Electrical Diagnostics for Nanosecond Pulsed Discharge Reactors

Abstract

This thesis provides an introduction to transmission line theory (telegrapher’s equations) as the mathematical background needed to correctly perform and interpret electrical measurements in nanosecond pulsed discharge reactors. The mathematical framework is implemented in a numerical tool called VI-View, which is made available to the community to aid with the interpretation of electrical measurements and help explain discrepancies between different experimental arrangements and probe configurations. A brief manual on how to use the tool is provided, followed by a series of six case studies relevant to experimental setups/situations encountered in practice. The analysis of these case studies summarizes best practices when performing electrical and energy measurements in nanosecond pulsed discharge reactors. Case Studies 1 and 2 cover in-situ and remote measurements for reactors using one voltage and one current probe. Case Study 3 covers how two current probes, one on the high-voltage end and one on the low-voltage end, can achieve the same energy measurements as Case Studies 1 and 2. Case Studies 4 and 5 show how cables with varying lengths and dissimilar properties — as can sometimes be encountered in practice — affect the electrical signals. Case Study 6 shows how a variable resistance — a step drop from 50MΩ to 10Ω — within a load can be a first approximation to a plasma reactor with a discharge. Finally, an outlook on how these case studies connect to real, experimental waveforms is presented along with the limitations of the tool.