Nuclear spectroscopic studies of the 23.7 h 248Bk

Abstract

Main features of the decay of the 23.7 h 248Bk have been determined by spectroscopy with scintillation and semiconductor detectors. The results are as follows: half-life 23.7 +/- 0.2 h; branching is (30 +/- 5)% to 248Cm ([approximate] 23% EC decay to 0+ ground state and [approximate] 7% to first 2+ state) and (70 +/- 5)%[beta]- decay to 248Cf(5 % to 592 keV K[pi] = 2- state and (65 +/- 5)% to the ground-state band). The [beta]- decay energy, Q[beta]-, has been measured to be 860 +/- 20 keV, and the electron capture decay energy, QEC, has been derived from closed cycle to be 705 +/- 25 keV. The deduced logft values of [beta]- and EC transitions restrict the spin of the 248Bk ground state to 1, with configuration assignment ; . It has also been deduced that the long lived isomer lies 65 +/- 40 keV abovethe 23.7h 248Bk ground state.