Measurements of the fast electron bremsstrahlung during lower hybrid current drive in the HL-2A tokamak

Y. P. Zhang; D. Mazon; Y. Peysson; P. Malard; P. F. Zhang; J. Zhang; X. L. Zou; J. Zhou; H. B. Xu; X. Y. Bai; J. W. Yang; G. L. Yuan; X. Y. Song; X. Li; W. L. Zhong; X. T. Ding; W. Chen; Y. G. Li; T. Hoang; L. Delpech; A. Ekedahl; M. Isobe; X. M. Song; B. Lu; Yi Liu; Z. B. Shi; Q. W. Yang; M. Xu; X. R. Duan; Y. Liu

doi:10.1063/1.5110233

AIP Advances (Aug 2019)

Measurements of the fast electron bremsstrahlung during lower hybrid current drive in the HL-2A tokamak

Y. P. Zhang,
D. Mazon,
Y. Peysson,
P. Malard,
P. F. Zhang,
J. Zhang,
X. L. Zou,
J. Zhou,
H. B. Xu,
X. Y. Bai,
J. W. Yang,
G. L. Yuan,
X. Y. Song,
X. Li,
W. L. Zhong,
X. T. Ding,
W. Chen,
Y. G. Li,
T. Hoang,
L. Delpech,
A. Ekedahl,
M. Isobe,
X. M. Song,
B. Lu,
Yi Liu,
Z. B. Shi,
Q. W. Yang,
M. Xu,
X. R. Duan,
Y. Liu

Affiliations

Y. P. Zhang: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
D. Mazon: CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
Y. Peysson: CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
P. Malard: CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
P. F. Zhang: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
J. Zhang: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
X. L. Zou: CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
J. Zhou: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
H. B. Xu: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
X. Y. Bai: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
J. W. Yang: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
G. L. Yuan: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
X. Y. Song: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
X. Li: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
W. L. Zhong: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
X. T. Ding: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
W. Chen: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
Y. G. Li: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
T. Hoang: CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
L. Delpech: CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
A. Ekedahl: CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
M. Isobe: Natinal Institute for Fusion Science, Natinal Institutes of Natural Sciences, 322-6 Oroshi-cho, Toki 509-5259, Japan
X. M. Song: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
B. Lu: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
Yi Liu: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
Z. B. Shi: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
Q. W. Yang: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
M. Xu: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
X. R. Duan: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China
Y. Liu: Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, China

DOI: https://doi.org/10.1063/1.5110233
Journal volume & issue: Vol. 9, no. 8
pp. 085019 – 085019-8

Abstract

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Physics related to fast electrons in lower hybrid (LH) current drive (LHCD) plasma is a very important issue, since these particles will play an important role in runaway electron (RE) generation and lower hybrid wave (LHW)-related physics. Utilizing a new hard X-ray (HXR) pinhole camera, recent HL-2A tokamak experiments have devoted to enhancing the understanding of the physics on fast electrons and LHW. The fast electron bremsstrahlung (FEB) emission in the HXR energy range between 20 and 200 keV was measured by the HXR camera. To study the conversion of LHW-produced fast electrons into REs, a very short pulse of LHW, so-called “blip”, with duration of 5 ms was injected into the plasma during the current flattop phase. A strong enhancement of REs was induced by the blip injection. Measurements from the HXR camera show that the fast electrons generated by LHWs is mainly concentrated in 40-60 keV, which is well consistent with the calculated value based on Landau damping theory. The energy of these seed electrons is higher than the critical runaway energy. This phenomenon may be come from the synergetic effects of Dreicer and avalanche RE generation. Moreover, the measurements indicate that the spatial distribution of the fast electrons during LHCD has a peaked profile, implying that the fast electrons are mainly produced in the plasma core. It also suggests that the energy of the LHW mainly deposited in the plasma core region.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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