Space potential and charged particles density variation in a glow discharge plasma during shock wave propagation

Abstract

The plasma parameters in a glow discharge plasma near the front of shock wave moving perpendicularly to the discharge axis has been investigated using a double electrical probe. It has been discovered that the shock wave propagation is accompanied by an increase in the potential of discharge plasma. A relatively small change in the potential is observed before the shock wave arrival and a significant one behind shock wave front. The varying potential in the glow discharge plasma distorts the current of the double probe. A method of its correction is proposed, which consists in the joint processing of two signals obtained in separate experiments with different surface areas of the negative probe electrode. The method allows us determine the ionic current and the change in the potential of space. The magnitude of ion current corresponding to the charged particles concentration remains unperturbed before the shock wave arrival to the measurement point. A gradual increase in the ionic current is observed behind the shock wave front in contrast with the abrupt change in gas-dynamic parameters on the shock wave front.