Single electron capture cross sections of the 2P3/2 and 2P1/2 state argon and krypton ions

The ionization probability curves of argon and krypton atoms within 1 eV of threshold have been studied for electron impact with an average electron energy distribution of 0.035 eV (FWHM). In krypton, changes in the slope of the ionization probability curves occur at electron energies close to the spectroscopically observed autoionization levels between the 2P3/2 and 2P1/2 levels. Ions which have been formed in such a manner are then used as primary ions in charge-transfer reactions. Total single electron capture cross sections have been measured for 2P3/2 and 2P1/2 state argon and krypton ions incident upon argon and krypton atoms, respectively. Upon the presumption of the applicability of the adiabatic hypothesis, it appears, for single electron capture reactions of krypton ions upon krypton atoms over the relative energy range 500–1500 eV, that (a) the reaction 2P3/2 → 2P3/2 is dominant over the reaction 2P3/2 → 2P1/2, (b) the cross section for the 2P3/2 → 2P3/2 reaction is greater than the 2P1/2 → 2P1/2 reaction cross section, and (c) little information can be deduced for the relative values of the forward and reverse [Formula: see text] reaction cross sections.