Development of a repetitive plasma source for simulation of mitigated edge localized mode transient heat load

Abstract

A repetitive plasma source for simulation of mitigated edge localized mode transient heat load is developed. The repetitive plasma source consists of a repetitive pulsed power supply and a pulsed plasma accelerator. The pulsed plasma accelerator is composed of a coaxial cathode, an anode, and an insulator. The inner electrode is the cathode with a diameter of 5 mm, and the outer electrode is the anode with a diameter of 15 mm. An angular magnetic field is generated by the discharge current and acts with the radial current to generate Lorentz force, which drives the plasma ejecting to the outlet. The repetitive pulsed power supply can be divided into three parts, the primary charge circuit, the resonant charge circuit, and the discharge circuit. The time interval between resonant charge and discharge is 4 ms. The repetitive discharge components include ten modules running in parallel. There are four working modes for discharge components, depending on the number of simultaneously discharged modules. For Mode A, the maximum repetitive frequency is 50 Hz, and the transient heat load is 0.06 MJ/m2 when the discharge current is 10.5 kA. For Mode D, the maximum repetitive frequency is 5 Hz, and the transient heat load is 0.45 MJ/m2 when the discharge current is 66 kA. This is of great significance for the study of the interaction between plasma and plasma-facing materials in tokamak.