1. AES, ANL, Boeing, Columbia U., CTD, GA, GIT, LLNL, INEEL, MIT, ORNL, PPPL, SNL, SRS, UCLA, UCSD, UIIC, UWisc FIRE Collaboration http://fire.pppl.gov High-  Steady-State Advanced Tokamak Scenarios for ITER and FIRE Dale Meade APS-DPP Annual Meeting Savannah, Georgia November 15, 2004

2. High-  Steady-State Advanced Tokamak Regimes for ITER and FIRE D. M. Meade 1, N. R. Sauthoff 1, C. E. Kessel 1, R.V. Budny 1, N. Gorelenkov 1, G.A. Navratil 2, J. Bialek 2, M. A. Ulrickson 3, T. Rognlein 4, J. Mandrekas 5, S. C. Jardin 1 and J. A. Schmidt 1, 1 Princeton Plasma Physics Laboratory, Princeton, NJ 08543, USA 2 Columbia University, New York, NY 10027, USA 3 Sandia National Laboratory, Albuquerque, NM 87185, USA 4 Lawrence Livermore National Laboratory, Livermore, CA 94551, USA 5 Georgia Institute of Technology, Atlanta, GA 30332, USA Abstract. An attractive tokamak-based fusion power plant will require the development of high-  steady-state advanced tokamak regimes to produce a high-gain burning plasma with a large fraction of self-driven current and high fusion-power density. Both ITER and FIRE are being designed with the objective to address these issues by exploring and under-standing burning plasma physics both in the conventional H-mode regime, and in advanced tokamak regimes with  N ~ 3 - 4, and f bs ~ 50 - 80%. ITER has employed conservative scenarios, as appropriate for its nuclear technology mission, while FIRE has employed more aggressive assumptions aimed at exploring the scenarios envisioned in the ARIES power-plant studies. The main characteristics of the advanced scenarios presently under study for ITER and FIRE are compared with advanced tokamak regimes envisioned for the European Power Plant Conceptual Study (PPCS-C), the US ARIES-RS Power Plant Study and the Japanese Advanced Steady-State Tokamak Reactor (ASSTR). The goal of the present work is to develop advanced tokamak scenarios that would fully exploit the capability of ITER and FIRE. This paper will summarize the status of the work and indicate critical areas where further R&D is needed. The PPPL work was supported by DOE Contract # DE-AC02-76CHO3073.

3. High Power Density P f /V~ 6 MWm -3 ~10 atm  n ≈ 4 MWm -2 High Gain Q ~ 25 - 50 n  E T ~ 6x10 21 m -3 skeV P  /P heat = f  ≈ 90% Steady-State ~ 90% Bootstrap ARIES Economic Studies have Defined the Plasma Requirements for an Attractive Fusion Power Plant Plasma Exhaust P heat /R x ~ 100MW/m Helium Pumping Tritium Retention Plasma Control Fueling Current Drive RWM Stabilization Significant advances are needed in each area. High gain, high power-density and steady-state are the critical issues.

4. Burning Plasma Experiments and Power Plants

5. Critical Issue #1- Plasma Energy Confinement: FIRE and ITER Require Modest (2.5 to 5) Extrapolation Tokamaks have established a solid basis for confinement scaling of the diverted H-Mode. B  E is the dimensionless metric for confinement time projection n  E T is the dimensional metric for fusion - n  E T =  B 2  E =  B. B  E ARIES-RS Power Plants require B  E only slightly larger than FIRE due high  and B. ARIES-RS (Q = 25)

6. (FESAC 2002) Two Furnaces to Test Fusion Fire

7. (FESAC 2002) Two Furnaces to Test Fusion Fire

8. ARIES and SSTR/CREST studies have determined requirements for an attractive power plant. 12 ITER would expand region  to  N ≈ 3 and f bs ≈ 50% at moderate magnetic field. FIRE would expand region to  N ≈ 4 and f bs ≈ 80% at reactor-like magnetic field. FIRE Would Test  N Limits at Power Plant Magnetic Fields. Modification of JT60-SC Figure Existing experiments, KSTAR, EAST and JT-SC would exp- and high  N region at low field. EAST JT60-SC KSTAR

10. Critical Issue #2 - High Power Densities: Requires Significant (x10) Extrapolation in Plasma Pressure FIRE Could Achieve ARIES-like Power Densities

