Development of the 1 MW 105GHz ECRH system and related technologies on J-TEXT

The advantages of electron cyclotron resonance heating (ECRH), such as localized power deposition and high coupling efficiency, have led to its widespread application in magnetic confinement fusion devices. To enhance the plasma parameters and expand the operational range of the Joint-TEXT (J-TEXT) tokamak, the development of an ECRH system was initiated in 2017. The first stage involved testing a gyrotron operating at 105 GHz with an output power of 500 kW for 1 s in 2019. Subsequently, another gyrotron with identical specifications completed its commissioning tests in 2022. As the core component of the ECRH system, each gyrotron is equipped with various subsystems to ensure safe and stable operation. Two high voltage power supplies which are the cathode power supply and anode power supply provide high voltage for establishing an accelerating electric field inside the gyrotron. Additionally, a magnet power supply is needed to charge the superconducting magnet. During the commissioning process of each gyrotron, the magnet cooling and alignment, MOU alignment, and gyrotron operation were successfully completed. The commissioning tests have demonstrated high power and long pulse output. Since 2019, the ECRH system has been utilized in J-TEXT physical experiments, which not only expanded the parameter range of J-TEXT, but also promoted the ECRH and ECCD related research.