ABSOLUTE CROSS-SECTIONS FOR ANION PRODUCTION BY LOW-ENERGY-ELECTRON IMPACT ON PHYSISORBED CO2

Total charge trapping cross sections are reported for CO2 physisorbed onto multilayer Kr substrates. For incident electron energies between 1 and 14 eV, charge trapping proceeds via a dissociative electron atta chment (DEA) mechanism, related to that observed in the gas phase. How ever, near 9.7 eV, coupling between CO2(-) and Kr*(-) states results in a significant increase in DEA, and hence charge trapping. Between 1 and 6 eV, we measure absolute total cross sections for anion producti on with peak values approximately 43 times larger than those for gas p hase CO2; this is attributed to effects of the solid's polarization en ergy.