Multipole expansion analysis of electron loss to the continuum for He+ions colliding with rare gases

The authors present an analysis of electron loss to the continuum (ELC) for 1.6-2.8 MeV He + colliding with He, Ne and Ar using the first six terms of the multipole expansion method. They give absolute values for B 00 and discuss the way in which the method of analysis influences the values of the dipole and quadrupole parameters. The authors' dipole parameter is slightly positive for the He target and becomes progressively more negative for Ne and Ar. Their quadrupole parameter is slightly positive for He and Ne and nearly zero for Ar. For He + +He the magnitude of B 00 and its velocity dependence are in reasonable quantitative agreement with a recent theoretical calculation based on the second Born approximation. However their dipole and quadrupole parameters are both more positive than predicted.