Electron collisions with positive ions. Progress report, April 1, 1983-March 31, 1984

Inelastic electron impact collision strengths were calculated for Mg+ from the 3s ground state to excited states, 3p, 4s, 3d and 4p in a five-state close coupling approximation for the electron impact energy range 15 < E < 1000 eV, and for excitation of Al++ from the 3s to 3p state in a two-state close coupling approximation for the electron impact energy range 15 < E < 400 eV. Accurate target functions were used in the expansion. In addition, cascade contributions added 20 to 40% to the total excitation cross section for the 3p level of Mg+, and less than 5% for Al++. While our manuscript has been completed, submission will be delayed until a companion paper on the experiments is prepared. Differential cross sections for excitation of Zn+ from the 4s ground state to the 4p excited state were calculated at energies between 15 and 100 eV in a five-state close coupling approximation in which the 4s, 4p, 3d94s2, 5s and 4d states were included. We used the reactance matrices obtained by Msezane and Henry in a program developed by Brandt, Truhlar, and Smith to calculate angular differential cross sections. Agreement in shape between theory and experiment at 75 eV is excellent. Experiments were carried out in a crossed electron-ion-beam geometry for the 4s → 4p transition in Zn+ at 75 eV, and they are the first measurements for differential electron-scattering cross sections for inelastic excitation of an ion