Electron scattering by atomic hydrogen using a pseudo-state expansion. II. Excitation of 2s and 2p states near threshold

Abstract

For pt.I. see abstr. A14168 of 1970. The pseudo-state modification of the close-coupling expansion is applied to the 2s and 2p excitation of atomic hydrogen by electron impact. Pseudo-states are used which ensure the implicit inclusion of all important excited state polarizabilities. A detailed comparison is made with results obtained from other modifications of the close-coupling expansion and the eigenphase minimum principle is used to determine the best result for each partial cross section. Comparison of the theory and experiment in the first electron volt above the n=2 threshold shows very good agreement in the ratio Q(1s-2s)/Q(1s-2p), but a 20% discrepancy exists between the individual cross section magnitudes when experiment is normalized to the Born approximation at higher energies.