Four-quasiparticle alignments in Ge-66

作者：Stefanova EA^*; Stefanescu I; de Angelis G; Curien D; Eberth J; Farnea E; Gadea A; Gersch G; Jungclaus A; Lieb KP; Martinez T; Schwengner R; Steinhardt T; Thelen O; Weisshaar D; Wyss R

来源：Physical Review C, 2003, 67(5): 054319.

DOI：10.1103/PhysRevC.67.054319

The neutron-deficient nucleus Ge-66 was populated at high spin in two experiments using the reaction Ca-40(S-32,alpha2p) at beam energies of 105 and 95 MeV. In the first experiment, a self-supporting Ca-40 target was used, while a gold-backed target of similar thickness was used in the second experiment. gamma rays were detected with the EUROBALL array, combined with the charged-particle detector array EUCLIDES and the Neutron Wall. The level scheme of Ge-66 was extended up to Eapproximate to18 MeV and I-pi=(23(-)). Above angular momentum 10(+), we found two sequences, connected by energetically staggered DeltaI=1 M1 transitions. The total Routhian surface calculations describe Ge-66 at lower spins as a gamma-soft nucleus having a moderate deformation of beta(2)approximate to0.23, while a triaxial deformation is predicted for the band structures above I-pi=10(+). To our knowledge, this is the first observation of staggered M1 transitions in a deformed four-quasiparticle pi(g(9/2)(2))nu(g(9/2)(2)) structure.

• 出版日期2003-5