Confinement consistent with L-mode but We is small fraction- NSTX约束一致的模式但我们是小部分：

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1、National Spherical Torus ExperimentFacility / Diagnostic OverviewSupported byColumbia UComp-XGeneral AtomicsINELJohns Hopkins ULANLLLNLLodestarMITNova PhotonicsNYUORNLPPPLPSISNLUC DavisUC IrvineUCLAUCSDU MarylandU New MexicoU RochesterU WashingtonU WisconsinCulham Sci CtrHiroshima UHISTKyushu Tokai

2、UNiigata UTsukuba UU TokyoJAERIIoffe InstTRINITIKBSIKAISTENEA, FrascatiCEA, CadaracheIPP, JlichIPP, GarchingU QuebecMasayuki OnoFor the NSTX Team46th Annual Meeting of Division of Plasma Physics, American Physical SocietyNovember 15 - 19, 2004Savannah, GeorgiaDesigned to Study High-TemperatureToroid

3、al Plasmas at Low Aspect-RatioAchieved ParametersAspect ratio A1.27Elongation 2.6Triangularity 0.8Major radius R00.85mPlasma Current Ip1.5MAToroidal Field BT00.6TSolenoid flux0.7VsAuxiliary heating & current drive:NBI (100kV)7 MWRF (30MHz)6 MWCHI0.4MAPulse Length1.1sStored Energy400 kJbT 40% tIp

4、 flattop 3.5tskin tW flattop 10 tE bT20%, bN5, tE/tE,L1.5 for 10 tE IBS/Ip = 0.5, IBeam/Ip = 0.1Operational and Physics Advances Have Led to Significant Progress Towards Goal of High-bT, Non-Inductive OperationfBS = IBS/Ip = 0.5 e1/2 bpolbT = /(BT02/2m0)H-mode plasmaResearch Topics to Achieve Long-P

5、ulse, High Performance Plasmas Are Identified Enhanced shaping improves ballooning stability Mode, rotation and error field control allows high beta NBI and bootstrap sustain most of current HHFW heating contributes to bootstrap EBW provides off-axis current & stabilizes tearing modes Particle a

6、nd wall control maintains proper density Successfully operated for 21.1 weeks with 2460 plasmasMet the Joule milestone of 18 weeks and programmatic goal of 20 weeks Significantly expanded plasma operational regimes toward the NSTX longer term goals:High k 2.5 plasma controlled by faster plasma contr

7、ol systemSimultaneous high bT - high j-bootstrap regimes expandedEffective plasma pulse duration (tpulse Ip/ITF) doubled Meeting all the FY 04 research milestones:High beta plasma (bT 25%) sustained for longer than 2 tE MSE-CIF now yielding core current profile informationCore and edge fluctuations

8、measured and characterizedEBW emission measurement suggests good coupling efficiencyNew solenoid-free start-up experiments conducted with “transient CHI and with outer PF coils NSTX had a very productive FY 04 Run Gradual joint resistance increase observed in many stressed joints at 4.5 kG Further j

9、oint monitoring revealed greater than anticipated flag movements For machine safety, TF limited to 3 kG during the last month of operation Out-of-spec flag movement traced to not-fully-penetrated epoxy fill Through R&D, a reliable full-penetration epoxy-fill technique developed Other improvement

10、s implemented Appropriate design reviews are being conductedTF-Joints issues being resolvedNSTX plasma operations to resume in Feb. 2005M acintosh PICTim age form atis not supportedMHDTools to reach near ideal MHD limitsImproved Plasma Control System Opened Operating Window During 2004 CampaignReduc

11、ed latency improved vertical control at high-, high-bTCapability for higher , allowed higher IP/aBT Significantly more high-bT(bN=6.8 %mT/MA achieved)More routine high , Longer current flattop duration tpulse = t(0.85 Ip,max)Time of peak bTNew PF 1A Coils to improve plasma shaping114465PF1AAchieved2