Polarization transfer in then 2 P-excitation of alkali atoms by longitudinally polarized electrons

In (ns — np)-excitation of alkali atoms by polarized electrons some of the spin orientation of the primary electron beam is transfered to the excited atoms because of exchange collisions. In the present work the polarization transfer to Na, K, Rb, and Cs respectively is studied by looking for the circular light polarization of (np — ns)-decay radiation emitted in forward direction following impact excitation by a beam of longitudinally polarized electrons. Maximum polarization transfers are observed at collision energies with values about 1.5 times that ofnp-thresholds. The transfer increases with increasing atomic number. In case of (6s — 6p)-excitation of cesium 45% of primary electron sp…