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22-27 October 2018
Mahatma Mandir Conference Centre
Asia/Kolkata timezone
CONFERENCE MATERIAL NOW AVAILABLE!

Integrated operation of steady-state long pulse H-mode in EAST

24 Oct 2018, 14:00
20m
Mahatma Mandir Conference Centre

Mahatma Mandir Conference Centre

Gandhinagar (nearest Airport: Ahmedabad), India
Oral EXC - Magnetic Confinement Experiments: Confinement EX/3 Plasma Performance & Control

Speaker

Prof. Xianzu Gong (Insititute of Plasma Physics, Chinese Academy Sciences)

Description

Recent EAST experiment has successfully demonstrated long-pulse steady-state scenario with a good plasma performance through the integrated operation since the last IAEA in 2016. A discharge with a duration over 100s has been obtained with multi-RF power heating and current drive. Plasma parameters are as follows, plasma current Ip=0.4 MA, poloidal βP ~1.2, toroidal magnetic field BT=2.5 T, elongation κ=1.6, the safety factor at the 95% normalized poloidal flux surface q95 ~6.6. The zero-loop voltage and pulse length (~ 250 times the current relaxation time) indicate the really steady state condition. Small ELMs were obtained in this long pulse H-mode discharge which facilitates the RF power coupling in the H-mode phase. In the operation, the optimization of X-point, plasma shape, the outer gap and local gas puffing near LHW antenna were investigated to maintain RF power coupling and particle exhaust and to avoid formation of hot spot on the 4.6 GHz LHW antenna. Global parameters of BT and line averaged electron density were optimized for higher current drive efficiency of LHW and on-axis deposition of ECH. A peaked electron temperature profile was observed with a weak ITB at rho ~0.4. No obvious MHD instabilities were found in the whole discharge. The maximum tungsten divertor temperature monitored by the IR camera shows the temperature raises quickly in several seconds and reaches a stable value, ~500 oC. As a key element, wall conditioning was addressed before long pulse plasma operation. Several difficulties are reported in the development of this 100s long pulse discharge. To achieve the next goal (≥400s long-pulse H-mode operations with ~50% bootstrap current fraction), 0-D predictions have been carried out. The modelling suggests that steady-state high performance will require not only increased injected power, but also significantly improved energy confinement quality. The recent long pulse H-mode has demonstrated several key elements and will increase a confidence in achieving high performance, steady state discharges with more key elements in integrated control on EAST. This work was supported by the National Magnetic Confinement Fusion Program of China No.2015GB102000, No. 2015GB110005 and No.2015GB103000.
Country or International Organization China, People's Republic of
Paper Number EX/3-1

Primary author

Prof. Xianzu Gong (Insititute of Plasma Physics, Chinese Academy Sciences)

Co-authors

Mr A. M. Garofalo (General Atomics) Dr Annika Ekedahl (CEA, IRFM) Dr Baonian Wan (Institute of Plasma Physics, Chinese Academy of Sciences) Prof. Biao SHEN (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Bin ZHANG (Institute of Plasma Physics, Chinese Academy of Sciences) Prof. Bingjia XIAO (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Bo Lyu (Institute of Plasma Physics, Chinese Academy of Sciences) Prof. Chundong HU (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Erzhong LI (Institute of Plasma Physics, Chinese Academy of Sciences) Prof. Fukun LIU (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Guosheng Xu (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Haiqing LIU (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Handong XU (Institute of Plasma Physics, Chinese Academy of Sciences) Prof. Jiangang Li (Institute of Plasma Physics, Chinese Academy of Sciences) Prof. Jiansheng HU (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Jinping Qian (Institute of plasma physics, Chinese academy of sciences) Ms Juan Huang (CnIPPCAS) Dr Liang Wang (Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP)) Ms Ling Zhang (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Linming SHAO (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Liqun Hu (Institute of Plasma Physcis, Chinese Academy of Sciences) Dr Long ZENG (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Mao WANG (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Nong Xiang (Institute of plasma physics, Chinese academy of science) Prof. Qing ZANG (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Shiyao LIN (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Siye Ding (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Xiaojie WANG (Institute of Plasma Physics, Chinese Academy of Sciences) Prof. Yanping ZHAO (Institute of Plasma Physics, Chinese Academy of Sciences) Dr Youwen Sun (Institute of Plasma Physics, Chinese Academy of Scienses) Prof. Yunfeng Liang (Forschungszentrum Jülich GmbH, Germany)

Presentation Materials

Paper