Summary of the 2007 Innovative Confinement Concepts Workshop Simon Woodruff WOODRUFF SCIENTIFIC, LLC, 1700 Seventh Ave, Suite 2100, Seattle, WA 98101 With useful comments from Adil Hassam, Brett Chapman, Sam Barish Fusion Power Associates Annual Meeting and Symposium Fusion Energy: Preparing for the NIF and ITER Era December 4-5, 2007 Doubletree Hotel, Oak Ridge, Tennessee [Photographs and diagrams of various ICC experimental devices] LDX, SIHI, FRX-L, MCX, TCS, SSPX, PFRC, MST, ZAP, SSX, AFRL Outline -- Meeting overview (history, purpose, talks, scope) -- Some highlights (by concept/subject): --Compact tori --Small tokamaks --IFE related --Simulations --Diagnostics -- Summary and call for papers for ICC2008 ICC Workshop 2007: evolving towards a conference for smaller fusion concepts. Meeting took place at the University of Maryland. In total, there were 120 contributions from ~35 separate institutions (national labs, universities, and industry in the USA and from Europe, and Japan). Written proceedings now published in the Journal of Fusion Energy contains ~40 papers to appear as a special edition. Subjects spanned a wide range of issues, from confinement studies through to completely novel ideas, and some controversial ones presented in a ‘Skunkworks’ session. ICC workshops started in 1997 and have continued, taking place once every 18 months. Typical workshop size is ~120 contributions, sometimes from abroad. Usually the meeting is a forum for ‘innovative concepts’ (classed as Basic Science, Concept Exploration, or Proof of Principal). ICC research is supported by 13 community planning activities in the last 15 years (e.g. FESAC, FEAC, OFES, PCAST, SEAB, IPPA), but most notably: - FESAC 1996 - OFES 1996 - SM 1999 - FESAC 2002 SM 2002 - “The ICC experiments address several programmatic and fusion energy science objectives by: 1. Working within a broad range of plasma and fusion energy sciences, including cross fertilization with other fields of plasma science; 2. Seeking concepts and innovations that work better or change the paradigm for fusion energy; 3. Broadening the physics of toroidal magnetic confinement by operating in parameter regimes inaccessible by the tokamak; 4. Strengthening university plasma science and technology programs, engaging faculty by providing opportunities to contribute to plasma and fusion science with small-to-medium size experiments; and 5. Attracting bright, young talent with the vision of unlimited energy for mankind while providing the opportunity to participate in experiments they can “get their hands around.” Workshop committee comprised of experts from many institutions (some more active than others). John Barnard - Lawrence Livermore National Laboratory Bruno Bauer - University of Nevada, Reno Brett Chapman - University of Wisconsin Darren Garnier - Columbia University Jean-Luc Gauvreau - University of California, Los Angeles Rob Goldston - Princeton Plasma Physics Laboratory Jeff Harris - Australian National University Adil Hassam - University of Maryland Bick Hooper - Lawrence Livermore National Laboratory Tom Jarboe - University of Washington Stephen Knowlton - Auburn University Harry Mclean - Lawrence Livermore National Laboratory Brian A. Nelson - University of Washington Paul Parks - General Atomics Thomas Pedersen - Columbia University John Perkins - Lawrence Livermore National Laboratory Carl Sovinec - University of Wisconsin Ed Synakowski - Lawrence Livermore National Laboratory Francis Thio - U.S. Department of Energy Simon Woodruff - Woodruff Scientific, LLC James W. Van Dam - University of Texas, Austin Glen Wurden - Los Alamos National Laboratory Mike Zarnstorff - Princeton Plasma Physics Laboratory During the last 10 years, a range of experimental configurations have been discussed at the ICC workshop: