PROGRAM RECENT RESULTS AND FUTURE PLANS by R.D. Stambaugh Presented at Fusion Power Associates Annual Meeting and Symposium Institute of the Americas, University of California at San Diego July 17, 15-/RDS/ci
INTERNATIONAL RESEARCH TEAM U.S. Labs Japan European Community Russia ANL INEL LANL LLNL ORNL PNL PPPL SNL JAERI JT 6U JFT-M NIFS LHD Tsukuba U. Cadarache (France) Culham (England) Frascati (Italy) FOM (Holland) IPP (Garching) Joint European Torus KFA (Germany) Lausanne (Switzerland) Ioffe Keldysh Kurchatov Moscow State Troitsk U.S. Universities Other International Industry Alaska Cal Tech Columbia Georgia Tech Hampton Johns Hopkins Lehigh Maryland MIT RPI Texas UCI UCLA UCSD Washington Wisconsin ASIPP (China) CCFM (Canada) Chalmers U. (Sweden) Helsinki U. (Finland) KAIST (Korea) KBSI (Korea) SWIP (China) U. Alberta (Canada) U. Toronto (Canada) U. Wales (Wales) CompX CPI Creare FAR Tech Gycom HiTech Metallurgical IR&T Orincon Surmet Thermacore TSI Research 15-/RDS/wj
INTRODUCTION Advanced Tokamak results and plans ECH and ECCD Divertor research Stability physics Confinement and ITB Overall future plans 15 /RDS/wj
THE PROGRAM WORK WITH OTHER PROGRAMS INTERNATIONALLY TO OPTIMIZE THE TOKAMAK APPROACH TO FUSION ENERGY PRODUCTION Main focus Advanced Tokamak research Resolve key enabling issues for next step toward fusion energy Advance the science of magnetic confinement on a broad front 15 /RDS/wj
OUTSTANDING RECENT RESEARCH RESULTS Advanced Tokamak Good progress on AT scenarios (β N H 89P ~ 9 for s) First results using smart conducting shells for wall stabilization Increased physics understanding of edge and internal plasma instabilities Exploration of internal transport barriers with counter injection and pellets Exciting new work affecting turbulence using impurity atoms Next Steps New discovery ELM-free H mode without impurity accumulation or density buildup New discovery H mode confinement quality above the Greenwald limit with gas fueling and pumping A scientific basis for the choice of the optimum shape of the plasma Broad Science Measurement of the complex D flow patterns in the edge plasma Studies of self-organized criticality Movies of edge-plasma turbulence from plasma fluctuation measurements 15 /RDS/wj
ADVANCED TOKAMAK 5 YEAR RESEARCH PLAN Physics Development β N H 89 ~9 for s (16τ E ) ITB Physics Edge Stability Neoclassical Tearing Resistive Wall Mode AT Divertor ECCD Physics Validation Physics Integration Integrated long duration scenarios (1 seconds) with high normalized beta, confinement enhancement, bootstrap fraction, and radiative divertor Increased stability limits Use and optimization of transport barriers at high beta Non-inductive current sustainment with high bootstrap current fraction Divertor power and particle control Progress Checkpoint FESAC Checkpoint CY 1999 1 3 Operation Periods Current Drive (EC) Fueling and Edge Control Resistive Wall Mode Control Diagnostics Other Options Inside launch pellet Upper Divertor Divertor Improvement Central Thomson 6 Coil Feedback Gyrotrons Upper Divertor Diagnostics 6 Gyrotrons 8 Gyrotrons 9.5 MW Long Pulse Edge J(r) 18 Coil Feedback Electron Transport 3-D Equilibrium Counter NBI Liquid Jet In-vessel wall stabilization systems Diagnostics = Completed = Planned = Option 15-/RDS/wj
