Orientation of He(21P) by Electron Impact Excitation and Polarization of the Radiative Decay

Abstract

A general description of electron-photon angular correlations is given which relates the quantummechanical observables to the structure of the coherently excited state. The wavefunction is expressed in terms of magnetic sublevel amplitudes and state vectors. A semiclassical impact parameter model of orientation is introduced, the experimental considerations are discussed, and experimental results for the orientation and polarization fraction are reviewed.