Plasma heating by electron cyclotron wave and the temperature effects on lower hybrid current drive on EAST

M.H. Li; H.D. Xu; X.J. Wang; M. Wang; B.J. Ding; C.B. Wu; G.H. Yan; L. Liu; L.M. Zhao; Z.G. Wu; W.Y. Xu; D.J. Wu; L.Y. Zhang; Y.Y. Tang; H. Li; G.M. Wallace; S.G. Baek; P.T. Bonoli; Q. Zang; S.Y. Lin; L.Y. Meng; H.L. Zhao; L.Q. Xu; M.R. Wang; X.J. Zhang; J. Huang; J.P. Qian; X.Z. Gong

doi:10.1088/1741-4326/acbec9

Nuclear Fusion (Jan 2023)

Plasma heating by electron cyclotron wave and the temperature effects on lower hybrid current drive on EAST

M.H. Li,
H.D. Xu,
X.J. Wang,
M. Wang,
B.J. Ding,
C.B. Wu,
G.H. Yan,
L. Liu,
L.M. Zhao,
Z.G. Wu,
W.Y. Xu,
D.J. Wu,
L.Y. Zhang,
Y.Y. Tang,
H. Li,
G.M. Wallace,
S.G. Baek,
P.T. Bonoli,
Q. Zang,
S.Y. Lin,
L.Y. Meng,
H.L. Zhao,
L.Q. Xu,
M.R. Wang,
X.J. Zhang,
J. Huang,
J.P. Qian,
X.Z. Gong

Affiliations

M.H. Li: ORCiD; Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
H.D. Xu: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
X.J. Wang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
M. Wang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
B.J. Ding: ORCiD; Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
C.B. Wu: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
G.H. Yan: ORCiD; Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China; University of Science and Technology of China , Hefei 230026, China
L. Liu: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
L.M. Zhao: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
Z.G. Wu: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
W.Y. Xu: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
D.J. Wu: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
L.Y. Zhang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
Y.Y. Tang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
H. Li: ORCiD; Advanced Energy Research Center, Shenzhen University , Shenzhen 518060, China
G.M. Wallace: ORCiD; MIT Plasma Science and Fusion Center , Cambridge, MA 02139, United States of America
S.G. Baek: MIT Plasma Science and Fusion Center , Cambridge, MA 02139, United States of America
P.T. Bonoli: MIT Plasma Science and Fusion Center , Cambridge, MA 02139, United States of America
Q. Zang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
S.Y. Lin: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
L.Y. Meng: ORCiD; Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
H.L. Zhao: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
L.Q. Xu: ORCiD; Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
M.R. Wang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
X.J. Zhang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
J. Huang: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
J.P. Qian: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China
X.Z. Gong: Institute of Plasma Physics, Chinese Academy of Sciences , Hefei 230031, China

DOI: https://doi.org/10.1088/1741-4326/acbec9
Journal volume & issue: Vol. 63, no. 4
p. 046019

Abstract

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This paper presents the progress in the long—pulse operation of the electron cyclotron (EC) system and the achievements in high—electron temperature plasmas by the combined EC and lower hybrid (LH) waves heating since the EC system was built in 2015. An electron temperature of up to 12 keV with a duration over 100 s was realized by the simultaneous heating of EC and LH waves at the line-averaged density ${\bar n_{\text{e}}}$ ∼ 1.8 × 10 ^19 m ^−3 . The plasma heating effect strongly depends on the location of EC power deposition. H-mode plasmas with solely EC wave auxiliary heating have been obtained on EAST for the first time. These H-mode discharges show an enhanced confinement factor H _98(y,2) around 1.0, which is higher than the previous H-mode using LH power alone (Xu et al 2011 Nucl. Fusion 51 072001). The total heating power is very close to the threshold value for L–H transition according to the international tokamak scaling. In addition to the temperature effects inside the separatrix, higher electron temperature produced by EC wave is found to reduce the LH power loss in the scrape-off layer due to collisional absorption, which is beneficial to further increase the LH current drive efficiency. Ray-tracing/Fokker–Planck modeling results indicate that higher electron temperature can shorten the LH wave propagation on EAST in a multiple-pass regime, thus decreasing the collisional dissipation.

Published in Nuclear Fusion

ISSN: 0029-5515 (Print); 1741-4326 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Physics: Nuclear and particle physics. Atomic energy. Radioactivity
Website: https://iopscience.iop.org/journal/0029-5515

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