Free-piston shock-tube study of nitrogen dissociation

Abstract

Time-resolved optical interferometry of the relaxation region after the primary shock wave in a free-piston shock tube is used to measure the dissociation rate of nitrogen by N 2 and N without inert gas dilution. The results cover a temperature range of 6000 − 14000°K and give for N 2 + N 2 → N + N + N 2, k d1 = 2.3 x 10 29 ± 0.2 T −3.5 exp(−113200/ T), for N 2 + N → N + N + N , k d2 = 8.5 x 10 25 ± 0.2 T −2.5 exp (−113200/ T) (cm 3 mole −1 sec −1) thus confirming the strong temperature dependence of the pre-exponential factor reported by Hanson and Baganoff.