Lifetime of the 186-kev Level of Thorium-231

Abstract

The lifetime of the 186-kev level of ${\mathrm{Th}}^{231}$ has been studied following ${\mathrm{U}}^{235}$ alpha decay. The half-life value of this level is 0.77\ifmmode\pm\else\textpm\fi{}0.12 m\ensuremath{\mu}sec.