Structure of the integral cross sections for excitation in ion-atom collisions calculated in the plane-wave Born approximation.

Abstract

We point out that the plane-wave Born approximation sometimes gives rise to a conspicuous minimum of the integral cross section for excitation in ion-atom collisions; for illustration we present results for a transition 1${s}^{2}$2${s}^{2}$ $^{1}s^{2}$2s3p $^{1}P$ of berylliumlike ions calculated by using configuration-mixing wave functions. The minimum of the integral cross section arises from a zero of the generalized oscillator strength.