is capable of neutron detection, arising predominantly from the order of 4 % boron content, use being made of linacs operating in the photon mode. In line with conventional wisdom, no evidence is found at 6 MV for photo-neutron contamination. Conversely, at 10 MV and in particular 15 MV, appreciable neutron contribution to the signal is seen. The evident dose-dependent non-linearity is suggested to arise from the 10B (n, ) 7Li reaction, the alpha particles delivering dose dependent damage to the glass insulating material, forming additional defects.
AB Garnsworthy, NJ Thompson, Z Podolyak, PM Walker, SJ Williams, GD Dracoulis, G de France, GJ Lane, K Andgren, AM Bruce, AP Byrne, WN Catford, B Cederwall, GA Jones, B McGuirk, S Mandal, ES Paul, V Pucknell, N Redon, B Rosse, RJ Senior, G Sletten (2005)Spectroscopy of Po-212 and At-213 using a He-8 radioactive beam and EXOGAM, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS31(10)pp. S1851-S1854
Laila Gurgi, Patrick Regan, P-A Söderström, H Watanabe, Philip Walker, Zsolt Podolyak, S Nishimura, Thomas Berry, P Doornenbal, G Lorusso, T Isobe, H Baba, ZY Xu, H Sakurai, T Sumikama, Wilton Catford, AM Bruce, F Browne, GJ Lane, FG Kondev, A Odahara, J Wu, HL Liu, FR Xu, Z Korkulu, P Lee, JJ Liu, VH Phong, A Yagi, GX Zhang, T Alharbi, RJ Carroll, KY Chae, Z Dombradi, A Estrade, N Fukuda, C Griffin, E Ideguchi, N Inabe, H Kanaoka, I Kojouharov, T Kubo, S Kubono, N Kurz, I Kuti, S Lalkovski, EJ Lee, CS Lee, Gavin Lotay, CB Moon, I Nishizuka, CR Nita, Z Patel, OJ Roberts, H Schaffner, Callum Shand, H Suzuki, H Takeda, S Terashima, Z Vajta, S Kanaya, J-J Valiente-Dobón (2017)Isomer Spectroscopy of Neutron-rich 165,167Tb, In: Acta Physica Polonica B48(3)pp. 601-608
We present information on the excited states in the prolate-deformed, neutron-rich nuclei 165;167Tb100;102. The nuclei of interest were synthesised following in-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm 9Be target at the Radioactive Ion-Beam Factory (RIBF), RIKEN, Japan. The exotic nuclei were separated and identified event-by-event using the BigRIPS separator, with discrete energy gamma-ray decays from isomeric states with half-lives in the s regime measured using the EURICA gamma-ray spectrometer. Metastable-state decays are identified in 165Tb and 167Tb and interpreted as arising from hindered E1 decay from the 7 2 [523] single quasi-proton Nilsson configuration to rotational states built on the 3 2 [411] single quasi-proton ground state. These data correspond to the first spectroscopic information in the heaviest, odd-A terbium isotopes reported to date and provide information on proton Nilsson configurations which reside close to the Fermi surface as the 170Dy doubly-midshell nucleus is approached.
M Grieser, YA Litvinov, R Raabe, K Blaum, Y Blumenfeld, PA Butler, F Wenander, PJ Woods, M Aliotta, A Andreyev, A Artemyev, D Atanasov, T Aumann, D Balabanski, A Barzakh, L Batist, A-P Bernardes, D Bernhardt, J Billowes, S Bishop, M Borge, I Borzov, F Bosch, AJ Boston, C Brandau, W Catford, R Catherall, J Cederkäll, D Cullen, T Davinson, I Dillmann, C Dimopoulou, G Dracoulis, CE Düllmann, P Egelhof, A Estrade, D Fischer, K Flanagan, L Fraile, MA Fraser, SJ Freeman, H Geissel, J Gerl, P Greenlees, RE Grisenti, D Habs, R von Hahn, S Hagmann, M Hausmann, JJ He, M Heil, M Huyse, D Jenkins, A Jokinen, B Jonson, DT Joss, Y Kadi, N Kalantar-Nayestanaki, BP Kay, O Kiselev, H-J Kluge, M Kowalska, C Kozhuharov, S Kreim, T Kröll, J Kurcewicz, M Labiche, RC Lemmon, M Lestinsky, G Lotay, XW Ma, M Marta, J Meng, D Mücher, I Mukha, A Müller, AS Murphy, G Neyens, T Nilsson, C Nociforo, W Nörtershäuser, RD Page, M Pasini, N Petridis, N Pietralla, M Pfützner, Z Podolyák, P Regan, MW Reed, R Reifarth, P Reiter, R Repnow, K Riisager, B Rubio, MS Sanjari, DW Savin, C Scheidenberger, S Schippers, D Schneider, R Schuch, D Schwalm, L Schweikhard, D Shubina, E Siesling, H Simon, J Simpson, J Smith, K Sonnabend, M Steck, T Stora, T Stöhlker, B Sun, A Surzhykov, F Suzaki, O Tarasov, S Trotsenko, XL Tu, P Van Duppen, C Volpe, D Voulot, PM Walker, E Wildner, N Winckler, DFA Winters, A Wolf, HS Xu, A Yakushev, T Yamaguchi, YJ Yuan, YH Zhang, K Zuber (2012)Storage ring at HIE-ISOLDE: Technical design report: Technical design report, In: European Physical Journal: Special Topics207(1)pp. 1-117 EDP Sciences/Springer
We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams that is unique in the world. The envisaged physics programme is rich and varied, spanning from investigations of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. The TSR might also be employed for removal of isobaric contaminants from stored ion beams and for systematic studies within the neutrino beam programme. In addition to experiments performed using beams recirculating within the ring, cooled beams can also be extracted and exploited by external spectrometers for high-precision measurements. The existing TSR, which is presently in operation at the Max-Planck Institute for Nuclear Physics in Heidelberg, is well-suited and can be employed for this purpose. The physics cases as well as technical details of the existing ring facility and of the beam and infrastructure requirements at HIE-ISOLDE are discussed in the present technical design report.
Laila Gurgi, Patrick Regan, P-A Söderström, H Watanabe, Philip Walker, Zsolt Podolyak, S Nishimura, Thomas Berry, P Doornenbal, G Lorusso, T Isobe, H Baba, ZY Xu, H Sakurai, T Sumikama, Wilton Catford, AM Bruce, F Browne, GJ Lane, FG Kondev, A Odahara, J Wu, HL Liu, FR Xu, Z Korkulu, P Lee, JJ Liu, VH Phong, A Yag, GX Zhang, T Alharbi, RJ Carroll, KY Chae, Zs Dombradi, A Estrade, N Fukuda, C Griffin, E Ideguchi, N Inabe, H Kanaoka, I Kojouharov, T Kubo, S Kubono, N Kurz, I Kuti, S Lalkovski, EJ Lee, CS Lee, Gavin Lotay, C-B Moon, I Nishizuka, CR Nita, Z Patel, OJ Roberts, H Schaffner, Callum Shand, H Suzuki, H Takeda, S Terashima, Zs Vajta, S Yoshida, JJ Valiente-Dòbon (2016)Isomer spectroscopy of neutron-rich 168Tb103, In: Radiation Physics and Chemistry140pp. 493-496 Elsevier
In-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm thick 9Be target has been used to produce and study the decays of a range of neutron-rich nuclei centred around the doubly mid-shell nucleus 170Dy at the RIBF Facility, RIKEN, Japan. The produced secondary fragments of interest were identified eventby- event using the BigRIPS separator. The fragments were implanted into the WAS3ABI position sensitive silicon active stopper which allowed pixelated correlations between implants and their subsequent β-decay. Discrete γ-ray transitions emitted following decays from either metastable states or excited states populated following beta decay were identified using the 84 coaxial high-purity germanium (HPGe) detectors of the EURICA spectrometer, which was complemented by 18 additional cerium-doped lanthanum bromide (LaBr3)
X Pereira-López, B Fernández-Domínguez, F Delaunay, N. L Achouri, N. A Orr, W. N Catford, M Assié, S Bailey, B Bastin, Y Blumenfeld, R Borcea, M Caamaño, L Caceres, E Clément, A Corsi, N Curtis, Q Deshayes, F Farget, M Fisichella, S Franchoo, G de France, M Freer, J Gibelin, A Gillibert, G. F Grinyer, F Hammache, O Kamalou, A Knapton, T Kokalova, V Lapoux, J. A Lay, B Le Crom, S Leblond, J Lois-Fuentes, F. M Marqués, A Matta, P Morfouace, A. M Moro, T Otsuka, J Pancin, L Perrot, J Piot, E Pollacco, D Ramos, C Rodríguez-Tajes, T Roger, F Rotaru, M Sénoville, N de Séréville, R Smith, O Sorlin, M Stanoiu, I Stefan, C Stodel, D Suzuki, T Suzuki, J. C Thomas, N Timofeyuk, M Vandebrouck, J Walshe, C Wheldon (2020)Low-lying single-particle structure of 17C and the N = 14 sub-shell closure, In: Physics Letters. B811135939 Elsevier
The first investigation of the single-particle structure of the bound states of 17C, via the C transfer reaction, has been undertaken. The measured angular distributions confirm the spin-parity assignments of and for the excited states located at 217 and 335 keV, respectively. The spectroscopic factors deduced for these states exhibit a marked single-particle character, in agreement with shell model and particle-core model calculations, and combined with their near degeneracy in energy provide clear evidence for the absence of the sub-shell closure. The very small spectroscopic factor found for the ground state is consistent with theoretical predictions and indicates that the strength is carried by unbound states. With a dominant valence neutron configuration and a very low separation energy, the excited state is a one-neutron halo candidate.
This dissertation presents an ab initio investigation of modern nuclear Hamiltonians predicted by chiral effective field theory (ChEFT) and lattice quantum chromodynamics (LQCD), in both infinite and finite matter using self-consistent Green's function (SCGF). The third order algebraic diagrammatic construction [ADC(3)] originally devised for quantum chemistry, was used to approximate the self-energy in both systems. This is the first application of ADC(3) to infinite matter. These calculations implemented both two- and three-nucleon ChEFT interactions to compute the equation of state of pure neutron matter and symmetric nuclear matter, whilst also obtaining the spectral function. The procedure was benchmarked using the NNLOsat interaction against a previous SCGF calculation based on the T-matrix approach. The benchmark showed good convergence with respect to the model space but it yielded an apparent lack in the binding energy of ~30% at the saturation density of symmetric nuclear matter when compared to the SCGF T-matrix results and the available literature. After the benchmark a preliminary investigation in to modern N²⁻⁴LO nucleon-nucleon interactions extended to include the N²LO three-nucleon interaction was conducted. These results were reviewed with in the current perceived limitations of the SCGF formalism developed here. In this study, increasing the regulator cut off or the order of the chiral expansion for the nucleon-nucleon interaction decreased the observed binding energy whilst also lowering the saturation density. The calculation of finite nuclei used a potential derived from LQCD by the HAL QCD collaboration at an unphysical pion mass, MPS=469 MeV/c². The short-range repulsion of this interaction requires one to include a resummation of ladder diagrams from the excluded model space. The effectiveness of the ladder resummation from outside the computational model space is considered by the infrared convergence of the total binding energies. The introduction of these missing ladder diagrams leads to a complete diagonalisation of short-range degrees of freedom independently of the choice of model space. The binding energy of Helium-4 was calculated to be -4.80 MeV. The heavier doubly magic nuclei, Oxygen-16 and Calcium-40, had binding energies of -17.9 MeV and -74.4 MeV respectively. This means whilst Calcium-40 is observed to be bound with respect to Alpha break up, Oxygen-16 is expected to be unstable.
