Auger spectrum of the noble gases. II. Argon

Abstract

Theory and experiment are compared for the ${L}_{23}\mathrm{MM}$ principal and satellite spectra of argon. For the principal spectrum it is shown that theory and experiment are in excellent agreement if the doublet conventionally assigned to ${L}_{23}\ensuremath{-}{M}_{1}{M}_{1}$ is reassigned to ${L}_{23}\ensuremath{-}{M}_{1}{M}_{23}$ ($^{1}P$). It is hypothesized that the splitting of the $^{1}P$ term is due to configuration interaction with the ${(3p)}^{3}^{2}D(3d)^{1}P$ term of ${\mathrm{Ar}}^{+2}$. The reassignments enable us to locate, tentatively, several unknown singlet levels in ${\mathrm{Ar}}^{+2}$. An examination of the satellite spectrum confirms Mehlhorn's assignment of the terms in the ${\mathrm{Ar}}^{+2}$ ${(2p)}^{5}{(3s)}^{2}{(3p)}^{5}$ configuration. The calculated satellite spectra agree with experiment in spectral shape (the location of peaks) and agree to a factor of 2 in individual satellite peak intensity. The satellite calculations support Mehlhorn's conclusion that theory considerably overestimates the ${L}_{1}\ensuremath{-}{L}_{23}{M}_{1}$ Auger transition rate.