Collisional quenching of Hg2 (AO+g)

The rate constants for quenching of the metastable A state of Hg2 in two and three body collisions with background Hg atoms have been measured by a pump−probe, laser-induced fluorescence technique. The Hg2 (A ) species was produced by photoassociating thermal Hg−Hg pairs at 266 nm which populates the D1u level of Hg2. Subsequent collisions relax the dimer into the A state. The temporal history of the A state number density was monitored by driving the G ← A transition in the yellow (λ ∼ 564 nm) and observing G → X emission in the ultraviolet (λ ∼ 210−240 nm). The two and three body rate constants for quenching of Hg2 (A ) by Hg were measured to be (4.5 ± 3.0) × 10-15 cm3·s-1 and (1.8 ± 0.4) × 10-33 cm6·s-1, respectively.