I. Bikit et al., POPULATION OF THE 283 KEV LEVEL OF BA-137 BY THE BETA-DECAY OF CS-137, Physical review. C. Nuclear physics, 54(6), 1996, pp. 3270-3272
The gamma spectrum of Cs-137 was measured by means of a low-level shie
lded and Compton-suppressed HpGe spectrometer. The gamma line with the
energy 283.4 keV and absolute intensity of 5.3(14)X10(-6) was found.
It was concluded that the 283.4 keV intermediate level in Ba-137 [seen
earlier in (n,n'gamma) measurements] is populated in the beta decay o
f Cs-137 with the comparative half-life of log ft=15.3(3).