11. Analysis Tools for These Studies 0-D Burning Plasma Systems Code (Kessel) operating space within physics and engineering constraints TSC-Tokamak Simulation Code (Kessel, Jardin) free boundary equilibria, transport, current drive, radiation time evolving coil currents VALEN (Navratil, Bialek) 3-D finite element electromagnetic code for RWM control modeling RWM mode structure provided by free boundary DCON stability analysis TRANSP (Budny) fixed boundary, detailed models for transport, NBCD, ICFW, LHCD TSC data are input for TRANSP Calculate energetic particle distribution functions NOVA-K (Gorelenkov) Global hybrid, kinetic/MHD, eigenvalue perturbative code Finite orbit width effects for the drive, most important damping mechanisms are included.

13. Recent ITPA Results on Confinement CDBM (Cordey et al) extended H-mode scaling to a two term (core and pedestal model). IAEA FEC 2002 and Nucl. Fusion 43 No 8 (August 2003) 670-674 H(y, 2) 1.0 1.03 1.18 1.25 1.22 1.27 Q 9 10 15 25 22 26 ITER98(y,2) is pessimistic relative to  scans in DIII-D and JET. A new scaling is being evolving from ITPA CDBM March 8-11 meeting that will reduce adverse  scaling (similar to electrostatic gyro-Bohm model). Increased pedestal pressure dependence on triangularity (Sugihara-2003).

14. New ITPA Scaling Opens High-Q H-Mode Regime for FIRE Systematic scans of  E vs  on DIII-D and JET show little degradation with  in contrast to the ITER 98(y, 2) scaling which has  E ~  -0.66 A new confinement scaling relation developed by ITPA has reduced adverse scaling with  see eq. 10 in IAEA-CN-116/IT/P3-32. Cordey et al. A route to ignition is now available if high  N regime can be stabilized.

15. New ITPA Scaling Opens High-Q H-Mode Regime for FIRE Systematic scans of  E vs  on DIII-D and JET show little degradation with  in contrast to the ITER 98(y, 2) scaling which has  E ~  -0.66 A new confinement scaling relation developed by ITPA has reduced adverse scaling with  see eq. 10 in IAEA-CN-116/IT/P3-32. Cordey et al. A route to ignition is now available if high  N regime can be stabilized.

16. Advanced Toroidal Physics (100% Non-inductively Driven AT-Mode) Q~ 5 as target, higher Q not precluded f bs = I bs /I p ~ 80% as target, ARIES-RS/AT≈90%  N ~ 4.0, n = 1 wall stabilized, RWM feedback Quasi-Stationary Burn Duration (use plasma time scales) Pressure profile evolution and burn control> 20 - 40  E Alpha ash accumulation/pumping> 4 - 10  He Plasma current profile evolution~ 2 to 5  skin Divertor pumping and heat removal> 10 - 20  divertor First wall heat removal> 1  first-wall FIRE Physics Objectives Burning Plasma Physics (Conventional Inductively Driven H-Mode) Q~10 as target, higher Q not precluded f  = P  /P heat ~ 66% as target, up to 83% @ Q = 25 TAE/EPMstable at nominal point, access to unstable

17. Fusion Ignition Research Experiment (FIRE) R = 2.14 m, a = 0.595 m B = 10 T, (~ 6.5 T, AT) I p = 7.7 MA, (~ 5 MA, AT) P ICRF = 20 MW P LHCD ≤ 30 MW (Upgrade) P fusion ~ 150 MW Q ≈ 10, (5 - 10, AT) Burn time ≈ 20s (2  CR - Hmode) ≈ 40s (< 5  CR - AT) Tokamak Cost = $350M (FY02) Total Project Cost = $1.2B (FY02) 1,400 tonne LN cooled coils Mission: to attain, explore, understand and optimize magnetically-confined fusion-dominated plasmas

18. FIRE is Based on ARIES-RS Vision 40% scale model of ARIES-RS plasma ARIES-like all metal PFCs Actively cooled W divertor Be tile FW, cooled between shots Close fitting conducting structure ARIES-level toroidal field LN cooled BeCu/OFHC TF ARIES-like current drive technology FWCD and LHCD (no NBI/ECCD) No momentum input Site needs comparable to previous DT tokamaks (TFTR/JET). T required/pulse ~ TFTR ≤ 0.3g-T

