Tripledifferential cross sections for single ionization of CO_{2} by 100 eV electron impact
Abstract
We present a combined experimental and theoretical study for electronimpact ionization of carbon dioxide (CO_{2}) for the projectile energy E _{0} = 100 eV. Experimental tripledifferential cross sections (TDCS) are obtained using a multiparticle momentum spectrometer (reaction microscope). For projectile scattering angles between 5° and 20° a large part of the full solid angle is covered for the slow ejected electron with energies between 5 and 15 eV. The experimental data are measured for the ionization of the three outer valence molecular orbitals 1π _{ g }, 1π _{ u }, and 3σ _{u} which lead to a nondissociating {{{{CO}}}_{2}}^{+} ion. The measured TDCS summed over all three orbitals are internormalized across the scattering angles and ejected electron energies. They are compared to the theoretical results from the multicenter distorted wave (MCDW) approximation, and from the MCDWWM approximation which includes postcollision interaction using the WardMacek factor (WM). Reasonable good agreement is found between the experiment and the MCDWWM calculations for the angular dependence and the relative magnitude of the cross sections in the coplanar plane, while for the perpendicular and full perpendicular planes larger discrepancies exist. Since postcollision interaction is not considered the MCDW method shows strong discrepancies with experiment for small mutual angles of the two outgoing electrons in the final state.
 Publication:

Journal of Physics B Atomic Molecular Physics
 Pub Date:
 November 2018
 DOI:
 10.1088/13616455/aae0ab
 Bibcode:
 2018JPhB...51u5201H