Multi-quasiparticle isomers and rotational bands in 181 Re

✍ Scribed by C.J. Pearson; P.M. Walker; C.S. Purry; G.D. Dracoulis; S. Bayer; A.P. Byrne; T. Kibédi; F.G. Kondev

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 447 KB
• Volume: 674
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(00)00143-3

✦ Synopsis

High-spin states in 181 Re have been populated using the 176 Yb( 11 B, 6n) reaction and their decays studied using the CAESAR γ -ray spectrometer. Thirteen bands of rotational states have been observed based on 1-, 3-and 5-quasiparticle structures, including two new 5-quasiparticle isomers, with half-lives of 1.2 µs and 22 ns. Angular correlation and distribution coefficients were obtained and γ -ray intensity ratios were used to extract |g Kg R |/Q 0 ratios. Three K-forbidden decays were observed and their reduced hindrance factors were obtained and found to be consistent with known systematic behaviour. Band crossings were observed between 1-and 3-quasiparticle bands. These rotation-aligned 3-quasiparticle bands appear to have high K, and are identified as t-bands. Band mixing calculations support the assigned K-values. A unique degeneracy was observed for two I π = 23/2 -states at 1883 keV.