The Characteristic Radiations ofCo60

The 10.7-minute period previously obtained from $\mathrm{Co}(n,\gamma )$ and $\mathrm{Ni}\mathrm{}(n,p)\mathrm{}$ reactions was produced by a $\mathrm{Co}\mathrm{}(d,p)\mathrm{}$ reaction. The increased activity from this latter reaction made energy measurements possible. The beta-rays were measured with a magnetic spectrometer. In spite of the difficulties caused by the rapid decay of the activity, the best interpretation of the data is that the beta-rays are a continuous spectrum. The end point was evaluated at 1.35±0.1 Mev. Absorption measurements indicated that each beta-ray is accompanied by approximately one gamma-ray of 1.5±0.2-Mev energy. The 5.3-year period radiations previously studied were also investigated and found to consist of a 1.7±0.2-Mev gamma-ray and a 220±20-Kev beta-ray spectrum. These data suggest that ${\mathrm{Co}}^{60}$ may consist of isomeric nuclei in which the two activities decay independently, as an alternative to the previously reported scheme of disintegration.