Kao, H. C., Kuo T. Y., Yen H. P., Wei C. M., & Huang K. N.
(1992).
RELATIVISTIC CROSS-SECTIONS OF ELECTRON-IMPACT IONIZATION OF HYDROGENIC IONS.
Physical Review A. 45, 4646-4652., Apr, Number 7
AbstractTotal and single-differential cross sections for electron-impact ionization are calculated in a relativistic formulation for ions in the hydrogen isoelectronic sequence: HI, He II, C VI, Ne X, Fe XXVI, and Ag XLVII. Transition amplitudes are evaluated in the two-potential distorted-wave approximation. Sets of different asymptotic charges are used to study the mutual screening of the primary and secondary electrons. Relativistic effects are investigated by taking the nonrelativistic limit and are found to increase the cross sections. Thomson’s scaling law along the isoelectronic sequence is also studied.
Kim, B., Chen J., Erskine J. L., Mei W. N., & Wei C. M.
(1993).
SURFACE AND BULK PHOTOELECTRON DIFFRACTION FROM W(110) 4F CORE LEVELS.
Physical Review B. 48, 4735-4740., Aug, Number 7
AbstractEnergy- and angle-dependent photoelectron cross sections from surface and bulk W(110) 4f7/2 core levels are measured and compared with dynamical multiple scattering calculations. The agreement between experimental and theoretical results is found to be significantly better than corresponding previous studies, permitting a determination of the first layer atomic plane distance: d12 = 2.26 +/- 0.05 angstrom. Forward-scattering enhancements along bond directions are observed under selected scattering conditions. In all cases, final-state multiple scattering accounts for the principal energy and angle dependencies in the cross section. Typical variation of bulk and surface 4f photoelectron intensities with kinetic energy or emission angle resulting from final-state effects is observed to be a factor of 2. This result suggests that previous core-level spectra for stepped W(110) surfaces have been incorrectly interpreted.
] 
