Scattering of Low-Energy H— Ions in Helium, Neon, and Argon

Abstract

Elastic and inelastic cross sections have been measured for the scattering of H^— ions in helium, neon, and argon gases, at incident ion energies in the range 5 ev to 350 ev. One term interaction potentials of the form V=—K/rⁿ were calculated from the low‐energy elastic cross sections. These potentials were: for H^— and He, V=—2.90/r^3.01 ev for r=1.30 A to 1.90 A; for H^— and Ne, V=—4.17/r^2.80 ev for r=1.00 A to 1.78 A; and for H^— and A, V=—7.82/r^3.40 ev for r=1.23 A to 2.12 A. The observed inelastic cross sections are interpreted as cross sections for electron detachment from H^—; they show a similar behavior with ion energy W in the three cases, appearing at W between 0 and 5 ev, rising rapidly to W=40 ev, and then rising very slowly to W=350 ev. Evidence was found for positive ion formation in H^— collisions with Ne and A atoms at ion energies above 100 ev.