N-Atom measurements in high temperature C2N2/NO/Ar reaction systems

N-atom concentration profiles were measured in highly diluted C2N2/NO/Ar reaction systems behind reflected shock waves at temperatures between 3050 K and 4430 K by applying atomic resonance absorption spectroscopy (ARAS). C2N2 served as a thermal source for CN radical which react with both, NO and the subsequently formed N atoms. Computer simulations based on a simplified reaction mechanism revealed strong sensitivity of the measured N atoms to the elementary reactions: A fitting procedure of all experiments allowed determination of individual values of the rate coefficients: The present results enlarge the temperature range of the recommended Arrhenius expression of k5 |1| and confirm recent measurements of the backward reaction of (R-9) |2,3|.