Theoretical modeling of the plasma erosion opening switch for inductive storage applications

Abstract

A theoretical model for the plasma erosion opening switch (PEOS) is presented which predicts its voltage, current and impedance history as a function of the input waveforms, geometry, and switch parameters. Scaling relations for the switch operation are developed from this model. System requirements for pulse compression and power multiplication using inductive storage are derived from a simple lumped circuit analysis and a transmission line analysis. These requirements are shown to be satisfied using the PEOS as a fast opening, vacuum switch in a configuration relevant for existing high-power accelerators. The switch model is incorporated into a transmission line code for comparison with recent inductive storage experiments. Code results agree well with the data showing conduction times of ∼60 ns and switching times of ∼10 ns with peak currents of ∼600 kA.

Current distribution in a plasma erosion opening switch

“…9 In this theory, current is conducted in a bipolar, space-charge-limited fashion across a small gap at the cathode side of the PEOS. The maximum current that the PEOS can conduct (without opening)…”

The Plasma Erosion Opening Switch

“…28 The final current channel width, Y, was estimated from the magnetic field measurements. 3 2 The model, which…”

Characterisation of the current switch mechanism in two-stage wire array Z-pinches

“…Plasma erosion opening switches (PEOSs) involve the erosion of an auxiliary conducting plasma channel positioned in parallel to the load. 9,10 These devices were first investigated as a means to reduce current pre-pulse into diode experiments. 11,12 PEOSs will often exhibit some flow switch behaviour, as the eroding plasma channel will be, to some extent, swept along the power feed by the J Â B force.…”