Alpha Spectroscopy ofAt212gandAt212m

Abstract

The $\alpha$ decay of ${}_{}{}^{212g}{}_{}{}^{}\mathrm{At}$ and ${}_{}{}^{212m}{}_{}{}^{}\mathrm{At}$ to excited states of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Bi}$ has been measured. Half-lives of 0.315±0.003 and 0.122±0.001 sec were determined in agreement with previous work. Out of a possible 28 transitions, 20 $\alpha$ transitions were observed to states in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Bi}$ below 1.11-MeV excitation.