Inelastic scattering of electrons from sodium

Differential cross sections for the excitation of the 3 2 P state in sodium have been measured over the angular range 2<or= theta <or=130 degrees at incident electron energies of 22.1 and 54.4 eV. The present measurements resolve the conflict between the previous data of Buckman et al. (1979) and of Srivastava et al. (1980). The present differential cross sections demonstrate the inadequacy of current theories in the prediction of large-angle scattering cross sections and indicate the need for the development of more sophisticated theories. The authors have also measured the alignment parameter lambda in the angular range 3<or= theta <or=15 degrees at incident energies of 22.1, 30 and 54.5 eV. These data are compared with the forward-angle predictions of several theories and the limitations of this parameter as a test of the theory of the excitation of the 3 2 P state in sodium is discussed.