Fast switching of megaampere current to the load

Abstract

Previous experiments on the MIG generator (2 MA, 80 ns) showed that the generator current can be switched to a load in 1–3 ns in the process of sweeping (pushing away from the load) by the magnetic field of the plasma, previously injected in the area of the load and the conical load holder. Fast switching of the megaampere current to a foil liner or a solid metal rod is accompanied by an explosion of the liner (rod) surface and the formation of a thin layer of hot (>100 eV) dense plasma. In the course of these experiments, the question arose of whether the formation of a surface plasma is the result of implosion onto the load surface of a part of the injected plasma swept by the current. To clarify this issue, test shots were made in this work with different configurations of the load area and the composition of the injected plasma. The performed studies confirm that when plasma is injected into the load region with a conical holder, the plasma is pushed away from the load and the current is switched over to the surface of the load (liner or rod) in a few nanoseconds.