Plasma Dynamics in Counter-Facing Plasma Guns

摘要

A plasma focus system, which consists of a pair of counter-facing coaxial plasma guns, has been developed and the behavior of current sheets in the plasma gun was investigated using a fast framing camera and an EUV photo-diode. With a trigger assist of flashover on the insulator surface and a connection of outer electrodes, current sheets were induced to collapse and shrink to the center of the electrodes, which made an ellipsoidal high energy density plasma. In case of the collapse mode, we have observed multi-EUV emissions with several μsec duration, which indicate that the current path can compress and confine the plasma at least for several μsec. This plasma focus system is expected to drive a long-lifetime and efficient extreme-ultraviolet plasma source.