Velocity Dependence of the Total Cross Section for the Scattering of Li and K by Xe

Abstract

The velocity dependence of the total cross section has been measured for the scattering of potassium by xenon at relative velocities between 350 and 1550 m/sec, and for the scattering of lithium-7 by xenon between 700 and 3800 m/sec. Although small deviations were seen, the potassium-xenon scattering was in general agreement with the Massey-Mohr theory, assuming an inverse sixth power interatomic potential. Large deviations from this theory were observed for the lithium-xenon scattering. To account for these deviations, phase shifts were calculated in the semiclassical framework of Ford and Wheeler, following a method of Bernstein. The Lennard-Jones interatomic potential was assumed. The velocity dependence of the cross sections which were calculated from the phase shifts shows the qualitative features of the experimental results.