Low-energy Coulomb excitation of neutron-rich zinc isotopes

J. van de Walle (1, 2) , F. Aksouh (2) , T. Behrens , V. Bildstein , A. Blazhev , J. Cederkall (1) , E. Clément (1, 3) , T. E. Cocolios (2) , T. Davinson , P. Delahaye (1) , J. Eberth , A. Ekstrom , D. V. Fedorov , V. N. Fedosseev (1) , L. M. Fraile (1) , S. Franchoo (1) , R. Gernhauser , G. Georgiev (1, 4) , D. Habs , K. Heyde , G. Huber , M. Huyse (2) , F. Ibrahim , O. Ivanov (2) , J. Iwanicki , J. Jolie , O. Kester , U. Köster (1, 5) , T. Kröll , R. Krücken , M. Lauer , A.F. Lisetskiy , R. Lutter , B.A. Marsh (1) , P. Mayet (2) , O. Niedermaier , M. Pantea , R. Raabe (2) , P. Reiter , M. Sawicka (2) , H. Scheit , G. Schrieder , D. Schwalm , M.D. Seliverstov , T. Sieber (1) , G. Sletten , N. Smirnova (6) , M. Stanoiu , I. Stefanescu (2) , J.C. Thomas (2, 7) , J.J. Valiente-Dobon , P. van Duppen (2) , D. Verney (8) , D. Voulot (1) , N. Warr , D. Weisshaar , F. Wenander (1) , B.H. Wolf (1) , M. Zielinska

1 CERN - European Organization for Nuclear Research
2 IKS - Instituut voor Kern-en Stralingsfysica
3 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
4 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
5 ILL - Institut Laue-Langevin
6 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
7 GANIL - Grand Accélérateur National d'Ions Lourds
8 IPNO - Institut de Physique Nucléaire d'Orsay

At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using lowenergy Coulomb excitation. These experiments have resulted in B(E2, 2+1 → 0+1 ) values in 74−80Zn, B(E2, 4+1 → 2+1 ) values in 74,76Zn and the determination of the energy of the first excited 2+1 states in 78,80Zn. The zinc isotopes were produced by high-energy proton- (A = 74, 76, 80) and neutron- (A = 78) induced fission of 238U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and howa reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N = 50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, including a recent empirical residual interaction constructed to describe the present experimental data up to 2004 in this region of the nuclear chart.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

J. van de Walle, F. Aksouh, T. Behrens, V. Bildstein, A. Blazhev, et al.. Low-energy Coulomb excitation of neutron-rich zinc isotopes. Physical Review C, 2009, 79, pp.014309. ⟨10.1103/PhysRevC.79.014309⟩. ⟨in2p3-00358075⟩