The Disintegration ofCo55andI130

Abstract

The nuclear spectra of ${\mathrm{Co}}^{55}$ (18 hr) and ${\mathrm{I}}^{130}$ (12.6 hr) have been studied with the help of a magnetic lens spectrograph, a coincidence lens, and scintillation counters. ${\mathrm{Co}}^{55}$ emits gamma rays having energies 0.477, 0.935, 1.41, 0.253, 1.84, and 2.17 Mev, the last three being quite weak; and four beta-ray groups of energies 1.500, 1.03, 0.53, and 0.26 Mev with relative abundances of 53.3, 39.5, 4.9, and 2.3 percent, respectively. A disintegration scheme is proposed. ${\mathrm{I}}^{130}$ emits gamma rays of energy 0.409, 0.528, 0.660, 0.744, and 1.15 Mev together with two beta-ray groups of energies 1.02 and 0.597 Mev. The energy-level scheme is discussed in the light of the collective model.