1. NSTX: Facility/Research Highlights and Near Term Facility Plans Office of Science Masa Ono, PPPL For the NSTX Research Team College W&M Colorado Sch Mines Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics New York U Old Dominion U ORNL PPPL PSI Princeton U SNL Think Tank, Inc. UC Davis UC Irvine UCLA UCSD U Colorado U Maryland U Rochester U Washington U Wisconsin Culham Sci Ctr U St. Andrews York U Chubu U Fukui U Hiroshima U Hyogo U Kyoto U Kyushu U Kyushu Tokai U NIFS Niigata U U Tokyo JAEA Hebrew U Ioffe Inst RRC Kurchatov Inst TRINITI KBSI KAIST POSTECH ASIPP ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching ASCR, Czech Rep U Quebec Supported by 4th IAEA Technical Meeting on Spherical Tori & 14th International Workshop on Spherical Torus ENEA, Frascati 7 – 10 October 2008

2. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 2 Talk Outline NSTX Mission and Facility / Diagnostic Status Overview Highlights and Facility Diagnostic Plans Organized by Science Topical Areas –MHD (M. Bell) –T&T (M. Bell) –Boundary Physics (M. Bell) –HHFW, EBW, and Energetic Particles –Start-up and Ramp-up (R. Raman) NSTX Near Term Plans (5 Year Plan) Conclusions

3. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 3 NSTX Facility Has Continued Rapid Progress in Operational and Experimental Capabilities Baseline Parameters Major Radius 0.85 m Minor Radius 0.68 m Elongation 1.8 - 3.0 Triangularity 0.2 - 0.8 Plasma Current 1 MA (1.5 MA peak) Toroidal Field 0.35 - 0.55 T Heating and CD 7 MW NBI (2 sec) 5 MWNBI (5 sec) 6 MW HHFW (5 sec) 0.2 MA CHI Pulse Length ~ 1 sec at 0.55 T ~ 2 sec at 0.38 T NSTX Facility Overview

4. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 4 NSTX Device Cross-Section and VV Internal Components Removable Center-Stack Design

5. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 5 NSTX Mission Elements 1.Establish attractive ST operating scenarios & configurations –Long-term goal: Understand and utilize advantages of the ST configuration for addressing key gaps between ITER performance and the expected performance of DEMO (including an ST-DEMO) 2.Complement tokamak physics and support ITER –Exploit unique ST features to improve tokamak understanding –Contribute to ITER final design activities and research preparation –Participate strongly in ITPA and U.S. BPO, benefit from tokamak R&D 3.Understand unique physics properties of the ST –Understand impact of low A, very high , high v fast / v A, … –ST understanding underpins missions 1 and 2 above

6. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 6 2007 FESAC Priorities Panel prioritized issues for getting from ITER to DEMO ST can contribute to all FESAC Priority Panel “Themes” A.Creating predictable high-performance steady-state plasmas –Measurement –Integration of high-performance, steady-state, burning plasmas –Validated predictive modeling –Control –Off-normal plasma events –Plasma modification by auxiliary systems –Magnets B.Taming the plasma material Interface (PMI) –Plasma wall interactions –Plasma facing components –RF antennas, launching structures, and other internal structures C.Harnessing fusion power –Fusion fuel cycle –Power extraction –Materials science in the fusion environment –Safety ST offers simplified, maintainable, affordable magnets for DEMO ST offers high heat flux at small size and cost for PMI R&D ST offers high neutron flux at small size and cost for testing fusion nuclear components ST expands knowledge-base for all aspects of Theme A

7. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 7 HHFW For Electron Heating and Current Drive for Start-up, Ramp-Up, and Sustainment HHFW Antenna Upgrades HHFW Antenna Array Double-feed upgrade for higher power in 2009 to utilize full power under various load conditions ELM resilience system upgrade in 2010 with ORNLfor H-mode operation Twelve antennas Six 1 MW transmitters Real time phasing Top-fed Wave reflectometers Edge rf probes Present Feed New Feed Present Gound New Desired Gound Feed-through voltage reduced to double power handing capability Mid-plane ground to optimize HHFW launching

8. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 8 || D, He Plasmas Heated to 5 keV with 3 MW HHFW at k || = 14 m -1 (Lithium has helped HHFW performance in deuterium, H-mode, and NBI) P. Ryan, et al C. K. Phillips et al.,(IAEA)

9. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 9 P rf ~ 1.8 MW in He-4 plasmas (~ 230 ms duration) P rf ~ 1.1 MW in D plasmas (~230 ms duration) Noticeable increase in  W EF with -30° phasing in D plasmas with Li edge conditioning, even with shorter rf duration (67 ms) HHFW-Induced Increase in Electron Stored Energy Comparable in Helium and D Plasmas

10. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 10 Experiments starting to study HHFW coupling into deuterium H-modes with upgraded antennas HHFW Heating of NBI-Driven H-mode Plasmas

11. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 Productive EBW Research EBW Current Drive Significantly Increases Performance for Future STs Remotely Steered EBW Emission System for Coupling Study S. J. Diem, G. Taylor et al., (IAEA) S. J. Diem PhD Thesis

12. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 12 LIThium EvaporatoR (LITER) provides PFC Conditioning Tool to Modify Plasma Edge B-X-O coupling depends on L n and T e –Li conditioning T e & n e near MC Reduction in edge n e moves MC layer to LCFS where T e ~ 20 eV H. Kugel, et al, PoP

13. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 13 Better T rad agreement with EBE simulation in Lithium conditioned plasma T rad (measured) T rad (sim., no collisions) T rad (sim., with collisions) For highest Li evaporation rate, 19 mg/min: –Measured T rad ~0.4 keV –Simulated T rad ~0.6 keV For 0 mg/min: –Measured T rad ~0.1 keV –Simulated T rad ~0.4 keV Control of edge conditions allows for good coupling to EBW

14. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 14 Extensive Energetic Particle Diagnostic Capability Measures Fast Ion Properties FIDA diagnostic on NSTX (2008) –Fast neutron rate monitors –Scanning NPA; –ssNPA; 4-channel compact NPA –sFLIP; scintillator lost ion probe, –iFLIP; Faraday cup lost ion probes –FIDA; spatial profile, energy resolved (2008) Collaboration contributions

15. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 15 Quasi-Continuous RSAE and Bursting AE Avalanche Produce Ion Losses Losses increase while frequency still increasing Avalanche also produces burst of loss Colors designate n numbers s-FLIP Scintillator Detector Principle of Operation D. Darrow, E. Fredrickson

16. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 16 MHD Instabilities Affect Confinement of Fast Ions Density profile of fast ions (15 – 65 keV) deduced from Doppler-shifted D  emission by energetic neutrals created by charge-exchange with NBI neutrals During TAE avalanches, measured fast-ion losses up to 30% –Consistent with neutron rate drop –Profile remains peaked Low-frequency (kink) activity redistributes fast ions outwards –Can destabilize Compressional Alfvén Eigenmodes (CAEs) in outboard midplane region Avalanche M. Podestá M. Podesta, APS

17. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 17 Gaps Between Present and Future STs Motivate NSTX Scientific Goals and Associated Upgrades 1. Increase and understand beam-driven current lower n e, *  Test increased NBI-CD with density reduction, higher T e, higher NBI power 2. Increase and understand H-mode confinement at low *  Determine modes responsible for transport, determine scaling vs. B T, I P, P HEAT 3. Demonstrate and understand non-inductive start-up and ramp-up  Increase ramp-up heating power & current drive to test I P ramp-up techniques 4. Sustain  N and understand MHD near and above no-wall limit  Improve control of , RWM/EF, rotation and q profiles to optimize stability

18. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 18 New NSTX Diagnostic Capabilities All diagnostics measure close to mid-plane to facilitate data analysis P-CHERS 75 Ch MSE-LIF (FY09-10) V  (r) E r (r), B(r) NBI paths 32 Ch BES - Low-k to comprement high-k R. Bell E. Foley, F. Levinton G. McKee, B. Stratton

19. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 19 Near Term upgrades will enable unique and exciting research in support of 3 highest priority research goals 2.Measure full wave-number spectrum of turbulence to determine modes responsible for anomalous transport 1.Reduce electron density using liquid lithium, improve understanding of how Li improves confinement and reduces/eliminates ELMs  Implement liquid lithium divertor (LLD) LLD-I = porous Mo surface bonded to heated Cu plate 3.Asses if higher power HHFW can ramp-up I P in H-mode (BS+RF overdrive) and heat high-  N NBI H-mode scenarios  Upgrade HHFW system for higher P RF + ELM resilience  Implement BES to complement existing high-k scattering diagnostic LLD-I 90° SEGMENT ORNL, PPPL U. Wisconsin, PPPL SNL, PPPL

20. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 6.07.08.0 I P =1.4MA New High-Performance Center-Stack will Expand Operational Space Toward Next-Step STs 6.07.08.0 I P =1.4MA 0.2 0.4 0.6 0.8 1.0 B T (T)  Pulse (sec) 1.02.03.01.04.05.06.07.08.0 1 MA 0.9 MA 0.75 MA Present CS New CS I P =1.4MA I P  2 MA Determine if the favorable ion and electron confinement scaling, and turbulence variation, observed in NSTX continues to higher magnetic fields and lower collisionality. Determine if the MHD stability of neoclassical tearing modes and resistive wall modes is favorable at lower collisionality and higher magnetic field. Using the higher magnetic field, which improves the efficiency of plasma heating and current drive both for RF and NBI, push further towards fully non-inductive start-up and current sustainment for long pulses.

21. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 21 2m Present CSNew CS New Center Stack will Utilize Interchangeable Design but will Incorporate Additional Key Improvements + 13 cm radial build PF 1C PF 1B PF 1A Improved TF joint design to minimize lift off PF 1A, 1B, and 1C at both top and bottom for improved divertor control flexibility (e.g. very high expansion for X-divertor) Incorporate additional capabilities (e.g. pellet guide tube for inside launch)

22. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 2nd NBI Addition of Second NBI Will Produce Plasma Parameters Relevant for Next-Step STs Pump Duct Extend Confinement scalings to higher power and plasma pressure, and lower collisionality, closer to next-step ST devices. Test Magneto-hydrodynamic stability at higher plasma pressure to explore the limits that could be encountered in future devices. Challenge the divertor in NSTX beyond the capabilities of any other device in the world (in terms of the scaling parameter, P/R) Greatly enhanced capabilities -Doubles P NBI from 7 to 14 MW (at 95 keV, 2s), 5 to 10 MW (at 80 keV, 5s) -Higher CD Efficiency and j(r) control

23. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 More Tangential Injection Enables Profile Control and Fully-Non-Inductive Current-Drive Scenarios Test predictions that more tangential injection increases beam current drive efficiency and can sustain a broadened and more MHD stable current profile. Increased Alfvén eigenmode activity and fast-ion redistribution/loss could result from more tangential injection and increased fast-ion pressure. Test plasma ramp-up using beam injection and demonstrate fully non-inductive sustainment to simulate the scenarios planned for future ST devices.

24. M. Ono 4th IAEA Technical Meeting & 14th International Workshop on ST, ENEA, Frascati October 7-10, 2008 24 NSTX is Assessing Potential of the ST for fusion NSTX produced exciting results in Waves and Energetic Particles: –Efficient HHFW electron heating is demonstrated in deuterium to ~ 5 keV. –Lithium has helped HHFW performance in H-mode and with NBI. –EBW emission improvement with Lithium in H-mode is shown to be reduced edge collisional absorption. –FIDA energetic particle diagnostic is producing important data on MHD- induced energetic particle transport. NSTX is implementing cutting edge advanced diagnostics –75 channel P-CHERS is yielding important results. –32 channel BES system is being installed to complement high-k. –MSE-LIF will measure E r and B total for the first time. Upgrades will greatly expand the scientific capabilities of NSTX for next-Step STs: –Access and understand impact of reduced collisionality on ST physics at higher B T and I p with new center-stack –Access and understand impact of varied NBI deposition profile for fully non-inductive sustainment