Active species in N2 flowing post-discharges

The afterglow in D.C. and H.F. N2 flowing discharges has been analysed by emission spectroscopy. Production of excited species has been studied in conditions of late Δt =(1 - 5) ×10-1 s and early Δt =(0.5 - 5) ×10-2 s afterglows. The late afterglow is characterized by the N2 1st positive emission with a strong enhancement of the N2(B, $v'~=~11$) level compared to the other N2(B, v') levels which is a signature of N atom density. By NO titration, we have determined that N/N2 dissociation degrees are respectively 4.1% and 2.7% in a 60 W H.F. and in a 50 mA D.C. post-discharge at 4.5 Torr. The early afterglow is characterized by a strong 1st positive emission which has been analysed from the N2(A) + N2(X, v>5) excitation transfer reaction. By introducing a little CH2(10-4-10-3) or H2(10-2-10-1) into the N2 D.C. and H.F. postdischarges, N2(A) quenching rates have been obtained indicating that the N2(A) is only excited on the two first vibrational states in the early afterglows.