Effect of the Mo/ller interaction on electron-impact ionization of high-Zhydrogenlike ions

Abstract

We have investigated the effects of the Mdller interaction in relativistic distorted-wave calculations of cross sections for electron-impact ionization of high-Z hydrogenlike ions. We found that the M611er interaction significantly increases the cross section for hydrogenlike uranium, and brings our calculated results into very good agreement with experimental results reported by Marrs, Elliott, and Knapp [Phys. Rev. Lett. 72, 4082 (1994)].We found similar increases in the cross sections for other hydrogenlike ions. Our results also show that these effects become important at much lower collision energy than previously reported [D. L. Moores and M. S. Pindzola, Phys. Rev. A 41, 3603 (1990)].With the Mtiller interaction included, our cross sections for these ions are in good agreement with preliminary results obtained in recent experiments on the electron-beam ion trap (EBIT).

Calculations of electron-impact single-ionization cross sections of helium isoelectronic systems

“…In particular, at 198 keV ͑t = 1.744͒, the experimental cross section of the former is 9.7 b, which compares very high relative to the value 2.82± 0.35 b of Ref. [51] and 2.88 b, the result estimated by Moore and Reed [52] from the cross section for U 91+ . The experimental value of Ref.…”

Electron‐impact single ionization cross sections of helium isoelectronic systems

“…In particular, at 198 keV ( t = 1.744), the experimental cross section of the former is 9.7 barns, which compares very high relative to the value 2.82 ± 0.35 barns of Ref. 48 and 2.88 barns, the result estimated by Moore and Reed 53 from the cross section for U 91+ . The experimental value of Ref.…”

Calculation of the relativistic rise in electron-impact-excitation cross sections for highly charged ions

“…For example, this was necessary in the polarization of x rays emitted during electron-impact excitation of highly charged ions [1,2], dielectronic and radiative recombination effects [3][4][5], electron-impact-ionization experiments [6][7][8], and electron-and proton-impact excitation experiments [9]. For electron-impact excitation of highly charged hydrogenlike ions, Walker [10], Fontes et al [11], and Moores and Pindzola [12] have demonstrated that the Møller interaction or GBI can increase electron-impact-excitation cross sections by up to 50% in comparison to calculations that employ only the Coulomb interaction.…”