0000000001174162
AUTHOR
D. Eriksen
Subshell closure effects on the collectivity of 36 88 Kr52 and the beta decay of88Br to levels in88Kr
The level structure of88Kr has been investigated by measurements on chemically separated bromine samples. A total of 146γ-rays have been assigned to the decay of88Br, and a level scheme with 58 levels is proposed. The collectivity of88Kr has been investigated within the framework of the Interacting Boson Approximation (IBA-2 model). Comparison of our detailedγ-ray data and calculations have led to the establishment of a protonhole boson desciption rather than protonparticle nature. This supports recent works establishingZ=40 as a major subshell closure.
The collective structure of106,108Ru
Levels in106,108Ru have been studied by measuringγγ coincidences andγγ directional correlations of theγ-rays following theβ−-decay of 36 s106Tc and 5 s108Tc. Tc activities were separated chemically from the fission products of thermal neutron induced fission of239Pu by the continuously running system “SISAK 2” and theγ-radiation was measured on-line. An extended level scheme for108Ru, spin assignments,E2/M1 multipole mixing ratios andB(E2) ratios for106Ru and108Ru have been obtained. The collective structure of the two nuclei is discussed in the framework of different nuclear models.