ELECTRON-POLARIZED-PHOTON COINCIDENCE PARAMETERS FOR THE SODIUM D-LINES

A delayed-coincidence technique has been used to measure the linear and circular polarisation fractions of the photons arising from the electron impact excitation of the 32P states of sodium at an incident electron energy of 100 eV. These measurements yield lambda , the ratio of The differential cross sections for the excitation of the magnetic sublevels, as well as information on the orientation of the excited atom. The influence of hyperfine structure in the excited state on the polarisation vector has been included in the analysis. The measured parameters are found to disagree with those predicted by a distorted-wave polarised-orbital calculation and with the first Born approximation.