Charge transfer and chemical reaction dynamics in hyperthermal O++NO collisions

The O+(S-4)+NO(X (2)Pi(r)) collision system has been investigated in a guid ed-ion beam experiment. Absolute cross sections for production of NO+ and O -2(+) have been measured at collision energies from near thermal to similar to 12 eV. Time-of-flight measurements of the NO+ product recoil velocities , at collision energies of 1.3, 3.3, 5.2, and 9.1 eV confirm two hypertherm al charge transfer channels with thresholds at 0.2 and 2.0 eV. A kinematic analysis indicates mechanisms that give rise to spin-forbidden NO+(X (1)Sig ma(+))+O(D-1) and endothermic NO+(a (3)Sigma(+))+O(P-3) products, respectiv ely. The O-2(+)+N channel is observed to have a threshold of 0.7 +/- 0.1 eV . Time-of-flight studies of the O-2(+) product at collision energies of 3.3 and 5.9 eV indicate a complex-mediated mechanism. [S0021-9606(00)01101-6].