M. Jentschel, A. Blanc, G. de France, U. Köster, S. Leoni, P. Mutti, G. Simpson, T. Soldner, C. Ur, W. Urban, S. Ahmed, A. Astier, L. Augey, T. Back, P. Ba̧czyk, A. Bajoga, D. Balabanski, T. Belgya, G. Benzoni, C. Bernards, D.C. Biswas, G. Bocchi, S. Bottoni, R. Britton, B. Bruyneel, J. Burnett, R.B. Cakirli, R. Carroll, Wilton Catford, B. Cederwall, I. Celikovic, N. Cieplicka-Oryńczak, E. Clement, N. Cooper, F. Crespi, M. Csatlos, D. Curien, M. Czerwiński, L.S. Danu, A. Davies, F. Didierjean, F. Drouet, G. Duchêne, C. Ducoin, K. Eberhardt, S. Erturk, L.M. Fraile, A. Gottardo, L. Grente, L. Grocutt, C. Guerrero, D. Guinet, A.-L. Hartig, C. Henrich, A. Ignatov, S. Ilieva, D. Ivanova, B.V. John, R. John, J. Jolie, S. Kisyov, M. Krticka, T. Konstantinopoulos, A. Korgul, A. Krasznahorkay, T. Kröll, J. Kurpeta, I. Kuti, S. Lalkovski, C. Larijani, R. Leguillon, R. Lica, O. Litaize, R. Lozeva, C. Magron, C. Mancuso, E. Ruiz Martinez, R. Massarczyk, C. Mazzocchi, B. Melon, D. Mengoni, C. Michelagnoli, B. Million, C. Mokry, S. Mukhopadhyay, K. Mulholland, A. Nannini, D.R. Napoli, B. Olaizola, R. Orlandi, Z. Patel, V. Paziy, C. Petrache, M. Pfeiffer, N. Pietralla, Z. Podolyak, M. Ramdhane, N. Redon, Patrick Regan, J.M. Regis, D. Regnier, R. J. Oliver, Matthias Rudigier, J. Runke, T. Rza̧ca-Urban, N. Saed-Samii, M.D. Salsac, M. Scheck, R. Schwengner, L. Sengele, P. Singh, J. Smith, O. Stezowski, B. Szpak, T. Thomas, M. Thürauf, J. Timar, A. Tom, I. Tomandl, T. Tornyi, C. Townsley, A. Tuerler, S. Valenta, A. Vancraeyenest, V. Vandone, J. Vanhoy, V. Vedia, N. Warr, V. Werner, D. Wilmsen, E. Wilson, T. Zerrouki, M. Zielinska (2017)EXILL—a high-efficiency, high-resolution setup for γ-spectroscopy at an intense cold neutron beam facility, In: Journal of Instrumentation12(11)pp. P11003-P11003 IOP Publishing
In the EXILL campaign a highly efficient array of high purity germanium (HPGe) detectors was operated at the cold neutron beam facility PF1B of the Institut Laue-Langevin (ILL) to carry out nuclear structure studies, via measurements of γ-rays following neutron-induced capture and fission reactions. The setup consisted of a collimation system producing a pencil beam with a thermal capture equivalent flux of about 108 n s−1cm−2 at the target position and negligible neutron halo. The target was surrounded by an array of eight to ten anti-Compton shielded EXOGAM Clover detectors, four to six anti-Compton shielded large coaxial GASP detectors and two standard Clover detectors. For a part of the campaign the array was combined with 16 LaBr3:(Ce) detectors from the FATIMA collaboration. The detectors were arranged in an array of rhombicuboctahedron geometry, providing the possibility to carry out very precise angular correlation and directional-polarization correlation measurements. The triggerless acquisition system allowed a signal collection rate of up to 6 × 105 Hz. The data allowed to set multi-fold coincidences to obtain decay schemes and in combination with the FATIMA array of LaBr3:(Ce) detectors to analyze half-lives of excited levels in the pico- to microsecond range. Precise energy and efficiency calibrations of EXILL were performed using standard calibration sources of 133Ba, 60Co and 152Eu as well as data from the reactions 27Al(n,γ)28Al and 35Cl(n,γ)36Cl in the energy range from 30 keV up to 10 MeV.
C Caesar, J Simonis, T Adachi, Y Aksyutina, J Alcantara, S Altstadt, H Alvarez-Pol, N Ashwood, T Aumann, V Avdeichikov, M Barr, S Beceiro, D Bemmerer, J Benlliure, CA Bertulani, K Boretzky, MJG Borge, G Burgunder, M Caamano, E Casarejos, W Catford, J Cederkaell, S Chakraborty, M Chartier, L Chulkov, D Cortina-Gil, UD Pramanik, PD Fernandez, I Dillmann, Z Elekes, J Enders, O Ershova, A Estrade, F Farinon, LM Fraile, M Freer, M Freudenberger, HOU Fynbo, D Galaviz, H Geissel, R Gernhaeuser, P Golubev, D Gonzalez Diaz, J Hagdahl, T Heftrich, M Heil, M Heine, A Heinz, A Henriques, M Holl, JD Holt, G Ickert, A Ignatov, B Jakobsson, HT Johansson, B Jonson, N Kalantar-Nayestanaki, R Kanungo, A Kelic-Heil, R Knoebel, T Kroell, R Kruecken, J Kurcewicz, M Labiche, C Langer, T Le Bleis, R Lemmon, O Lepyoshkina, S Lindberg, J Machado, J Marganiec, V Maroussov, J Menendez, M Mostazo, A Movsesyan, A Najafi, T Nilsson, C Nociforo, V Panin, A Perea, S Pietri, R Plag, A Prochazka, A Rahaman, G Rastrepina, R Reifarth, G Ribeiro, MV Ricciardi, C Rigollet, K Riisager, M Roeder, D Rossi, JS del Rio, D Savran, H Scheit, A Schwenk, H Simon, O Sorlin, V Stoica, B Streicher, J Taylor, O Tengblad, S Terashima, R Thies, Y Togano, E Uberseder, J Van de Walle, P Velho, V Volkov, A Wagner, F Wamers, H Weick, M Weigand, C Wheldon, G Wilson, C Wimmer, JS Winfield, P Woods, D Yakorev, MV Zhukov, A Zilges, M Zoric, K Zuber (2013)Beyond the neutron drip line: The unbound oxygen isotopes O-25 and O-26, In: PHYSICAL REVIEW C88(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
R Reifarthl, S Altstadt, K Goebell, T Heftrich, M Heil, A Koloczek, C Langer, R Plag, M Pohl, K Sonnabend, M Weigand, T Adachi, F Aksouh, J Al-Khalili, M AlGarawi, S AlGhamdi, G Alkhazov, N Alkhomashi, H Alvarez-Pol, R Alvarez-Rodriguez, V Andreev, B Andrei, L Atar, T Aumann, V Adeichikov, C Bacri, S Bagchi, C Barbieri, S Beceiro, C Beck, C Beinrucker, G Belier, D Bemmerer, M Bendel, J Benlliure, G Benzoni, R Berjillos, D Bertini, C Bertulani, S Bishop, N Blasi, T Bloch, Y Blumenfeld, A Bonaccorso, K Boretzky, A Botvina, A Boudard, P Boutachkov, I Boztosun, A Bracco, S Brambilla, J Briz Monago, M Caamano, C Caesar, F Camera, E Casarejos, W Catford, J Cederkall, B Cederwall, M Chartier, A Chatillon, M Cherciu, L Chulkov, P Coleman-Smith, D Cortina-Gil, F Crespi, R Crespo, J Cresswell, M Csatlos, F Dechery, B Davids, T Davinson, V Derya, P Detistov, P Diaz Fernandez, D DiJuliot, S Dmitry, D Dore, J Duenas, E Dupont, P Egelhof, I Egorova, Z Elekes, J Enders, J Endres, S Ershov, O Ershova, B Fernandez-Dominguez, A Fetisov, E Fiori, A Fomichev, M Fonseca, L Fraile, M Freer, J Friese, MG Borge, D Galaviz Redondo, S Gannon, U Garg, I Gasparic, L Gasques, B Gastineau, H Geissel, R Gernhaeuser, T Ghosh, M Gilbert, J Glorius, P Golubev, A Gorshkov, A Gourishett, L Grigorenko, J Gulyas, M Haiduc, F Hammache, M Harakeh, M Hass, M Heine, A Hennig, A Henriques, R Herzberg, M Holl, A Ignatov, A Ignatyuk, S Ilieva, M Ivanov, N Iwasa, B Jakobsson, H Johansson, B Jonson, P Joshi, A Junghans, B Jurado, G Koerner, N Kalantar, R Kanungo, A Kelic-Heil, K Kezzar, E Khan, A Khanzadeev, O Kiselev, M Kogimtzis, D Koerper, S Kraeckmann, T Kroell, R Kruecken, A Krasznahorkay, J Kratz, D Kresan, T Krings, A Krumbholz, S Krupko, R Kulessa, S Kumar, N Kurz, E Kuzmin, M Labiche, K Langanke, I Lazarus, T Le Bleis, C Lederer, A Lemasson, R Lemmon, V Liberati, Y Litvinov, B Loeher, J Lopez Herraiz, G Muenzenberg, J Machado, E Maev, K Mahata, D Mancusi, J Marganiec, M Martinez Perez, V Marusov, D Mengoni, B Million, V Morcelle, O Moreno, A Movsesyan, E Nacher, M Najafi, T Nakamura, F Naqvi, E Nikolski, T Nilsson, C Nociforo, P Nolan, B Novatsky, G Nyman, A Ornelas, R Palit, S Pandit, V Panin, C Paradela, V Parkar, S Paschalis, P Pawlowski, A Perea, J Pereira, C Petrache, M Petri, S Pickstone, N Pietralla, S Pietri, Y Pivovarov, P Potlog, A Prokofiev, G Rastrepina, T Rauscher, G Ribeiro, M Ricciardi, A Richter, C Rigollet, K Riisager, A Rios, C Ritter, TR Frutos, J Rodriguez Vignote, M Roeder, C Romig, D Rossi, P Roussel-Chomaz, P Rout, S Roy, P Soederstroem, MS Sarkar, S Sakuta, M Salsac, J Sampson, JS del Rio Saez, J Sanchez Rosado, S Sanjari, P Sarriguren, A Sauerwein, D Savran, C Scheidenberger, H Scheit, S Schmidt, C Schmitt, L Schnorrenberger, P Schrock, R Schwengner, D Seddon, B Sherrill, A Shrivastava, S Sidorchuk, J Silva, H Simon, E Simpson, P Singh, D Slobodan, D Sohler, M Spieker, D Stach, E Stan, M Stanoiu, S Stepantsov, P Stevenson, F Strieder, L Stuhl, T Suda, K Suemmerer, B Streicher, J Taieb, M Takechi, I Tanihata, J Taylor, O Tengblad, G Ter-Akopian, S Terashima, P Teubig, R Thies, M Thoennessen, T Thomas, J Thornhill, G Thungstrom, J Timar, Y Togano, U Tomohiro, T Tornyi, J Tostevin, C Townsley, W Trautmann, T Trivedi, S Typel, E Uberseder, J Udias, T Uesaka, L Uvarov, Z Vajta, P Velho, V Vikhrov, M Volknandt, V Volkov, P von Neumann-Cose, M von Schmid, A Wagner, F Wamers, H Weick, D Wells, L Westerberg, O Wieland, M Wiescher, C Wimmer, K Wimmer, JS Winfield, M Winkel, P Woods, R Wyss, D Yakorev, M Yavor, JZ Cardona, I Zartova, T Zerguerras, I Zgura, A Zhdanov, M Zhukov, M Zieblinski, A Zilges, K Zuber (2016)Nuclear astrophysics with radioactive ions at FAIR, In: Nuclear Physics in Astrophysics VI (NPA6). Journal of Physics: Conference Series665(1)
The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process, β-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.
The 19Ne(p,γ)20Na reaction is thought to play a significant role in the nucleosynthesis of explosive stellar phenomena, with a single narrow resonant state located above the proton emission threshold in 20Na thought to dominate the stellar reaction rate at oxygen-neon (ONe) novae and X-ray burst temperatures. In this thesis, the properties of this resonance of astrophysical interest, the subject of experimental and theoretical debate for nearly thirty years, have been measured directly for the first time, using the DRAGON recoil separator to investigate an energy region approximately 10 keV higher than previous direct measurements. The resonance of astrophysical interest was populated by bombarding a windowless hydrogen gas target with a beam of 19Ne, produced by the ISAC facility at TRIUMF National Laboratory. The resulting 20Na recoils were transported to the focal plane of DRAGON, where they were stopped and detected, whilst the radiative capture γ-rays were detected in a BGO array surrounding the target, allowing both the resonance energy and resonance strength to be measured. Doing so made it possible to re-evaluate the stellar reaction rate, relative to the results of recent theoretical and indirect studies of the same reaction. This resonant state of interest has also been measured indirectly via a study of the 19F(d,p)20F reaction, performed primarily to commission the TIARA array at Texas A&M University. The silicon array, coupled to the MDM-2 magnetic spectrometer, Oxford focal plane detector and HPGe clover detectors for the first time, was used to measure the highest energy particle-γ coincidence dataset investigating the structure of 20F. This allowed a decay scheme as well as angular distributions to be produced. The TWOFNR reaction code was used to produce theoretical angular distributions which were used to determine spectroscopic factors, the absolute values of which were then compared with the results of historical studies of the 19F(d,p)20F reaction. By commissioning the new experimental set-up, it can now be used to perform indirect measurements of astrophysical reactions, the direct study of which is beyond contemporary technical capabilities.
R Orlandi, SD Pain, S Ahn, A Jungclaus, KT Schmitt, DW Bardayan, Wilton Catford, R Chapman, KA Chipps, JA Cizewski, CG Gross, ME Howard, KL Jones, RL Kozub, B Manning, M Matos, K Nishio, PD O’ Malley, WA Peters, ST Pittman, A Ratkiewicz, Callum Shand, JF Smith, MS Smith, T Fukui, Jeffrey Tostevin, Y Utsuno (2018)Neutron-hole states in 131Sn and spin-orbit splitting in neutron-rich nuclei, In: Physics Letters B785pp. 615-620 Elsevier
In atomic nuclei, the spin-orbit interaction originates from the coupling of the orbital motion of a nucleon with its intrinsic spin. Recent experimental and theoretical works have suggested a weakening of the spin-orbit interaction in neutron-rich nuclei far from stability. To study this phenomenon, we have investigated the spin-orbit energy splittings of single-hole and single-particle valence neutron orbits of 132Sn. The spectroscopic strength of single-hole states in 131Sn was determined from the measured differential cross sections of the tritons from the neutron-removing 132Sn(d,t)131Sn reaction, which was studied in inverse kinematics at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The spectroscopic factors of the lowest 3=2+, 1=2+ and 5=2+states were found to be (2 j+1), confirming the robust N = 82 shell closure at 132Sn. We compared the spin-orbit splitting of neutron single-hole states in 131Sn to those of single-particle states in 133Sn determined in a recent measurement of the 132Sn(d,p)133Sn reaction. We found a significant reduction of the energy splitting of the weakly bound 3p orbits compared to the well-bound 2d orbits, and that all the observed energy splittings can be reproduced remarkably well by calculations using a onebody spin-orbit interaction and a Woods-Saxon potential of standard radius and diffuseness. The observed reduction of spin-orbit splitting can be explained by the extended radial wavefunctions of the weakly bound orbits, without invoking a weakening of the spin-orbit strength.
