The states of 117Sn

Abstract

Gamma rays emitted in the decay of 2.8 h 117Sb have been investigated with 2.5 to 45 cm 3 Ge(Li) detectors. Gamma rays of energies (and relative intensities) 158.5 (99.6), 553.2 (0.07), 846.2 (0.04), 861.7 (0.29), 1004.5 (0.22), 1020.6 (0.09), 1021.0 (0.10), 1287.6 (0.026), 1339.5 (0.009), 1420.1 (0.016), 1446.4 (0.051) and 1578.0 (0.018) keV have been observed. On the basis of energy sums, relative intensities and two-dimensional Ge(Li)-Ge(Li) coincidence experiments, states are placed in 117Sn at 0 ( 1 2 + ), 158.5 ( 3 2 + ), 711.7 ( 7 2 + ), 1004.5 ( 3 2 + ), 1020.2 ( 5 2 + ), 1179 ( 5 2 + ), 1446.4 ( 3 2 +, 5 2 + ), 1498.0 ( 5 2 +, 3 2 + ) and 1578.3 keV ( 5 2 +, 3 2 + ). The spin assignments and limits have been made on the basis of log ƒt values and relative photon intensities from 117Sb decay, which were aided in some cases by 117In decay, and also by information gleaned from nuclear reaction data. The structures of the states are discussed in terms of current nuclear models, and the behavior of these states is followed as a function of neutron number.