Physical Parameters and Chemical Composition of a Nitrogen DC Discharge with Water Cathode

Abstract

This paper reports the results of the experimental study and chemical composition modeling for a DC nitrogen discharge burning above water cathode in the pressure range of 0.1-1 bar and at discharge current of 40 mA. The gas temperature, vibrational temperatures, reduced electric field strength, cathode voltage drop, and emission intensities of some nitrogen bands were obtained from experiment. The modeling chemical composition of plasma was carried out on the basis of these data. At modeling, the combined solution of Boltzmann equation for electrons, equations of vibrational kinetics for ground states of N2 ,O 2 ,H 2 Oa nd NO molecules, equations of chemical kinetics and plasma conductivity equation were used. The calculations agree with the measured bands intensities for the second positive system of N2 and vibrational temperatures of N2ðC 3 PuÞ. In the frame of the model proposed, the data of other studies were explained. The second kind collision of electrons with N2 vibration excited states was shown to affect strongly the electron gas parameters. The electron av- erage energy and electron density are given. The difference between the properties of the discharges in N2 and air at the same conditions are discussed as well.