Electron impact excitation of theHg(6P0,23)metastable states

Electron impact excitation functions for the $\mathrm{Hg}\left(6\mathrm{}{}_{}{}^3{}_{}{}^{}P_{0,2}^{}{}_{}{}^{}\right)$ metastable states were measured from threshold to 8.5 eV. The $6{}_{}{}^3{}_{}{}^{}P_{0,2}^{}{}_{}{}^{}$ states were detected by monitoring the forbidden photon emission. The $6{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$ state was also selectively detected by monitoring the 2537-Å emission from collisional deexcitation to the $6{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ state followed by radiative decay to $6{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$. Structure observed in the excitation functions appears to be due to autoionization of short-lived excited states of ${\mathrm{Hg}}^{-}$. The ratio of cross sections for formation of the $6{}_{}{}^3{}_{}{}^{}P_{2,0}^{}{}_{}{}^{}$ states, $\frac{{\sigma }_2}{{\sigma }_0}$, determined at the peak of the $6{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$ excitation function ($E\simeq 5.8$ eV), is 9.1. The ratio of cross sections at the peak of each excitation function ($6{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$, $E\simeq 5.8$ eV; $6{}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$, $E\simeq 5.2$ eV) is 5.2.