The gamma spectrum of ${}_{}{}^{137}{}_{}{}^{}\mathrm{Cs}$ was measured by means of a low-level shielded and Compton-suppressed HpGe spectrometer. The gamma line with the energy 283.4 keV and absolute intensity of 5.3(14)×${10}^{\mathrm{-}6}$ was found. It was concluded that the 283.4 keV intermediate level in ${}_{}{}^{137}{}_{}{}^{}\mathrm{Ba}$ [seen earlier in (n,n′γ) measurements] is populated in the β decay of ${}_{}{}^{137}{}_{}{}^{}\mathrm{Cs}$ with the comparative half-life of log ft=15.3(3). © 1996 The American Physical Society.

• Received 15 July 1996

DOI:https://doi.org/10.1103/PhysRevC.54.3270