Population of 2p 55s levels of neon atoms in He-Ne plasma. 2. Temperature dependences of partial coefficients of recombination of HeNe+ ions and electrons

Abstract

A spectroscopic study of population of the excited 3s2-3s5 states (in Paschen’s notation) of neon atoms of the 2p55s configuration was carried out in a pulsed discharge helium plasma with a small admixture of neon (pressure 38.1 Torr, [He]/[Ne] ≌ 105). Study the response of the spectral line intensities to pulsed heating of electron gas by an electric field in the late afterglow made it possible to determine the dependences of the partial rates of population of the 3s2-3s5 states on electron temperature Te for kTe = 0.03–0.40 eV. At temperatures of 0.03–0.20 eV, the 3s2–3s5 states are populated mainly due to dissociative recombination of HeNe+ ions and electrons with the temperature dependences of recombination fluxes close to Te−1.2. At temperatures of 0.20–0.40 eV, the rate of population of the 3s2–3s5 states was observed to increase via two mechanisms. One of them is the electron-impact excitation He(23S1) + e + 0.8 eV → He(21S0) + e followed by excitation transfer from He(21S0) to neon atoms; the second mechanism is presumably the threshold process of dissociative recombination of Ne2+ ions (v = 0) in the ground vibrational state with electrons.