MEASUREMENT OF QUENCHING CROSS-SECTIONS FOR LASER-INDUCED FLUORESCENCE OF ATOMIC ARSENIC

The measurement of collisional quenching cross sections for the (4p)(2 ) (5s)(1) P-4(1/2) state of atomic arsenic is reported. The arsenic P- 4(1/2) state was prepared by excitation from the (4p)(3) S-4(3/2) grou nd state with 197.2-nm laser radiation. The fluorescence signal from t he (4p)(2) (5s)(1) P-4(1/2) --> (4p)(3) D-2(1/2) transition was monito red at 249.3 nm. Quenching cross sections were obtained for hydrogen, methane, nitrogen, carbon nonoxide, and ethylene. (C) 1998 Optical Soc iety of America.