ABSOLUTE CROSS-SECTIONS FOR THE ELECTRON-IMPACT DISSOCIATION OF CF4 AND CHF3 INTO THE CFX (X=1-3) NEUTRAL RADICALS

The electron-impact energy dependence of the dissociation cross sectio ns of CF4 and CHF3 into the CFx (x = 1-3) free radicals was previously reported, in which the absolute values of the cross sections were ten tatively estimated based on certain assumptions for the unknown ioniza tion cross sections of the CF2 and CF radicals. These assumptions are no longer needed, since a complete set of absolute parent and dissocia tive ionization cross sections of CFx radicals has been reported recen tly by BECKER and co-workers. Based on these data, the absolute cross sections for the electron-impact neutral dissociation of CF4 and CHF3 into CF3, CF2 and CF from the threshold up to 200 - 300 eV have now be en accurately calibrated. Adjustments to the previously reported absol ute cross sections of up to a factor of 16 were necessary.