The excited states of the neutral and ionized carbon in the regenerative sooting discharges

Abstract

We report the mechanisms of production and the state of excitation of the neutral and singly charged monatomic carbon in the regenerative soot as a function of the discharge parameters in graphite hollow cathode (HC) sources. Two distinctly different source configurations have been investigated. Comparisons of the level densities of various charged states of C 1 have identified the regenerative properties of the C radicals in graphite HC soot.

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

“…The cycling of i dis shows hysteresis in figure 2(a) and not in figure 2(b). This situation is similar to the hysteresis seen and reported by Uzair et al (2003) for the level densities of CI and CII. Figure 3 is the levels diagram of those levels that participate in the transitions that are being discussed in this paper.…”

“…The cycling shows hysteresis in figure 2(a) and not in figure 2(b). This situation is similar to the hysteresis seen and reported by Uzair et al (2003)[3] for the level densities of CI and CII.…”

“…We have studied the discharges of helium and neon in graphite hollow cathodes with interesting observations of hysteresis of the level populations of CI and CII when the discharge current was cycled, as in a recent study [3]. This prompted us to look at the level densities of all the discharge species especially those of the support gases, i.e.…”

“…The discharge current cycling between the minimum and maximum values provides important clues to the level densities of the respective transitions. In a recent study [3], we focused on the excited and ionized states of C 1 under similar experimental conditions, where we pointed out hysteresis in the level densities as a function of the cycling of i dis between min → max → min. Since C 1 is created as a by-product of the sooting discharge, one can argue that it may not constitute conclusive evidence of the mechanism of hysteresis.…”

“…The lower energy electrons are expected to have Maxwellian velocity distributions; therefore, one can estimate the electron temperature of the positive column of the glow discharge and approximate it with the excitation temperature of the support gas by using the most pronounced emission lines with the same lower levels. However, the presence of the higher energy electrons ( 10 eV) near the electron-emitting cathode and the role of the sooted surface of the hollow 3 Author to whom any correspondence should be addressed. cathode as well as the inter-and intra-species collisions in the positive column of the discharge provide additional sources of excitation besides the low energy electrons ( 1 eV).…”