L- andM-shell electron shake-off accompanying alpha decay

Abstract

The ${L}_{\mathrm{I}}$-, ${L}_{\mathrm{II}}$-, ${L}_{\mathrm{III}}$-, and $M$-shell vacancy distributions accompanying electron shake-off in the $\ensuremath{\alpha}$ decay of $^{210}\mathrm{Po}$ have been measured by $\ensuremath{\alpha}$-x-ray two parameter coincidence techniques. The ionization probabilities and the errors due to our measurements were (5.11\ifmmode\pm\else\textpm\fi{}0.40, 0.62\ifmmode\pm\else\textpm\fi{}0.06, and 1.50\ifmmode\pm\else\textpm\fi{}0.19) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}4}$ for the ${L}_{\mathrm{I}}$, ${L}_{\mathrm{II}}$, and ${L}_{\mathrm{III}}$ subshells, respectively, and (1.8\ifmmode\pm\else\textpm\fi{}0.4) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}2}$ for the $M$ shell. Possible errors in tabulated fluorescence and Coster-Kronig yields could increase the uncertainties to (1.7, 0.5, 0.8) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}4}$ and 0.6 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}2}$, respectively. The energies and peak shapes of the $\ensuremath{\alpha}$ groups in coincidence with $L\ensuremath{\alpha}$, $L\ensuremath{\beta}$, $L\ensuremath{\gamma}$, and $M$ x rays were also measured. The coincident groups were, respectively, 12.6\ifmmode\pm\else\textpm\fi{}1.4, 13.8\ifmmode\pm\else\textpm\fi{}1.4, 17.6\ifmmode\pm\else\textpm\fi{}2.1, and 3.1\ifmmode\pm\else\textpm\fi{}1.0 keV lower in energy than the $^{210}\mathrm{Po}$ ${\ensuremath{\alpha}}_{0}$ peak. Theoretical calculations by Hansen are in closer agreement with the experimental values for the $L$ subshells than Migdal's theory, but discrepancies of about a factor of 2 still exist.RADIOACTIVITY $^{210}\mathrm{Po}$; measured $\ensuremath{\alpha}\ensuremath{-}L$ and $\ensuremath{\alpha}\ensuremath{-}M$ x-ray coin. Deduced ${L}_{\mathrm{I}}$, ${L}_{\mathrm{II}}$, ${L}_{\mathrm{III}}$, $M$ electron shake-off abundances, energy distribution.