Multiple-pulse, twin-output, high-voltage generator

Abstract

This paper describes the development of a compact, proof-of-principle generator for the production of two synchronized series of high-voltage pulses from the single discharge of a capacitor. The pulses are produced by an array of parallel-connected exploding fuses, with compact transformers enabling the required level of output voltage to be obtained. Experimental results are presented and compared with theoretical predictions.

A high-power high-voltage multi-pulse twin-output driver for radiation generators

“…The accuracy that was achieved is evident in figure 2. Numerical modelling of the complete system employed the filamentary technique developed at Loughborough [1]. The predicted results were again extremely accurate, as is clear from figure 7.…”

“…Opening switches are necessary to produce the large and rapid negative excursions of current (dI /dt) that are needed in the primary circuit of the transformers to provide the required high-voltage pulses to the output loads. Exploding wires were used for the switches, as these are known to be more efficient than the foils used in the earlier low-energy system [1]. A large number of experiments were performed to establish the optimum tamping element for the wires.…”

“…Although a very compact oil-filled transformer was developed and successfully operated at up to 300 kV for the low-energy system [1], it was decided, nevertheless, to use a simpler but extremely robust air-cored transformer in the present system. A high-dielectric-strength Melinex film bonded with a polyethylene layer and having a thickness of 250 µm is commercially available, and by thermally bonding adjacent polyethylene layers with an intervening 0.1 mm thick, 0.5 m wide copper foil, a flat long (15 m) sandwich-like structure is produced.…”

“…It was therefore necessary to develop a polaritysensitive spark gap (a diode D) for this purpose. This was based on the point/plane configuration described previously [1], in which the pronounced polarity effect results in a positive/negative voltage breakdown ratio of almost two. Figure 3 shows the diode action resulting in both suppression and sharpening.…”

“…A low-energy prototype was built and tested as a first stage of the research programme and the results obtained were reported in [1]. The generator functioned very successfully, producing either a single pulse in excess of 250 kV, two pulses exceeding 200 kV or three pulses above 150 kV, on each of two 6 k loads [1].…”