Associative ionization reactions involving excited atoms in nitrogen plasma

A model of kinetic processes in gas-discharge plasmas of pure nitrogen and its mixtures with nitrogen oxide and oxygen is presented. A distinctive feature of the model is that it includes associative ionization reactions involving N(² P) electronically excited atoms. Taking into account these processes allows one to explain both the anomalously slow decay of gas-discharge nitrogen plasma and the increase in the electron density in the region of the so-called pink afterglow in nitrogen. The possibility of substantially accelerating secondary ionization by adding NO molecules to a partially dissociated nitrogen is demonstrated. It is shown that such acceleration is caused by the associative ionization reaction N(² P) + O(³ P) → e + NO⁺. The calculated results agree well with available experimental data.