19. FIRE Plasma Regimes Operating Modes Elmy H-Mode Improved H-Mode Hybrid Mode Two Freq ICRF ITB Reversed Shear AT - “steady-state” (100% NI) H-ModeAT(ss)ARIES-RS/AT R/a 3.6 3.6 4 B (T) 10 6.5 8 - 6 I p (MA) 7.7 5 12.3-11.3 n/n G 0.70.851.7-0.85 H(y,2) 1.11.2 – 1.70.9 - 1.4  N 1.8≤ 4.24.8 - 5.4 f bs,% 25 ~7788 - 91 Burn/  CR 2 3 - 5steady H-mode facilitated by  x = 0.7,  x = 2, n/n G = 0.7, DN reduction of Elms. AT mode facilitated by strong shaping, close fitting wall and RWM coils.

20. FIRE Conventional H-Mode Operating Range Expanded Nominal operating point Q =10 P f = 150 MW, 5.5 MWm -3 Power handling improved P f ~ 300 MW, 10 MWm -3 Physics basis improved (ITPA) DN enhances  E  N DN reduces Elms Hybrid mode has Q ~ 20 Engineering Design Improved Pulse repetition rate tripled divertor & baffle integrated

21. FIRE AT Mode Operating Range Greatly Expanded Q = 5 Nominal operating point Q = 5 P f = 150 MW, P f /V p = 5.5 MWm -3 (ARIES) ≈ steady-state 4 to 5  CR Physics basis improving (ITPA) required confinement H factor and  N attained transiently C-Mod LHCD experiments will be very important First Wall is the main limit Improve cooling revisit FW design Opportunity for additional improvement.

22. Integrated Modeling for FIRE Burning Plasmas TSC LSC TRANSP SPRUCE/ICRF NUBEAM CURRAY ACCOME AORSA JSOLVER BALMSC PEST2 VALEN GTWHIST Impurity transport WHIST Parks PRL SOL/Divertor Neutrals PEST3 Other 3D MHD FP QL, DKE AE/EP Modes

23. Modeling FIRE Burning Advanced Tokamak FIRE Advanced Tokamak Free boundary Energy and current transport Density profile assumed Empirical thermal diffusivities ICRF/FW from AORSA LHCD from LSC/ACCOME Bootstrap current, Sauter single ion Coronal equilibrium impurities Ar introduced to radiate more power PF coils and structures Control of plasma current, position and shape t = 12-41 s I p = 4.5 MA B T = 6.5 T

24. Modeling FIRE Burning Advanced Tokamak I p = 4.5 MA B T = 6.5 T H-mode edge also simulated

25. “Steady-State” High-  Advanced Tokamak Discharge on FIRE P f /V = 5.5 MWm -3  n ≈ 2 MWm -2 B = 6.5T  N = 4.1 f bs = 77% 100% non-inductive Q ≈ 5 H98 = 1.7 n/n GW = 0.85 Flat top Duration = 48  E = 10  He = 4  cr FT/P7-23

26. Examining Perturbations of FIRE Burning AT 5 MW perturbation to P LH Flattop time is sufficient to examine CD control t = 12 s t = 25 s t = 41 s Also examined density perturbations

27. Application to ITER is also being studied as part of ITPA.

28. FIRE has Passed DOE Physics Validation Review The DOE FIRE Physics Validation Review (PVR) was held March 30-31 in Germantown. The Committee included: S. Prager, (Chair) Univ of Wisc, Earl Marmar, MIT, N. Sauthoff PPPL, F. Najmabadi, UCSD, Jerry Navratil, Columbia (unable to attend), John Menard PPPL, R. Boivin GA, P. Mioduszewski ORNL, Michael Bell, PPPL, S. Parker Univ of Co, C. Petty GA, P. Bonoli MIT, B. Breizman Texas, PVR Committee Consensus Report: The FIRE team is on track for completing the pre-conceptual design within FY 04. FIRE would then be ready to launch the conceptual design. The product of the FIRE work, and their contributions to and leadership within the overall burning plasma effort, is stellar. Is the proposed physical device sufficiently capable and flexible to answer the critical burning plasma science issues proposed above? The 2002 Snowmass study also provided a strong affirmative answer to this question. Since the Snowmass meeting the evolution of the FIRE design has only strengthened ability of FIRE to contribute to burning plasma science.

