Enhanced production of runaway electrons during electron cyclotron resonance heating and in the presence of supersonic molecular beam injection in the HL-2A tokamak

Journal Article · Thu Jul 15 04:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3457922· OSTI ID:21389117

Zhang, Y P; Liu, Yi; Yang, J W; Song, X Y; Yuan, G L; Zhou, J; Yao, L H; Feng, B B; Li, X; Yang, Q W; Duan, X R; Pan, C H; Liu, Y ^[1]

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1. Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China)

In the present paper, it is reported that a large production of runaway electrons has been observed during the flattop phase of electron cyclotron resonance heating (ECRH) discharges and in the presence of supersonic molecular beam injection (SMBI) in the HuanLiuqi-2A (commonly referred to as HL-2A) [Q. W. Yang, Nucl. Fusion 47, S635 (2007)] tokamak. For the set of discharges carried out in the present experiment, the ranges of ECRH power and plasma electron density are 0.8-1.0 MW and (3.0-4.0)x10{sup 19} m{sup -3}, respectively. A large number of superthermal electrons are produced through the avalanche effect [A. Lazaros, Phys. Plasmas 8, 1263 (2001)] during ECRH. The loop voltage increase due to SMBI gives rise to a decline in the critical runaway energy, which leads to that many superthermal electrons could be converted into runaway region. Therefore, this phenomenon may come from the synergetic effects of ECRH and SMBI. That is, the superthermal electrons created by ECRH are accelerated into runaway regime via the Dreicer process which is triggered by SMBI. The experimental results are in well agreement with the calculational ones based on the superthermal electron avalanche effect and the Dreicer runaway theory.

• OSTI ID: 21389117
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAMS
CLOSED PLASMA DEVICES
ECR HEATING
ELECTRON DENSITY
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HEATING
HIGH-FREQUENCY HEATING
HL-2A TOKAMAK
INJECTION
INTAKE
LEPTONS
MOLECULAR BEAMS
PLASMA
PLASMA HEATING
RUNAWAY ELECTRONS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES