Levels ofRb91andSr

Abstract

Level schemes for~~R b and 9~Sr are proposed based on the study of the P decay of S~Kr and 9~Rb, respectively. The samples mexe obtained using on-line mass-separation techniques applied to~3 5U fission products. y-, P-, and x-ray singles spectra, as mell as (y, y} and (P, y} coincidence spectra, mere taken with Ge(Li} and Si(I i} detectors. Internal-conversion coefficients mere determined for several transitions and the half-lives for the first two levels in Gab and 9~Sr mere measured. In viem of the observed parity change between lorn-lying excited states and the ground state in 9~3b the possibility of deformations to explain this level structure is discussed.

Gamma-ray decay schemes for ⁹³Kr, ⁹³Rb, and ⁹³Sr

“…All energies are in agreement with at least one of the previous Ge(Li) detector studies cf this nuclide for which energy uncertainties are quoted (26,28). Relati~e intensities and trar.sition assignments (for those gamma rays placed in the level scheme) are also provided in Table 7.…”

“…~i sl• (28) were not observed in this study. However three of these gamma rays could not be placed in the level scheme proposed in that reference and four other gamma rays were used to define two new levels.…”

“…0-ki;!V ll;!vel (J 7T = 1;2-, 3/2.;. ;) : Two M 1 -transit icnE are :reported (28) to depopulate this level. These two transitions limit the spin to leEs than 7/2~ and because both feed negative parity levels,.…”

“…However, these values disagree in a systematic fashion with those reported by.Achterberg, tt al• (28). In a similar manner a comparison can be made among relative intensities quoted in these three works.…”

Gamma-ray decay schemes for 93Kr, 93Rb, and 93Sr

“…The pres ence of such a low-lying negative-parity state cannot be ex plained on the basis of the spherical potential shell model. A negative-parity state at this low energy is also inconsist ent with the predominance cf positive-parity states in this energy region in other odd-A strontium isotopes.In an earlier work on the decay cf '^Kr, Achterberg, et al(54) had reported a positive-parity state in the level scheme of 9iRb. The parity was based on the supposed El multipolarity of the transition depopulating that level.In a later study.Wohn, et al(55) established that the multipolarity of this transition was Ml and not El and that therefore no change in parity occurs.…”