Excited states in 115In

Abstract

The energy levels in 115In have been studied from the β − decay of 115gCd and 115mCd and by Coulomb excitation of 115In using helium ions and oxygen ions. The half-lives of the levels at 829 and 864 keV have been determined by the βγ delayed coincidence method. The K-conversion coefficient for the 864 → 829 keV transition has been measured using a Si(Li) detector in a coincidence arrangement. Upper limits have been placed on the half-lives of the levels at 934 and 1419 keV; Ge(Li) detectors were used in the Coulomb excitation experiments and B(E2) values extracted for the levels at 934, 1078, 1133, 1291, 1419 and 1450 keV and for a proposed level at 1645±8 keV. A 199 keV gamma ray seen in the Coulomb excitation has been assigned to an 1133 → 934 keV transition. The nature of the upper levels is discussed first in terms of the coupling of the proton hole to vibrations of the core and also in terms of a rotational band based on the 864 keV level.