Collision-induced transitions between electronic states B→A and C→B of laser-excited Li2 molecules

Nonradiative transitions between the Li2 (C 1Pi/sub u/, B 1Pi/sub u/, A 1Σ+/sub u/) states have been studied using monochromatic laser excitation. In a cell experiment under single-collision conditions, the B--A transfer was induced by rare gas atom collisions. With argon, the cross section is 240 A2. B→A and C→B transfer by Li atom collisions was observed with cross sections of 1200 and 330 A2, while C→B transfer is not measurably induced by argon collisions. The final state rotational-vibrational level population distribution is very broad and non-Boltzmann