OVERVIEW OF THE DIII–D PROGRAM AND CONSTRUCTION

PLANS

Presented byPeter I. Petersen

for the DIII–D Team

23rd Symposium on Fusion Technology20 - 24 September 2004 - Fondazione Cini, Venice, Italy

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OUTLINE

Advanced Tokamak Internal Coils (I-coils) Electron Cyclotron System Plasma Control System Diagnostics 2005 – 2006 Upgrades Conclusion

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60 different diagnostics

DIII–D CAPABILITIES ALLOW A WIDE RANGE OF RESEARCH AND TECHNOLOGY ISSUES TO BE

ADDRESSED

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MAIN RESEARCH GOAL FOR DIII–D IS THE ADVANCED

TOKAMAK, WHICH INTEGRATES MANY PHYSICS

ELEMENTS

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6 section, external C-coil12 section, internal I-coil5 C-supplies each @5 kA, 350 V or 7kA at lower voltage tap4 Switching Power Amplifiers (SPAs) each @5 kA, 300 V, ~ 4 - 5 s

System must provide for both correction of error fields and feedback stabilization of the RWM.

TOOLS TO MINIMIZE ERROR FIELDS AND RESISTIVE WALL MODES AT HIGH PLASMA PRESSURE

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FLEXIBLE I-COIL POWER SUPPLY CONFIGURATIONS

POSSIBLE WITH PATCH PANEL

Relative small impact on core confinement

Small islands might beresponsible for the ELMsuppression

Enhance magnetic and density fluctuations with no indication of increasedstochasticity

I-COILS PROVIDE A FLEXIBLE SYSTEMFOR ELM CONTROL

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N=3 mode

3 CPI gyrotrons with diamond window, 1 MW 10 s3 Gycom gyrotrons with boron nitride window, 0.75 MW 2 s

ECH System Layout Gyrotron in stand ECH launcher

1 MW ECH waveguide

CURRENT ECH SYSTEM

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Feedback system adjusts q=3/2 surface location to minimize mode amplitude Active tracking keeps ECCD at the q = 3/2 surface in the absence of the mode

compensates for the Shafranov shift as the plasma pressure increases

Mode does not reappear when is raised above the initial stability limit Stabilization of the 2/1 mode has also been done.

ECCD STABILIZATION OF NEO-CLASSICALTEARING MODES

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THE LITHIUM BEAM DIAGNOSTIC USES ZEEMAN

POLARIZATION SPECTROSCOPY TO MEASURETHE EDGE CURRENT DENSITY

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THE UPGRADED BEAM EMISSION SPECTROSCOPY (BES) DIAGNOSTIC BRINGS NEW INSIGHT INTO CORE

TURBULENCE AND MHD

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Open jet (Aug. 2003) Directed jet (Mar. 2004) Directed jet w/ reduced

back volume (Oct. 2004)

Experiments show significant (2-3x) reduction in halo currents and divertor heat loads (over VDE disruption). Large (4x) variation in thermal quench time with gas jet pressure indicates that jet design plays important role. No observed runaway electron generation (except in low pressure Ar gas puff).

MASSIVE GAS PUFF SUCCESFULLY MITIGATES PLASMA DISRUPTIONS

• Pjet (=1) ~ 0.04 atm. • Pjet (=1) ~ 0.02 atm. • Pjet (=1) ~ 0.04 atm.• Fast (~ 1ms) rise time • Slower (~3ms) rise time. • Medium (~ 2ms) rise.

