Injection of a streaming plasma into a mirror machine

The axial injection of a supersonically streaming plasma beam into a mirror machine is investigated experimentally. The object of the experiment is to obtain qualitative and quantitative data on the injection and trapping processes and in particular the transition from supersonic to subsonic flow and attendant shock formation. It is shown that for a mirror ratio of 3.3 and for a peak mirror field in excess of 3 kG, a shock is formed in the downstream mirror and results in increased density and temperature confinement time within the mirror machine. The helium plasma beam is produced by a conical theta-pinch gun driven by a capacitor bank with a stored energy of 2.5 kJ. Measurements are made of the plasma density, temperature and streaming velocity.