The angular variation of the asymmetry in scattering of spin-polarised electrons by hydrogen

The angular distribution of the asymmetry in scattering of spin-polarised electrons by spin-polarised hydrogen atoms has been calculated for the first time, for the 1s-1s and 1s-2s transitions, at impact energies of 35 and 54.4 eV. A full six-state calculation was done at 54.4 eV and ten-state localised exchange calculations at both energies. The predicted behaviour of A 1s,1s ( theta ) is smooth with a maximum of about -0.25 near 20 degrees (54.4 eV). However, A 1s,2s ( theta ) is always positive and shows a strong narrow 'resonance' near 40 degrees .