A New Scheme for Measuring the Electric Field of Nanosecond Short-Pulse Discharge Using E-Fish

Nanosecond short-pulse discharge has been applied in many important fields. Due to its very high breakdown voltage, the electric field in the air gap is very strong and thus there are some unconventional physical phenomena. It is currently difficult to measure its electric field. In recent years, an electric field measurement method, named electric-field-induced second harmoni (E-Fish), has been introduced into the field of gas discharge plasma. Many researchers have used it to measure the electric field during gas discharges, but some of them have chosen measurement schemes that may be inaccurate. We derive the classical model and the ideal model of E-Fish in principle and analyze their corresponding measurement schemes. The hypotheses made in the derivation of the classical model of E-Fish do not accord with the actual situation, so the application conditions are harsh, and it is not suitable for the discharge electric field where the electric field will be distorted. There are no unreasonable hypotheses in the derivation of the ideal model of E-Fish, so it has high accuracy. However, it needs to use the inverse Abel transform, so the experimental scheme is troublesome. And because the formation delay is on the order of a 100 ps, it is almost impossible to use the inverse Abel transform in nanosecond short-pulse discharge. To solve this problem, we propose an approximate solution: to predict the electric field distribution law in advance. The electric field evolution process of nanosecond short-pulse discharge is measured using the proposed scheme, which corresponds to the simulation results.