Disintegration ofI124andI126

The nuclear radiations from ${\mathrm{I}}^{124}$ (4 days) and ${\mathrm{I}}^{126}$ (13 days) have been measured. ${\mathrm{I}}^{124}$ decays to ${\mathrm{Te}}^{124}$ with the emission of three positron groups with end points at 2.20±0.01, 1.50±0.01, and 0.67±0.05 Mev, possibly accompanied by some $K$-electron capture. Gamma-rays of energy 0.603±0.002, 0.73±0.01, 1.72±0.02, and 1.95±0.05 are given off in the distintegration. ${\mathrm{I}}^{126}$ decays to ${\mathrm{Xe}}^{126}$ with the emission of two beta-ray groups of energies 1.268±0.010 and 0.85±0.01 Mev, together with a gamma-ray of energy 0.395±0.005 Mev. An active state of I, of 13.0±0.5 hr. half-life, which decays by $K$-capture and the emission of an internally converted gamma-ray of energy 0.159 Mev, has been found. This activity is assigned to ${\mathrm{I}}^{123}$.