We discuss the ionization of aligned hydrogen molecules into their ionic ground state by 200 eV electrons. Using a reaction microscope, the complete electron scattering kinematics is imaged over a large solid angle. Simultaneously, the molecular alignment is derived from postcollision dissociation of the residual ion. It is found that the ionization cross section is maximized for small angles between the internuclear axis and the momentum transfer. Fivefold differential cross sections (5DCSs) reveal subtle differences in the scattering process for the distinct alignments. We compare our observations with theoretical 5DCSs obtained with an adapted molecular three-body distorted wave model that reproduces most of the results, although discrepancies remain.
A. Senftleben et al., "Fivefold Differential Cross Sections for Ground-state Ionization of Aligned H2 by Electron Impact," Journal of Chemical Physics, vol. 133, no. 4, pp. 044302-1-044302-7, American Institute of Physics (AIP), Jul 2010.
The definitive version is available at http://dx.doi.org/10.1063/1.3457155
Keywords and Phrases
Differential cross section; Distorted-wave models; Electron impact; Hydrogen molecule; Internuclear axis; Ionic ground state; Ionization cross section; Molecular alignment; Post-collision; Reaction microscopes; Residual ion; Scattering process; Solid angle; Alignment; Electron energy loss spectroscopy; Ground state; Ionization; Particle detectors
International Standard Serial Number (ISSN)
Article - Journal
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