Veloce: A Compact Pulser for Magnetically Driven Isentropic Compression Experiments

Abstract

The use of magnetic fields to isentropically compress materials for equation-of-state studies has been first demonstrated on the Z machine at Sandia National Laboratories. Sharing similarities with the GEPI pulser, a compact pulser has been designed and built, focusing on isentropic compression experiments. In order to achieve high compacity and fast turn around, the design is built around a solid dielectric transmission line to couple current from eight low-inductance capacitors that are switched with ultralow-inductance multichannel gas switches operating in dry air at atmospheric pressure. A peaking stage made of 72 capacitors enhanced by a low-inductance multichannel sharpening switch brings the fundamental rise time of the pulser down to 350 ns (10%-90%). A set of inductances in parallel with the sharpening switch as well as using various gases into this switch allow us to modify the current wave shape. The pulser delivers a peak current of 4 MA at a charge voltage of 80 kV on a short circuit. The rise time can be lengthened to around 650 ns for a current of 4.2 MA. The use of postholes convoluting in a solid dielectric insulation design makes that pulser unique, as well as its compact size, ease of use, and ease of access to the load.Index Terms-Equations of states, high pressure, low inductance, solid dielectric.

A compact platform for the investigation of material dynamics in quasi-isentropic compression to ~ 19 GPa

“…There are technical and economic difficulties in developing such large facilities. Meanwhile, some laboratories have developed relatively compact pulsed power devices, such as Veloce 29 , Phelix 30 , GEPI 31 , CEPAGE 32 , and the CQ series 25,33 . These facilities usually output current of 1-10 MA and thus have a much lower loading ability.…”