PRIMARY INTEGRATED SCENARIO NCS USING OFF AXIS ECCD 1 P EC (MW).3 P FW (MW) 3.5 P NBI (MW).1 B T (T) 1.6 I P (MA) 1. I BOOT (MA).65 I ECCD (MA).15 β N. H 89P.8 n/n G.3 Wall stabilization 6-coil.5 3.5 3.8 1.75 1.3.9. 5.3 3.5. 18-coil 3 7. 6.5 6.5 1.95 1.6 1.7.35 5.7 3.5. 18-coil (ρ ITB ~ ρ qmin ) χ e various models χ i ~ neoclassical inside ρ(qmin) ~ 5 neoclassical at edge Solved for T e, T i, J(r) Off-axis ECCD n e (r) fixed (MA/m ) 1.5 1..5 J NB J tot J BS J ECCD.... ρ.6.8 1. 38 /TST/wj
SIGNIFICANT IMPROVEMENT IN LONG-PULSE ADVANCED TOKAMAK PERFORMANCE HAS BEEN ACHIEVED (T#) Recent emphasis is on increasing the duration of high performance and increasing the fraction of bootstrap current β N H = 9 for 16 τ E 1 goal, β N H > 1, τ dur > s, f BS > 5% ELM-free H-mode ELMy H-mode L-mode edge 5 β N l i H 89 ARIES-RS SSTR ARIES-RS SSTR 8713 β N H89p 15 1 5 87977 988 95983 931 96686 991 98965 9876 9695 9319 89756 DIII-D Advanced Tokamak Target ARIES-RS 98977 1999 Progress 89795 85 Conventional Tokamak 5 1 15 5 96568 9835 96 15 β N H 89 P NBI I P D α s 1. MA 11 MW f bs = ~ 5% ARIES-RS SSTR τ duration /τ E 5 1 15 5 3 35 Time (ms) 9-99/rs
DENSITY CONTROL AND NON-INDUCTIVE CURRENT SUSTAINMENT ARE REQUIRED TO ACHIEVE STATIONARY HIGH PERFORMANCE Current profile diffuses to unstable profile Density continuously grows at constant β J (A/cm ) 1 L mode 1 Early H mode 1 Late H mode 8 8 6 n e (1 19 m 3 ) 6 L mode Early H mode Late H mode....6.8 1. ρ... ρ.6.8 1. Future work Density control with high triangularity closed divertor Current profile control with ECCD QTYUIOP 38 /TST/wj
s Katya Boris Natasha Dorothy.7 MW, s.7 MW, s.7 MW, s.7 MW, 1 s EC SYSTEM PLAN CY CY1 CY CY3 CY 1 s EC Waveforms (MW) Toto Scarecrow Nominal Tube Power Power into Plasma.7 MW, 1 s 1. MW, 1 s Tin Man Lion 1. MW, 1 s 1. MW, 1 s CPI # LP CPI #5 LP 1. MW, 1 s 1. MW, 1 s 5.1 5.7 3.7 5. 3.1 3.6 1.7.7.3. 1. 1 Time (s) 7.1 VLT #1 VLT # VLT #3 1.5 MW, 1 s 1.5 MW, 1 s 1.5 MW, 1 s 9.5 6.7 9.5 6.7 1 Time (s) 38-/RDS/wj
HIGH POWER EC SYSTEMS (11 GHz) BEING IMPLEMENTED FOR ADVANCED TOKAMAK PROFILE CONTROL All 1 MW Class Gyrotrons New Diamond Window Gyrotron Short pulse ( seconds) gyrotrons from TdeV 1 from Russia CPI Gyrotron Mirror Interface Unit Long-pulse Diamond window gyrotrons (1 seconds) 1 development unit 3 new units 55 kw, 1 s test Cryomagnetics Magnet GA Dummy Load PPPL / GA Support Tank 15 /RDS/wj
CPI GYROTRON TOTO READY FOR OPS 65 kw FOR.5 s INTO USING PPPL LAUNCHER 38 /RDS/wj
PPPL FULLY ARTICULATING ECH LAUNCHER Co-counter experiment already performed in a single day using this launcher and TOTO Weakly focusing fixed copper mirrors Waveguide aperture Independently rotatable toroidal and poloidal steering mirrors molybdenum on graphite 38 /RDS/wj
