Simultaneous Excitation and Ionization of Argon by Electrons to the Upper Laser States of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">Ar</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>

Experimental cross sections for the simultaneous excitation and ionization of argon to the $4p$ configuration of ${\mathrm{Ar}}^{+}$ are presented. The data are found to be in considerable disagreement with previous work. Optical excitation functions for the important argon-ion laser lines are given, and the results are compared with the observed relative gains of the lines in a pulsed laser. The cross sections for excitation to the $4p^{2}P$ states of ${\mathrm{Ar}}^{+}$ are found to have an ${E}^{\ensuremath{-}1}$ dependence with energy in the range 250-700 eV, in disagreement with the asymptotic behavior predicted from the sudden approximation.