A study of population inversion of He I and Ne I in regenerative sooting discharges

Abstract

The mechanisms for population inversion among the excited states of He I and Ne I in regenerative sooting discharges have been investigated as a function of the geometry and the physical parameters of the graphite hollow cathode sources. The effect of the state of sooting of the hollow cathode, the gas pressure and the role of the cycling of i dis on the population inversion of the excited He I and Ne I levels have been investigated.

Formation of CN in N2+ He discharges in graphite hollow cathodes

“…The average T exc of He I is 3500± 500 K in the entire range of i dis from 12.5 to 200 mA. This value is of the same order of magnitude as reported earlier [2] for sooting discharges with the difference being the observation that a reverse trend is seen in figure 4(a) when i dis is increasing as compared to that while it decreases, in figure 4(b). As i dis increases, the probability of He ion production increases.…”

“…The present communication is part of an ongoing activity in which we have investigated the role that various discharge parameters play in the formation mechanism of CN in the special carbon + nitrogen environment that is created in graphite hollow cathodes. As pure N 2 discharges are difficult to stabilize in a broad range of the pressure and discharge current i dis , N 2 + He mixtures in various ratios have been used to create the multi-component, sooting glow discharge that has already been investigated with noble gases but without nitrogen [2]. The N 2 + He discharges that we are reporting here, are shown to provide an environment where C radicals (C 1 , C 2 , .…”