Experimental and theoretical study of electron-impact ionization of atomic ions in the Sm isonuclear sequence

K. Aichele, W. Arnold, D. Hathiramani, F. Scheuermann, E. Salzborn, D. M. Mitnik, D. C. Griffin, J. Colgan, M. S. Pindzola
2001 Physical Review A. Atomic, Molecular, and Optical Physics  
Experimental measurements and theoretical calculations of absolute cross sections are carried out for the electron-impact ionization of atomic ions in the Sm rare-earth-metal isonuclear sequence. Absolute cross sections for Sm qϩ ions for qϭ1Ϫ12 were measured using the electron-ion crossed-beam technique and calculated with the configuration-average distorted-wave method for the charge states qϭ4Ϫ12. The theory includes both direct ionization and excitation-autoionization contributions, and
more » ... udes transitions from both ground and metastable levels. We present the cross sections in an electron-impact energy range from threshold up to 1000 eV for all Sm ions up to Sm 12ϩ . These systems are extremally complex, but the configurationaverage method, when combined with statistical averaging of the cross sections over the many levels, provides results that are in overall good agreement with the experimental measurements. The single-ionization cross sections are dominated by contributions from indirect mechanisms of excitation-autoionization in the lowenergy region.
doi:10.1103/physreva.64.052706 fatcat:j2nq4hxf6reixmlljdzgaimoce