Electron capture intensities in the decay of133Ba
The ground state decay of133Ba was investigated using NaI(Tl) scintillation crystals.PL/PK electron capture ratios were measured for the transitions to the 437 keV and to the 384 keV level of133Cs. The results are: (PL/PK)437=0.371±0.007 and (PPL/PK)384=0.221±0.005. From these data a mass difference between the ground states of the133Ba- and the133Cs-atom of (515±3) keV was derived. Besides, these capture ratios yield an exchange correction of 1.03±0.03. Furthermore, the intensity of the transition to the 161 keV level was determined to be smaller than 0.5% of all decays.