State-to-state study of the electron transfer reactions N+2(X,v' = 0--2)+Ar(1S0)→N2(X,v) +Ar+(2P/sub 3/2,1/2/)

Relative vibrational-state-selected total cross sections σ/sub v//sub '/, v' = 0--2, for the reaction N+2(X,v' = 0--2)+Ar(1S0)→N2(X,v +Ar+(2P/sub 3/2,1/2/) [reaction (1)], over the center-of-mass collisional energy (E/sub c.m./) range of 1.2--320 eV have been determined using the crossed ion--neutral beam photoionization apparatus. The experimental results at E/sub c.m./ = 1.2--40 eV are in agreement with those obtained in previous experimental and theoretical studies, indicating that σ0 is substantially less than σ1 and σ2. As E/sub c.m./ is increased, σ0 becomes comparable to σ1 and σ2 in the E/sub c.m./ range of --140--200 eV. At E/sub c.m./ = 260 and 320 eV, the cross sections are in the order σ0>σ1>σ2. The fractions of Ar+(2P1/sub //2) resulting from reaction (1), X/sub v//sub '//sub →//sub 1/2/, v' = 0--2, at E/sub c.m./ = 4--320 eV have been measured by the charge exchange method. The measurement shows that the Ar+ product ions are predominantly(approx. >80%) formed in the 2P3/sub //2 state, an observation qualitatively in accord with the predictions of semiclassical multistate calculations. The predicted values for X/sub v//sub '//sub →//sub 1/2/, v' = 0--2, at E/sub c.m./ = 8, 20, and 40 eV are higher than the experimental values