Abstract
Electron impact excitation of the 31P state in magnesium has been studied by electron-photon coincidence techniques. Two types of experiments have been performed. An extensive set of measurements have been undertaken in which the three components of the Stokes vector were measured at incident energies of 20 and 40 eV for electron scattering angles between 5 and 20'. These measurements not only provide data on the coherence of the excitation process but also they form a basis by which approximations in scattering theory can be tested. In addition, an angular correlation function has been measured at 40 eV and at a scattering angle of 7'. The scattering parameters derived from this measurement agree with those measured in the polarisation study. The scattering parameters derived from the present work are in very good agreement with the recent close-coupling calculation of Mitroy and McCarthy (1989).