No abstract

The Ta L x-ray spectrum from the 140 d electron capture decay of lslw was studied with high resolution semiconductor detectors and fast coincidence techniques. Measurement of L x-ray--K x-ray and L x-ray--y-ray coincidence rates yielded the following L shell fluorescence and Coster-Kronig yields and radiative decay branching ratios: 0) 2= 0.250__. 0.013, 093= 0.228 _ 0.013 (corrected for angular correlation effects), f23 = 0.180 q-0.007, v 1 = 0.218 _ 0.016, s3= 0.205 + 0.010, s2= 0.215 -t-0.010, fla--l-f12f23=0.36~ 0.02, and co1-I-f12o92~-0.14 0.02, from which upper limits were obtained of f13 < 0.36 and o91 < 0.14.

Recently published experimental values of the L2-L3 total Coster-Kronig and L~-subshell fluorescence yields for Z =65, 70, 73, and 80 have been corrected for the presence of the unresolved L"tr 2-M~] x-ray line in the L~fJ.S-M4 5] x-ray group. It is shown that this appreciable correction does not explain the discrepancy between experiment and theory.As pointed out in a recent paper by Chen et al. , '