NEW CAPABILITY PROVIDED BY PPPL STEERABLE LAUNCHER ALLOWS CO/COUNTER ECCD COMPARISON ECCD reversed on successive shots using PPPL launcher 15 Time Slice at 115 Narrow profile of driven current: main current drive effects occur between one pair of MSE chords Future work Validation of current drive models X-ray camera (PPPL) Validation of NTM stabilization by reversing current drive Transport barrier control Long-pulse steerable launcher (PPPL) B z Difference (A/cm ) 1 5-5 1.6 1.8.. Major Radius (m) 38 /RDS/wj
NEW GYROTRON ROOM IS FILLING UP CPI (Scarecrow left) and TdeV (Boris and Natasha right) 38 /RDS/wj
EC SYSTEMS FOR LONG-PULSE DEMONSTRATION OF INTERMEDIATE AT SCENARIOS FY1 system 8 gyrotrons in 8 sockets Further system development HV supply # to condition spares while 6 gyrotrons are used for research Two more transmission lines so all 8 gyrotrons can be used for research Two short pulse tubes useful for reverse shear formation during current rise and for NTM control RADIATION SHIELD PENETRATION TOTO TRANSMISSION LINE ~9.5 METERS DOROTHY TRANSMISSION LINE ~5.5 METERS TRANSMISSION LINE #5 - ~91 METERS TRANSMISSION LINE #6 ~89.5 METERS GYROTRON # GYROTRON #5 TdeV GYROTRON #1 TdeV GYROTRON # GYROTRON #6 POLARIZER TOTO DOROTHY FAST WAVEGUIDE SHUTTER TURBO MOLECULAR PUMP MANUAL WAVEGUIDE VALVES KATYA TRANSMISSION LINE ~38.5 METERS FWD/REV POWER MONITOR KATYA T de V WAVEGUIDES WAVEGUIDES 1, WAVEGUIDES 5, 6 WAVEGUIDES 3, 15 /RDS/wj
ECH/ECCD IS USEFUL CONTROL TOOL FOR EVALUATING ELECTRON TRANSPORT AND TRANSPORT BARRIERS T e (kev) 8 6 T e profile shows very strong gradient 99696.5 = Core Thomson = ECE T e.8.6 q ECH 3 (W/cm ). 5.. 3.. Electron diffusivity is near ion neoclassical diffusivity in the steep gradient region (m /s) χ e. q ECH....6.8 1. 1. ρ 1. χ neoclassical....6 ρ.8 1. Future work: evaluate ITB control Location of deposition ρ ITB Width of deposition width of ITB Steerable antennas, long pulse ECH 38-/TST/jy
THE DIVERTOR HAS SEVERAL UNIQUE FEATURES TO SUPPORT ADVANCED TOKAMAK PROGRAM AND DIVERTOR RESEARCH Independently operated divertor pumps at both upper strike points and at the lower outer strike point provide flexibilty Allow particle control in a wide range of triangularity, elongation, double null and single null Comparison of open and baffles configurations in same device Detachment control by adjusting the ratio of inboard to outboard exhausts Impurity enrichment by puff and pump at low density Low leakage to pumping speed ratios nearly eliminates recycling through baffle structure Outer upper pump; m 3 s 1 : 37 m 3 s 1 Inner upper pump; 1 m 3 s 1 : m 3 s 1 Lower pump; m 3 s 1 : m 3 s 1 11-/jy
NEW DIVERTOR SUPPORTS HIGH TRIANGULARITY PLASMAS New cryopump expands density and impurity control capabilities Existing baffle nose augmented Private flux dome protects pump, reduces recycling New contoured tiles with reduced gap and height variation 15-/RDS/wj
