Isotope shift in the bulge effect of molecular scattering

Abstract

The recently observed "bulge" effect in rotationally inelastic scattering is substantiated by the detection of its isotope shift in K-CO collisions. This effect is a classical rainbow-type phenomenon which has been seen in the energy transfer or recoil-velocity dependence of K-CO and K-${\mathrm{N}}_{2}$ scattering at large angles and collision energies of about 1 eV. It is caused by the nonspherical bulge of the repulsive equipotentials of the intermolecular force and may be useful as a probe to its anisotropy.