29. FIRE FIRE Physics Validation Review successfully passed. March 30-31, 2004 FIRE Pre-Conceptual Activities are completed. September 30, 2004 Ready to begin Conceptual Design Activities. Now “Hold our FIRE” as per Fusion Energy Sciences Advisory Committee recommendation ITER AT Extend performance of ITER using Advanced Tokamak operation Fully exploit the capability of ITER (increase power to ~1GW at steady-state) Recover original ITER capability for nuclear testing Would address several physics tasks requested by IT Leader Next Step Option Activities

30. Current Profiles for FIRE and ITER “AT” Modes Desired AT profiles achieved for FIRE q > 2.5 everywhere q min = 2.7 @ r/a ≈ 0.8 above has L-Mode edge, also have H-mode edge case- little change Desired AT profiles not yet achieved for ITER q > 1.9 everywhere, some residual ohmic rising q, working on flattening and reversal q min @ r/a ≈ 0.8 optimization of startup and NINB/ICFW mix  iterating with TRANSP source info  working on H-mode edge case ITER 97 % non-inductive and quasi- stationary FIRE 100 % non-inductive and quasi- stationary

31. First Results from ITER-AT Studies Using TSC,TRANSP and NOVA-K Goal is Steady-State,  N ≈ 3.5, f bs > 60% f bs, Q > 5 using NINB, ICFW and LHCD First case has  N ≈ 2.5, f bs ≈ 44%, ≈ 97% non-inductive and Q ≈ 5. Optimize CD mix & startup to flatten q profile

32. ITER PF Coils Baseline RWM coils located outside TF coils Applying FIRE-Like RWM Feedback Coils to ITER Increases  limit for n = 1 from  N = 2.5 to 4.9 Engineering feasibility of internal control coils needs to be determined VALEN Analysis Columbia University FIRE-like RWM coils would have large stabilizing effect on n=1 No-wall limit RWM Coils in every third port G. Navratil, J. Bialek

33. ITER and FIRE AT Scenarios Can be Extended Goals: 2X ITER power level to 1000 MW and 2X FIRE Pulse Length ARIES-AT (  N = 5.4, fbs = 90%)

34. TAE Modes in FIRE AT Regime Nova-K: N. Gorelenkov   (0) = 0.62%, R   = 3.34 %, T(0) = 14 keV n = 6 - 8 unstable radially localized just inside q min @r/a = 0.8 modes are weakly unstable due to low alpha-particle beta

35. TAE Modes in ITER Hybrid Regime   = 2.1%, R   =15.5 %, T e (0) = 34 keV n = 3 - 11 unstable (only odd modes have been studied). radially localized near r/a = 0.5 TAEs are strongly driven with beam ions as much as alphas (H.Berk talk) strong drive is due to high   as a result of high ion temperature Perturbative approach may not be valid. Strong particle transport is expected (H.Berk talk). Nova-K: N. Gorelenkov

36. Both ITER and FIRE are Proposing to Explore and Exploit Advanced Tokamak Operating Modes Physics Items Existing ToksITER-ATFIRE-ATARIES- RS/AT xx ≤ 2.21.852.0 xx ≤ 0.80.490.7 ConfigurationSN & DNSNDN NN ≤ 4.5~ 3~ 4~ 5 % Non-inductive100 % bootstrap≤ 85508090 Equilibration %~50~100 steady Plasma rotationhighlowVery low RWM Coils (rel. to First Wall) Inside VV Outside TF Integrated With FW Inside TF Outside VV On axis CDPNB,NINBNINBICFW Off axis CDLH,PNB,(EC)LH

37. ITER and FIRE Advanced Tokamak Operating Modes Pose Challenges for Plasma Technology Technology Items Existing Toks ITER-ATFIRE-ATARIES- RS/AT B(T)1.5 - 75.36.56 - 8 I p (MA)1 - 39511 Core Power Density (MWm -3 ) 0.15 - 0.30.555 - 6 FW -  N (MW/m -2 ) 0.10.524 FW - P rad (MWm -2 )515 100 First WallC, BeBe Mo Div Target (MWm -2 )15 - 20 Divertor TargetC, (Mo,W)C,W?WW Pulse Length(s,  cr ) Typical 5, 2 (max = 5 hrs) 3000, 840, 5months Cooling Divertor, First Wall Inertial(SS) inertial Steady steady Steady inertial Steady steady

