Radioactivity from Enriched Isotopes of Cadmium

By irradiating in the pile specimens of cadmium enriched in mass 108 and in mass 114, it is possible to interpret more positively the observed radioactivities and to evaluate the gamma-rays associated with each. Cadmium 109 produced by neutron capture in cadmium 108 decays with a half-life of approximately 250 days by $K$-capture to silver 109 in which a strong gamma-ray of 87.5 kev is emitted. Cadmium 115 is isomeric with half-lives of 54 hours and 42.6 days, both isomers decaying to indium 115 by beta-emission. The 54-hour activity yields many gamma-rays in indium whose energies are 335.5, 343.7, 348.9, 369.3, 423.7, 451.9, 525.4, 559.1, and 713.1 kev. These gamma-energies fit well a proposed nuclear level scheme in indium 115.