Thermal analysis of ICRH antenna in HL-3 tokamak

Abstract Ion cyclotron resonance heating (ICRH) is a vital auxiliary heating method for tokamak devices. As the core component of the ICRH system, the antenna directly faces the plasma and is subjected to complex thermal loads from multiple sources. In this study, thermal loads on the ICRH antenna under two representative heating schemes (6 MW ICRH + 5 MW NBI, 5 s pulse duration in Deuterium-Tritium and Hydrogen-Deuterium-Helium3 plasmas) are systematically analyzed. The heat flux on the Faraday screen surface caused by plasma radiation, fast ion loss, and the antenna’s inherent RF loss are evaluated. Simulation adopts the plasma radiation as the primary heat source on the faraday screen, contributing up to 60% of the total thermal load, while fast ion loss and RF loss account for 25% and 15%, respectively. Transient thermal analysis reveals that antenna components reach peak temperatures of approximately 300 °C during the first heating cycle. Following passive cooling, the second heating cycle elevates the temperature to about 450 °C, with each heating cycle producing a cumulative temperature rise of approximately 150 °C. These results demonstrate that real-time temperature monitoring and an active cooling system are critical for safe operation.