Impurity Control In AT Plasmas With Careful Tile Shaping Up the Centerpost Wall Strike point moved UP wall from old tiles to new shaped tiles Heat Flux LOW on shaped tiles Heat Flux HIGH on Edges of Old Tiles Infrared Camera Signal 15 1 5 flat contoured Infrared TV Temperature Signal is NOT peaked on Shaped Tiles 6 8 1 1 Toroidally Along the Centerpost Wall 8 3 Carbon Concentration (%) is Reduced Compared to Previous Operation Edge RDP-1999 RDP- Core 6 8 1 1 1 Time (ms) 13- jy
AT Scenario Uses Divertor Shapes For Real-time Control UN Pumped L mode L To H mode Transition drsep ~ Pumped H mode Maintain low n e drsep ~1 for pumping B 13- jy
With available ECH power on, density and impurity control are critical - these are provided by the divertor 3 Simulation P EC =3 MW; ρ EC =.8 I p = 1. MA 9911.18 / 9859.181 I (ka) 1 I ECCD I OHMIC CY #9911 pump CY1999 #9859 unpump x1 13 1135 6. Density....5 H Factor H 93 ~1 n e /n egw 3 5 6 n e (1 19 m 3 ).. D α ICD Te 1 n e (Zeff + 5). 5 1 15 5 3 35 5 Time (ms) 13-/Allen/jy
Magnetic balance can be used for power and particle control 1. 1..5 Divertor Heat Flux Balance (Top - Bot)/Total.5 Divertor Particle Flux Balance (Top - Bot)/Total...5.5 1. Magnetic Balance 1. Magnetic Balance 13-/Allen/jy
We have a high density divertor solution We have a reasonable scientific basis for a conventional long-pulse tokamak divertor solution at high density (collisional edge, detached) Low Te recombining plasma leads to low heat and particle fluxes at wall Adequate ash control, compatible with ELMing H mode confinement Appropriate for future tokamaks (e.g. to high density ITER-RC) Concerns about simultaneously handling disruptions/elms and tritium inventory which shorten divertor lifetime The challenge is to find self consistent operating modes for other configurations... (U.S. Snowmass working group, July ) 13-/Allen/jy
Detached divertors for particle and power handling Data Shows Low Te Recombining Plasma Near Plate (Dγ/D α ) 1.5 1.6 R (m) Model Shows Low Te Divertor Heat Flux is Reduced Erosion is Reduced 5 1.5 1.6 R (m) 5 5 75 1 Electron Temperature (ev) Heat Flux (W/cm ) 3 1 8 1 1 1 16 Major Radius (cm) Shot 7931@3ms 18 Ve (cm/exp-yr) 3 erosion deposition 3 8 DR OSP (cm) 13-/Allen/jy
New physics in the x-point and private flux region Flow Reversal E x B Drifts Recombination in Private Flux 3. 1 6 Reversal in Plasma Flow 5 Electric Field En Plasma Potential H Mode D α Mach number.5. V p (V) 15 1 5 E n E B Away From Plate E n E B To Plate Flow Reversal.5 6 8 1 1 Height from Target Plate Z (cm).99 1. 1.1 1. 1.3 Ψ n Appreciable T e, n e In this Region 13-/Allen/jy
Puff And Pump In Both The Open And Closed Divertors D Puff Argon D Puff 8 1 13 6 1 13 Density 11661 1 13 1 13 1 8 X-point puff Upstream puff D Puff Impurity Exhaust. Argon puff 1.5 1..5.. Argon density.3..1. 1 3 Time (ms) 13- jy
AT Divertors are not just for heat flux reduction Advances in detached plasmas by this community have made possible a high density divertor solution (with some caveats, of course!)... Now divertor particle control is vital for AT modes Shaped plasmas are "standard", needed for high performance Real Time Shape control enables H-mode power threshold control, particle control Current profile control (ECCD) is at the heart of the AT, Impurities are important! Heat flux control in AT plasmas is expected to require impurity flow control "Puff and Pump" or active flow control, need progress in understanding flows Lots of new, exciting physics in the pedestal and x-point region 13- jy
