Lifetimes of the First Two Levels inP30

Abstract

The lifetimes of the first two levels in ${}_{}{}^{30}{}_{}{}^{}\mathrm{P}$ were measured by the attenuated-Doppler-shift technique. The measurements were analyzed by use of the universal stopping cross section given by Lindhard, Scharff, and Schiott, and a mean life $\tau =(1.55\mathrm{}\pm 0.30)\times {10}^{-13\mathrm{}}$ sec was obtained for the first level; for the second level only a lower limit ($\tau \ge 3.0\times {10}^{-12\mathrm{}}$ sec) was obtained. The experimental result for the first level is compared with the value calculated from the corresponding Gamow-Teller $\beta$ transition according to the relation given by Kurath. Slightly revised energies of 677.0±1.0 and 709.0±1.0 keV are assigned to these levels.