Experimental determination of penetration parameter forM1 conversion,and theE2 admixtures for 77 and 191 keV transitions in197Au

TheL-subshell conversion for 77 keV transition andK,L ₁,L ₂-shell conversion for 191 keV transition in¹⁹⁷Au, as well asK-shell conversion transition of 158 keV in¹⁹⁹Hg were measured by means of Π√2-iron free electron spectrometer. Relative gamma-ray intensities have been determined by Ge(Li) spectrometer. From these measurements the α _K conversion coefficient value has been deduced for 191 keV transition as α_K(191 keV)=0.86±0.03. This value shows that the spin of the level at 268 keV in¹⁹⁷Au is 3/2⁺. For the penetration parameter (λ) and intensity ratio (left( {delta ^2 = frac{{leftlangle {E2} rightrangle ^2 }}{{leftlangle {MI} rightrangle ^2 }}} right)) the following values are obtained: $$begin{gathered} lambda = 3.4 pm _{1.5}^{1.9} delta ^2 = 0.11 pm 0.03for 77 keV transition hfill lambda = 3.2 pm _{0.6}^{0.8} delta ^2 = 0.17 pm 0.04for 191 keV transition. hfill end{gathered} $$ The agreement of these results with the predictions of De Shalit model is discussed.