The electron capture decay of 85gsr

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 -.…”

The electron capture decay of85Sr-measurements of theK X-Ray emission probability, half-life, and decay scheme

“…Their relative intensity remained constant with time, and from an average of all the measurements the ratio I(869):I(514) was (1.25 +_0.05) x 10 -4. Source 1 showed very slight traces of 6SZn, but no trace of 33 d *~Rb which emits an 882 keV y-ray and has often been seen as a contaminant in 8SSr [28,29], No evidence was seen for a 355 keV -/-ray which would be present if the 869 keV state decayed by cascade through the 514 keV state. Because of the Compton background from the 514 keV y-ray, a weak 355 keV y-ray would be difficult to detect.…”

“…In a more recent study using Ge(Li) detectors, Bubb et al [28] saw a 7-ray at 868 keV but assigned it to a contaminating activity on the evidence of decreasing intensity of the 7-ray with successive chemical separations. However, in direct contrast, Vatai et al [29], again using Ge(Li) detectors, found a 7-ray at 868.5 keV with a half-life of 65_+ 5 d, and an intensity relative to the 514 keV y-ray which remained constant with time. There is now separate evidence from Coulomb excitation [30] and neutron inelastic scattering [31] for the existence of a level in 85Rb at 869 keV, but the evidence for population of this state in the decay of 85Sr is contradictory.…”