still evolving. Toroidal high B (~$7M): HBT-EP, Resistive-wall stab., Tokamak trans. phys., Divertor innovation, Pegasus, LTX, HSX, CTH, QPS Toroidal low B (~$7M): Reversed field pinch (MST), Dipole LDX Toroidal no applied B (~$10M): Spheromak (SSPX, HIT-SI, SSX, CalTech), FRC (TCS-U, Odd-parity RMF, SSX, PHD, PFRC, Theory), Magneto-Bern. Exp., Magneto-Inertial Fusion (FRX-L, Solid liner, theory, stand-off driver), Accelerated FRC, CT Accel, Inverse Z-pinch Linear (~$3M): Mirror Mary. Centr. Exp., Flow Pinch (ZAP) Non magnetic (~$?M): IEC, Fast ignition Broadly, ICCs seek to reduce size and complexity of the fusion system. Doubly: structure links plasma (Torus, Ro, a, Blanket) Simply: nothing links plasma Can magnetic systems operate with lower applied toroidal field? Or inertial: (Overlap with HEDP) Magnetized plasma/solid Can magnetic fields improve inertial systems? ICC2007 Workshop organized into 5 oral sessions and a skunkworks, with ~6 talks per session + parallel poster sessions + OFES input. - High Beta Magnetic Confinement: RFP, LDX, Pegasus, ZaP & MCX | Chair: Darren Garnier - Inertial Fusion Energy Research | Chair: John Perkins - Simply Connected and/or Current Drive Solutions: Spheromaks, Stellarators and Others | Chair: Bick Hooper - Theory and Computation | Chair: James Van Dam - High-Beta and Simply Connected: FRC | Chair: Alan Hoffman Compact Tori: High temperatures in devices with good surface conditioning. - Obtained 500eV in the LLNL SSPX Spheromak experiment, benchmarked with 3D MHD simulations to show toroidal mode evolution. - Obtained higher confinement mode in TCS-U FRC after upgrading vacuum system. - FRX-L - obtaining high density operations ready for FRC compression with AFRL Shiva-Star cap bank (first shot for March). - PFRC demonstrating odd-parity rotating magnetic field sustainment. A new record for spheromaks: SSPX attains 500eV (Electron Temperature vs. Radius plot, kind permission of H. McLean). Tokamaks: Attainment of High Normalized Current by J(r) Manipulation in the Pegasus Toroidal Experiment The Pegasus Toroidal Experiment is an ST designed with the purpose of studying pressure and current limits at very low aspect ratio. At A<1.2, kink stability is expected for values of Ip/Itf up to 3 (IN up to 18 MA/m-T). At this level, stable values of Troyon beta in excess of 70% are predicted. [1] G. Gartska et al to appear Journal of Fusion Energy Special Edition (2007) See also, e.g.: - Bogatu, Ioan N. Hyper-Velocity Dusty Plasma Jets for Disruption Mitigation - Ryutov, Dmitri D. A ‘snow-flake’ divertor as a possible approach to reducing divertor heat loads in tokamaks IFE: Magneto-Inertial Approach to Direct-Drive Laser Fusion - Gotchev et al Magneto-Inertial Approach to Direct-Drive Laser Fusion O. V. Gotchev, N. W. Jang, J. P. Knauer, M. D. Barbero, and R. Betti (Laboratory for Laser Energetics & Fusion Science Center, Univ. of Rochester) C. K. Li and R. D. Petrasso (Plasma Science and Fusion Center, MIT) Keywords: inertial confinement, high-beta plasmas, magnetic insulation A magneto-inertial fusion (MIF) approach to inertial confinement fusion (ICF), based on laser-driven magnetic-flux compression (LDFC) is described. This approach benefits from both the high-energy-density characteristic to ICF and the thermal insulation of the fuel by magnetic fields, typical of MFE. The reduction in thermal-conduction losses in the hot spot of an imploding target that has trapped and amplified a pre-seeded magnetic flux leads to increased hot-spot temperatures at lower implosion velocities than required in conventional ICF. This can lead to ignition designs with larger energy gains. This work describes the main concept and the use of a compact magnetic-pulse system to seed a macroscopic magnetic field into cylindrical DD-filled