A technique and device for studying alternating-current discharge dynamics. Stratification of a discharge in an argon flow at atmospheric pressure

The technique for studying discharge emission dynamics by high-speed photoregistration methods is based on self-tuning of the frequency (44 kHz) and phase of the discharge-supplying generator current to the rotational frequency of the mirror of a high-speed camera, the ratio of these frequencies being equal to 40:1. This technique has revealed that the discharge in a system with a hollow copper electrode and an inductor electrode in an argon flow at atmospheric pressure is stratified. Both standing and traveling ionization waves were observed, and their length and speed were determined. A device for supplying powder-like samples to the discharge plasma allowed for measurements of the temperature and electron density distributions along the discharge length. It is shown that the electron density values determined from the width of the H-beta hydrogen line and by the method of relative intensities of spectral lines differ by an order of magnitude; therefore, the plasma cannot be considered in thermodynamical equilibrium.