中国物理B ›› 2009, Vol. 18 ›› Issue (12): 5385-5394.doi: 10.1088/1674-1056/18/12/044

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Study of runaway electron behaviour during electron cyclotron resonance heating in the HL-2A Tokamak

张轶泼, 杨进蔚, 刘仪, 宋先瑛, 袁国梁, 李旭, 周艳, 周俊, 杨青巍, 陈燎原, 饶军, 段旭如, 潘传红, HL-2A Team   

  1. Southwestern Institute of Physics, P O Box 432, Chengdu 610041, China
  • 收稿日期:2009-04-01 修回日期:2009-05-05 出版日期:2009-12-20 发布日期:2009-12-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10675124, 10775041 and 10775045).

Study of runaway electron behaviour during electron cyclotron resonance heating in the HL-2A Tokamak

Zhang Yi-Po(张轶泼),Yang Jin-Wei(杨进蔚),Liu Yi(刘仪), Song Xian-Ying(宋先瑛),Yuan Guo-Liang(袁国梁),Li Xu(李旭), Zhou Yan(周艳), Zhou Jun(周俊),Yang Qing-Wei(杨青巍), Chen Liao-Yuan(陈燎原),Rao Jun(饶军),Duan Xu-Ru(段旭如), Pan Chuan-Hong(潘传红), and HL-2A Team   

  1. Southwestern Institute of Physics, P O Box 432, Chengdu 610041, China
  • Received:2009-04-01 Revised:2009-05-05 Online:2009-12-20 Published:2009-12-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10675124, 10775041 and 10775045).

摘要: During the current flat-top phase of electron cyclotron resonance heating discharges in the HL-2A Tokamak, the behaviour of runaway electrons has been studied by means of hard x-ray detectors and neutron diagnostics. During electron cyclotron resonance heating, it can be found that both hard x-ray radiation intensity and neutron emission flux fall rapidly to a very low level, which suggests that runaway electrons have been suppressed by electron cyclotron resonance heating. From the set of discharges studied in the present experiments, it has also been observed that the efficiency of runaway suppression by electron cyclotron resonance heating was apparently affected by two factors: electron cyclotron resonance heating power and duration. These results have been analysed by using a test particle model. The decrease of the toroidal electric field due to electron cyclotron resonance heating results in a rapid fall in the runaway electron energy that may lead to a suppression of runaway electrons. During electron cyclotron resonance heating with different powers and durations, the runaway electrons will experience different slowing down processes. These different decay processes are the major cause for influencing the efficiency of runaway suppression. This result is related to the safe operation of the Tokamak and may bring an effective control of runaway electrons.

Abstract: During the current flat-top phase of electron cyclotron resonance heating discharges in the HL-2A Tokamak, the behaviour of runaway electrons has been studied by means of hard x-ray detectors and neutron diagnostics. During electron cyclotron resonance heating, it can be found that both hard x-ray radiation intensity and neutron emission flux fall rapidly to a very low level, which suggests that runaway electrons have been suppressed by electron cyclotron resonance heating. From the set of discharges studied in the present experiments, it has also been observed that the efficiency of runaway suppression by electron cyclotron resonance heating was apparently affected by two factors: electron cyclotron resonance heating power and duration. These results have been analysed by using a test particle model. The decrease of the toroidal electric field due to electron cyclotron resonance heating results in a rapid fall in the runaway electron energy that may lead to a suppression of runaway electrons. During electron cyclotron resonance heating with different powers and durations, the runaway electrons will experience different slowing down processes. These different decay processes are the major cause for influencing the efficiency of runaway suppression. This result is related to the safe operation of the Tokamak and may bring an effective control of runaway electrons.

Key words: runaway electron, electron cyclotron resonance heating, runaway suppression, suppression efficiency

中图分类号:  (Tokamaks, spherical tokamaks)

  • 52.55.Fa
28.52.Cx (Fueling, heating and ignition) 28.52.Lf (Components and instrumentation) 52.50.Sw (Plasma heating by microwaves; ECR, LH, collisional heating) 52.70.La (X-ray and γ-ray measurements) 52.70.Nc (Particle measurements)