WALL STABILIZATION AND PLASMA SHAPING ESSENTIAL FOR HIGH PERFORMANCE ADVANCED TOKAMAK OPERATION β N B T /(I/aB β N ~ 6 with wall stabilization β N ~ 3 without wall stabilization β N 8 7 6 5 3 1 Ideal Stability, n = 1, GATO q 3....6.8 ρ 1.5 1..5. J TOR B T B p = 5 ( 1 + k ) ( ) 6 β N (%-m-t/ma) β N 1 f BS = C BS ε 1/ B p P FUS B T B T.5 1. 1.5..5 rwall /rwall ~ ~ motivates RWM Thrust # motivates optimal divertor shape Thrust #5 3 /TST/wj
3 ACTIVE FEEDBACK STABILIZATION EXTENDS HIGH β DURATION (March ) Feedback turn-on time 11951 11953 11956 (gauss) (km/s) 1 3 β N RWM AMPLITUDE NO-WALL LIMIT (approx.) NO FEEDBACK PLASMA TOROIDAL ROTATION ρ ~.5 MODE CONTROL + DERIV. GAIN SMART SHELL + DERIV. GAIN 1 11 1 13 1 15 Time (ms) Sensor loops C coil sections o x C-coil 38-/TST/jy
VALEN 3D FEEDBACK CONTROL MODEL PREDICTS β CAN BE IMPROVED TOWARDS IDEAL LIMIT IN DIII-D Existing 6 coil set can increase RWM stability limit to β ~ 3. for basic N smart shell control algorithm. Three control system improvements: shorter sensor coils internal sensor coils extended 18 coil set -1 Growth Rate (sec ) System improvements can extend performance towards ideal wallβ limit N 1 1 resistive wall mode no wall β limit No Feedback Base C-Coil C-coil with short, internal sensors 18 coil set with internal sensors ideal kink 1 1 3 5 β N ideal wall β limit C o lu m b ia U n iv e rsity
DETAILED EDGE MEASUREMENTS AND THEORY ARE LEADING TO AN UNDERSTANDING OF EDGE PEDESTAL PHYSICS P exceeds prediction from first regime ballooning n ~ 5 driven by local P and local J BS p' confinement. Unstable Stable Stable Equil. p' Un.9.95 1. ψ ~. 1.6 6 Scaling with Triangularity α e /αbal CRIT n = 5 Calculated Stability Threshold (1 Pa). P.8 (1 6 A/m ) Type I ELMs αbal Last % of ELM Cycle CRIT... Triangularity, δ = (δ UPPER + δ LOWER )/ J BS..8.9. 1. r/a Future plan to measure J edge to validate models with Lithium beam polarimetry 38- TT/rs
THE GOAL OF THRUST 7 IS TO ESTABLISH CONTROL OVER THE INTERNAL TRANSPORT BARRIER Increase spatial extent of barrier. Increased fusion performance. Control pressure gradient in barrier. Avoid MHD instabilities which can terminate ITB or disrupt discharge. 1.5 a.u... 1. ρ 1999 MHD limits.5 a.u. Counter-NBI Neon puffing Off-axis ECH Off-axis pellets Off-axis NBI. 1. ρ Maintain elevated/reversed q profile. Avoid MHD instabilities when q min 1. Impacts ITB characteristics, especially in n e and T e profiles. Take advantage of favorable impact of counter-nbcd and bootstrap currents in broadened barriers. Improved stability 1.5 a.u. local p.. 1. ρ Counter-NBI Modulated off-axis ECH Neon injection ρ ITB Improved fusion performance?.6 a.u.. 1. ρ Greenfield DAC
