EXPERIMENTAL INVESTIGATIONS ON ELECTRON CAPTURE DECAY OF 85 STRONTIUM AND 88 YTTRIUM

The electron capture decay of85Sr and55Y has been investigated using NaI(Tl)-detectors. Spectroscopic-coincidence techniques have been employed to examine the K-electron capture rates. The experimental results are PKωK(Sr)=.5959 ± 0.0035 and PKωK(Y)=0.6340± 0.0032. Using the K-capture probabilities, derived from the capture ratios of Brysk and Rose with the exchange correction of Bahcall:PK(Sr)=0.880± 0.008 and PK(Y)=0.883 ± 0.008, one can derive from these results the fluorescence yields ωK(Rb)=0.677± 0.009 and ωK(Sr)=0.712± 0.010. Functions of ωK(Z) were fitted to recent experimental data and tabulated for Z=5-90. In addition to these results the half life of the 514 keV state of85Rb and the branching ratios and the positron rate of the88Y-decay have been measured with the same techniques. The data obtained partly disagree from measurements of other authors. © 1969 Springer-Verlag.