On the nature of oscillations ofZ-pinch in n-InSb under impact ionization

Using computer technique, we calculated the time sweeps of the electric field in the sample with account for the quadratic bulk recombination and electron-hole scattering, provided that the current is constant. The process is shown to develop in an oscillating way due to the excitation of an ionization domain in the sample under pinch-effect. The domain entering the region of high plasma compression, the conductivity changes drastically. At this moment at the crystal periphery a new domain arises, which moves to the center of the crystal. The process mentioned above is periodically repeated with damping in time. The development of domain in space and time has been investigated and frequency of oscillations was calculated.     

Influence of the erosion of the discharge channel wall on the efficiency of a stationary plasma thruster

The integral characteristics of stationary plasma thrusters are studied experimentally during their long-term operation. It is shown that the monotonic fall of the thrust efficiency and specific impulse within the initial 500?C1000 h of operation is explained, in particular, by a decrease in the propellant utilization efficiency. A physical mechanism underlying this phenomenon is suggested, and expressions predicting the variation of the output characteristics of the thrusters during the operating life are derived. Satisfactory agreement is observed between experimental and predicted results on the anode specific impulse variation in the course of testing several thrusters with different powers for endurance. An experimentally found correlation between the magnetic field configuration and the position of the erosion zone boundary on the discharge chamber wall is accounted for.