Differential cross sections for elastic and inelastic n=2 excitation of ground-state helium at 29.6 and 40.1 ev

Abstract

Differential cross sections have been measured for elastic and inelastic (23S, 21S, 23P and 21P) scattering of electrons by ground-state helium at 29.6 and 40.1 eV. The normalisation of the cross sections is discussed. Theoretical cross sections have been obtained using a ten-state coupled-channels-optical calculation. In general, there is good agreement between theory and experiment for singlet states but not for triplet. © 1990 IOP Publishing Ltd.