| Affiliation: | (1) Department of Physics, Kyushu University, Fukuoka 812-8581, Japan, JP;(2) Nishinippon Institute of Technology, Kanda, Fukuoka 800-03, Japan, JP;(3) Department of Chemistry, Washington University, St. Louis 63130, USA, US;(4) RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan, JP;(5) Royal Institute of Technology, S-104 05 Stockholm, Sweden, SE;(6) Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China, CN;(7) University of Aizu, Fukushima 965-8580, Japan, JP |
| Abstract: | Isomers in N = 83 isotones of Z = 60-66, were studied systematically. Their spins and parities are 49/2+ and 27+ for odd and odd-odd nuclei, respectively. Nearly constant excitation energies of these isomers indicated a decrease of a Z = 64 shell gap energy as Z decreases from 64 to 60 within the framework of a deformed independent-particle model (DIPM). Their configurations are [ν(f 7/2 h 9/2 i 13/2),π(h 11/2)2]49/2+ and [ν(f 7/2 h 9/2 i 13/2),π(h 11/2)2(d 5/2)-1]27+ for odd and odd-odd nuclei, respectively. The shape of the yrast states changes suddenly at spin 49/2(odd) and 27(odd-odd) from a near spherical to an oblate shape. Transitions from isomers are highly hindered because of the shape changes. They may be categorized to be shape isomers. The development of a secondary beam produced by using these high-spin isomers is also described. Received: 1 May 2001 / Accepted: 4 December 2001 |
