Level structure of ¹¹⁷In from the decay of ¹¹⁷Cd

Abstract

The levels in ¹¹⁷ In populated in the decay of ≈ 2.7 h ¹¹⁷Cd and ^117mCd have been studied using a Ge(Li) detector and scintillation techniques. In all 45 gamma rays have been identified. A total of 23 energy levels extending up to 2461 keV has been proposed on the basis of the gamma-gamma and beta-gamma coincidence measurements. The K-conversion coefficient of the 88 keV transition is measured to be 1.3±0.3. The gamma-gamma directional correlations of 1028-1068 keV and 567-1430 keV cascades have been found to be W(θ) = 1-0.022(±0.012)P₂(cos θ)+0.015(±0.038)P₄(cos θ) ,W(θ) = 1-0.011(±0.012)P₂(cos θ)+0.060(±0.038)P₄(cos θ). The beta-gamma differential correlation of the beta group feeding the 748 keV level and the following 433 keV gamma ray is found to be isotropic. The levels at 660, 748, 881, 1249 and 1715 keV have been identified as the members of a possible K = ½ ⁺ rotational band. The levels at 860, 950, 1056, 1068 and 1430 keV have been suggested to be the members of a (½ ⁺ proton hole + 2⁺ core) multiplet. The possible nature of the other higher-excited states has been discussed.