Simulation of a Plasma Load Equivalent for Testing the Ion Cyclotron Resonance Heating System of the Kazakhstan Material Testing Tokamak (KTM)

In the Kazakhstan Material Testing Tokamak (KTM), additional plasma heating will be achieved by injecting power in the ion cyclotron resonance frequency range using four identical generators, each delivering 2 MW of output power. Prior to transitioning the KTM into regular operation, it is necessary to tune these generators using a load equivalent that simulates plasma-like operating conditions. This article presents the electrodynamic design and analysis of a load equivalent capable of absorbing up to 2 MW of high-frequency power. The geometry and key parameters of the load equivalent for the additional high-frequency (HF) plasma heating system of the KTM tokamak are defined. The calculations are based on the assumption that the optimal solution is to construct the load equivalent as a resonator containing a saline aqueous solution absorber housed in a tank with a dielectric window. A dielectric material with high permittivity is proposed for use in the resonator structure. The results demonstrate that the developed load equivalent enables effective testing and tuning of the high-power generators, thus ensuring the readiness of the additional power injection system for scheduled activation on the KTM tokamak. Two plasma load equivalent (PLE) configurations were investigated for different bench-testing purposes. The large PLE was optimized for high RF power absorption in the standing-wave regime, whereas the small PLE was designed to provide a low-impedance loading condition for antenna-matching tests in preparation for plasma operation.