SD Pain, WN Catford, NA Orr, JC Angelique, NI Ashwood, V Bouchat, NM Clarke, N Curtis, M Freer, BR Fulton, F Hanappe, M Labiche, JL Lecouey, RC Lemmon, D Mahboub, A Ninane, G Normand, N Soic, L Stuttge, CN Timis, JA Tostevin, JS Winfield, V Ziman (2006)Structure of Be-12: Intruder d-wave strength at N=8, In: PHYSICAL REVIEW LETTERS96(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
S. Ota, G. Christian, G. Lotay, W.N Catford, E.A Bennett, S. Dede, Daniel Doherty, Sam Hallam, J. Hooker, C. Hunt, H. Jayatissa, A. Matta, Mohamad Moukaddam, G.V Rogachev, A. Saastamoinen, Jeffrey Tostevin, S. Upadhyayula, Ryan Wilkinson Decay properties of 22Ne + resonances and their impact on s-process nucleosynthesis, In: Physics Letters B802135256 Elsevier
The astrophysical s-process is one of the two main processes forming elements heavier than iron. A key outstanding uncertainty surrounding s-process nucleosynthesis is the neutron flux generated by the 22Ne(; n)25Mg reaction during the He-core and C-shell burning phases of massive stars. This reaction, as well as the competing 22Ne(;)26Mg reaction, is not well constrained in the important temperature regime from 0:2–0:4 GK, owing to uncertainties in the nuclear properties of resonances lying within the Gamow window. To address these uncertainties, we have performed a new measurement of the 22Ne(6Li; d)26Mg reaction in inverse kinematics, detecting the outgoing deuterons and 25;26Mg recoils in coincidence. We have established a new n= decay branching ratio of 1:14(26) for the key Ex = 11:32 MeV resonance in 26Mg, which results in a new (; n) strength for this resonance of 42(11) eV when combined with the well-established (; ) strength of this resonance. We have also determined new upper limits on the partial widths of neutron-unbound resonances at Ex = 11:112; 11:163, 11:169, and 11:171 MeV. Monte-Carlo calculations of the stellar 22Ne(; n)25Mg and 22Ne(; )26Mg rates, which incorporate these results, indicate that both rates are substantially lower than previously thought in the temperature range from 0:2–0:4 GK.
SD Pain, WN Catford, NA Orr, JC Angelique, NI Ashwood, V Bouchat, NM Clarke, N Curtis, M Freer, B Fulton, F Hanappe, M Labiche, JL Lecouey, R Lemmon, D Mahboub, A Ninane, G Normand, N Soic, L Stuttge, CN Timis, JA Tostevin, V Ziman, J Winfield, D Seweryniak, TL Khoo (2005)Evidence of a (1d(5/2))(2) component to the Be-12 ground state, In: Nuclei at the Limits764pp. 373-378
Data have been obtained on exclusive single neutron knockout cross sections from 12Be to study its ground state structure. The cross sections for the production of 11Be in its ground state (1/2 +) and first excited state (0.32 MeV, 1/2 -) have previously been measured, indicating a strong (2s 1 2) 2 component to the 12Be ground state. In the present experiment, performed at the GANIL laboratory, cross sections for the first (0.32 MeV, 1/2 -) and second (1.78 MeV, 5/2 +, unbound) excited states in 11Be were measured, which gives information on the admixture of (1p 1 2) 2 and (1d 5 2) 2 components in the ground state of 12Be. A fragmentation beam of 12Be of ∼10000 pps (95% pure) was incident on a carbon target at 41 MeV/u. The beam particles were tracked onto the target, and their energies were measured event-by-event. The beam-like residues were measured in a position sensitive telescope mounted at zero degrees, and neutrons were measured in the DéMoN array. The 1/2 - state of 11Be was identified by measuring coincident 320 keV γ-rays, using four NaI detectors. Full kinematic reconstruction of unbound states in 11Be was performed using coincident neutrons and 10Be ions. Detailed simulations were performed in order to interpret the data, and spectroscopic factors were calculated, using preliminary single particle removal cross sections calculated using a Glauber model. © 2005 American Institute of Physics.
J Walshe, M Freer, C Wheldon, LN Achouri, NI Ashwood, WN Catford, IC Celik, N Curtis, F Delaunay, B Fernández-Domínguez, L Grassi, T Kokalova, M Marqués, NA Orr, L Prepolec, V Scuderi, N Soić, V Tokić (2014)The thick target inverse kinematics technique with a large acceptance silicon detector array, In: Journal of Physics: Conference Series569(1)
© Published under licence by IOP Publishing Ltd.An experimental technique for studying elastic scattering using a thick gas target is described, with a measurement of the α(24Ne,α) reaction used as an example. Advantages such as ease, detector efficiency, and the possibility of measuring the cross section at 180° in the centre-of-mass are discussed. It is shown that a resolution of tens of keV is practical at zero degrees, and that the dominant contribution to the resolution for large angles is angular straggling of the beam in the entrance window. The use of helium gas as the target allows direct measurement of a-cluster states.
GL Wilson, WN Catford, NA Orr, C Diget, A Matta, G Hackman, SJ Williams, IC Celik, NL Achouri, H Al Falou, R Ashley, RAE Austin, GC Ball, JC Blackmon, AJ Boston, HC Boston, SM Brown, DS Cross, M Djongolov, TE Drake, U Hager, SP Fox, BR Fulton, N Galinski, AB Garnsworthy, D Jamieson, R Kanungo, KG Leach, JN Orce, CJ Pearson, M Porter-Peden, F Sarazin, EC Simpson, S Sjue, D Smalley, C Sumithrarachchi, C Unsworth, S Triambak, R Wadsworth (2016)Shell evolution approaching the N = 20 island of inversion: Structure of 26Na, In: Physics Letters B Elsevier
The levels in 26Na with single particle character have been observed for the first time using the d(25Na, pγ ) reaction at 5 MeV/nucleon. The measured excitation energies and the deduced spectroscopic factors are in good overall agreement with (0+1)ħω(0+1)ħω shell model calculations performed in a complete spsdfpspsdfp basis and incorporating a reduction in the N=20 gapN=20 gap. Notably, the 1p3/21p3/2 neutron configuration was found to play an enhanced role in the structure of the low-lying negative parity states in 26Na, compared to the isotone 28Al. Thus, the lowering of the 1p3/21p3/2 orbital relative to the 0f7/20f7/2 occurring in the neighbouring Z=10Z=10 and 12 nuclei – 25,27Ne and 27,29Mg – is seen also to occur at Z=11Z=11 and further strengthens the constraints on the modelling of the transition into the island of inversion.
S Chakraborty, UD Pramanik, T Aumann, S Beceiro, K Boretzky, C Caesar, BV Carlson, WN Catford, S Chatterjee, M Chartier, D Cortina-Gil, GD Angelis, D Gonzalez-Diaz, H Emling, PD Fernandez, LM Fraile, O Ershova, H Geissel, M Heil, B Jonson, A Kelic, H Johansson, R Kruecken, T Kroll, J Kurcewicz, C Langer, TL Bleis, Y Leifels, G Munzenberg, J Marganiec, C Nociforo, A Najafi, V Panin, S Paschalis, S Pietri, R Plag, A Rahaman, R Reifarth, V Ricciardi, D Rossi, J Ray, H Simon, C Scheidenberger, S Typel, J Taylor, Y Togano, V Volkov, H Weick, A Wagner, F Wamers, M Weigand, JS Winfield, D Yakorev, M Zoric (2014)Ground-state configuration of neutron-rich Aluminum isotopes through Coulomb breakup, In: EPJ Web of Conferences66
Neutron-rich 34,35Al isotopes have been studied through Coulomb excitation using LAND-FRS setup at GSI, Darmstadt. The method of invariant mass analysis has been used to reconstruct the excitation energy of the nucleus prior to decay. Comparison of experimental CD cross-section with direct breakup model calculation with neutron in p3/2 orbital favours 34Al(g.s) - νp3/2 as ground state configuration of 35Al. But ground state configuration of 34Al is complicated as evident from γ-ray spectra of 33Al after Coulomb breakup of 34Al. © Owned by the authors, published by EDP Sciences, 2014.
P Papka, TAD Brown, BR Fulton, DL Watson, SP Fox, D Groombridge, M Freer, NM Clarke, NI Ashwood, N Curtis, V Ziman, P McEwan, S Ahmed, WN Catford, D Mahboub, CN Timis, TD Baldwin, DC Weisser (2007)Decay path measurements for the 2.429 MeV state in Be-9: Implications for the astrophysical alpha+alpha+n reaction, In: PHYSICAL REVIEW C75(4)ARTN 0pp. ?-? AMER PHYSICAL SOC
M Freer, NI Ashwood, N Curtis, J Malcolm, T Munoz-Britton, C Wheldon, VA Ziman, J Carter, H Fujita, I Usman, Z Buthelezi, SV Fortsch, R Neveling, SM Perez, FD Smit, RW Fearick, P Papka, JA Swartz, S Brown, WN Catford, G Wilson, D Bardayan, SD Pain, K Chipps, K Grzywacz-Jones, N Soic, NL Achouri (2010)CLUSTER STATES IN C-12 AND C-14, In: MODERN PHYSICS LETTERS A25(21-23)pp. 1833-1837 WORLD SCIENTIFIC PUBL CO PTE LTD
The cluster structure of C-12 is explored and recent measurements of proton inelastic scattering, suggesting a 2(+) state close to 9.6 MeV are presented. Resonant scattering studies of Be-10+He-4 used to populate resonances in C-14 are briefly discussed.
M Assie, JA Scarpaci, D Lacroix, JC Angelique, D Bazin, D Beaumel, Y Blumenfeld, WN Catford, M Chabot, A Chatterjee, M Fallot, H Iwasaki, F Marechal, C Monrozeau, J Nyberg, C Petrache, F Skaza, T Tuna (2010)NEUTRON CORRELATIONS IN He-6 VIEWED THROUGH NUCLEAR BREAK-UP, In: MODERN PHYSICS LETTERS A25(21-23)pp. 1846-1849
L Atar, S Paschalis, Carlo Barbieri, C Bertulani, P Díaz Fernández, M Hollington, M Najafi, V Panin, H Alvarez-Pol, T Aumann, V Avdeichikov, S Beceiro-Novo, D Bemmerer, J Benlliure, J Boillos, K Boretzky, M Borge, M Caamaño, C Caesar, E Casarejos, Wilton Catford, J Cederkall, M Chartier, L Chulkov, D Cortina-Gil, E Cravo, R Crespo, I Dillmann, Z Elekes, J Enders, O Ershova, A Estrade, F Farinon, L Fraile, M Freer, D Galaviz Redondo, H Geissel, R Gernhäuser, P Golubev, K Göbel, J Hagdahl, T Heftrich, M Heil, M Heine, A Heinz, A Henriques, A Hufnagel, A Ignatov, H Johansson, B Jonson, J Kahlbow, N Kalantar-Nayestanaki, R Kanungo, A Kelic-Heil, A Knyazev, T Kröll, N Kurz, M Labiche, C Langer, T Le Bleis, R Lemmon, S Lindberg, J Machado, J Marganiec-Gałązka, A Movsesyan, E Nacher, E Nikolskii, T Nilsson, C Nociforo, A Perea, M Petri, S Pietri, R Plag, R Reifarth, G Ribeiro, C Rigollet, D Rossi, M Röder, D Savran, H Scheit, H Simon, O Sorlin, I Syndikus, J Taylor, O Tengblad, R Thies, Y Togano, M Vandebrouck, P Velho, V Volkov, A Wagner, F Wamers, H Weick, C Wheldon, G Wilson, J Winfield, P Woods, D Yakorev, M Zhukov, A Zilges, K Zuber (2018)Quasifree ( p , 2p ) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength, In: Physical Review Letters120(5)052501 American Physical Society
Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R3B=LAND setup with incident beam energies in the range of 300–450 MeV=u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy onenucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type AOðp; 2pÞA−1N have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.
M Roeder, T Adachi, Y Aksyutina, J Alcantara, S Altstadt, H Alvarez-Pol, N Ashwood, L Atar, T Aumann, V Avdeichikov, M Barr, S Beceiro, D Bemmerer, J Benlliure, C Bertulani, K Boretzky, MJG Borge, G Burgunder, M Caamano, C Caesar, E Casarejos, W Catford, J Cederkall, S Chakraborty, M Chartier, L Chulkov, D Cortina-Gil, R Crespo, UD Pramanik, P Diaz-Fernandez, I Dillmann, Z Elekes, J Enders, O Ershova, A Estrade, F Farinon, LM Fraile, M Freer, M Freudenberger, H Fynbo, D Galaviz, H Geissel, R Gernhaeuser, K Goebel, P Golubev, DG Diaz, J Hagdahl, T Heftrich, M Heil, M Heine, A Heinz, A Henriques, M Holl, G Ickert, A Ignatov, B Jakobsson, H Johansson, B Jonson, N Kalantar-Nayestanaki, R Kanungo, A Kelic-Heil, R Knoebel, T Kroell, R Kruecken, J Kurcewicz, N Kurz, M Labiche, C Langer, T Le Bleis, R Lemmon, O Lepyoshkina, S Lindberg, J Machado, J Marganiec, M Mostazo Caro, A Movsesyan, MA Najafi, T Nilsson, C Nociforo, V Panin, S Paschalis, A Perea, M Petri, S Pietri, R Plag, A Prochazka, MA Rahaman, G Rastrepina, R Reifarth, G Ribeiro, MV Ricciardi, C Rigollet, K Riisager, D Rossi, JS del Rio Saez, D Savran, H Scheit, H Simon, O Sorlin, V Stoica, B Streicher, J Taylor, O Tengblad, S Terashima, R Thies, Y Togano, E Uberseder, J Van de Walle, P Velho, V Volkov, A Wagner, F Wamers, H Weick, M Weigand, C Wheldon, G Wilson, C Wimmer, JS Winfield, P Woods, D Yakorev, M Zhukov, A Zilges, K Zuber (2016)Coulomb dissociation of N-20,N-21, In: PHYSICAL REVIEW C93(6)ARTN 06580 AMER PHYSICAL SOC
Neutron-rich light nuclei and their reactions play an important role for the creation of chemical elements. Here, data from a Coulomb dissociation experiment on 20,21N are reported. Relativistic 20,21N ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the 19N(n, γ) 20N and 20N(n, γ) 21N excitation functions and thermonuclear reaction rates have been determined. The 19N(n, γ) 20N rate is up to a factor of 5 higher at T < 1 GK with respect to previous theoretical calculations, leading to a 10 % decrease in the predicted fluorine abundance.