β N (%-m-t/ma) 8 6 STABILITY LIMIT IMPROVES WITH INTERNAL TRANSPORT BARRIER WIDTH AND RADIUS Fixed shape DND, q 95 = 5.1, q = 3., q min =. Hyperbolic tangent pressure representation Ideal n = 1, wall at 1.5a P ψ ITB =.36 Half Width W ITB (flux space) β N (%-m-t/ma) 8 6 P W ITB =.3 Stable Stable Unstable Unstable....6....6.8 ITB Radius ψ ITB (flux space) 31 99/RDS/jy
9989 (1.17s): Counter-NBI W =.9 MJ P NBI = 11. MW (6.5 MW absorbed). COUNTER-NBI RESULTS IN BROADER PROFILES kev 15 1 5 T e counter co T i 1 19 m -3 8 6 n e 8731 (1.8s): Co-NBI W = 1. MJ P NBI = 9.6 MW (7.6 MW absorbed). 1 5 s -1 3 1 Ω 6 q....6.8 1. ρ....6.8 1. ρ Greenfield DAC 5
COMBINATION OF p AND ROTATION EFFECTS IN ω E B NATURALLY BROADENS COUNTER BARRIERS Shearing rate ω E B separated into thermal main ion rotation and pressure gradient terms. Total calculated from CER impurity measurements. Main ion pressure term from profile measurements. Rotation term by subtraction. Stability to drift ballooning modes calculated using a linear gyrokinetic stability (GKS) code. Non-circular, finite aspect ratio equilibria with fully electromagnetic dynamics. With counter-nbi: Linear growth rates smaller at at large ρ, possibly due to higher Z eff near edge (core Z eff ª.5 in both cases). Shearing rate profile extends to larger ρ. 1 5 s -1-1 5-5 - 8731 1.8s (co) 9989 1.17s (counter)... ρ.6.8 1.... ρ.6.8 1. 1 5 s -1 6 5 3 1 ω E B p ω E B rotation ω E B co (8731 1.8s) ctr (9989 1.17s) ω E B ω E B γ max p ω E B rotation ω E B... ρ.6.8 1. Greenfield DAC 6
GAS FUELED H MODE DISCHARGES WELL ABOVE THE GREENWALD DENITY IN H Factor (89P).5. 1.5 1..5 PUMPED q95 = 3.1 q95 = 3.5 q95 = 5.9 Gas Puffed Discharges H-Factor (89P) DISCHARGES....6.8 1. 1. 1. Fraction of the Greenwald Density 15-/jy
GAS PUFF FUELED H MODE DISCHARGES WITH HIGH ENERGY CONFINEMENT ABOVE THE GREENWALD LIMIT ON Plasma stored energy, W, increases with density after an initial decrease following the start of gas injection n and W increase limited by MHD Stored energy is comparable to low density discharge at the same heating power. 1.1 H = H-ITER89P β n Low n Discharge NTM β n 1.5 98893. 1 3 Time (s) 5 1..9.6.3. n e /n G = 1 n e /n G D Puff 1 3 Time (s) H PED n e /n G 3 I P ( MA) ng ( 1 m ) = 1.1 πa ( m).85 1..11.17.3.66.67 ITER89P = τe /( I p R a ne BT κ / PL 5 ) 1.5 1..5 H93 n e /n G L-mode With Impurity Injection Ar ELMy H mode DIII-D Puff and Pump ELMy H-mode JET ELMy H mode TEXTOR RImode JT 6U ELMy H mode H = 1...5 n /n 1. 1.5 e G 15-/jy
n e (1 19 m 3 ) 6 LOW AND HIGH DENSITY PUMPED DISCHARGES HAVE SIMILAR DENSITY PROFILES 98889.5 98889.35 98889.1 98889.18 Density shot: 98889 Thomson Data = Core = Tangential Te (kev) 3 1 Te vs rho shot: 98889 = Core Thomson = Tang Thomson 98889.5 98889.315 98889.1 98889.18....6.8 1. 1. ρ....6 ρ.8 1. 1. n e (1 19 m 3 ) 5 15 1 Density shot: 98893 Te vs rho shot: 98893 Thomson Data = Core = Tangential 98893.15 98893.3 98893.1 98893.18 Te (kev). 1.5 1. = Core Thomson = Tang Thomson 98893.15 98893.3 98893.1 98893.18 5.5 S A N D I E G O, C A L I F O R N I A....6 ρ.8 1. 1......6 ρ.8 1. 1. 15- jy
