NSTX research and the connection to community needs

1. Supported by Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics NYU ORNL PPPL PSI SNL UC Davis UC Irvine UCLA UCSD U Maryland U New Mexico U Rochester U Washington U Wisconsin Culham Sci Ctr Hiroshima U HIST Kyushu Tokai U Niigata U Tsukuba U U Tokyo Ioffe Inst TRINITI KBSI KAIST ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching U Quebec NSTX research and the connection to community needs E.J. Synakowski NSTX Team Meeting December 15, 2004

2. Internal modes & flows (Menard, IAEA poster) RWM (Sabbagh, IAEA oral; Sontag, APS invited) Fast ion MHD (Fredrickson, IAEA oral) NSTX research had a strong presence in the national and international stages this fall… • Strong, clear papers underscored that we are competitive or leading in critical areas, including, in MHD…

3. Te 1.5 Ti Fast Ramp (t1) 1.0 Boundary physics & ELMs… (Maingi, IAEA oral) Transport (Stutman, APS invited) 0.5 R0 1.5 Te Slow Ramp (t2) Ti 1.0 0.5 R0 160 40 80 120 Scenario modeling (Kessel, IAEA poster) R (cm) HHFW physics (Biewer, APS invited) NSTX research had a strong presence in the national and international stages this fall…

4. In addition, at the APS there were… • 12 contributed orals • 40 posters (2 sessions) Overall, a very good showing.

5. ET’s are/need to be working towards a sharp research program in ‘05 • Activities include • Boundary physics: discussions are taking place on how to approach lithium pellet experiments this year (Kaita, Kugel) • CHI: Important research operations work (Bell) in preionization, insulation, and control. • MHD: global mode stabilization discussions have taken place. The bar is set high (Sabbagh, Menard). • Transport: discussions regarding sensitivity studies to be performed with linear gk codes to assess robustness of results (Kaye, Redi, Mikk…) • HHFW/EBW: discussions on run priorities at the APS • Control: meeting on what we can strike for and how to manage the control development effort (Gates, Mueller, Bell) • Jon Menard is beginning to work with ET leaders on run planning, with attention paid to cross-cutting issues

6. Point of concern that we have to continually confront: what is the relation between our goals and national/international considerations • We all know and talk about ITER and its impact on our research. • Despite this, for me there was nothing like “being there.” There was no substitute for the experience of being at the IAEA and being immersed in the world of ITER • This raises good questions • What is our relationship to ITER? • What is the right balancein our program between ITER contributions, an ST-centric mission, and contributions to toroidal confinement overall? Do they help each other, or are they at odds?

8. Experimental collaboration Theory-experiment coupling Recall how we described things at the last PAC: “Unique NSTX plasma properties provide scientific leverage in all major areas of toroidal confinement research” Strengthen the scientific basis for fusion energy Edge transport & stability Core transport & turbulence MHD: stability & helicity injection Wave/particle interactions Test theory by isolating important physics and challenging models at their extremes of applicability

9. Belief: ST-, ITER-, and science-oriented pursuits are consonant with each other Consonant: being in agreement or harmony : free from elements making for discord • For example, to be able to extrapolate high beta,high confinement, long pulse, non-inductive operations, we must • Understand confinement • Push stability towards the with-wall limit • Manage high heat fluxes and control the density • Keep q elevated, drive lots of bootstrap, drive current off-axis ITER considerations include Critical issue RWM control considered ITER-relevant heat fluxes Common interest in advanced scenarios Physics issues include Electron transport & high k RWM control. Flows & MHD Potentially very high power densities Integration of JBS, EBW, NBI CD. NTM stabilization

10. The ITPA is an international forum that provides a critical opportunity & challenge for NSTX • It is to your benefit, and the benefit of NSTX, to take part in these forums • We have the elements to lead in many of the discussions. Increasingly, we are seeing the benefits of joint research. Such experiments will be embraced by the ITPA process • These are forums by which our approach to science “by compare & contrast” naturally contributes to ITER-relevant discussions • Participation is growing, but • We have to be prepared to share the burden of travel with each other

11. Recent ITPA participation in Lisbon includes… • Jon • Martin • Rajesh • Roger • Stan • myself

12. Another significant feature of the program is the dialogue of the Priorities Panel • Report due out very soon. Public session held at APS (Baker). Message: Liven it up! • Priorities are not device-specific, but rather are topical • NSTX has a great opportunity to contribute in several key areas, and to lead via contrast/compare experiments • We need to be visible in these areas

13. Areas that make the “top 6” research topics from the Priorities Panel include areas central to the NSTX program • Electron thermal transport • Developing predictive capability of the pedestal Don’t’ recall them all, but two are… • High k scattering opportunity. e-m effects • Edge diagnostics improving. Opp for tests of role of ri, role of magnetic shear Report coming out soon.

14. NSTX milestones for FY ‘05 speak to ST needs as well as national program priorities • Milestone FY05-1 on Physics Integration: Plasma stability and confinement of strongly shaped high-beta plasmas for longer durations will be characterized. (September 2005) • Milestone FY05-2 for MHD Stability: Produce and characterize strongly shaped ST plasmas approaching the “wall-stabilized” pressure limits. (September 2005) • Milestone FY05-3 on Wave-Particle Interactions: Assess the requirements for the high-power Electron Bernstein Wave (EBW) heating and current drive systems on NSTX. (September 2005) • Milestone FY05-4 on Boundary Physics: Characterize the plasma edge pedestals and scrape-off layer in high performance spherical torus plasmas. (September 2005) • Milestone FY05-5 on Turbulence and Transport: The effects of variations in the magnetic shear and gradients in Te on electron transport will be characterized. (September 2005)

15. NSTX research for ‘05 - ‘07 is well aligned with the fusion program’s scientific priorities and supports strategic goals FESAC Theme: Understand the role of magnetic structure on confinement, & plasma pressure limits FESAC Theme: Learn to use energetic particles & e-m waves to sustain and control high temperature plasmas NSTX Stability pressure limits & magnetic reconnection vs. A, shape, profile, q & flows, for internal & external modes with Vflow/VA < 0.4 & unity b; helicity transport EM waves in overdense plasma; Phase space manipulation with high electron trapping; energetic ions with large orbits; Alfven eigenmodes and turbulence with Vfast/VA >> 1 _ Determine Most Promising Configurations Develop New Materials, Components, & Technologies Demonstrate Feasibility with Burning Plasmas Develop Understanding and Predicitve Capability Microscopic ion, electron, and tearing turbulence measurement & theory comparison over wide range in b, flows, and magnetic shear, with good average curvature and high trapping Physics of ELMs, pedestal, SOL turbulence & high divertor heat flux, with large in/out asymmetry; Li coatings & liquid surface interactions with plasma. • FESAC Theme: Learn to control the interface between a 100 million degree plasma and its room temperature surroundings FESAC Theme: Understand & control the processes that govern confinement of heat, momentum, and particles