摘要

The rotational T_r and vibrational T_v temperatures in the relaxation zone of high enthalpy atmospheric pressure nitrogen plasma jets are derived using the line-by-line numerical simulation of the (0-0), (0-1) and (1-2) bands of the N₂⁺ First Negative System and the integrated intensities of the N₂ Second Positive System bands belonging to the sequence Δv=−1. Also involved are several CN “violet” bands of the principal sequence (Δv=0). Plasma jets are generated by a high-current electric arc plasmatron with a divergent channel-anode and vortex stabilization by a plasma-forming gas. A simplified model describing the kinetics of atomic nitrogen has been developed. This model combined with the previously obtained data on the electron component in the relaxation zone is applied to describe varying the magnitudes of T_r and T_v with distance from the plasmatron cathode. It is shown that the three-body recombination of atomic nitrogen and electron-ion dissociative recombination are capable of considerably slowing down a drop in rotational and vibrational temperatures in the far relaxation zone.