Kinetic study of the temperature effect on the quenching of the N _2(a'~1Π_g) and N_2(a′ ~1Σ_u~-) states in pure nitrogen and the quenching of the N_2(a~1Π_g) state by molecular oxygen in N_2-O_2 mixtures

摘要

We have investigated the effect of temperature on the collisional decay of the a~1Π_g and a′~1Σ _u~- states of nitrogen. A temporal study of the VUV emission of nitrogen has been performed from 1 mbar to atmospheric pressure after a selective excitation of the a~1Π_g state by two-photon absorption with a dye laser. In our gas temperature range, from 193 to 333 K, we observed two opposite behaviours for the decays of the a′~1Σ_u~- and a~1Π _g states, and we attributed these behaviours to the strong coupling between the a~1Π_g and w~1Δ_u states at high pressure. We then studied the effect of molecular oxygen on the decay of the N_2(a~1Π_g) state at 293 K and identified the product of the quenching reaction of this state by molecular oxygen.