ELECTRON-IMPACT IONIZATION OF MULTIPLY CHARGED MANGANESE IONS R. Rejoub,* R. E. H. Clark # and R. A. Phaneuf* *Department of Physics, University of Nevada, Reno, Nevada, USA. #Applied Theoretical and Computational Physics Division, Los Alamos National Laboratory, USA. Absolute cross sections have been measured for electron-impact single and double ionization of multiply charged manganese ions in initial charge states 5+ through 8+. Analysis of the data and comparison to theoretical calculations for 5+ suggest that excitation-autoionization substantially enhances the single ionization cross sections at energies just above the ionization threshold. L-shell ionization-autoionization dominates the double-ionization cross sections.