A compact, high-current pulse power generator for experiments on low-impedance loads

A fast and compact pulse power generator has been developed for creating conditions for high-pressure dynamic compression in solids as well as in pulsed plasma. The generator consists of four identical capacitor-switch units connected concentrically around a coaxial load section. Each capacitor-switch unit consists of a low-inductance configuration of a 2100 nF/55 kV capacitor with coaxial terminals and an ambient air-operated, planar, 5-gap, 4-channel multi-gap, multi-channel spark gap switch to exhibit unit impedance up to 0.25 Ω. For a maximum charging voltage of 50 kV, the energy stored in the generator is ∼10 kJ. A negative-polarity HV pulse of magnitude -68 kV and fall time ∼56 ns is used to trigger all four switches simultaneously into the load section. Under short-circuit characterization at 50 kV, the developed generator has been found to generate current pulses of magnitude 735 kA with a rise-time (10%-90%) of 600 ns. The overall dimensions of the generator are 985 × 985 × 760 mm3, and the total weight is ∼500 kg, thereby making it a simple, low-cost apparatus for conducting dynamic compression experiments under laboratory conditions. Ambient air operation of the generator up to 50 kV and its extremely low generator impedance of ∼0.076 Ω make it a robust and small-footprint pulse power driver suited for experiments on low-impedance loads in a laboratory environment.