Abstract
An experiment to gather spectroscopic information on a newly discovered isomer in Hf was performed using the ISOLDE facility at CERN. Protons from the PSBooster were incident on a Ta/W/Ir target and fluorination using a CF 4 leak allowed the 184 Hf to be extracted from the ion source. The beam was then accelerated to 30 keV and mass separated using the General Purpose Separator (GPS). The data was analysed but it was found that the method used to produce the beam introduced too much contamination for the isomer to be positively identified. It was possible, however, to verify the successful production of 184 Hf. 184 Another experiment was performed at ANU, Canberra, this time to look at a high-lying isomer in 173 Ta. A 10 B − beam was produced using the Multi-Cathode SNICS ion source. The beam was then accelerated to 68 M eV in the 14UD pelletron. This 10 B − beam was then incident on a 168 Er target and the CAESAR Array, which surrounds the target, was used to detect γ rays from the reaction products. The isomer was positively identified and its decay γ rays were measured to be E = 351 keV , 604 keV and 835 keV . The half-life of this isomer was measured to be 148 ns with K π = 21/2 − and f ν = 18.1, 19.3 and 12.5. Information about the structure above the isomer was also gathered, along with g K values associated with these bands. Multi-quasiparticle Nilsson-model calculations were performed in order to understand the observed structures, and a consistent interpretation was found.