A Compact High-Power Conditioning Unit for Radiation Generators

An ongoing research programme at Loughborough University is concerned with investigating a number of unconventional techniques for the generation of high-power microwaves. As part of the experimental programme it is necessary to inject 1 GW of power into a vacuum spark gap, with this being obtained from the output of a capacitor bank fed through a flat-strip transmission line to a fast high-voltage conditioning unit. The paper presents details of the conditioning unit, which comprises an exploding wire opening switch, a vacuum spark gap and a ballast inductor. The inductor is needed to ensure a sufficiently fast transfer of energy into the exploding wires and at the same time to protect the capacitor bank from the high-voltage of almost 250 kV generated by the explosion. The novel design adopted in constructing the inductor will be explained and the overall optimisation of the conditioning unit will be described. A sample of the very reproducible results obtained from a series of nominally identical experiments will be presented and compared with those theoretically predicted