Investigations on afterglows of neon gas discharges

Experimental and numerical investigations of afterglows of neon gas discharges are reported. The studied gas pressure range extends from 1 to 100 torr, the discharge current from 1 to 100 mA. The densities of the 1s-levels are measured with the help of the selective excitation spectroscopy (fluorescence technique). In this way a great number of decay curves of the 1s-densities have been measured in the afterglow of neon gas discharges. From these curves the diffusion coefficient of the metastable 1s-atoms, the coefficients of atomic collisional transfer between the 1s5- and 1s4-level, as well as the three body collision coefficient between metastable 1s5-atoms and neon ground state atoms have been determined. Besides these experiments a numerical model of the neon afterglows has been developed. With this model the afterglow phenomena can be simulated and the influence of the particular processes on the whole afterglow can be studied conveniently. Comparison is made between the experimentally and numerically obtained decay curves. For the application of the numerical model a number of starting conditions, such as radial density profiles, gas temperature, (relative) densities of the 1s-levels, have been measured. Results of these measurements are presented. Also with the help of the selective excitation spectroscopy the coefficients of atomic collisional transfer between the 2p-levels have been measured in the afterglow. From these results, together with the measured (relative) intensities of the neon spectral lines in the afterglow the partial recombination coefficients for the 2p-levels were calculated. (author)