D Smalley, F Sarazin, FM Nunes, BA Brown, P Adsley, H Al-Falou, C Andreoiu, B Baartman, GC Ball, JC Blackmon, HC Boston, WN Catford, S Chagnon-Lessard, A Chester, RM Churchman, DS Cross, CA Diget, D Di Valentino, SP Fox, BR Fulton, A Garnsworthy, G Hackman, U Hager, R Kshetri, JN Orce, NA Orr, E Paul, M Pearson, ET Rand, J Rees, S Sjue, CE Svensson, E Tardiff, AD Varela, SJ Williams, S Yates (2014)Two-neutron transfer reaction mechanisms in C-12(He-6,He-4)C-14 using a realistic three-body He-6 model, In: PHYSICAL REVIEW C89(2)ARTN 02460 AMER PHYSICAL SOC
In this thesis, the radioactive beam (RIB) 25Na at 5 MeV/u with an intensity of up to 3 times 107 pps is exploited to study states in 26Na using a 0.5 mg/cm2 deuterated polyethylene (CD2) target via the highly selective (d,p gamma) transfer reaction. The reaction products are recorded by using both SHARC (the Silicon Highly-segmented Array for Reactions and Coulex) and TIGRESS (The TRIUMF-ISAC Gamma-Ray Escape-Suppressed Spectrometer). The SHARC array is installed at the ISAC-2 facility in TRIUMF (Canada) to study a variety of reactions, but single-particle transfer with a radioactive ion beam is the reaction mechanism of interest here. This experimental study was the first radioactive beam experiment making use of the TIGRESS/SHARC detector set-up in 2009. This work significantly extends an earlier analysis. The motivation of this work is to combine the information extracted from the particle and the gamma detection in 25Na(d,p gamma) 26Na reaction data to compare the experimentally observed results and the shell model predictions. A total of 24 states were studied, of which 10 had not been reported previously, and detailed new information was extracted for most of these. Properties measured and discussed include: (1) the observed gamma-ray decay branching ratios, (2) the observed spectroscopic factors (population strength) in the (d,p) reaction, (3) the observed angular momentum transfer in the (d,p) reaction, (4) a comparison between experimental and the predicted excitation energies from shell model calculations, (5) spin assignments based on the predicted reaction strengths and observed gamma-ray decay scheme, and (6) analogies with the experimentally observed gamma-decay properties of the isotone 28Al. An extra new feature of this work, for the important interpretation of similar future experiments, is a detailed study of the gamma-ray angular distributions and their dependence upon the scattered proton angles in (d,p).
M Lewitowicz, JM Daugas, R Grzywacz, L Achouri, JC Angélique, D Baiborodin, R Bentida, R Béraud, C Bingham, C Borcea, W Catford, A Emsallem, G De France, M Glogowski, H Grawe, D Guillemaud-Mueller, M Houry, S Hurskanen, KL Jones, RC Lemmon, AC Mueller, A Nowak, F De Oliveira-Santos, A Płochocki, M Pfützner, PH Regan, K Rykaczewski, MG Saint-Laurent, JE Sauvestre, M Sawicka, M Schaefer, G Sletten, O Sorlin, M Stanoiu, J Szerypo, W Trinder, S Viteritti, J Winfield (1999)Study of μs-isomers in neutron-rich nuclei around Z=28 and N=40 shell closures, In: Nuclear Physics A654(1 SUPP)
B Fernandez-Dominguez, JS Thomas, WN Catford, F Delaunay, SM Brown, NA Orr, M Rejmund, M Labiche, M Chartier, NL Achouri, H Al Falou, NI Ashwood, D Beaumel, Y Blumenfeld, BA Brown, R Chapman, N Curtis, C Force, G de France, S Franchoo, J Guillot, P Haigh, F Hammache, V Lapoux, RC Lemmon, F Marechal, M Moro, X Mougeot, B Mouginot, L Nalpas, A Navin, N Patterson, B Pietras, EC Pollacco, A Leprince, A Ramus, JA Scarpaci, N de Sereville, I Stephan, O Sorlin, GL Wilson (2011)Emergence of the N=16 shell gap in O-21, In: PHYSICAL REVIEW C84(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
NK Timofeyuk, B Fernandez-Dominguez, P Descouvemont, WN Catford, F Delaunay, JS Thomas (2012)Core excitations and narrow states beyond the proton dripline: The exotic nucleus Al-21, In: PHYSICAL REVIEW C86(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
PJ Haigh, M Freer, NI Ashwood, T Bloxham, N Curtis, HG Bohlen, T Dorsch, T Kokalova, C Wheldon, WN Catford, NP Patterson, JS Thomas (2010)Alpha decay widths of excited states of O-16, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS37(3)ARTN 0pp. ?-? IOP PUBLISHING LTD
R Thies, A Heinz, T Adachi, Y Aksyutina, J Alcantara-Nunes, S Altstadt, H Alvarez-Pol, N Ashwood, T Aumann, V Avdeichikov, M Barr, S Beceiro-Novo, D Bemmerer, J Benlliure, CA Bertulani, K Boretzky, MJG Borge, G Burgunder, M Camano, C Caesar, E Casarejos, W Catford, J Cederkall, S Chakraborty, M Chartier, LV Chulkov, D Cortina-Gil, R Crespo, U Datta, P Diaz Fernandez, I Dillmann, Z Elekes, J Enders, O Ershova, A Estrade, F Farinon, LM Fraile, M Freer, M Freudenberger, HOU Fynbo, D Galaviz, H Geissel, R Gernhauser, K Gobel, P Golubev, DG Diaz, J Hagdahl, T Heftrich, M Heil, M Heine, A Henriques, M Holl, G Ickert, A Ignatov, B Jakobsson, HT Johansson, B Jonson, N Kalantar-Nayestanaki, R Kanungo, R Knobel, T Kroll, R Krucken, J Kurcewicz, N Kurz, M Labiche, C Langer, T Le Bleis, R Lemmon, O Lepyoshkina, S Lindberg, J Machado, J Marganiec, V Maroussov, M Mostazo, A Movsesyan, A Najafi, T Nilsson, C Nociforo, V Panin, S Paschalis, A Perea, M Petri, S Pietri, R Plag, A Prochazka, A Rahaman, G Rastrepina, R Reifarth, G Ribeiro, MV Ricciardi, C Rigollet, K Riisager, M Roder, D Rossi, J Sanchez del Rio, D Savran, H Scheit, H Simon, O Sorlin, V Stoica, B Streicher, JT Taylor, O Tengblad, S Terashima, Y Togano, E Uberseder, J Van de Walle, P Velho, V Volkov, A Wagner, F Wamers, H Weick, M Weigand, C Wheldon, G Wilson, C Wimmer, JS Winfield, P Woods, D Yakorev, MV Zhukov, A Zilges, K Zuber (2016)Systematic investigation of projectile fragmentation using beams of unstable B and C isotopes, In: PHYSICAL REVIEW C93(5)ARTN 05460 AMER PHYSICAL SOC
Background: Models describing nuclear fragmentation and fragmentation-fission deliver important input for planning nuclear physics experiments and future radioactive ion beam facilities. These models are usually benchmarked against data from stable beam experiments. In the future, two-step fragmentation reactions with exotic nuclei as stepping stones are a promising tool to reach the most neutron-rich nuclei, creating a need for models to describe also these reactions. Purpose: We want to extend the presently available data on fragmentation reactions towards the light exotic region on the nuclear chart. Furthermore, we want to improve the understanding of projectile fragmentation especially for unstable isotopes. Method: We have measured projectile fragments from 10,12-18C and 10-15B isotopes colliding with a carbon target. These measurements were all performed within one experiment, which gives rise to a very consistent dataset. We compare our data to model calculations. Results: One-proton removal cross sections with different final neutron numbers (1pxn) for relativistic 10,12-18C and 10-15B isotopes impinging on a carbon target. Comparing model calculations to the data, we find that EPAX is not able to describe the data satisfactorily. Using ABRABLA07 on the other hand, we find that the average excitation energy per abraded nucleon needs to be decreased from 27 MeV to 8.1 MeV. With that decrease ABRABLA07 describes the data surprisingly well. Conclusions: Extending the available data towards light unstable nuclei with a consistent set of new data have allowed for a systematic investigation of the role of the excitation energy induced in projectile fragmentation. Most striking is the apparent mass dependence of the average excitation energy per abraded nucleon. Nevertheless, this parameter, which has been related to final-state interactions, requires further study.
E Clement, G De France, JM Casandjian, A Goergen, W Korten, L Bouchez, A Chatillon, A Huerstel, Y Le Coz, A Obertelli, C Theisen, JN Wilson, J-P Delaroche, M Girod, H Goutte, S Peru, T Czosnyka, J Iwanicki, PJ Napiorkowski, J Srebrny, K Wrzosek-Lipska, M Zielinska, N Bree, I Stefanescu, J Van De Walle, C Andreoiu, PA Butler, R-D Herzberg, DG Jenkins, GD Jones, A Petts, F Becker, J Gerl, WN Catford, CN Timis, G Sletten, G Georgiev, J Ljungvall (2011)EXPERIMENTAL MEASUREMENT OF THE DEFORMATION THROUGH THE ELECTROMAGNETIC PROBE: SHAPE COEXISTENCE IN EXOTIC KR AND SR ISOTOPES, In: INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS20(2)pp. 415-421 WORLD SCIENTIFIC PUBL CO PTE LTD
E Clement, A Gorgen, W Korten, E Bouchez, A Chatillon, J-P Delaroche, M Girod, H Goutte, A Hurstel, Y Le Coz, A Obertelli, S Peru, C Theisen, JN Wilson, M Zielinska, C Andreoiu, F Becker, PA Butler, JM Casandjian, WN Catford, T Czosnyka, G de France, J Gerl, R-D Herzberg, J Iwanicki, DG Jenkins, GD Jones, PJ Napiorkowski, G Sletten, CN Timis (2007)Shape coexistence in neutron-deficient krypton isotopes, In: PHYSICAL REVIEW C75(5)ARTN 0pp. ?-? AMERICAN PHYSICAL SOC
S Calinescu, L Caceres, S Grevy, O Sorlin, Z Dombradi, M Stanoiu, R Astabatyan, C Borcea, R Borcea, M Bowry, Wilton Catford, E Clement, S Franchoo, R Garcia, R Gillibert, IH Guerin, I Kuti, S Lukyanov, A Lepailleur, V Maslov, P Morfouace, J Mrazek, F Negoita, M Niikura, L Perrot, Zsolt Podolyak, C Petrone, Y Penionzhkevich, T Roger, F Rotaru, D Sohler, I Stefan, JC Thomas, Z Vajta, E Wilson (2016)Coulomb excitation of Ca-44 and Ar-46, In: PHYSICAL REVIEW C93(4)ARTN 04433 AMER PHYSICAL SOC
The reduced transition probabilities B(E2; 0+ g.s. → 2+ 1 ) of the 46Ar and 44Ca nuclei were studied using the Coulomb excitation technique at intermediate energy at the LISE/GANIL facility. The in-flight γ rays, emitted after the Coulomb excitation of their first 2+ states, were detected in an array of 64 BaF2 crystals. The present B(E2 ↑) value for 44Ca, 475(36) e2fm4 , agrees well with the value of 495(35) e2fm4 obtained by averaging results of previous experiments. Consistent B(E2; 0+ g.s. → 2+ 1 ) values of 225(29) e2fm4 and 234(19) e2fm4 have been obtained for 46Ar from an absolute and a relative measurement, normalized to the 44Ca value. Both results agree with the ones obtained with the same experimental technique at the NSCL facility but are a factor of 2 smaller than the shell model predictions. The drop in B(E2; 0+ g.s. → 2+ 1 ) in the Ar chain at N = 28, confirmed in this experiment, shows that 46Ar is sensitive to the N = 28 shell closure.
A Rahaman, U Datta Pramanik, T Aumann, S Beceiro, K Boretzky, C Caesar, BV Carlson, WN Catford, S Chakraborty, S Chatterjee, M Chartier, G De Angelis, D Cortina-Gil, D Gonzalez-Diaz, H Emling, P Diaz Fernandez, LM Fraile, O Ershova, H Geissel, M Heil, B Jonson, A Kelic, H Johansson, R Kruecken, T Kroll, J Kurcewicz, C Langer, T Le Bleis, Y Leifels, G Munzenberg, J Marganiec, C Nociforo, A Najafi, V Panin, S Paschalis, S Pietri, R Plag, R Reifarth, V Ricciardi, D Rossi, J Ray, H Simon, C Scheidenberge, S Typel, J Taylor, Y Togano, V Volkov, H Weick, A Wagner, F Wamers, M Weigand, JS Winfield, D Yakorev, M Zoric (2014)Study of ground state wave-function of the Neutron-rich 29,30Na isotopes through coulomb breakup, In: EPJ Web of Conferences66
Coulomb breakup of unstable neutron rich nuclei 29,30Na around the 'island of inversion' has been studied at energy around 434 MeV/nucleon and 409 MeV/nucleon respectively. Four momentum vectors of fragments, decay neutron from excited projectile and γ-rays emitted from excited fragments after Coulomb breakup are measured in coincidence. For these nuclei, the low-lying dipole strength above one neutron threshold can be explained by direct breakup model. The analysis for Coulomb breakup of 29,30Na shows that large amount of the cross section yields the 28Na, 29Na core in ground state. The predominant ground-state configuration of 29,30Na is found to be 28Na(g.s) νs1/2 and 29Na(g.s) νs1/2,respectively. © Owned by the authors, published by EDP Sciences, 2014.
