Electrostatic Energy Dependence of Intensity Ratio between Nitrogen Spectral Lines of Monovalent Ion and Neutral Atom in Electrostatic Spark Discharge in Air

Abstract

For the development of a practical method to estimate the energy of electrostatic air discharge without electrical measurements, the dependence of spectral characteristics of light emission from the spark discharge on electrostatic energy was investigated. It was found that the relative light intensity emitted from a monovalent positive ion of nitrogen (N II) to a nitrogen atom (N I) increased with the electrostatic energy from 0.02 mJ to 20 mJ. In the same electrostatic energy, the intensity ratio, that is the intensity of N II divided by that of N I, increased with the decrease of applied voltage. This implied that the ratio becomes large when increasing the electrostatic energy divided by the breakdown gap length. Separating the measurements into similar voltage groups, the relation between the ratio and the electrostatic energy became clear.