Electron-polarised photon coincidence experiments on the 32P state in sodium

Abstract

Components of the Stokes vector have been measured using an electron-photon coincidence technique for radiation emitted normal to the scattering plane in the electron excitation of the 32P state in sodium at several energies from 5.1 to 30 eV. The coherence of the excitation process is probed through the concept of the reduced polarisation. The data are compared with those derived from optical pumping experiments, which are the time-reversed equivalent of the present experiments. In general, very good agreement is found with the data from the two techniques. Scattering amplitudes derived from the components of the Stokes vector are compared with theoretical predictions. It is observed that there is only moderate agreement between theory and experiment.