N Curtis, NI Ashwood, WN Catford, NM Clarke, M Freer, D Mahboub, CJ Metelko, SD Pain, N Soić, DC Weisser (2006)Search for three centre cluster structures in 10,11,12B, In: AIP Conference Proceedings853pp. 160-164
The 7Li(7Li, 11B*)t, 12C(7Li, 10B*)9Be and 7Li(7Li, 12B*)d reactions have been studied at 58 MeV in order to determine the relative strengths of the H + Be and α + Li decay of 10,11,12B. A study of the relative yields for the decay of a number of excited states in 10,11,12B*, obtained following the coincident detection of the H + Be and α + Li decay fragments, indicates that the α-decay channel dominates in all cases. © 2006 American Institute of Physics.
N. Curtis, N. I. Ashwood, L. T. Baby, T. D. Baldwin, T. R. Bloxham, W. N. Catford, D. D. Caussyn, M. Freer, C. W. Harlin, P. McEwan, D. L. Price, D. Spingler, I. Wiedenhover (2006)alpha-decaying states in Be10,12 populated in the Be10(C14,Be10,12) reaction., In: Physical Review C73(057301)

A search has been made for the 6He+6He and alpha + 8He decay of the molecular rotational band in 12Be using the 10Be(14C,12Be*)12C reaction at 88.5 MeV. Although the alpha + 6He decay of 10Be was observed in the data set there is no evidence for the breakup of 12Be. The cross-section upper limits for the 10Be(14C,6He 6He)12C and 10Be(14C,alpha 8He)12C reactions are 50 and 300 nb respectively.

N Curtis, AS Murphy, NM Clarke, M Freer, BR Fulton, SJ Hall, MJ Leddy, JS Pople, G Tungate, RP Ward, WN Catford, GJ Gyapong, SM Singer, SPG Chappell, SP Fox, CD Jones, DL Watson, WDM Rae, PM Simmons, PH Regan (1996)Evidence for a highly deformed band in O-16+O-16 breakup of S-32, In: PHYSICAL REVIEW C53(4)pp. 1804-1810 AMERICAN PHYSICAL SOC
NI Ashwood, M Freer, NL Achouri, TR Bloxham, WN Catford, N Curtis, PJ Haigh, CW Harlin, NP Patterson, DL Price, N Soić, JS Thomas (2009)Spectroscopy of 16O using α + 12C resonant scattering in inverse kinematics, In: Journal of Physics G: Nuclear and Particle Physics36(5)055105pp. ?-? Institute of Physics
Ameasurement of the α(12C, α) 12Creaction has been performed using resonant scattering with a gas target. Beam energies of 46, 52, 56 and 63 MeV were used to populate resonances in the excitation energy range of 11.6–22.9 MeV in 16O. The angular distributions of the elastic scattering were measured at zero degrees, using an array of segmented silicon strip detectors with a minimum range of 0◦–30◦ in the centre-of-mass. The spins of 8 resonances between 14.1 and 18.5 MeV were obtained, confirming spin assignments made using elastic scattering in normal kinematics. An R-matrix analysis of the data was performed which indicates that the present understanding of 16O in this region is good, but not complete.
JC Angélique, C Timis, S Piétri, NL Achouri, P Baumann, C Borcea, A Buta, W Catford, S Courtin, JM Daugas, P Dessagne, F De Oliveira, Z Dlouhy, S Grévy, D Guillemaud-Mueller, R Hadeler, A Knipper, FR Lecolley, JL Lecouey, M Lewitowicz, E Liénard, C Miehe, J Mrazek, F Negoita, F Nowacki, NA Orr, Y Penionzhkevich, J Peter, E Poirier, M Stanoiu, O Tarasov, G Walter (2006)Spectroscopy near the N=20 shell closure: β-n decay studies of 33Mg and 35Al, In: AIP Conference Proceedings831pp. 134-138
An experimental spectroscopic investigation of some neutron rich Mg and Al isotopes around the shell closure N=20 has been performed. The delayed neutron and γ spectra, following the β-decay of 33Mg and 35Al have been measured using the delayed neutron detector array TONNERRE coupled with high efficiency EXOGAM clover detectors, a LEPS detector and eight low-energy neutron detectors. A detailed analysis of such spectra allows one to construct the level schemes of their daughters, 32,33Al and 34,35Si. The resulting spectroscopic information will provide stringent tests of large scale shell model calculations including np - nh excitations aimed at the understanding of the structural effects occurring in this region. © 2006 American Institute of Physics.
TAD Brown, P Papka, BR Fulton, DL Watson, SP Fox, D Groombridge, M Freer, NM Clarke, NI Ashwood, N Curtis, V Ziman, P McEwan, S Ahmed, WN Catford, D Mahboub, CN Timis, TD Baldwin, DC Weisser (2007)Decay studies for states in (9)Be up to 11 MeV: Insights into the n+(8)Be and alpha+(5)He cluster structure, In: PHYSICAL REVIEW C76(5)ARTN 0pp. ?-? AMER PHYSICAL SOC
M Pfutzner, P Armbruster, T Baumann, J Benlliure, M Bernas, WN Catford, D Cortina-Gil, JM Daugas, H Geissel, M Gorska, H Grawe, R Grzywacz, M Hellstrom, N Iwasa, Z Janas, AR Junghans, M Karny, S Leenhardt, M Lewitowicz, AC Mueller, F de Oliviera, PH Regan, M Rejmund, K Rykaczewski, K Summerer (1998)New isotopes and isomers produced by the fragmentation of U-238 at 1000 MeV/nucleon, In: PHYSICS LETTERS B444(1-2)pp. 32-37 ELSEVIER SCIENCE BV
A Rahaman, U Datta, T Aumann, S Beceiro-Novo, K Boretzky, C Caesar, BV Carlson, Wilton Catford, S Chakraborty, M Chartier, D Cortina-Gil, G De Angelis, P Diaz Fernandez, H Emling (2017)Coulomb breakup of neutron-rich 29,30Na isotopes near the island of inversion, In: Journal of Physics G: Nuclear and Particle Physics44(4)045101 Institute of Physics
First results are reported on the ground state configurations of the neutron-rich 29,30Na isotopes, obtained via Coulomb dissociation (CD) measurements. The invariant mass spectra of these nuclei have been obtained through measurement of the four-momenta of all decay products after Coulomb excitation of those nuclei on a 208Pb target at energies of 400-430 MeV/nucleon using the FRS-ALADIN-LAND setup at GSI, Darmstadt. Integrated inclusive Coulomb-dissociation cross-sections (CD) of 89 (7) mb and 167 (13) mb for one neutron removal from 29Na and 30Na, respectively, have been extracted up to an excitation energy of 10 MeV. The major part of one neutron removal, CD cross-sections of those nuclei populate the core, in its’ ground state. A comparison with the direct breakup model, suggests the predominant occupation of the valence neutron in the ground state of 29Na(3/2+) and 30Na(2+) is the d-orbital with a small contribution from the s-orbital, which are coupled with the ground state of the core. One of the major components of the ground state configurations of these nuclei are 28Nags(1+) ⊗ νs,d and 29Nags(3/2+) ⊗ νs,d, respectively. The ground state spin and parity of these nuclei obtained from this experiment are in agreement with earlier reported values. The spectroscopic factors for the valence neutron occupying the s and d orbitals for these nuclei in the ground state have been extracted and reported for the first time. A comparison of the experimental findings with shell model calculation using the MCSM suggests a lower limit of around 4.3 MeV of the sd − pf shell gap in 30Na.
WN Catford (2013)Conference summary: an experimental perspective, In: 10TH INTERNATIONAL CONFERENCE ON CLUSTERING ASPECTS OF NUCLEAR STRUCTURE AND DYNAMICS (CLUSTER'12)436UNSP 0pp. ?-? IOP PUBLISHING LTD
M Heine, S Typel, M-R Wu, T Adachi, Y Aksyutina, J Alcantara, S Altstadt, H Alvarez-Pol, N Ashwood, T Aumann, V Avdeichikov, M Barr, S Beceiro-Novo, D Bemmerer, J Benlliure, CA Bertulani, Wilton Catford, G Wilson (2017)Determination of the Neutron-Capture Rate of 17C for the R-process Nucleosynthesis, In: Physical Review C: Nuclear Physics95(1)014613 American Physical Society
With the R3B-LAND setup at GSI we have measured exclusive relative-energy spectra of the Coulomb dissociation of 18C at a projectile energy around 425 AMeV on a lead target, which are needed to determine the radiative neutron-capture cross sections of 17C into the ground state of 18C. Those data have been used to constrain theoretical calculations for transitions populating excited states in 18C. This allowed to derive the astrophysical cross section n accounting for the thermal population of 17C target states in astrophysical scenarios. The experimentally veri ed capture rate is signi cantly lower than those of previously obtained Hauser-Feshbach estimations at temperatures T9 1 GK. Network simulations with updated neutron-capture rates and hydrodynamics according to the neutrino-driven wind model as well as the neutron-star merger scenario reveal no pronounced in uence of neutron capture of 17C on the production of second- and third-peak elements in contrast to earlier sensitivity studies.
S Calinescu, L Caceres, S Grevy, O Sorlin, D Sohler, M Stanoiu, F Negoita, E Clement, R Astabatyan, C Borcea, R Borcea, M Bowry, W Catford, Z Dombradi, S Franchoo, R Garcia, R Gillibert, H Guerin, JC Thomas, I Kuti, S Lukyanov, A Lepailleur, V Maslov, P Morfouace, J Mrazek, M Niikura, L Perrot, Z Podolyak, C Petrone, Y Penionzhkevich, T Roger, F Rotaru, I Stefan, Z Vajta, E Wilson (2014)STUDY OF THE NEUTRON-RICH ISOTOPE Ar-46 THROUGH INTERMEDIATE ENERGY COULOMB EXCITATION, In: ACTA PHYSICA POLONICA B45(2)pp. 199-204
GL Wilson, Wilton Catford, SM Brown, CA Diget, P Adsley, SP Fox, BR Fulton, R Wadsworth, NA Orr, H Al-Falou, GC Ball, RM Churchman, DS Cross, J Dech, M Djongolov, U Hager, N Galinski, AB Garnsworthy, G Hackman, JN Orce, CJ Pearson, S Sjue, C Sumithrarachchi, S Triambak, SJ Williams, R Ashley, AJ Boston, HJ Boston, C Unsworth, RAE Austin, R Kanungo, JC Blackmon, AA Chen, J Chen, TE Drake, J-P Martin, M Porter-Peden, F Sarazin, D Jamieson, K Leach, CE Svensson (2012)Towards Na via (d,p) with SHARC and TIGRESS and a novel zero-degree detector, In: Journal of Physics: Conference Series381(1)012097 Institute of Physics
Nucleon transfer experiments have in recent years begun to be exploited in the study of nuclei far from stability, using radioactive beams in inverse kinematics. New techniques are still being developed in order to perform these experiments. The present experiment is designed to study the odd-odd nucleus Na which has a high density of states and therefore requires gamma-ray detection to distinguish between them. The experiment employed an intense beam of up to 3×10 pps of Na at 5.0 MeV/nucleon from the ISAC-II facility at triumf. The new silicon array SHARC was used for the first time and was coupled to the segmented clover gamma-ray array TIGRESS. A novel thin plastic scintillator detector was employed at zero degrees to identify and reject reactions occurring on the carbon component of the (CD) target. The efficiency of the background rejection using this detector is described with respect to the proton and gamma-ray spectra from the (d,p) reaction. © Published under licence by IOP Publishing Ltd.
C Beck, ASI Zafra, P Papka, S Thummerer, F Azaiez, P Bednarczyk, S Courtin, D Curien, O Dorvaux, D Lebhertz, A Nourreddine, J Robin, M Rousseau, W Von Oertzen, B Gebauer, T Kokalova, C Wheldon, G De Angelis, A Gadea, S Lenzi, S Szilner, DR Napoli, WN Catford, DG Jenkins, G Royer (2008)ALPHA-CLUSTER STATES POPULATED IN Mg-24+C-12, In: INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS17(10)pp. 2049-2054
A Banu, L Trache, RE Tribble, F Carstoiu, F Negoita, F Rotaru, N Orr, L Achouri, B Laurent, B Roeder, M Chartier, B Fernandez-Dominguez, S Paschalis, B Pietras, P Roussel-Chomaz, L Gaudefroy, R Lemmon, M Labiche, W Catford, N Patterson, J Thomas, M Freer, M Horoi, A Bonaccorso (2008)Breakup of proton-rich nuclei 24Si, 23Al, 22Mg, 21Na at intermediate energies for reaction rates in explosive H-burning in novae, In: Proceedings of Science
We discuss the use of one proton-removal reactions of loosely bound nuclei at intermediate energies as an indirect method in nuclear astrophysics, with particular reference to the results of a GANIL experiment with a cocktail beam around 23Al at 50 MeV/nucleon. Momentum distributions of the core fragments, inclusive and in coincidence with gamma rays detected with EXOGAM, were measured. From them we determine mixing ratios in the structure of the ground states of the projectile nuclei and the asymptotic normalization of their wave functions. The method has the advantage that can be used for beams of low quality, such as cocktail beams, and intensities as low as a few pps. The proton breakup reactions provide information to determine astrophysical (p,γ) reaction rates that are outside the reach of other direct or indirect methods, or complementary information to the use of transfer reactions (the ANC method) which require radioactive beams of much better purity and intensity. Preliminary results on proton breakup of 24Si, 23Al, 22Mg and 21Na will be presented. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial- ShareAlikeLicence.
