COLLISIONAL IONIZATION OF EXCITED-STATE NEON IN A GAS-DISCHARGE PLASMA

We report the first case where it is possible to clearly identify and quantitatively characterize the dominant physical processes contributi ng to production of the optogalvanic effect (OGE) signal in a discharg e plasma. This work concentrates on the simplest case where only two s tates are involved in the optical transition. The theoretical model wi th only four parameters is in excellent agreement with the experimenta lly obtained time-resolved OGE waveforms. The collisional ionization r ate in the upper state is twice as fast as that in the lower state alt hough the two states are only separated by 1.94 eV. We conclude that t he optogalvanic effect of the neon 640.22 nm transition is due primari ly to the electron collisional ionization of the neon atoms. An altern ative interpretation for the lengthening of the final state lifetime i s also included (see Appendix).