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Reaction Dynamics In Double Ionization Of Helium By Electron Impact, Marcelo F. Ciappina, Michael Schulz, Tom Kirchner
Reaction Dynamics In Double Ionization Of Helium By Electron Impact, Marcelo F. Ciappina, Michael Schulz, Tom Kirchner
Physics Faculty Research & Creative Works
We present theoretical fully differential cross sections (FDCS) for double ionization of helium by 500 eV and 2 keV electron impact. Contributions from various reaction mechanisms to the FDCS were calculated separately and compared to experimental data. Our theoretical methods are based on the first Born approximation. Higher-order effects are incorporated using the Monte Carlo event generator technique. Earlier, we successfully applied this approach to double ionization by ion impact, and in the work reported here it is extended to electron impact. We demonstrate that at 500 eV impact energy, double ionization is dominated by higher-order mechanisms. Even at 2 …
Differential Cross Sections For Non-Sequential Double Ionization Of He By 52 Ev Photons From The Free Electron Laser In Hamburg, Flash, Moritz Kurka, Johannes Feist, Daniel A. Horner, Artem Rudenko, Yuhai Jiang, Kai Uwe Kuhnel, Lutz M. Foucar, Thomas N. Rescigno, Clyde William Mccurdy, Renate Pazourek, Stefan Nagele, Michael Schulz, Oliver Herrwerth, Matthias Lezius, Matthias F. Kling, Markus S. Schoffler, Ali Belkacem, Stefan Dusterer, Rolf Treusch, Barry I. Schneider, Lee A. Collins, Joachim Burgdorfer, Claus Dieter Schroter
Differential Cross Sections For Non-Sequential Double Ionization Of He By 52 Ev Photons From The Free Electron Laser In Hamburg, Flash, Moritz Kurka, Johannes Feist, Daniel A. Horner, Artem Rudenko, Yuhai Jiang, Kai Uwe Kuhnel, Lutz M. Foucar, Thomas N. Rescigno, Clyde William Mccurdy, Renate Pazourek, Stefan Nagele, Michael Schulz, Oliver Herrwerth, Matthias Lezius, Matthias F. Kling, Markus S. Schoffler, Ali Belkacem, Stefan Dusterer, Rolf Treusch, Barry I. Schneider, Lee A. Collins, Joachim Burgdorfer, Claus Dieter Schroter
Physics Faculty Research & Creative Works
Two-photon double ionization of He is studied at the Free Electron Laser in Hamburg (FLASH) by inspecting He2+ momentum (P-(He 2+)) distributions at 52 eV photon energy. We demonstrate that recoil ion momentum distributions can be used to infer information about highly correlated electron dynamics and find the first experimental evidence for 'virtual sequential ionization'. The experimental data are compared with the results of two calculations, both solving the time-dependent Schrodinger equation. We find good overall agreement between experiment and theory, with significant differences for cuts along the polarization direction that cannot be explained by the experimental resolution …
Electron-Impact-Ionization Cross Sections Of H₂ For Low Outgoing Electron Energies From 1 To 10 Ev, Ola A. Al-Hagan, Andrew James Murray, Christian V. Kaiser, James Colgan, Don H. Madison
Electron-Impact-Ionization Cross Sections Of H₂ For Low Outgoing Electron Energies From 1 To 10 Ev, Ola A. Al-Hagan, Andrew James Murray, Christian V. Kaiser, James Colgan, Don H. Madison
Physics Faculty Research & Creative Works
Theoretical and experimental fully differential cross sections are presented for electron-impact ionization of molecular hydrogen in a plane perpendicular to the incident beam direction. The experimental data exhibit a maximum for 1-eV electrons detected 180° apart and a minimum for 10-eV electrons. We investigate the different physical effects which cause back-to-back scattering and demonstrate that, over the energy range from 10 to 1 eV, a direct transition is observed from a region where Wannier threshold physics is essentially unimportant to where it completely dominates.