Atomic Vacancy Distributions Produced by Inner-Shell Ionization

Abstract

Average $L$- and $M$-shell-vacancy distributions produced in the deexcitation of atoms that have been singly ionized in the $K$ shell or one of the $L$ subshells are derived from a comprehensive set of available experimental and theoretical data on radiative- and Auger-transition rates. The data are supplemented by new calculations in $j\ensuremath{-}j$ coupling from nonrelativistic screened hydrogenic wave functions of the following radiationless transition rates: $K\ensuremath{-}LL$, $K\ensuremath{-}LM$, and $K\ensuremath{-}LN$ for selected elements with $20\ensuremath{\le}Z\ensuremath{\le}81$, and ${L}_{i}\ensuremath{-}MM$, ${L}_{i}\ensuremath{-}MX$, and ${L}_{i}\ensuremath{-}XY$ for $26\ensuremath{\le}Z\ensuremath{\le}93$. Experimental and theoretical data on Auger- and radiative-transition probabilities are critically compared. Auger-electron intensity ratios and $\frac{K{\ensuremath{\alpha}}_{2}}{K{\ensuremath{\alpha}}_{1}}$ and $\frac{K\ensuremath{\beta}}{K\ensuremath{\alpha}}$ x-ray intensity ratios from a best fit to experimental data are tabulated for even atomic numbers from 20 to 94. The probability, per initial $K$ vacancy, of vacancy production in each ${L}_{i}$ subshell is derived from experimental data and tabulated for $20\ensuremath{\le}Z\ensuremath{\le}94$; components due to Auger and x-ray transitions are listed separately. These probabilities agree well with purely theoretical vacancy distributions also derived here. The probability of $M$-shell-vacancy production in the decay of $K$ and ${L}_{i}$ vacancies is derived from theory and tabulated for selected atoms with $16\ensuremath{\le}Z\ensuremath{\le}93$.