Electromagnetic Compatibility in Electron Cyclotron Resonance Heating System

The electron cyclotron resonance heating (ECRH) is a very important plasma heating method in experimental advanced superconducting tokamak (EAST). There are four gyrotrons in the EAST ECRH system that can generate 4-MW/100-s/0.14-THz wave. The ECRH system is a complex terahertz system that involves ultralow temperature, ultrahigh vacuum, strong magnetic field, high-power electromagnetic wave, and weak diagnostic signal. There are many electromagnetic compatibility problems in the ECRH system. This is the first report about the electromagnetic compatibility for the ECRH system. In the operation of the ECRH system, many electromagnetic compatibility problems have been found and resolved. We can suppress the interference and improve the accuracy of power monitoring and the effectiveness of radio frequency protection by using the magnetic rings. The influence of the magnetic field on the current transformers was analyzed. Some electromagnetic compatibility issues in the data acquisition system were discussed. After solving the electromagnetic compatibility problems, the EAST ECRH system can stably output high-power terahertz wave.