38. 25 MW/m 2

39. database extended down to q 95  3.5 closeness to DN necessary: type II obtained in whole  -range accessible when  Xp  0.02 m (0.35    0.5) stability analysis: edge shear stabilises lower n, squeezes eigenfunction Exhaust: Type II ELMs occur with strong shaping Zohm IAEA 2002

40. T e ped. (keV) n e ped l, (x10 19 m -2 ) 1.5 MA 1.35 MA 1.2 MA DD DD DD DD DD Pure Type-II ELMy phases achieved at high  pol in the QDN configuration 1.2 1.3 1.5 1.6 1.8 Type-II ELMs in “JT-60U high-β pol ” scheme ELMs get smaller with increasing  pol and frequency/irregularity increases T e,ped and n e,ped remain high at high  pol : not consistent with Type-III ELMs Type-II ELMs may be accessible at higher I p with higher power: to be done Not seen with lower single-null configuration at high  pol : QDN configuration may be necessary (although j edge was also different) 1.2 0.9 3.6 2 19.6019.6519.75 Time (s)  pol. = Presentation to STAC Jerome Pamela EFDA-CSU, 05 March 2004

41. Note: ITER and FIRE first wall (Be to VV) cost/PFC area ≈ equal at $0.25M/m 2

45. Status and Plans for FIRE FIRE has made significant progress in increasing physics and engineering capability since the Snowmass/FESAC recommendations of 2002. FIRE successfully passed the DOE Physics Validation Review (PVR) in March 2004. “ The FIRE team is on track for completing the pre-conceptual design within FY 04. They will then be ready to launch the conceptual design. The product of their work, and their contributions to and leadership within the overall burning plasma effort, is stellar. ” - PVR Panel Most of the FIRE resources were transferred to US - ITER activities in late 2003. The resources remaining in 2005 will focus on development of advanced capabilities for ITER - e.g., integrated AT modes, high power PFCs. The present US plan assumes that a decision to construct ITER is imminent. If an agreement on ITER is not attained, FIRE is ready, to be put forward as recommended by FESAC.

46. FIRE Pre-Conceptual Design has been completed - exceeding original goals. Steady-state FIRE AT mode using FWCD and LHCD has f bs ≈ 77% and is 100% non-inductive. High  N (~4) with close coupled RWM stabilization would produce power-plant-level fusion-power densities of 5 MWm -3 for 4  CR. FIRE has passed DOE PVR and is ready to be put forward as an attractive burning plasma experiment if the six-party ITER negotiations breakdown. Transition of NSO activities to supporting the “option” of extending ITER performance using AT operation has been accomplished without missing a step. The goal is to recover most of the capability of the original ITER. Initial ITER-AT studies successfully at producing steady-state scenario using FWCD and LHCD with f bs ≈ 48% and 97% non-inductive current drive. Studies are continuing to optimize the current drive, and to increase  N from 2.5 to 3.5. Close coupled RWM coils proposed by FIRE are expected to provide n = 1 stability up to  N = 4.2 in FIRE and 4.9 in ITER. TAE instability studies indicate that AT modes in both ITER and FIRE will have multiple unstable modes, with NINB ions being a significant drive term in ITER. Concluding Remarks

47. Recent six-party Vice Ministers meeting (P4) on November 8-9 failed to arrive at an agreement on the construction site for ITER. Europe continues discussions “to go it alone.” a new negotiating mandate is expected to be proposed next week by the European Commission, the EU's executive arm.The new mandate, to be unveiled on Tuesday (Nov 16, will "give priority to a solution involving all six parties, but there is a fallback option which is to do it with less than six," said one EU source. (AFP-Agency French Press-Nov 12, 2004) EU ministers for science and research will debate the commission's recommendations at their next meeting on November 26. US continues to move forward. DOE budget proposals for FY 2006 are now before the OMB. These budgets should contain a budget increase for ITER construction. They must be finalized by ~ late December to be included in the President’s FY 2006 budget in early February. Bottom Line - we will know by end of December. We should be ready. Recent News