TIME-RESOLVED LASER-INDUCED FLUORESCENCE OF ATOMIC NITROGEN IN A FREE-BURNING ARC-DISCHARGE

An experiment to detect ground-state atomic nitrogen in an atmospheric -pressure argon-nitrogen free-burning 200 A are by time-resolved two-p hoton laser-induced fluorescence is described, The time decay of the f luorescence pulses showed that quenching of the laser-excited state is rapid, Upper bound estimates of the pulse-decay time were determined as a function of radius, and were found to be on the order of 1 ns, an d to decrease with increasing radii, The implications of rapid quenchi ng of the laser-excited state to the application of laser-induced fluo rescence as a plasma diagnostic tool are discussed.