Relative differential cross sections for the electron impact excitation of the 33P, 31D and 33D states of helium

Abstract

The authors present measurements of relative differential cross sections for the electron impact excitation of the 31D, 33D and 33P states of helium at energies of 40, 45, 60 and 80 eV and for scattering angles ranging from 30' to 120'. The results are extracted from existing data of electron-photon coincidence experiments. The results are in agreement with distorted wave calculations. The authors point out the consistency of the results with the angular behaviour of the coherence parameter rho 00 also obtained from these coincidence experiments.