JM Daugas, R Grzywacz, M Lewitowicz, L Achouri, JC Angelique, D Baiborodin, K Bennaceur, R Bentida, R Beraud, C Borcea, C Bingham, WN Catford, A Emsallem, G de France, H Grawe, KL Jones, RC Lemmon, MJL Jimenez, F Nowacki, FD Santos, M Pfutzner, PH Regan, K Rykaczewski, JE Sauvestre, M Sawicka, G Sletten, M Stanoiu (2000)The 8(+) isomer in Zn-78 and the doubly magic character of Ni-78, In: PHYSICS LETTERS B476(3-4)pp. 213-218 ELSEVIER SCIENCE BV
N Soić, M Freer, L Donadille, NM Clarke, PJ Leask, WN Catford, KL Jones, D Mahboub, BR Fulton, BJ Greenhalgh, DL Watson (2006)Experimental evidence for cluster structure of 11B excited states, In: AIP Conference Proceedings853pp. 171-176
The kinematically complete measurements of the 7Li( 9Be,ααt)5He reaction at Ebeam = 55 and 70 MeV have been performed and the reconstructed 11B excitation energy spectra were compared with the 7Li(9Be, α7Li)5He results obtained at the same beam energies. Evidence was found for the t+8Be(g.s.) decay of the 11B excited states at 13.1 and 14.4 MeV, the α+7Li*(4.652 MeV) decay of the states at 14.4 and 17.5 MeV and for the t+ 8Be*(3.03 MeV) decay of the 17.5 MeV state in 11B. A study of the relative yields for the decay of the 14.4 MeV state indicates that significant part of α-decay strength goes into the 2α+t three-body decay channel. © 2006 American Institute of Physics.
C Beck, ASI Zafra, P Papka, S Thummerer, F Azaiez, S Courtin, D Curien, O Dorvaux, D Lebhertz, A Nourreddine, M Rousseau, W Von Oertzen, B Gebauer, T Kokalova, C Wheldon, G De Angelis, A Gadea, S Lenzi, DR Napoli, S Szilner, WN Catford, DG Jenkins, G Royer (2009)Reaction mechanisms in 24Mg+ 12C and32S+ 24Mg, In: AIP Conference Proceedings1098pp. 207-212
The occurence of ``exotic'' shapes in light N = Z α-like nuclei is investigated for 24Mg+12C and 32S+24Mg. Various approaches of superdeformed and hyperdeformed bands associated with quasimolecular resonant structures with low spin are presented. For both reactions, exclusive data were collected with the Binary Reaction Spectrometer in coincidence with EUROBALL IV installed at the VIVITRON Tandem facility of Strasbourg. Specific structures with large deformation were selectively populated in binary reactions and their associated γ-decays studied. The analysis of the binary and ternary reaction channels is discussed.
B Fernández-Domínguez, B Pietras, N Patterson, JS Thomas, N Orr, M Chartier, W Catford, NL Achouri, JC Angêlique, NI Ashwood, A Banu, B Bastin, J Brown, R Borcea, S Franchoo, M Freer, L Gaudefroy, B Laurent, M Labiche, RC Lemmon, F Negoita, S Paschalis, ES Paul, M Petri, P Roussel-Chomaz, M Staniou, MJ Taylor, L Trache (2010)Structure around the island of inversion with single-neutron knockout reactions at GANIL, In: CERN-Proceedings1pp. 145-149
The nuclear structure of the 31Mg nucleus has been studied with the single-neutron knockout reaction. We report on the preliminary results of an experiment performed with the EXOGAM array coupled, for the first time, to the SPEG spectrometer at GANIL. We present a provisional result for the inclusive single-neutron knockout cross section of σinc= 90(5) mb. Preliminary exclusive cross sections for the measured bound states, including the ground state, are also presented. Finally, preliminary longitudinal momentum distributions for the ground state and first excited state are also shown. These results are compared to Monte Carlo Shell-Model calculations in the sd-pf region.
B Fernández-Domínguez, B Pietras, Wilton Catford, N Orr, M Petri, M. Chartier, S. Paschalis, N Patterson, J Thomas, M. Caamaño, T. Otsuka, A. Poves, N. Tsunoda, N. Achouri, J. Angélique, N Ashwood, A. Banu, B. Bastin, R. Borcea, J. Brown, F. Delaunay, S. Franchoo, M. Freer, L. Gaudefroy, S. Heil, M. Labiche, B. Laurent, R Lemmon, A Macchiavelli, F. Negoita, E Paul, C. Rodríguez-Tajes, P. Roussel-Chomaz, M. Staniou, M Taylor, L. Trache, G Wilson (2018)Re-examining the transition into the N = 20 island of inversion: Structure of 30 Mg, In: Physics Letters B779pp. 124-129 Elsevier
Intermediate energy single-neutron removal from 31Mg has been employed to investigate the transition into the N = 20 island of inversion. Levels up to 5 MeV excitation energy in 30Mg were populated and spin-parity assignments were inferred from the corresponding longitudinal momentum distributions and γ -ray decay scheme. Comparison with eikonal-model calculations also permitted spectroscopic factors to be deduced. Surprisingly, the 0+ 2 level in 30Mg was found to have a strength much weaker than expected in the conventional picture of a predominantly 2p−2h intruder configuration having a large overlap with the deformed 31Mg ground state. In addition, negative parity levels were identified for the first time in 30Mg, one of which is located at low excitation energy. The results are discussed in the light of shell-model calculations employing two newly developed approaches with markedly different descriptions of the structure of 30Mg. It is concluded that the cross-shell effects in the region of the island of inversion at Z = 12 are considerably more complex than previously thought and that np−nh configurations play a major role in the structure of 30Mg.
TD Baldwin, WN Catford, D Mahboub, CN Timis, NI Ashwood, NM Clarke, N Curtis, V Ziman, TAD Brown, SP Fox, BR Fulton, D Groombridge, DL Watson, VFE Pucknell, DC Weisser (2012)First excited 1/2(+) state in B-9, In: PHYSICAL REVIEW C86(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
M Freer, JD Malcolm, NL Achouri, NI Ashwood, DW Bardayan, SM Brown, WN Catford, KA Chipps, J Cizewski, N Curtis, KL Jones, T Munoz-Britton, SD Pain, N Soic, C Wheldon, GL Wilson, VA Ziman (2014)Resonances in C-14 observed in the He-4(Be-10,alpha)Be-10 reaction, In: PHYSICAL REVIEW C90(5)ARTN 05432 AMER PHYSICAL SOC
J. N. Wilson, M. Lebois, L. Qi, P. Amador-Celdran, D. Bleuel, J. A. Briz, R. Carroll, Wilton Catford, H. De Witte, D. T. Doherty, R. Eloirdi, G. Georgiev, A. Gottardo, A. Goasduff, K. Hadyńska-Klęk, K. Hauschild, H. Hess, V. Ingeberg, T. Konstantinopoulos, J. Ljungvall, A. Lopez-Martens, G. Lorusso, R. Lozeva, R. Lutter, P. Marini, I. Matea, T. Materna, L. Mathieu, A. Oberstedt, S. Oberstedt, S. Panebianco, Zsolt Podolyak, A. Porta, Patrick Regan, P. Reiter, K. Rezynkina, S. J. Rose, E. Sahin, M. Seidlitz, O. Serot, Robert Shearman, B. Siebeck, S. Siem, A. G. Smith, G. M. Tveten, D. Verney, N. Warr, F. Zeiser, M. Zielinska (2017)Anomalies in the Charge Yields of Fission Fragments from the U(n,f)238 Reaction, In: Physical Review Letters118(22)pp. 222501-1 American Physical Society
Fast-neutron-induced fission of 238U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ−γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.
C Beck, P Papka, A Sanchez i Zafraa, S Thummerer, F Azaiez, P Bednarczyk, S Courtin, D Curien, O Dorvaux, A Goasduff, D Lebhertz, A Nourreddine, M Rousseau, M-D Salsac, W von Oertzen, B Gebauer, C Wheldon, T Kokalova, G Efimov, V Zherebchevsky, C Schulz, HG Bohlen, D Kamanin, G de Angelis, A Gadea, S Lenzi, DR Napoli, S Szilner, M Milin, WN Catford, DG Jenkins, G Royer (2011)CLUSTERS IN LIGHT NUCLEI, In: ACTA PHYSICA POLONICA B42(3-4)pp. 747-756
SM Brown, WN Catford, JS Thomas, B Fernandez-Dominguez, NA Orr, M Labiche, M Rejmund, NL Achouri, H Al Falou, NI Ashwood, D Beaumel, Y Blumenfeld, BA Brown, R Chapman, M Chartier, N Curtis, G de France, N de Sereville, F Delaunay, A Drouart, C Force, S Franchoo, J Guillot, P Haigh, F Hammache, V Lapoux, RC Lemmon, A Leprince, F Marechal, X Mougeot, B Mouginot, L Nalpas, A Navin, NP Patterson, B Pietras, EC Pollacco, A Ramus, JA Scarpaci, I Stefan, GL Wilson (2012)Low-lying neutron f p-shell intruder states in Ne-27, In: PHYSICAL REVIEW C85011302 American Physical Society
The quenching of the N=20 shell gap in neutron-rich nuclei is investigated by studying the single-particle structure of 27Ne via neutron transfer using a 26Ne beam. Two low-lying negative-parity intruder states have been observed, the lowest of which is identified as Jπ=3/2−, confirming earlier speculations. A level identified as 7/2− is observed higher in energy than the 3/2−, contrary to the ordering at β-stability and at an energy significantly different from the predictions of previous shell-model calculations. The measured energies and deduced spectroscopic factors are well reproduced in full (0,1)-ℏω 0s-0p-0d-1s-0f-1p calculations in which there is a significant ad hoc reduction (∼0.7 MeV) in the N=20 shell gap.
S Calinescu, M Stanoiu, F Negoita, C Borcea, R Borcea, C Petrone, F Rotaru, L Cáceres, JC Thomas, A Lepailleur, T Roger, O Sorlin, S Grévy, D Sohler, Z Dombradi, I Kuti, Z Vajta, M Bowry, W Catford, Z Podolyak, E Wilson, S Franchoo, M Niikura, I Stefan, S Lukyanov, Y Penionzhkevich, J Mrazek, R Gillibert (2013)Study of the neutron rich sulfure isotope S through intermediate energy Coulomb excitation, In: Journal of Physics: Conference Series413(1)
The reduced transition probability B(E2: 3/2→7/2 ) has been measured in S using Coulomb excitation at intermediate energy. The nucleus of interest was produced by fragmentation of a Ca beam at GANIL. The reaction products were separated in the LISE spectrometer. After Coulomb-excitation of S in a Pb target, the γ rays emitted inflight were detected by 64 BaF detectors of the Chteau de Cristal array. The preliminary value deduced for the reduced transition probability B(E2: 3/2 →7/2 ) is in agreement with the predictions of the shell model calculations and supports a prolate-spherical shape coexistence in the S nucleus.
A Ramus, NL Achouri, H Al Falou, NI Ashwood, D Beaumel, Y Blumenfeld, SM Brown, WN Catford, R Chapman, M Chartier, N Curtis, F Delaunay, B Fernandez-Dominguez, C Force, G De France, S Franchoo, J Guillot, D Gupta, P Haigh, F Hammache, M Labiche, V Lapoux, RC Lemmon, F Marechal, B Martin, X Mougeot, B Mouginot, L Nalpas, A Navin, NA Orr, N Patterson, B Pietras, EC Pollacco, A Le Prince, M Rejmund, JA Scarpaci, N De Sereville, I Stefan, O Sorlin, JS Thomas, GL Wilson (2009)STUDY OF THE O-20(d,t) REACTION WITH THE TIARA-MUST2-VAMOS-EXOGAM SETUP, In: INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS18(10)pp. 2056-2060
M Assie, JA Scarpaci, D Lacroix, JC Angelique, D Bazin, D Beaumel, Y Blumenfeld, WN Catford, M Chabot, A Chatterjee, M Fallot, H Iwasaki, F Marechal, D Mengoni, C Monrozeau, J Nyberg, C Petrache, F Skaza, T Tuna (2009)Neutron correlations in He-6 viewed through nuclear break-up, In: EUROPEAN PHYSICAL JOURNAL A42(3)pp. 441-446
B Fernandez-Dominguez, X Pereira-Lopez, NK Timofeyuk, P Descouvemont, WN Catford, F Delaunay (2015)Spectroscopic study of the exotic nucleus P-25, In: PHYSICAL REVIEW C91(2)ARTN 0 American Physical Society
Motivated by the importance of P25 for the two-proton decay of S26 and for searches of the mirror analog of the island of inversion near N=16, we present the first predictions for the spectroscopy of the exotic isotope P25 obtained in the shell model, a potential model, and a microscopic-cluster model. All models predict P25 to be unbound, with an energy in the range 0.78-1.03 MeV, which favors previous mass systematics over more recent revisions. We show that P25 possesses a rich low-lying spectrum that should be accessible by experimental studies. All of the predicted states below 7 MeV, except one, are narrow. Many of them are built on the excited-core states of 24Si for which the Coulomb barrier is raised. For decays into the 24Si(g.s.)+p channel we determined the proton widths based on their link to the asymptotic normalization coefficients (ANCs) of their mirror analogs in 25Ne. We determine these ANCs from the analysis of the transfer reaction 24Ne(d,p)25Ne. The proton widths for decay into excited-state channels are obtained in model calculations. The only broad state is the intruder 3/2-, the mirror analog of which has been recently observed in 25Ne. The 25P(3/2-) energy is lower than that in 25Ne, suggesting that the island of inversion may persist on the proton-rich side. All excited states of P25 have at least two decay modes and are expected to populate variously the 21,2+ and 4+ states in 24Si, which then decay electromagnetically.
