The ECRH (Electron Cyclotron Resonance Heating) system was used in the EAST (Experimental Advanced Superconducting Tokamak) experiments for several years, and some good experimental results have been obtained. However, the performance of the gyrotrons is degraded and the ability to stabilize output RF (Radio Frequency) power is reduced. Two single-frequency 140 GHz gyrotrons are planned to be repaired in order to improve the performance of the gyrotrons. At the same time, some internal components of the gyrotrons (such as collectors, electron guns, mode conversion mirrors) will be upgraded to make the gyrotrons have the output capability of 0.6 MW/1 MW at 105 GHz/140 GHz. The MOUs (Matching Optical Units), transmission lines, the low voltage power supplies, the measurement and control system, and the water-cooling system also need to be modified for the dual-frequency operation of the new gyrotrons. The retrofitted design of the EAST ECRH system using dual-frequency gyrotrons is discussed in the paper. The upgraded ECRH system will be used for future EAST experiments to explore the range of low q₉₅ and high β_N, to study the steady-state operation mode for the future nuclear fusion power plants.

ECRH（电子回旋共振加热）系统用于EAST（实验高级超导托卡马克）实验已有数年，并获得了一些良好的实验结果。但是，回旋管的性能下降，并且稳定输出RF（射频）功率的能力降低。计划维修两个单频140 GHz回旋管，以提高回旋管的性能。同时，将对回旋管的一些内部组件（例如收集器，电子枪，模式转换镜）进行升级，以使回旋管在105 GHz / 140 GHz时的输出能力为0.6 MW / 1 MW。MOU（匹配光学单元），传输线，低压电源，测量和控制系统，新的回旋管的双频运行还需要修改水冷系统。本文讨论了采用双频回旋管的EAST ECRH系统的改进设计。升级后的ECRH系统将用于未来的EAST实验，以探索低辐射范围q ₉₅和高β _Ñ，研究对未来核聚变电厂的稳态操作模式。