Quenching of the B /super 2/Sigma-plus state of the CN radical.

The quenching of the B (super 2)Sigma-plus fluorescence from the CN radical has been studied as a function of the relative velocity of the quenching collision and the total pressure in the fluorescence cell. The rate constant for the quenching of the CN fragment by ICN vapor was found to be directly proportional to the relative velocity of the quenching collision. Electronic quenching was also observed for methane, diatomic hydrogen, Kr, and Ar.