J. Plasma Fusion Res. SERIES, Vol.5 (2002) 106-111 Magnetic Confinement Fusion Research in Ghina YUAN xi Wan Institute of Plasma Physics, Chinese Academy of Sciences P.O. Box 1126 Hefei Anhui 230031 P.R. China (Received: 11 December 2001 / Accepted: 8 May 2002) Abstract China will face to serious energy problems in near future and the magnetic confinement fusion research is getting more support. SWIP and ASIPP are two largest research centers for the research. Five tokamks (HT-7, HL-IM, HT-6M, KT-5 and CT-6) are running and many experimental progresses have been achieved. Three new projects have been approved and the new facilities (HT-7U, HL-2A and SUNIST) are under construction. Keywords: energy, China, magnetic confinement fusion research, tokamak 1. lntroduction 2. Organization and Facilities With the rapid socio-economic development during Southwest Institute of Physics (SWP) which now last l0 to 15 years in China the magnetic confinement belongs to the National Committee of Defense Sciences fusion research is getting more and more support via and Industry of China and Institute of Plasma Physics different channels by the government. Three new (ASIPP) which belong to the Chinese Academy of projects have been approved and the new facilities are Sciences are two largest research centers for the under construction. The research budget for magnetic magnetic confinement fusion research in China.The confinement fusion research is increasing smoothly year main facility in ASIPP is the medium sized by year. The number of graduated students also superconducting tokamak HT-7 (Fig. l). Its main increases rapidly with the reformation of education purpose is to explore high performance plasma system in China. Because China will face to more operation under steady-state condition. The machine serious problems on the shortage of energy and the runs normally with 1o = 150 KA, Br = 2T, R = t22 cm pollution of the environment in near future with the and a = 27.5 cm [1,2]. Another small tokamak HT-6M rapid economic development, the government now is with 1o = 100 kA, Br = 1.5 T, R = 90 cm, a = 20 cm in very interested in the prospect of magnetic fusion ASIPP is used to study ICRF and transport. The facility research, especially the tokamak research. The in SWIP is tokamak HL-IM (Fig. 2). It is a medium govemment is also interested in the further information sized tokamak with Rs = l.O2 m, a = 0.26 m and Bt = 3 about ITER. Many high level officers of the government T in circular limiter configuration. Its objectives are to have visited both SWIP and ASIPP. Two institutes are conduct experiments on high power auxiliary heating making effort together to promote China to participate and current drive and to explore new fueling techniques in the ITER program by some way if it will be in order to develop the physics and technology for next constructed in the near future. generation tokamak [3]. @2OO2by The Japan Society of Plasma Corresponding author's e-mail: wanyx@ mail.ipp.ac.cn Science and Nuclear Fusion Research 106 Yuan X.W., Magnetic Confinement Fusion Research in China Fig. 1 HT-7 superconducting tokamak Fig. 3 KT-5 tokamak in USTC Fig. 2 HL-1M tokamak in SWIP Fig.4 CT-68 tokamak in IPCAS Other two small tokamaks are KT-5 (Fig. 3) in the significantly and the stable region in the Hugill diagram University of Sciences and Technology of China was extended by the new type of wall conditioning and (USTC) in Hefei and CT-6B (Fig. a) in the Institute of Boronization (Fig. 5) t4l. Physics, Chinese Academy of Sciences (IP/CAS, For the long pulse discharge and future steady-state Beijing), Both of them are operated for edge turbulence/ operation on supercoducting tokamak the LHCD system transport study and alternative concept development. with 1.2 MW (CW) and 2.45 GHz have been bult and tested. Using these system the long pulse discharges 3. Main Experimental Progresses on with higher performace and plasma current fully driven Existant Devices by LHW for more than 3 seconds have been achieved 3.1 HT-7 Tokamak Experiments (Fig. 6). The ramp-up of plasma current by LHW, which The stable continuous operation for l-3 months will be very important to set-up the plasma current by a during each campaign has been achieved on HT-7 non-inductive current on superconducting tokamak, was