Studies of decaying plasmas produced in neon and helium-neon mixtures

Abstract

This paper reports simultaneous measurements of the time dependence of the intensities of spectral lines and that of the number density of atomic and molecular ions in decaying plasmas produced in neon and helium-neon mixtures. The measurements in neon resulting in the mobility value, μ o(Ne +) = 4.0 cm 2/V.s, at a gas temperature of 335°K, while the frequency of conversion of Ne + into Ne + 2 was found to be ν conv = 52 P 2 0 s −1. A study of the time dependences, during the neon afterglow, of the intensity of spectral lines originating from transitions from the 4 d levels strongly indicates that these levels are mainly populated by a recombination process involving Ne +. Analogous studies of the behavior of spectral lines originating from transitions from the 2 P and 3 P levels show that these energy levels are mainly populated by the dissociative recombination process Ne + 2 + e → Ne ∗ + Ne → 2Ne + hv. Preliminary studies on decaying plasmas produced in a helium-neon mixture confirmed the occurence of the processes He + 2 + Ne → Ne + + 2He and Ne + + 2He → (HeNe) + + He as previously postulated by Oskam. Moreover, these studies indicated the occurrence of the conversion process (HeNe) + + Ne + He → Ne + 2 + 2He.