Filament Power Control for Gyrotrons in EAST ECRH System

TL;DR

This paper presents a filament power control system for gyrotrons used in EAST ECRH, demonstrating stable operation and a novel 'burst' function to prevent rapid current drops.

Contribution

Developed a filament power control and measurement system with a Labview program, including a 'burst' function to enhance gyrotron stability.

Findings

Filament current fits an exponential function of voltage.

Filament resistance increases with voltage.

The control system operates stably for gyrotrons.

Abstract

The electron cyclotron heating system including four gyrotrons is under developed in the Institute of Plasma Physics, Chinese Academy of Sciences. The filament is an important part of the gyrotron, which is used to heat the cathode. Each gyrotron has a filament power supply to adjust the filament power. The filament power control and measurement system was developed to control the beam current and the output power of the gyrotrons. The control program was developed in Labview. The filament characteristics were tested using the power control system. The test results show that the filament current can be fitted with the e-exponential function of the filament voltage. It can be seen that as the voltage increases, the filament resistance gradually increases. The 'burst' function was developed to prevent the beam current from dropping too fast. The filament control system can work stably for the gyrotrons.