Decay of 85Sr

The level structure of85Rb and87Rb from (n, n??) reaction measurements

“…The SSRb nucleus lies in a transition region and exhibits a level structure more complex than that of STRb due to the two additional holes in the neutron shell. The low-lying levels of 85Rb have been studied by electron capture [20,21,22], coulomb excitation [17], single-particle transfer reactions [23,24], as well as by inelastic neutron scattering [18,19]. The present measurements, although again being in general agreement with previous data, have served to resolve several discrepancies, establish six new levels and assign more accurate level energies whilst also resolving spin assignment ambiguities in several cases.…”

“…Spin values of 1/2 and 9/2 are eliminated by the angular distribution of the ground-state transition [17]. Since it has now been definitely established that this level is populated in the 85Sr EC decay (64.84 D) from the 9/2+ 8~Sr ground state [20,21,22] with a logft value less than 11 [20], the only remaining spin possibilities are 5/2-and 7/2-, where the negative parity is implied by the E2 nature of the coulomb excitation process. In the present experiment this level is observed to decay to the 5/2-ground state, 3/2 -and 9/2 + levels leading to a definitive spin assignment of 7/2 -.…”