Electronic quenching of Bi2A(0u+) v′ = 18-23 by rare gases and nitrogen

The rates for electronic quenching of the A(0u+) state of Bi2 by rare gases and nitrogen near the onset of predissociation, v′ = 18-23, have been measured using pulsed laser induced fluorescence. The rate coefficient for helium is 2.2 ± 0.1 × 10−11 cm3/molecule s for v′ = 18-22, and increases to 1.0 ± 0.1 × 10−10 cm3/molecule s for v′ = 23. The probability of quenching per collision for v′ = 22 by rare gases ranges from 0.03 to 0.44 and for v′ = 23 from 0.15 to 0.80. The quenching probabilities for nitrogen are slightly larger than those for argon. Despite the onset of rotationally dependent predissociation at v′ = 21, no significant dependence of quenching rates on rotational state J′ < 117 was observed.