Decay ofU232(74 yr)

Abstract

The decay of the $\alpha$ emitter ${\mathrm{U}}^{232}$ (74 yr) was studied by means of $\gamma$-ray scintillation counters and by a technique involving the impregnation of a scintillating crystal with this source. Excited states were found at 60 kev, 190 kev, and 330 kev. The first two are interpreted as rotational states of character 2+ and 4+ and the third as probably a 1- state. The branching ratios for transitions from the 330-kev state to the 2+ state and ground state are 57 percent and 43 percent respectively. The half-life of the 60-kev state was found to be shorter than 2×${10}^{-8\mathrm{}}$ sec, in contrast to earlier reports based on a study of the ${\beta }^{-}$ decay of ${\mathrm{Ac}}^{228}$.