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Projectile Angular-Differential Cross Sections For Transfer And Transfer Excitation In Proton Collisions With Helium, M. Zapukhlyak, T. Kirchner, Ahmad Hasan, B. Tooke, Michael Schulz
Projectile Angular-Differential Cross Sections For Transfer And Transfer Excitation In Proton Collisions With Helium, M. Zapukhlyak, T. Kirchner, Ahmad Hasan, B. Tooke, Michael Schulz
Physics Faculty Research & Creative Works
Projectile angular-differential cross sections for single-transfer and transfer excitation have been calculated with the two-center extension of the nonperturbative basis generator method for 5-200 keV proton-helium collisions. The calculations are based on the independent electron model, and the eikonal approximation has been used to extract angular-differential cross sections from impact-parameter-dependent transition amplitudes. The present results are compared with experimental and previous theoretical data where available. In particular, we consider the ratio of transfer excitation to single capture versus double excitation to single excitation at intermediate energies. An experimentally observed structure in this ratio at a scattering angle about 0.5 mrad …
Triple-Differential Cross Sections For Target Ionization With Simultaneous Projectile Detachment In 200-Kev H⁻ + He Collisions, T. Ferger, Michael Schulz, Daniel Fischer, B. Najjari, R. Moshammer, J. D. Ullrich
Triple-Differential Cross Sections For Target Ionization With Simultaneous Projectile Detachment In 200-Kev H⁻ + He Collisions, T. Ferger, Michael Schulz, Daniel Fischer, B. Najjari, R. Moshammer, J. D. Ullrich
Physics Faculty Research & Creative Works
We have performed a kinematically complete experiment for target ionization with simultaneous projectile detachment (TIPD) in 200-keV H− + He collisions. From the data we extracted triple-differential cross sections (TDCSs) for each electron separately. These TDCSs closely resemble corresponding data for single ionization by charged-particle impact. Surprisingly, the contributions from higher-order processes to TIPD, proceeding through two independent interactions of each electron with the core of the respective other collision partner, are found to be somewhat larger than the first-order process proceeding through the electron-electron interaction.
Multiple Scattering Mechanisms In Simultaneous Projectile-Electron And Target-Electron Ejection In H⁻ + He Collisions, Michael Schulz, T. Ferger, Daniel Fischer, R. Moshammer, J. D. Ullrich
Multiple Scattering Mechanisms In Simultaneous Projectile-Electron And Target-Electron Ejection In H⁻ + He Collisions, Michael Schulz, T. Ferger, Daniel Fischer, R. Moshammer, J. D. Ullrich
Physics Faculty Research & Creative Works
We studied simultaneous electron ejection from both collision partners in 200-keV H-+He collisions in a kinematically complete experiment by measuring the fully momentum-analyzed recoil ions and both active electrons in coincidence. The data were analyzed in terms of Dalitz spectra, in which the momentum exchange between three particles is plotted simultaneously in a single spectrum. We found that the energy transfer occurs predominantly between the active electrons, but most of the momentum is exchanged in elastic scattering between the cores of the collision partners.