HIGH FIELD SIDE PELLET INJECTION ALLOWS EVALUATION OF INTERNAL TRANSPORT BARRIERS WITH T e ~ T i n e (1 19 m 3 ) 1 5.7 mm Pellets - HFS 5 vs LFS New capability in ITB control 98796 - measured n e HFS 5 v p = 118 m/s t = 5 ms....6.8 1. 1. ρ LFS v p = 586 m/s t = 1 ms T e, T i (kev) n e, (1 19 m 3 ) 1 8 6 PEP ITB non- PEP ITB 99787 5 PEP T i (CER) T e (TS) 3 1 q...6.8 1. ρ 6 5 3 HFS pellet injection yields deeper particle deposition than LFS injection, consistant with theory Future work on ITB control and H mode control with pellet 38-/TST/jy
CONFINEMENT INCREASES DRAMATICALLY WITH NEON Neutron Rate (s 1) W PLASMA (J) PRAD (MW) H (τ E /τ 89P ) 3.x1 6. 1.. 6x1 5 8x1 1 6. 1.5 1..5 Neon Reference Neon Department of Engineering Physics Radiated power: 3.5 MW, 75% of input power Stored energy increases by 8% Neutron rate doubles; confinement increase overwhelms dilution τ E increases to H 89P = 1.8 despite radiation τ E = W PLASMA / (P INPUT - dw/dt). 5 3-/KHB/jy 1 Time (ms) 15 George McKee, APS 1999 M A DI S N O OUNIVERSITY OF WISC NSIN
GKS CALCULATIONS OF LINEAR STABILITY GROWTH RATES SHOW SIGNIFICANT REDUCTION AT LOW-k Growth Rate (1 5 /s) 1. 1..8.6.. Growth rates at ρ =.7, t = 116 ms, BES (low-k) Region BES Range Neon Reference ω ExB Spectra, (<ñ>/n) /khz 5x1 8 3 1 Measured Fluctuation Spectra Neon Reference. 1 3 1 k (cm ) 5 1 Frequency (khz) 3 ExB shearing rates exhibit opposite behavior, increasing in neon shot, further suppressing turbulence: 3-/KHB/jy Neon: γ lin < ω EXB, Reference: γ lin > ω EXB George McKee, APS 1999 M A DI S N O OUNIVERSITY OF WISC NSIN Department of Engineering Physics
FUTURE RESEARCH DIRECTION - HIGH k TURBULENCE AND ELECTRON TRANSPORT Measurements in range.5 < ρ <.8, k θ = 13.3 cm 1 Frequency (khz) 1 5 5 1 kθ = 13.3 cm -1 r = cm ±9 cm Color Enhanced Contour Plot of Scattered Power Spectrum Evolution neon injection 98779 9878 8 1 1 1 16 Time (ms) 1 k θ = 13.3 cm -1 no neon r = cm ±9 cm 5 Frequency (khz) 5 1.e-3 1.e-3..... 98781 no neon 9878 Frequency Integrated Fluctuation Level. T-l/s neon 9878. 3. T-l/s neon 1 1 1 16 18 k θ = 13.3 cm 1 Time (ms) firs1f rms -99 to 19 khz R = cm 9 cm χ e (m/s) χ e (m/s) χ e (m/s) 1 98781 1 1 16 Time (ms) Improved short wavelength measurements needed (improved FIR scatting) UCLAUCLA UCLA 38-/TST/jy
. 6. 3...8 3. 1 STEADY-STATE, ELM-FREE, SAWTOOTH-FREE SHOT WITH DENSITY CONTROL I p (MA) n e (1 19 m 3 ) β N H 89P Divertor D α SXR P B (MW) Shot 99851 5 1 15 5 3 35 5 5 Time (ms) QTYUIOP -99/rs
THE ADVANCED TOKAMAK RESEARCH THRUSTS FOR 1 3 INTERNAL TRANSPORT BARRIER PHYSICS RESISTIVE WALL MODE FEEDBACK AT DIVERTOR RWM STABILIZATION AT AND RADIATIVE DIVERTOR OPTIMAL MODE SPECTRUM ITB AT LARGE RADIUS ADVANCED METHODS HIGH BOOTSTRAP FRACTION ADVANCED TOKAMAK (INTERMEDIATE SCENARIOS) SUSTAIN OPTIMIZE MODERATE PULSE ADVANCED TOKAMAK FESAC ASSESS- MENT ECH/ECCD VALIDATION EDGE STABILITY STUDIES NEOCLASSICAL TEARING- AFFECT MODE EDGE STABILITY CONTROL NTM-CONTROL MODE GROWTH NTM-STABILIZE MODE HIGH l i SCENARIO PHYSICS INTERMEDIATE SCENARIO DEMONSTRATION 3-/RDS/rs