Disintegration Schemes of Radioactive Substances. III.I131

Abstract

The disintegration of the 8-day isotope of iodine, ${\mathrm{I}}^{131}$, has been studied by spectrometer and coincidence techniques. The beta-ray spectrum is simple and has an end point of 0.595±0.01 Mev. Each beta-ray is accompanied by two cascade gamma-rays of energies 367±7 and 80±1 kev, respectively. Both gamma-rays are partially internally converted, the 367-kev gammaray in the $K$ shell in 0.8 percent of the disintegrations.