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Full-Text Articles in Physical Sciences and Mathematics

Three-Body Coulomb Problem Probed By Mapping The Bethe Surface In Ionizing Ion-Atom Collisions, Robert Moshammer, Appathurai N. Perumal, Michael Schulz, V. D. Rodriguez, Holger Kollmus, Rido Mann, Siegbert Hagmann, Joachim Hermann Ullrich Nov 2001

Three-Body Coulomb Problem Probed By Mapping The Bethe Surface In Ionizing Ion-Atom Collisions, Robert Moshammer, Appathurai N. Perumal, Michael Schulz, V. D. Rodriguez, Holger Kollmus, Rido Mann, Siegbert Hagmann, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

The three-body Coulomb problem has been explored in kinematically complete experiments on single ionization of helium by 100 MeV / u C 6 + and 3.6 MeV / u u 5 3 + impact. Low-energy electron emission (E e < 150 eV ) as a function of the projectile deflection ϑ p (momentum transfer), i.e., the Bethe surface [[15]], has been mapped with Δ ϑ p ± 25 nanoradian resolution at extremely large perturbations (3.6 MeV / uAu53+ ) where single ionization occurs at impact parameters of typically 10 times the He K -shell radius. The experimental data are not in agreement with state-of-the-art continuum distorted wave-eikonal initial state theory.


Fully Differential Cusp Electron Production Cross Sections For 75-Kev H₂⁺ + He Collisions, L. An, Kh Khayvat, Michael Schulz Feb 2001

Fully Differential Cusp Electron Production Cross Sections For 75-Kev H₂⁺ + He Collisions, L. An, Kh Khayvat, Michael Schulz

Physics Faculty Research & Creative Works

A kinematically complete experiment on single ionization for 75-keV H2+ + H e collisions was performed by measuring the fully momentum analyzed projectiles and recoil ions in coincidence. The electron momentum was deduced from momentum conservation. Clear signatures of the postcollision interaction between the outgoing projectiles and the electrons were observed in the momentum spectra of all collision products simultaneously.


Excitation Plus Ionization In Electron-Atom Collisions To He^{+} (N=2): (E,2e), (E, E\Gamma ) And (E, 2e\Gamma ) Studies, Mevlut Dogan, Albert Crowe Jan 2001

Excitation Plus Ionization In Electron-Atom Collisions To He^{+} (N=2): (E,2e), (E, E\Gamma ) And (E, 2e\Gamma ) Studies, Mevlut Dogan, Albert Crowe

Turkish Journal of Physics

Simultaneous excitation-ionization of helium atoms by electron impact is observed by the coincidence detection of the outgoing particles. The relationship between (e,2e), (e,e\gamma ) and (e,2e\gamma ) experiments is discussed.


Autoionization Resonances In The Simultaneous Excitation-Ionization Of Helium, Mevlut Dogan, Albert Crowe Jan 2001

Autoionization Resonances In The Simultaneous Excitation-Ionization Of Helium, Mevlut Dogan, Albert Crowe

Turkish Journal of Physics

The effect of autoionizing states on excitation-ionization processes has been investigated experimentally by observation of the electron impact ionization process leading to He^{ + }(2p) with the excitation energy region in helium corresponding to doubly excitated states above the second ionization threshold. Also, the process arising from the decay of the doubly excited `parity unfavoured' (2p^{2})^{3}P state of helium, is studied.