Interaction potentials and energy transfer cross sections for collisions of metastable helium and neon. II. He(21S)+Ne

Abstract

Differential cross sections for elastic and excitation transfer scattering were measured for He(21S)+Ne collisions at kinetic energies between 25 and 225 meV. A kinematic analysis and time-of-flight measurements show that Ne atoms can be excited into all energetically allowed states. From simultaneous fits of the elastic and inelastic differential cross sections information is obtained on the interaction potentials and the energy transfer cross sections. Total cross sections are in agreement with measurements in He-Ne discharges. The threshold for the pumping process of the 6328 AA line of the He-Ne laser, He(21S)+Ne to He+Ne(2p55s 1P1), is higher than previously assumed. The potential curves derived offer a simple explanation of the large differences in the cross sections for He(21S)+Ne to He+Ne(2p55s1P1 and 3P0,1,2), which is inconsistent with the commonly accepted Wigner spin rule.