DYNAMICS OF ELECTRONICALLY INELASTIC-COLLISIONS FROM 3D DOPPLER MEASUREMENTS

Flux-velocity contour maps were obtained for the inelastic collision process Ba(1P1) + O2, N2 --> Ba(3P2) + O2, N2 from Doppler scans of scattered Ba(3P2) taken over a range of probe-laser directions in a crossed-beam experiment. The distributions suggest the importance of large-impact-parameter collisions and near-resonant energy transfer in the case Of O2, while for N2 close collisions dominate despite the presence of an analogous near-resonant channel. The results represent the first direct experimental demonstration of a near-resonant quenching process.