Techniques for shaping of the output pulse in high current generators

摘要

This paper presents the design and test of a 0.5 MA generator with a tunable pulse shape. The main parts are: the storage capacitor (3.95 mu F similar to 12.6 kJ at 80 kV), mull-channel coaxial switch, strip transmission line, load, pulse forming block (two versions are considered here, namely with peaking capacitor and wire opening switch). A set of inductances in parallel with the peaking switch as well as using various gases into this switch allow us to modify the current wave shape. Jitter from shot to shot did not exceed 10 ns in the experiments. This paper describes the design of main module elements and the results of experiments for two schemes at operation on load equivalent. In combination of the two pulse forming blocks, the generator proves the possibility of pulse shape tuning in a very wide range, namely delivering between 400 and 600 kA with a 200-800 ns rise time. The generator weight was similar to 200 kg and the dimensions are 1x0.6x0.8 1 m(3) with a pumping system. The generator design allowed for an easy increase in the number of modules in the arbitrary series-parallel combination in order to get the required current amplitude and pulse shape. Operation and handling are very simple, because no oil, water, nor SF6 are required for the generator.