Study of cathode plasma expansion in high-current magnetically insulated diodes

In the paper experimental results on a vacuum discharge and cathode plasma expansion across and along the magnetic field in magnetically insulated coaxial diodes are presented. It is shown that a breakdown of cathode-anode and cathode-Paradey cap gaps is caused by a cathode plasma. It is discovered that a dependence of the commutation time of cathode-anode gap on the magnetic field has a maximum that drifts towards higher magnetic fields with decreasing the gap. A velocity of the outlying plasma layers along the magnetic field Ì3 founded to increase with a distance to cathode, while the internal plasma layers move at a practically constant velocity. On a basis of the investigation results a mechanism of cathode plasma motion in the magnetically insulated diode is discussed.