Levels in 115In populated in the decay of 115mCd

Abstract

The decay of 115mCd to 115In is studied. Gamma intensities are measured with a Ge(Li) detector. Two new transitions are observed and placed in the level scheme. The following γ-γ directional correlations are determined (energies in keV): 484.35–933.6, 158.1–1132.5 and 316.1–1132.5. The M1 strengths are derived for two transitions connecting members of the vibrational multiplet: B( M1, 1290.5 13 2 + → 1132.5 11 2 +) = 0.5 ± 0.1 μ 2 0 and B( M1, 1448.7 9 2 + 1132.5 11 2 +) = 0.5 ± 0.3 μ 2 0 . The half-life of the 933.6 7 2 + state as measured by the delayed-coincidence technique is T 1 2 = 57 ± 5 ps . The partial half-life of the 933.6 7 2 + → 828.4 3 2 + E2 transition is 55 times less than the Weisskopf estimate. The static quadrupole moment of the 7 2 + and 3 2 + states is evaluated on the assumption that these levels are members of the proposed rotational band: Q 0 = 2.7 ± 0.3 b. This is in agreement with the corresponding value for the 864.0 1 2 + → 828.4 3 2 + transition, and the result of a recent direct measurement of the static quadrupole moment of the 828.4 3 2 + state. The suggestion that the 1418.0 9 2 + level is also deformed is supported by the fact that the decay occurs preferentially to the 933.6 7 2 + state, whereas no transition connecting the 1448.7 9 2 + state with the 933.6 7 2 + state is observed.