Coulomb excitation of 73Ga

Phys. Rev. C

82
064309
(2010)
J. Diriken, I. Stefanescu, D. Balabanski, N. Blasi, A. Blazhev, N. Bree, J. Cederkäll, T.E. Cocolios, T. Davinson, J. Eberth, A. Ekström, D.V. Fedorov, V.N. Fedosseev, L.M. Fraile, S. Franchoo, G. Georgiev, K. Gladnishki, M. Huyse, O.V. Ivanov, V.S. Ivanov, J. Iwanicki, J. Jolie, T. Konstantinopoulos, Th. Kröll, R. Krücken, U. Köster, A. Lagoyannis, G. Lo Bianco, P. Maierbeck, B.A. Marsh, P. Napiorkowski, N. Patronis, D. Pauwels, P. Reiter, M. Seliverstov, G. Sletten, J. Van de Walle, P. Van Duppen, D. Voulot, W.B. Walters, N. Warr, F. Wenander, K. Wrzosek

The 𝐵⁡(𝐸⁢2;𝐼𝑖→𝐼𝑓) values for transitions in 71
31⁢Ga40 and 73
31⁢Ga42 were deduced from a Coulomb excitation experiment at the safe energy of 2.95 MeV/nucleon using post-accelerated beams of  
71,73
 Ga 
  at the REX-ISOLDE on-line isotope mass separator facility. The emitted 𝛾 rays were detected by the MINIBALL 𝛾-detector array, and 𝐵⁡(𝐸⁢2;𝐼𝑖→𝐼𝑓) values were obtained from the yields normalized to the known strength of the 2+→0+ transition in the  
120
 Sn 
  target. The comparison of these new results with the data of less neutron-rich gallium isotopes shows a shift of the 𝐸2 collectivity toward lower excitation energy when adding neutrons beyond 𝑁=40. This supports conclusions from previous studies of the gallium isotopes, which indicated a structural change in this isotopic chain between 𝑁=40 and 42. Combined with recent measurements from collinear laser spectroscopy showing a 1/2− spin and parity for the ground state, the extracted results revealed evidence for a 1/2−,3/2− doublet near the ground state in 73
31⁢Ga42 differing by at most 0.8 keV in energy.

DOI
10.1103/PhysRevC.82.064309
Published on
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