Radioactive Isotopes of Gadolinium

Abstract

A 236-day neutron induced activity in gadolinium purified by ion exchange methods is assigned to ${\mathrm{Gd}}^{153}$. The activity decays by $K$-electron capture emitting a 106-kev $\gamma$-ray giving rise to $K$- and $L$-electron groups. A 7.2±0.2 day and approximately 24-hour activity present in the neutron bombarded gadolinium were separated on an ion exchange column. The 7.2-day activity assigned to ${\mathrm{Tb}}^{161}$ decays by emission of 0.50-Mev $\beta$-particles. The 24-hour activity is tentatively assigned to ${\mathrm{Gd}}^{159}$.