Performance Evaluation of Ferroelectric Trigger Unit for Multigap Multiaperture Pseudospark Switch

Abstract

In this article, the experimental investigation has been performed for the characterization of the ferroelectric (FE) trigger unit for single-gap and multigap multiaperture pseudospark switch (MGMA-PSS) configurations. The role of the different gases and circuit parameters is analyzed to optimize the trigger behavior during the switching operation of the PSS. A high dielectric lead zirconate titanate (PZT) material is used to fabricate the trigger unit. The electron emission and breakdown characteristics of the FE trigger source have been studied at different operating parameters, such as working gas (Ar, H2, He, and N2), gas pressures, voltages, and circuit resistances for the generation of required seed electrons for fast switching operation. It has been observed that the electron emission characteristics of the FE trigger are strongly dependent on the operating gas pressures. Short pulse voltage up to ~5 kV and trigger circuit resistances ( $10~\Omega $ –20 k $\Omega $ ) are used at different gas pressures (10–200 Pa) for the characterization of trigger unit. The pulse generator is used to generate the negative voltage required to operate the trigger source. The FE trigger source has been arranged ~15 mm below the baffle in hollow cathode (HC) for efficient seed electron generation. The FE trigger shows better emission characteristics with hydrogen gas at ~60-Pa gas pressure. The achieved trigger discharge current is ~25 A at ~4-kV operating voltage with 1-k $\Omega $ ( $185~\mu $ H) trigger circuit resistance. The study is very much suitable for the optimization of FE trigger parameters in high-power PSS.