KINETICS OF THE (A(3)SIGMA(U)+, V=0) STATE OF N-2 IN THE NEAR AFTERGLOW OF A NITROGEN PULSED DISCHARGE

The absolute densities of the nitrogen metastable molecules N2(A3SIGMA(u)+, v = 0) were measured as a function of time using a high resolution laser absorption within the first positive system (B3PI(g)(v' = 2) <-- A3SIGMA(u)+(v'' = 0)) in a stationary afterglow of the pure nitrogen pulsed electric discharge. The experiments were performed at various pressures (0.25-1.25 Torr), discharge currents (0.4-1.3 A) and pulse lengths (5-30 mus). The lifetimes and populations are in the range 100-470 mus and (0.3-2.7) x 10(12) cm-3 respectively. The postulated kinetic model describes the measured lifetimes within an experimental error. The model takes into consideration the loss of N2(A) metastables due to energy pooling, quenching by nitrogen atoms and diffusion to the walls. Calculations of dissociation rates and nitrogen atom densities are based on the vibrational excitation of the ground electronic state N2(X).