Low Energy Ion-Neutral Reactions. I. ²²Ne⁺+²⁰Ne, and Ar⁺+N₂

Abstract

A series of experiments has been performed using drift tube technique, in which both the primary and secondary ions are mass identified. Design of the apparatus is described briefly. Drift velocities of ions in the drift tube are measured with gate pulse technique. Cross sections of reactions 22 Ne + + 20 Ne→ 22 Ne+ 20 Ne + and Ar + +N 2 →Ar+N 2 + are determined as functions of mean energies of the ions in the range from 0.04 to 4 eV. Cross section of the former reaction decreases from 5.2±0.2×10 -15 cm 2 at 0.045 eV to 3.7±0.2×10 -15 cm 2 at 2.5 eV. Comparisons of measured cross section with the theory of Rapp-Francis and the previous experiments show that the technique and apparatus used are quite reliable. Cross section of the latter reaction increases from 3.0±0.3×10 -16 cm 2 at 0.43 eV to 2.2±0.2×10 -15 cm 2 at 4.4 eV, and it does not agree with the previous experiments using beam technique at higher energy.