M Zielinska, A Goergen, E Clement, J-P Delaroche, M Girod, W Korten, A Buerger, W Catford, C Dossat, J Iwanicki, J Libert, J Ljungvall, PJ Napiorkowski, A Obertelli, D Pietak, R Rodriguez-Guzman, G Sletten, J Srebrny, C Theisen, K Wrzosek (2009)Shape of Ar-44: Onset of deformation in neutron-rich nuclei near Ca-48, In: PHYSICAL REVIEW C80(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
JN Wilson, M Lebois, L Qi, P Amador-Celdran, D Bleuel, JA Briz, R Carroll, Wilton Catford, H De Witte, D Doherty, R Eloirdi, G Georgiev, A Gottardo, A Goasduff, K Hadynska-Klek, K Hauschild, M Hess, V Ingeberg, T Konstantinopoulos, J Ljungvall, A Lopez-Martens, G Lorusso, R Lozeva, R Lutter, P Marini, I Matea, T Materna, L Mathieu, A Oberstedt, S Oberstedt, S Panebianco, Zsolt Podolyak, D Porta, Patrick Regan, P Reiter, K Rezynkina, SJ Rose, E Sahin, M Seidlitz, Robert Shearman, B Siebeck, S Siem, AG Smith, GM Tveten, D Verney, N Warr, F Zeiser, M Zielinska (2017)PRODUCTION AND STUDY OF NEUTRON-RICH NUCLEI USING THE LICORNE DIRECTIONAL NEUTRON SOURCE, In: Acta Physica Polonica B48(3)pp. 395-401 Państwowe Wydawn. Naukowe
We have recently successfully demonstrated a new technique for production and study of many of the most exotic neutron-rich nuclei at moderate spins. LICORNE, a newly developed directional inverse-kinematic fast neutron source at the IPN Orsay, was coupled to the MINIBALL high resolution -ray spectrometer to study nuclei the furthest from stability using the 238U(n; f) reaction. This reaction and 232Th(n; f) are the most neutron-rich fission production mechanisms achievable and can be used to simultaneously populate hundreds of neutron-rich nuclei up to spins of 16 ~. High selectivity in the experiment was achieved via triple -ray coincidences and the use of a 400 ns period pulsed neutron beam, a technique which is unavailable to other population mechanisms such as 235U(nth; f) and 252Cf(SF). The pulsing allows time correlations to be exploited to separate delayed rays from isomeric states in the hundreds of nuclei produced, which are then used to cleanly select a particular nucleus and its exotic binary partners. In the recent experiment, several physics cases are simultaneously addressed such as shape coexistence, the evolution of shell closures far from stability, and the spectroscopy of nuclei in the r-process path near N = 82. Preliminary physics results on anomalies in the 238U(n; f) fission yields and the structure of the 138Te and 100Sr nuclei will soon be published. A future project, -ball, to couple LICORNE with a hybrid escape-suppressed spectrometer to refine further the technique and achieve a large increase in the observational limit is discussed.
C Beck, P Papka, A Sanchez i Zafra, S Thummerer, F Azaiez, P Bednarczyk, S Courtin, D Curien, O Dorvaux, D Lebhertz, A Nourreddine, M Rousseau, W von Oertzen, B Gebauer, C Wheldon, T Kokalova, G de Angelis, A Gadea, S Lenzi, S Szilner, DR Napoli, WN Catford, DG Jenkins, G Royer (2009)Binary reaction decays from Mg-24+C-12, In: PHYSICAL REVIEW C80(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
N Curtis, NI Ashwood, M Freer, T Munoz-Britton, C Wheldon, VA Ziman, S Brown, WN Catford, NP Patterson, JS Thomas, DC Weisser (2009)Search for the alpha + (6)He decay of (10)Be via the (16)O((18)O, (10)Be*)(24)Mg reaction, In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS36(1)ARTN 01510 IOP PUBLISHING LTD
WN Catford, IC Celik, GL Wilson, A Matta, NA Orr, CA Diget, P Adsley, H Al-Falou, R Ashley, RAE Austin, GC Ball, JC Blackmon, AJ Boston, HC Boston, SM Brown, DS Cross, M Djongolov, TE Drake, U Hager, SP Fox, BR Fulton, N Galinski, AB Garnsworthy, G Hackman, D Jamieson, R Kanungo, K Leach, J-P Martin, JN Orce, CJ Pearson, M Porter-Peden, F Sarazin, S Sjue, C Sumithrarachchi, CE Svensson, S Triambak, C Unsworth, R Wadsworth, SJ Williams (2015)STRUCTURE OF Na-26 VIA A NOVEL TECHNIQUE USING (d, p gamma) WITH A RADIOACTIVE Na-25 BEAM, In: ACTA PHYSICA POLONICA B46(3)pp. 527-536 WYDAWNICTWO UNIWERSYTETU JAGIELLONSKIEGO
States in 26Na were populated in the (d, pγ) reaction, induced by bombarding deuterium target nuclei with an intense reaccelerated beam of 25Na ions from the ISAC2 accelerator at TRIUMF. Gamma-rays were recorded in coincidence with protons and used to extract differential cross sections for 21 states up to the neutron decay threshold of 5 MeV. Results for levels below 3 MeV are discussed in detail and compared with shell model calculations and with previous work. The angular distributions of decay gamma-rays were measured for individual states and are compared to theoretically calculated distributions, highlighting some issues for future work.
A Gorgen, E Clement, W Korten, E Bouchez, A Chatillon, A Hurstel, Y Le Coz, C Theisen, JN Wilson, M Zielinska, C Andreoiu, F Becker, P Butler, JM Casandjian, WN Catford, T Czosnyka, G de France, J Gerl, R-D Herzberg, J Iwanicki, DG Jenkins, GD Jones, PJ Napiorkowski, G Sletten, C Timis (2007)Shape coexistence in Kr-74 and Kr-76, In: EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS150pp. 117-120
PJ Haigh, NI Ashwood, T Bloxham, N Curtis, M Freer, P McEwan, D Price, V Ziman, HG Bohlen, T Kokalova, C Schulz, R Torabi, W von Oertzen, C Wheldon, W Catford, C Harlin, R Kalpakchieva, TN Massey (2008)Measurement of alpha and neutron decay widths of excited states of (14)C, In: PHYSICAL REVIEW C78(1)ARTN 01431 AMER PHYSICAL SOC
M Zielinska, A Goergen, A Buerger, W Catford, E Clement, C Dossat, J Iwanicki, W Korten, J Liungvall, PJ Napiorkowski, D Pietak, G Sletten, J Srebrny, CH Theisen, K Wrzosek (2008)Coulomb excitation of neutron-rich Ar-44 at spiral, In: ACTA PHYSICA POLONICA B39(2)pp. 519-524
JM Daugas, T Faul, H Grawe, M Pfuetzner, R Grzywacz, M Lewitowicz, NL Achouri, JC Angelique, D Baiborodin, R Bentida, R Beraud, C Borcea, CR Bingham, WN Catford, A Emsallem, G de France, KL Grzywacz, RC Lemmon, MJL Jimenez, FDO Santos, PH Regan, K Rykaczewski, JE Sauvestre, M Sawicka, M Stanoiu, K Sieja, F Nowacki (2010)Low-lying isomeric levels in Cu-75, In: PHYSICAL REVIEW C81(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
C Beck, ASI Zafra, F Haas, P Papka, V Rauch, M Rousseau, F Azaiez, P Bednarczyk, D Curien, O Dorvaux, A Nourreddine, J Robin, WV Oertzen, B Gebauer, T Kokalova, S Thummerer, GD Angelis, A Gadea, S Lenzi, DR Napoli, S Szilner, WN Catford, D Jenkins (2003)Search for 12C+12C molecule in 24Mg* populated by 24Mg+12C, In: Nucl.Phys.A734pp. 453-456
The gamma-decay properties of 24Mg excited states are investigated in the inverse reaction 24Mg+12C at E(24Mg) = 130 MeV. At this energy the direct inelastic scattering populates a 24Mg* energy region where 12C+12C breakup resonances can occur. Very exclusive data were collected with the Binary Reaction Spectrometer (BRS) in coincidence with EUROBALL installed at the VIVITRON Tandem facility of the IReS at Strasbourg. The experimental detection system is decribed and preliminary results of binary reaction coincid data are presented.
T Muñoz-Britton, M Freer, NI Ashwood, TAD Brown, WN Catford, N Curtis, SP Fox, BR Fulton, CW Harlin, AM Laird, P Mumby-Croft, ASJ Murphy, P Papka, DL Price, K Vaughan, DL Watson, DC Weisser (2010)Search for the 2+ excitation of the Hoyle state in 12C using the 12C(12C,3α)12C reaction, In: Journal of Physics G: Nuclear and Particle Physics37(10)105104
A Banu, L Trache, F Carstoiu, NA Orr, NL Achouri, A Bonaccorso, WN Catford, M Chartier, B Fernandez-Dominguez, M Freer, L Gaudefroy, M Horoi, M Labiche, B Laurent, RC Lemmon, F Negoita, S Paschalis, N Patterson, B Pietras, B Roeder, F Rotaru, P Roussel-Chomaz, E Simmons, JS Thomas, RE Tribble (2010)Astrophysically important reaction rates for novae and X-ray bursts from proton breakup at intermediate energies, In: AIP Conference Proceedings1304pp. 339-343
We discuss the use of one-nucleon removal reactions of loosely bound nuclei at intermediate energies as an indirect method in nuclear astrophysics. The breakup reactions are proved to be good spectroscopic tools and can be used to study a large number of loosely bound proton- or neutron-rich nuclei over a wide range of beam energies. As peripheral processes, they can be used to extract asymptotic normalization coefficients (ANCs) from which non-resonant capture reaction rates of astrophysical interest can be calculated parameter free. In this talk, we present results of a proton-breakup experiment carried out at GANIL (France) with a cocktail beam centered around 23Al at 50 MeV/nucleon. Momentum distributions of the breakup fragments, inclusive and in coincidence with gamma rays detected by EXOGAM Germanium clover array, were measured in the focal plan of SPEG energy-loss spectrometer. We present in particular the investigations of reaction rates for 22Mg(p,γ)23Al and 23Al(p,γ)24Si important for novae and X-ray bursts, respectively.
NC Summers, SD Pain, NA Orr, WN Catford, JC Angelique, NI Ashwood, V Bouchat, NM Clarke, N Curtis, M Freer, BR Fulton, F Hanappe, M Labiche, JL Lecouey, RC Lemmon, D Mahboub, A Ninane, G Normand, FM Nunes, N Soic, L Stuttge, CN Timis, IJ Thompson, JS Winfield, V Ziman (2007)B(E1) strengths from Coulomb excitation of Be-11, In: PHYSICS LETTERS B650(2-3)pp. 124-128 ELSEVIER SCIENCE BV
KJ Jones, SD Pain, RL Kozub, AS Adekola, DW Bardayan, JC Blackmon, WN Catford, KY Chae, K Chipps, JA Cizewskit, L Erikson, AL Gaddis, U Greife, R Grzywacz, C Harlin, R Hatarik, JA Howard, J James, R Kapler, JF WKrólas, Z Liang, C Ma, BH Matei, CD Moazen, PD Nesaraja, NP O'Malley, SV Patterson, D Paulauskas, JF Shapira, M Shriner Jr, DJ Sikora, MS Sissom, TP Smith, JS Swan, GL Thomas, Wilson (2009)Studies of nuclei close to132 Sn using single-neutron transfer reactions, In: AIP Conference Proceedings1098pp. 153-160
N Curtis, NL Achouri, NI Ashwood, HG Bohlen, WN Catford, NM Clarke, M Freer, PJ Haigh, B Laurent, NA Orr, NP Patterson, N Soić, JS Thomas, V Ziman (2008)Structure of the brunnian nucleus 10C, In: Journal of Physics: Conference Series111(1)
SG Altstadt, T Adachi, Y Aksyutina, J Alcantara, H Alvarez-Pol, N Ashwood, L Atar, T Aumann, V Avdeichikov, M Barr, S Beceiro, D Bemmerer, J Benlliure, CA Bertulani, K Boretzky, MJG Borge, G Burgunder, M Caamano, C Caesar, E Casarejos, W Catford, J Cederkall, S Chakraborty, M Chartier, L Chulkov, D Cortina-Gil, UD Pramanik, PD Fernandez, I Dillmann, Z Elekes, J Enders, O Ershova, A Estrade, F Farinon, LM Fraile, M Freer, M Freudenberger, HOU Fynbo, D Galaviz, H Geissel, R Gernhaeuser, K Goebel, P Golubev, D Gonzalez Diaz, J Hagdahl, T Heftrich, M Heil, M Heine, A Heinz, A Henriques, M Holl, JD Holt, G Ickert, A Ignatov, B Jakobsson, HT Johansson, B Jonson, N Kalantar-Nayestanaki, R Kanungo, A Kelic-Heil, R Knoebel, T Kroell, R Kruecken, J Kurcewicz, N Kurz, M Labiche, C Langer, T Le Bleis, R Lemmon, O Lepyoshkina, J Machado, J Marganiec, V Maroussov, J Menendez, M Mostazo, A Movsesyan, MA Najafi, T Nilsson, C Nociforo, V Panin, A Perea, S Pietri, R Plag, A Prochazka, A Rahaman, G Rastrepina, R Reifarth, G Ribeiro, MV Ricciardi, C Rigollet, K Riisager, M Roeder, D Rossi, J Sanchez del Rio, D Savran, H Scheit, A Schwenk, H Simon, J Simonis, K Sonnabend, O Sorlin, V Stoica, B Streicher, J Taylor, O Tengblad, S Terashima, R Thies, Y Togano, E Uberseder, J Van de Walle, P Velho, V Volkov, A Wagner, F Wamers, H Weick, M Weigand, C Wheldon, G Wilson, C Wimmer, JS Winfield, P Woods, D Yakorev, MV Zhukov, A Zilges, M Zoric, K Zuber (2014)B-13,B-14(n,gamma) via Coulomb Dissociation for Nucleosynthesis towards the r-Process, In: NUCLEAR DATA SHEETS120pp. 197-200 ACADEMIC PRESS INC ELSEVIER SCIENCE
M Freer, NI Ashwood, N Curtis, JD Malcolm, T Munoz-Britton, D Price, C Wheldon, VA Ziman, NL Achouri, B Laurent, NA Orr, C Angulo, P Demaret, DW Bardayan, SD Pain, S Brown, WN Catford, C Harlin, JS Thomas, G Wilson, KA Chipps, M Milin, R Raabe, N Soić (2012)Resonances in 11C observed in the 4He(7Be,α)7Be and 4He(7Be,p)10B reactions, In: Physical Review C - Nuclear Physics85(1) American Physical Society
Measurements of the 4He(7Be,α)7Be and 4He(7Be,p)10B reactions were performed using 7Be beam energies of 7.1 and 23 MeV and a helium-4 target, employing the thick target technique. Resonances were observed between E 11C)=8.6 to 13.8 MeV. An R-matrix analysis was performed to characterize the spins and partial widths. This analysis showed that the observed sequence of states was consistent with that found for 7Li + α resonant scattering populating resonances in 11B. A comparison of the proposed partial widths for decay with the Wigner limit indicates that several of the states are associated with cluster-like structures. © 2012 American Physical Society.