INTEGRATED PLASMA CONTROL ISKEY TO THE DIII–D AT PROGRAM

Te: ECH,ECE

NTM:ECCD, magnetics

Disruption:Gas jet, magnetics, bolometers

Plasma :Paux, RTEFITRWM:

C-Coil, I-Coil, RTEFIT

Equilibrium:PF-Coils, RTEFIT

Density:Pellet/Cryopumps/Gas valves, CO2 Interferometers

Real Time Feedback Controlled (Actuator, Sensor) Long experience:

Global parameters and equilibrium

Recent progress:Two-point Te control

Under development:Real-time, multi-point profile control

– Te(,t): ECH, ECE, Thomson scattering

– j(,t): ECCD, MSE

– …

NBI

FLEXIBLE DIII–D PLASMA CONTROL SYSTEM SUPPORTS INTEGRATED PLASMA CONTROL

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3 CPI gyrotrons have been purchased

— Delivery scheduled Jul 05 – Jan 06

— Ready for operation in May 06

1 CPI development gyrotron will be available for DIII–D FY05

1 Russian short pulse gyrotron will be available

8 operating gyrotrons might be available in May 06

but only power supplies and transmission lines for 6

PLANNED ECH UPGRADE DURING 2005 - 2006

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Current configuration New configurationdouble null shape

New configurationITER shape

LOWER DIVERTOR WILL BE MODIFIED FOR DENSITY CONTROL OF HIGH TRIANGULARITY

DOUBLE NULL DIVERTORS

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A BEAMLINE REVERSAL IS NECESSARY FOR NEW PHYSICS

STUDIES AND IMPROVED PLASMA MEASUREMENTS

QDB regime with central co-rotation

Understanding physics of rotation

Transport barrier control (separate ExBand Shafranov shift effects)

RWM stability with low rotation

NTM stabilization with modulated rf

Separate Er and J(r) in MSE measurement

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OTHER DIII–D UPGRADES

Two Cooling Tower (replace old ones) Beltbus (upgrade to 10 s)

Upgrade 2 Toroidal Field Circuit Diodes (1 shown)(upgrade to 10 s)

12 audio amplifiersto stabilize RWMs

2 shown on this picture

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DIII–D LONG TORUS OPENING ACTIVITIES SCHEDULE

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P3C-A-72 OVERVIEW OF THE DIII–D PROGRAM AND CONSTRUCTION PLANS* PETERSEN, P.I.Selected also for oral presentation O3B-A-72

P3T-B-78 THE UPGRADE OF THE DIII-D EC SYSTEM USING 120 GHZ ITER GYROTRONS CALLIS, R.W.

P3T-B-246 ECH MW-LEVEL CW TRANSMISSION LINE COMPONENTS SUITABLE FOR ITER OLSTAD, R.A

P3C-C-77 HIGH PERFORMANCE INTEGRATED PLASMA CONTROL IN DIII–D* HUMPHREYS, D.A.

P3C-C-79 PROGRESS TOWARDS ACHIEVING PROFILE CONTROL IN THERECENTLY UPGRADED DIII-D PLASMA CONTROL SYSTEM* PENAFLOR, B.G

P3C-C-149 DIII-D INTEGRATED PLASMA CONTROL TOOLS APPLIED TO NEXT GENERATION TOKAMAKS*LEUER, J.A

P2C-D-80 REAL-TIME MULTIPLE NETWORKED VIEWER CAPABILITY OFTHE DIII-D EC DATA ACQUISITION SYSTEM* PONCE, D.

P2T-E-81 OVERVIEW OF THE DIII–D INTERNAL RESISTIVE WALL MODE STABILIZATION POWER SUPPLY SYSTEM* SZYMANSKI, D.D

P4T-G-71 STRUCTURAL UPGRADE OF IN-VESSEL CONTROL COIL ON DIII D* ANDERSON, P.M.

P2C-D-251 ADVANCES IN REMOTE PARTICIPATION FOR FUSION EXPERIMENTS* SCHISSEL, D.P

Selected also for oral presentation O2B-D-251

P1C-H-467 EVALUATION OF SUPER CRITICAL HELIUM AS A COOLANT FOR DIII-D TYPE CRYOCONDENSATION BAXI, C.B.,

OTHER DIII–D/GA PAPERS

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