Features of emission of electrodes in a railgun with a plasma piston (emission crisis)

The problem of matching the electronic emission current from the cathode and the charge current can appear at high acceleration rates of a solid in a railgun with a plasma piston because of the high current density needed and the small time of the contact between the charge and the electrode. The conditions under which this effect (emission crisis) is manifested have been found. This effect leads to a decrease in the plasma piston speed and, respectively, to a decrease in the acceleration speed up to a full stop. Experimental diagrams of the piston motion in the railgun are presented, and the acceleration regions in which the emission crisis may occur are revealed.