The course in time of the field strength and the ion concentration in the spark discharge

Abstract

The course in time of ion concentration and field strength in a spark channel has been determined with the aid of time-resolved spectra. Using experimentally determined wavelength shifts of spectral lines, the field strength and ion concentrations are calculated from equations derived by Unsöld and Holtsmark. In the spark channels of Mg, Zn, Cd and Hg, the highest field strength observed was about 600 kV cm for an ion concentration of about 10 18 ion cm 3 . Using time-resolved spectra, the variation in time of field strength and ion concentration was observed. Maximum line shifts occur during the initial stages of each discharge, indicating that field strengths, ion concentrations, and Stark effect are at a maximum. With the passage of time the temperature of the spark channel decreases, as well as the field strength and ion concentration. Normal wavelengths are observed after the field strength has decreased below a certain limit.