A study of 30P levels below 5 MeV

Abstract

Spins of 16 excited states of 30P have been investigated in conjunction with multipole mixing and branching ratios of a number of gamma transitions via the reaction 28Si( 3He, p γ) 30P. Spin assignments are consistent with those of other investigators in all cases except for the 4.921 MeV level whose branching ratios are also in disagreement with those previously reported. Assuming, as suggested by the present results, a transition from the 4.921 MeV level to the 0.680 MeV level rather than to the 0.709 MeV level, a unique assignment of J = 1 is made to the 4.921 MeV level. A new probable assignment of J = 1 has been made to the 3.736 MeV level. The previously unstudied 2.839, 3.836, 3.928 and 4.734 MeV levels have been assigned possible spin values together with branching ratios and multipole mixing ratios for their decay transitions. Branching ratios for transitions from the 3.736, 3.836, 3.928 and 4.501 MeV levels are in serious disagreement with those of previous studies. Using shell-model wave functions, calculations of lifetimes, multipole mixing ratios and branching ratios corresponding to five low-lying states showed agreement with experimental values for only the first two excited states.