The Decay of 1.25-Min Rb82

Abstract

Gamma rays accompanying the decay of 25.0-day Sr ⁸² have been investigated. Single and coincidence spectra taken with scintillation counter have shown the presence of gamma rays with energies of 0.69, 0.78 and 1.41 Mev in the decay of 1.25-min Rb ⁸² and their relative intensities have been determined. Log ft values have been evaluated on the basis of the proposed decay scheme. The allowed beta transitions from the 1+ ground state of Rb ⁸² to the ground state and the first and second 2+ states are found to be successively hindered, in accord with Sakai's empirical rule. This problem is discussed in connection with the systematic trend of ft values in the neighboring nuclei. The E2/M1 mixing ratio of the 0.69-MeV gamma ray decaying from the second 2+ state to the first 2+ state have been determined from angular correlation pattern of the 0.78–0.69-MeV cascade and found to be -5.8 _-22 ^+5.5 . The negative phase is consistant with the systematic trend of δ in the neighboring nuclei.