Partial-ionization cross sections of a CO2 molecule due to impact of 10-26-keV electrons

Abstract

Experimental data on total- and partial-ionization cross sections of ionic fragments of CO2 molecule produced by impact of 10-26-keV electrons are obtained on a crossed-beam apparatus in our laboratory. An ejected electron-produced ion-coincidence technique is employed together with a time-of-flight mass spectrometer for analysis of the ions. The six ionic fragments, CO2⊃+, CO⊃+, CO22⊃+, O⊃+, C⊃+, and C2⊃+, resulting from dissociative ionization of the CO 2 molecule are observed and identified; their relative ionization cross sections and branching ratios are determined as a function of impact energy. The binary-encounter Bethe model is found to overestimate the experimental data for total-ionization cross sections of the observed ions. No other experimental or theoretical data exist in the investigated energy range to make a direct comparison with the present results. © 2010 The American Physical Society.