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Differential cross sections for the ionization of oriented H2 molecules by electron impact
J Colgan1, M S Pindzola, F Robicheaux
1Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Physical Review Letters
|December 31, 2008
Summary
This study calculates electron-impact ionization of hydrogen molecules (H2) using a nonperturbative close-coupling method. Results reveal new cross-section features dependent on molecular orientation, agreeing well with experiments when averaged.
Area of Science:
- Atomic and Molecular Physics
- Quantum Chemistry
- Electron Scattering
Background:
- Electron-impact ionization is fundamental to understanding molecular behavior.
- Previous studies often averaged molecular orientations, potentially obscuring detailed dynamics.
- Accurate theoretical models are crucial for interpreting experimental data.
Purpose of the Study:
- To investigate the electron-impact ionization of hydrogen molecules (H2) at 35.4 eV.
- To analyze differential cross sections considering specific molecular orientations.
- To compare orientation-dependent results with averaged calculations and experimental data.
Main Methods:
- Employed a nonperturbative close-coupling technique.
- Calculated differential cross sections for electron-impact ionization of H2.
- Analyzed cross sections for various molecular orientations relative to the incident electron beam.
Main Results:
- Observed novel features in cross sections when molecular orientation was considered.
- Found discrepancies between orientation-dependent and orientation-averaged cross sections.
- Demonstrated good agreement with experimental results upon averaging over all molecular orientations.
Conclusions:
- Molecular orientation significantly influences electron-impact ionization cross sections of H2.
- The nonperturbative close-coupling method provides detailed insights into ionization dynamics.
- Averaging over orientations reconciles theoretical predictions with experimental observations for H2 ionization.
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