Experimental Studies On Plasma Characteristics Of Coaxial Gun Pulsed Discharge

The coaxial gun pulsed discharge is a strong discharge generated by pulsed high voltage between the inner and outer electrodes of the coaxial gun.In the meantime,neutral gases are beoken down to produce the plasma which is accelerated to produce a high speed jet under the action of Lorenz force.The coaxial gun pulsed discharge plasma is characterized by high density,high velocity and high temperature.It has a broad application in the fields of space propulsion,dust particle acceleration,space micro debris impact effect,et al.With the expansion of the application field,the research on plasma parameters,plasma transport characteristics and energy efficiency of coaxial gun pulsed discharge becomes more and more important.In this paper,basic parameters and transport characteristics of the pulsed discharge plasma of the coaxial gun under the different experimental parameters are studied by the measurement of the electrical signals and optical signals.the change of inductance and resistance in discharge circuit under different discharge conditions is calculated through a RLC circuit model.The experimental results are compared with the calculation by the loop model.the optimization of the coaxial gun discharge device is proposed.The effects of charging voltage,gas pressure and loop inductance on the plasma characteristics are studied.The effects of charge voltage,gas pressure and loop inductance on plasma acceleration time,plasma velocity and plasma density are also analyzed.The results show that the plasma density and transport speed increase with the increase of charging voltage,while the acceleration time of plasma in the coaxial gun decreases with the increase of charging voltage.The plasma density increases with the increase of gas pressure,the transport velocity decreases with the increase of gas pressure,and the acceleration time of plasma increases with the increase of gas pressure.the plasma density and the transport speed increase with the decrease of the loop inductance.and the peak current of the pulsed discharge increases,andthe discharge is enhanced.the influence of different working parameters on the characteristics of the coaxial gun discharge plasma is summarized,which provides some theoretical and experimental reference for the further experiment.