Theoretical calculations and experimental crossed-beam measurements are compared for electron-impact single ionization of ${\mathrm{Bi}}^{q+}$ for $q=1–10$. The configuration-average distorted-wave calculations include both direct ionization and indirect excitation-autoionization contributions. For ${\mathrm{Bi}}^{2+}$ it is necessary to account for levels within an excited configuration that straddle the ionization threshold. This was included via level-resolved atomic structure calculations, from which statistical partitions of the configuration-averaged cross sections could then be made. Evidence is found for ionization contributions from an excited configuration in ${\mathrm{Bi}}^{3+}$ and ${\mathrm{Bi}}^{5+}$. Good agreement is found between theory and experiment for all the ionization stages of Bi studied.

• Received 11 May 2004

DOI:https://doi.org/10.1103/PhysRevA.70.052714