A Banu, L Trache, F Carstoiu, NL Achouri, A Bonaccorso, WN Catford, M Chartier, M Dimmock, B Fernandez-Dominguez, M Freer, L Gaudefroy, M Horoi, M Labiche, B Laurent, RC Lemmon, F Negoita, NA Orr, S Paschalis, N Patterson, ES Paul, M Petri, B Pietras, BT Roeder, F Rotaru, P Roussel-Chomaz, E Simmons, JS Thomas, RE Tribble (2011)Structure of Al-23 from the one-proton breakup reaction and astrophysical implications, In: PHYSICAL REVIEW C84(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
G Randisi, A Leprince, H Al Falou, NA Orr, FM Marques, NL Achouri, J-C Angelique, N Ashwood, B Bastin, T Bloxham, BA Brown, WN Catford, N Curtis, F Delaunay, M Freer, EDG Brennand, P Haigh, F Hanappe, C Harlin, B Laurent, J-L Lecouey, A Ninane, N Patterson, D Price, L Stuttge, JS Thomas (2014)Structure of Be-13 probed via secondary-beam reactions, In: PHYSICAL REVIEW C89(3)ARTN 03432 AMER PHYSICAL SOC
WN Catford, CN Timis, RC Lemmon, M Labiche, NA Orr, L Caballero, R Chapman, M Chartier, M Rejmund, H Savajols (2006)Neutron transfer studied with a radioactive beam of Ne-24, using TIARA at spiral, In: Exotic Nuclei and Nuclear/Particle Astrophysicspp. 12-19
JA Cizewski, KL Jones, SD Pain, JS Thomas, C Baktash, DW Bardayan, JC Blackmon, C Gross, JF Liang, D Shapira, MS Smith, RL Kozub, BH Moazen, CD Nesaraja, HK Carter, MS Johnson, RP Fitzgerald, DW Visser, U Greife, RJ Livesay, W Catford, Z Ma (2005)Neutron transfer reactions with neutron-rich radioactive ion beams, In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS241(1-4)pp. 200-203
A Khouaja, ACC Villari, M Benjelloun, D Hirata, G Auger, H Savajols, W Mittig, P Roussel-Chomaz, NA Orr, MG Saint-Laurent, S Pita, A Gillibert, M Chartier, CE Demonchy, L Giot, D Baiborodin, Y Penionzhkevich, WN Catford, A Lepine-Szily, Z Dlouhy (2006)Reaction cross-section and reduced strong absorption radius measurements of neutron-rich nuclei in the vicinity of closed shells N=20 and N=28, In: NUCLEAR PHYSICS A780(1-2)pp. 1-12 ELSEVIER SCIENCE BV
T. L. Tang, B. P. Kay, C. R. Hoffman, J. P. Schiffer, D. K. Sharp, L. P. Gaffney, S. J. Freeman, M. R. Mumpower, A. Arokiaraj, E. F. Baader, P. A. Butler, W. N. Catford, G. de Angelis, F. Flavigny, M. D Gott, E. T. Gregor, J. Konki, M. Labiche, I. H. Lazurus, P. T. MacGregor, I. Martel, R. D. Page, Zs Podolyak, O. Poleshchuk, R. Raabe, F. Recchia, J. F. Smith, S. V. Szwec, J. Yang First Exploration of Neutron Shell Structure Below Lead and Beyond N = 126, In: Physical Review Letters American Physical Society
The nuclei below lead but with more than 126 neutrons are crucial to an understanding of the astrophysical r-process in producing nuclei heavier than A ~ 190. Despite their importance, the structure and properties of these nuclei remain experimentally untested as they are difficult to produce in nuclear reactions with stable beams. In a first exploration of the shell structure of this region, neutron excitations in 207Hg have been probed using the neutron-adding (d,p) reaction in inverse kinematics. The radioactive beam of 206Hg was delivered to the new ISOLDE Solenoidal Spectrometer at an energy above the Coulomb barrier. The spectroscopy of 207Hg marks a first step in improving our understanding of the relevant structural properties of nuclei involved in a key part of the path of the r-process.
JM Daugas, M Sawicka, M Pfützner, I Matea, H Grawe, R Grzywacz, NL Achouri, JC Angélique, D Baiborodin, F Becker, G Bélier, R Bentida, R Béraud, C Bingham, C Borcea, R Borcea, E Bouchez, A Buta, WN Catford, E Dragulescu, A Emsallem, G De France, J Giovinazzo, M Girod, H Goutte, G Gorgiev, KL Grzywacz-Jones, F Hammache, F Ibrahim, RC Lemmon, M Lewitowicz, MJ Lopez-Jimenez, P Mayet, V Méot, F Negoita, F De Oliveira-Santos, O Perru, PH Regan, O Roig, K Rykaczewski, MG Saint-Laurent, JE Sauvestre, G Sletten, O Sorlin, M Stanoiu, I Stefan, C Stodel, C Theisen, D Verney, J Zylicz (2006)Isomeric island in the vicinity of 66Fe, In: AIP Conference Proceedings831pp. 427-429
An island of isomers have recently been observed on both sides of the N=40 shell below the Ni isotopes. Isomeric states in the 65Fe and 67Fe allow the knowledge of the single particle structure around the νg 9/2 shell. Moreover, the excitation energy of the first 2+ and 4+ states in the 68Fe have been established by β-γ correlation. The evolution of the structure of the Fe isotopes going far away from the valley of stability is, for the first time, given for N>40. © 2006 American Institute of Physics.
JA Cizewski, KL Jones, RL Kozub, SD Pain, A Adekola, DW Bardayan, JC Blackmon, WN Catford, KY Chae, KA Chipps, L Erikson, A Gaddis, R Grzywacz, C Harlin, R Hatarik, J Howard, MS Johnson, R Kapler, W Królas, JF Liang, R Livesay, Z Ma, C Matei, B Moazen, CD Nesaraja, P O'Malley, SV Paulauskas, WA Peters, D Shapira, JF Shriner Jr, DJ Sissom, MS Smith, TP Swan, JS Thomas, GL Wilson (2009)Neutron-transfer reaction studies with fission fragment radioactive ion beams near 132Sn, In: AIP Conference Proceedings1175pp. 147-153
B Jurado, H Savajols, W Mittig, NA Orr, P Roussel-Chomaz, D Baiborodin, WN Catford, M Chartier, CE Demonchy, Z Dlouhy, A Gillibert, L Giot, A Khouaja, A Lepine-Szily, S Lukyanov, J Mrazek, YE Penionzhkevich, S Pita, M Rousseau, AC Villari (2007)Mass measurements of neutron-rich nuclei near the N=20 and 28 shell closures, In: PHYSICS LETTERS B649(1)pp. 43-48 ELSEVIER SCIENCE BV
M Freer, NL Achouri, C Angulo, NI Ashwood, DW Bardayan, S Brown, WN Catford, KA Chipps, N Curtis, P Demaret, C Harlin, B Laurent, JD Malcolm, M Milin, T Munoz-Britton, NA Orr, SD Pain, D Price, R Raabe, N Soic, JS Thomas, C Wheldon, G Wilson, VA Ziman (2012)Resonances in (11)C observed in the (4)He((7)Be, alpha)(7)Be and (4)He((7)Be, p)(10)B reactions, In: PHYSICAL REVIEW C85ARTN 0 American Physical Society
Measurements of the 4He(7Be,α)7Be and 4He(7Be,p)10B reactions were performed using 7Be beam energies of 7.1 and 23 MeV and a helium-4 target, employing the thick target technique. Resonances were observed between Ex(11C)=8.6 to 13.8 MeV. An R-matrix analysis was performed to characterize the spins and partial widths. This analysis showed that the observed sequence of states was consistent with that found for 7Li + α resonant scattering populating resonances in 11B. A comparison of the proposed partial widths for decay with the Wigner limit indicates that several of the states are associated with cluster-like structures.
M Freer, NI Ashwood, N Curtis, T Munoz-Britton, C Wheldon, VA Ziman, S Brown, WN Catford, NP Patterson, JS Thomas, DC Weisser (2008)Excited states of 8Be populated via the p(7Li, 4He)4He and p(7Li, 4He*) 4He resonant reactions, In: Journal of Physics G: Nuclear and Particle Physics35(12)
N Curtis, NL Achouri, NI Ashwood, HG Bohlen, WN Catford, NM Clarke, M Freer, PJ Haigh, B Laurent, NA Orr, NP Patterson, N Soic, JS Thomas, V Ziman (2008)Breakup reaction study of the Brunnian nucleus (10)C, In: PHYSICAL REVIEW C77(2)ARTN 0pp. ?-? AMER PHYSICAL SOC
A Banu, F Carstoiu, NL Achouri, WN Catford, M Chartier, B Fernandez-Dominguez, M Horoi, B Laurent, NA Orr, S Paschalis, N Patterson, B Pietras, BT Roeder, P Roussel-Chomaz, JS Thomas, L Trache, RE Tribble (2012)One-proton breakup of Si-24 and the Al-23(p, gamma)Si-24 reaction in type I x-ray bursts, In: PHYSICAL REVIEW C86(1)ARTN 0pp. ?-? AMER PHYSICAL SOC
P Haigh, NI Ashwood, T Bloxham, N Curtis, M Freer, D Price, V Ziman, HG Bohlen, T Kokalova, C Schulz, W Von Oertzen, C Weldon, W Catford, C Harlin (2008)Decay width measurements of excited states in 14C, In: Journal of Physics: Conference Series111(1)
C Beck, A SÀnchez I Zafra, P Papka, S Thummerer, F Azaiez, P Bednarczyk, S Courtin, D Curien, O Dorvaux, D Lebhertz, A Nourreddine, J Robin, M Rousseau, W Von Oertzen, B Gebauer, T Kokalova, C Wheldon, G De Angelis, A Gadea, S Lenzi, S Szilner, DR Napoli, WN Catford, DG Jenkins, G Royer (2008)Alpha-cluster states populated in 24Mg + 12C, In: International Journal of Modern Physics E17(10)pp. 2049-2054
The structure of 25Na is studied using the (d, p) transfer reaction using the ISAC-II accelerator at TRIUMF, Canada. An 8 MeV per nucleon beam of 24Na, incident onto a 1.0 mg CD2 target was used to populate excited states in 25Na. The target was surrounded by the SHARC and TIGRESS arrays, which were used to detect the ejected protons, and coincident gamma-rays emitted from the excited 25Na nuclei respectively. The angular distribution of the protons has been analysed for each state observed and compared to the theoretical distributions generated using TWOFNR to get a value of the spectroscopic factors. Data were compared to WBC shell-model calculations in order to assign spin and parities to each observed state. States at 2.788 MeV and 3.455 MeV are strongly populated and show a strong s-wave contribution to the wave functions. In addition, the structure of the astrophysically relevant mirror nucleus 25Si is commented on. The reaction 24Al(p, gamma)25Si reaction is thought to occur in hot stellar environments, but little to no experimental data exist that confirm reaction rates calculated for this reaction. The spectroscopic factors found in this work for 25Na are used as a point of comparison and used to determine the validity of theoretical reaction rate calculations used for the astrophysical reaction. The relevant energy region in the reaction 24Al(p, gamma)25Si is between the proton separation energy of 3.414 and 4 MeV. Two states are observed in this energy range in 25Na at 3.455 and 3.995 MeV, though the 3.455 MeV state is expected to be Thomas-Ehrman shifted below the 3.414 MeV threshold in the mirror 25Si. The state at 3.995 MeV was found to have an s-wave component that matched the predicted value from literature. No other states were observed within the relevant energy region in 25Na.