Impact excitation of 4 2P-potassium by polarized electrons

The present work investigates the 4 2P impact excitation of potassium by longitudinally polarized electrons. Exchange scattering causes a polarization transfer from the primary electron beam to the ensemble of excited atoms which results in a non zero circular polarization of the fluorescence light emitted in foreward direction. The experimental values of light polarization agree well with values calculated using close coupling data of Moores. (orig.)