Nuclear Techniques ›› 2017, Vol. 40 ›› Issue (11): 110603-110603.doi: 10.11889/j.0253-3219.2017.hjs.40.110603

• NUCLEAR ENERGY SCIENCE AND ENGINEERING • Previous Articles     Next Articles

Analysis and processing of breakdown of ion source for EAST neutral beam injector

XU Yongjian1, ZHANG Li1,2, XIE Yahong1, JIANG Caichao1,2, LIANG Lizhen1, HU Chundong1   

  1. 1 Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China;
    2 University of Science and Technology of China, Hefei 230026, China
  • Received:2017-02-24 Revised:2017-06-07 Online:2017-11-10 Published:2017-11-08
  • Supported by:
    Supported by National Natural Science Foundation of China (No.11405207, No.11675215), Institute of Plasma Physics Foundation of Chinese Academy of Sciences (No.DSJJ-15-GC03)

Abstract: Background: The high current ion source is a key component of neutral beam injector, and its reachable performance determines the achievable targets of the experimental advanced superconducting tokamak (EAST) neutral beam injector (NBI). Electrode breakdown of ion source happens occasionally during the beam extraction, which has a very serious impact on the normal operation of ion source and even endangers the life of the ion source. Purpose: This paper aims to analyze the reason of breakdown and propose improvement measures. Methods: The waveforms of beam extraction and the data of water flow calorimetry (WFC) of the abnormal shot of 7801 and normal shot of 7799 were studied. Results: The analysis shows that the cause of breakdown is the dual effect of over-focus and under-focus of extraction beam. Optimizing the matching of the plasma and the high pressure can effectively reduce the phenomenon of breakdown, and in order to protect ion source, a hardware protection mechanism is added. Conclusion: The analysis results lay a foundation for the safe and stable operation of ion source.

Key words: Ion source, Beam extraction, Electrode breakdown, Water flow calorimetry

CLC Number: 

  • TL65+4