superconducting tokamak Il,2). A new type of wall also acheived (Fig.7) t5l. conditioning and Boronization and Siliconization using Effective IBW heating with 300 kW (CW) RF ICRW instead of the glow discharge or Taylor discharge system has been demonstrated (Fig. 8) [6]. Gas puffing, have been well developed. It is easy to get high quality pellet injection and supersonic beam injection have been film of Boron or Silicon with very high efficiency to used for plasma fuelling and density control. A real-time control impurity and to decrease the loop voltage and multivariable control system has been developed for the recycling. The perfomance of discharge was improved fast equilibrium control. Combining above efforts the ro7 Yuan X.W., Magnetic Confinement Fusion Research in China 100 80 The film on C base after 250 shots oooo o =605,0 -.-.€E$-. E ;*:"" 20 -x-x-xojj_x_-e , "1r'^:"-*:. rA 80 Fresh film on C base "$t""t"r":oj:** . e60 -, -.-. -.-.-.- 8Jj-. s&ftffisi}.Ei*fiidi{$$.8 -.-. \ o 5oo tefde ICRF bomidid c o After RF siliconiztion 20 0 -i i::rr"il-:ii"=1it,==,: 0 100 200 300 400 500 M: nr R./B Deposition depth {nm ) Fig. 5 High efficiency and quality Boronization using ICRW and Extended Hugill diagram euo 4.0 fn 3.5 -al a1 $z 3.0 tI f |l 2.5 - [t (6 2.O t! a c 14 Itt= 1t x 1.0 flE'" a Fi1 rr 0.5 1! Iir''' 16 r- [i -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 [[ 01?3d ila Ii me lsecl Fig. I Plasma off-axis heating by IBW forms a ITB-Iike profle in SX emission, OH- 0.27 Fig. 6 Long pulse high performance plasma discharge sustained by LHCD F li11 f1 1.5 !::{ .r 1.! 0.5 r'll2ll X [,0 t'o+- 2 80 "l >*L ( lr 0 5 401' 200 -o o-U :lu> 400 r 100 f sool : 2mf 0 5 rm-l c o-l- t.5 0.8 ar) t.! F; 0.s Time lsecl 0.0 0 ? 4 E I l0 Fig. 7 Plasma current ramp-up by LHCD t [sl Fig.9 Repeatable 10 seconds discharges 108 Yuan X.W., Magnetic Confinement Fusion Research in China long pulse discharge with several seconds and the and the MHD activities were supressed significantly. longest one w;th 10.7 seconds on HT-7 can be easily The double sawtooth in soft X-ray radiation were achieved (Fig. 9). observed (Fig. l0) [7]. The new fueling techniques with pellet injection and supersonic molecular beam injection 3.2 HL-1M Experiment (SMBI) were also employed to significantly improve the On HL-1M, plasma performance was greatly energy confinement time and density limit. The fuelling improved through the use ofboronization, siliconization of SMBI has been improved in the HL-IM tokamak and lithiumization [3]. The maximum parameters recently and a simple model of "cold injection path" obtained in Hl,-lM ohmic heated plasmas are: Ip- 32O during the SMBI has been proposed, which is supported kA, n" = 8 x lCt1e m-3, Br= 2.8 T. ICRF at a power level by measurements of the edge temperature (7"), density of 0.3 MW, NIII at a power level of 0.4 MW, ECRH at (2"), Hu intensity profile (OF9, OFl 1) and HCN average a level of 0.3Ct MW and LHCD at a power level of 1 electron density as shown in Fig. 11 [8]. MW have been carried out. By the off axis ECRH, the electron temperature increased from 450 eV to 750 eV 3.3 KT-SC Experiment On KT-5C tokamak (R = 32.5 cm, a = I2.5 cm, Io= 10-20 kA) the interesting results of fluctuation and transport investigation in the edge of plasmas have been obtained. The suppression ofthe turbulent transport with the change of the radial electric field E, induced by the biased electrode is observed. It is found that the poloidal contributes the main part the Er. The change O. ET flow to of of the poloidal flow has a lead of about 20 ps to the O. TE formation of E as shown in Fig. 12. It suggests that a O. EB :- lE radial current responding to the biasing voltage drives a poloidal which LOE flow, in turn drives the radial electric field. o. 99 a5E t_ E5 3.4 CT-6B Experiment 111 In the AC operation experiments on CT-6B 554 55T 5{O l{t t{E tokamak, the plasma current profile and the flux surface during the current reversal have been reconstructed and Fig. 10 Double sawtooth in soft X-ray radiation during a novel method of the electron cyclotron wave current ECRH startup was demonstrated (Fig. l3). 200 z= 100 90 0 358 -100 a 200 olz 0 290 I >Z d'0 E rro ,,':..' 100 ; 2Q > 1n g 3-o F -10 t0 ; 2.6 t.6'7 "5 2.4 * z.z w 9-)^ 760 800 840 880 T(ps) 44t) 12 Time(ms) Fig.