Ejected electron spectra from the vicinity of the (2p2)1D and (2s2p)1P autoionising states of helium

The electron impact excitation of the (2p2)1D and (2s2p)1 P autoionizing states of helium and their subsequent radiationless decay are studied by observation of ejected electrons. The study is carried out in the incident electron energy range 70-200 eV and for ejected electron scattering angles of 40-130o. The ejected electron spectra are analysed using the Shore-Balashov parametrization. The resulting parameters are compared with other experiments and theory where possible. (author)