Design of a Fast-Plate Generator Driving Plasma Flow Switch

摘要

Over the last fifteen years, there has been continuing interest in the use of magnetic flux compression generators to drive plasma implosion loads. Studies of fast plate-type generators coupled to cylindrical foil-plasma discharges in z-pinch geometry indicated that operation in the few microsecond time regime (generator time approx. = implosion time) might be successful. Later experiments and two-dimensional MHD calculations demonstrated that penetration of the effects of cold, nonmoving boundaries into the plasma implosion, combined with Rayleigh-Taylor instability, prevents practical attainment of microsecond implosions of cylindrical plasmas (a few cm or less in axial extent). Use of longer plasmas and/or shorter implosion times, however, implies higher effective driving voltages and shorter current risetimes at the load. Since explosively-driven plate generators may already represent the limit of generator performance in terms of speed, it is therefore necessary to include an intermediate stage of power conditioning between microsecond generators and submicrosecond implosion loads. The present paper discusses coupling the plasma flow switch to a fast plate generator in order to accumulate magnetic energy in vacuum on a few microsecond timescale and then release this energy rapidly to a submicrosecond implosion load. (ERA citation 11:048306)