MEASURED AND CALCULATED ABSOLUTE TOTAL CROSS-SECTIONS FOR THE SINGLE IONIZATION OF CFX AND NFX BY ELECTRON-IMPACT

Various additivity rules and the Deutsch-Mark (DM) formalism have been used to calculate total absolute electron-impact cross-sections for single ionization of the CFx (x = 1-3) free radicals, the NFx (x = 1, 2) free radicals and the NF3 molecule. A comparison is made with experimentally determined total single ionization cross-sections which have been obtained from recently measured absolute partial ionization cross-sections for the parent and dissociative ionization of these species. The overall best agreement between the measured and the calculated cross-sections in terms of the absolute values, the shapes and the cross-section ordering was obtained using a recently proposed ''new'' additivity rule. Common trends and tendencies in the ionization cross-sections within each class of targets, CFx and NFx, and between the two target families CFx and NFx are highlighted and a comparison will be made with the previously measured and calculated ionization cross-sections for the SiFx (x = 1-3) free radicals.