Population of 2p 54p levels of Ne in the afterglow of discharge in helium with small admixtrue of neon

Abstract

The processes of population of 3p1, 3p3, 3p6, and 3p9 levels (in Paschen’s notation) of neon atom has been studied by spectroscopic methods during the decay period of plasma produced in helium containing small concentrations of neon ([Ne]/[He] ≈ 10–5). Based on the comparative analysis of temporal variation of the intensities of NeI spectral lines of 2p54p → 2p53s and 2p54d → 2p53p transitions, it is established that the formation of exited Ne(2p54p) atoms in the afterglow is related to the dissociative recombination (DR) of homo- and heteronuclear ions and electrons via reactions HeNe+ + e → Ne(2p54p) + Ne and Ne2+ e → Ne(2p54p) + Ne. The relative contributions of these processes to the rate of population of various Ne(3pj) states depend on the energies of 3pj levels. The upper 3p1 level lying above the ground state of Ne2+(v = 0) ion is populated almost entirely due to the DR of HeNe+ heteronuclear ions. The DR of Ne2+ ions and electrons significantly contributes to \(\Gamma _{3p_j }^{Ne_2^ + }\) flux in population of low-lying 3p3, 3p6, and 3p9 levels; \(\Gamma _{3p_j }^{Ne_2^ + }\) value increases with decreasing energy of 3pj level.