Spin-dependent electron-impact excitation of sodium

The spin-dependent cross sections for electron excitation of the 3p level of sodium at energies just above threshold are studied using the R-matrix approach. In addition to the total cross section for excitation, we present results for the excitation cross sections as a function of the change in the spin and orbital angular-momentum projection of the target. Calculations were made in the four- (3s,3p,4s,3d), five- (+4p), and six-state (+4p,4d) approximations, for electron energies ranging from threshold to 4.0 eV. The results are compared with other calculations and with the recent experimental results of Han, Schinn, and Gallagher [Phys. Rev. A 38, 535 (1988)].