Abrupt shape transition at neutron number N=60: B(E2) values in Sr-94,Sr-96,Sr-98 from fast gamma-gamma timing

作者：Regis J M^*; Jolie J; Saed Samii N; Warr N; Pfeiffer M; Blanc A; Jentschel M; Koster U; Mutti P; Soldner T; Simpson G S; Drouet F; Vancraeyenest A; de France G; Clement E; Stezowski O; Ur C A; Urban W; Regan P H; Podolyak Zs; Larijani C; Townsley C; Carroll R; Wilson E; Fraile L M; Mach H; Paziy V; Olaizola B; Vedia V; Bruce A M; Roberts O J; Smith J F; Scheck M; Kroell T; Hartig A L; Ignatov A; Ilieva S; Lalkovski S; Korten W; Marginean N

来源：PHYSICAL REVIEW C, 2017, 95(5): 054319.

DOI：10.1103/PhysRevC.95.054319

Lifetimes of low-lying yrast states in neutron-rich Sr-94,Sr-96,Sr-98 have been measured by Germanium-gated gamma-gamma fast timing with LaBr3(Ce) detectors using the EXILL& FATIMA spectrometer at the Institut Laue-Langevin. Sr fission products were generated using cold-neutron-induced fission of 235U and stopped almost instantaneously within the thick target. The experimental B(E2) values are compared with results of Monte Carlo shell-model calculations made without truncation on the occupation numbers of the orbits spanned by eight proton and eight neutron orbits and show good agreement. Similarly to the Zr isotopes, the abrupt shape transition in the Sr isotopes near neutron number N = 60 is identified as being caused by many-proton excitations to its g(9/2) orbit.

• 出版日期2017-5-23
• 单位中国地震局