targets, which are radially driven with the OMEGA laser. The compression of the internal magnetic flux is measured with proton deflectometry. Magnetohydrodynamic simulations predict compression of a 0.1-MG seed field to multi-megagauss values, at which levels the radial electron thermal conduction in the hot spot is significantly inhibited. Initial benchmark experiments are described. See also, e.g.: - Dunne, Mike. A European path to Fast Ignition Fusion Energy - Erlandson, Alvin C. New Concepts for Reducing Costs and Improving Efficiency of Solid-State Laser Drivers for Inertial Fusion Energy - Sethian, John D. Laser Fusion Energy and the Fusion Test Facility Naval Research Laboratory Simulation: PPPL, U. Wisconsin and U. Washington pushing MHD code development - aiming for predictive capability. - FRC Theory and Modeling (PPPL): PI: Belova, Davidson, H. Ji, M. Yamada. Develop and apply state-of-the-art numerical simulations to provide an improved understanding of FRC formation / stability properties. - NIMROD Team (U.Wisc): PI: Sovinec. 3D resistive MHD simulations with the NIMROD code address fundamental physics in many ICC and tokamak expts. - PSI Center (U. Washington): PIs: Jarboe, Milroy. In concert with experiments refine present computational tools with sufficient physics. [Includes Poloidal Flux (Wb) contour and 3D Te (eV) plot by Sovinec] Diagnostics: Temperature Measurements on the ZaP Experiment - Golingo (UW) The Plasma Characteristics are measured with an Array of Diagnostics: • Plasma density: A two chord heterodyne quadrature interferometer, A holographic interferometer • Plasma velocity: A 0.5 m spectrometer which views 20 parallel chords through the plasma (ICCD), A 1.0 m spectrometer with a 16 channel PMT at the exit slit (IDS) • Shape and position of the emission from the plasma: An Imacon fast-framing camera, A 16 chord photodiode array and two 32 chord photodiode arrays • Magnetic fields and current location: An axial array of surface magnetic probes, Four azimuthal arrays of surface magnetic probes, Zeeman splitting measurements • Other diagnostics are used to verify these measurements: A 0.5 m spectrometer with a CCD and PMT, A bolometer and filter scopes, Gridded energy analyzer, Langmuir/Mach probe See also e.g.: Teodorescu, Catalin. Measurements of plasma isorotation on MCX University of Maryland Summary - ICC 2007 was well attended - 120 contributions from 35 institutions in the USA and abroad. - Scientific program moving towards a conference with published proceedings in JOFE. - ICCs continue to explore important critical physics issues, employing advanced simulations, novel diagnostics and innovative approaches to technical problems. [Photographs of LDX, SIHI, TCS, FRX-L, SSPX, MCX, PFRC] Call for papers for ICC 2008 The Innovative Confinement Concepts Workshop (ICC2008) will take place June 24 to 27, 2008 in Reno, Nevada. Abstract submission, registration, and hotel reservations can be handled through the website: http://iccworkshops.org/icc2008/ [Photographs of MST, ZAP, SSX, FRX-L, AFRL] Extra material Innovative Confinement Concepts • Cutting-edge plasma science across the nation. • Experiments offer to fundamentally change the paradigm of Fusion Energy Sciences. • Experiments aim to operate in new plasma regimes. • Premier method to train the next generation of plasma researchers (more than 100 students/year). • Small-scale experiments (<1-2M/year) deliver value science. SM 1999 _ Reduce or eliminate applied toroidal field _ Reduce level and number of external controls _ Reduce energy for high-gain inertial fusion ignition or reduce auxiliary heating _ Utilize more favorable spherical or linear geometry puters) to obtain an idea of the range of possible futures. _ Utilize high or __ __ (plasma pressure relative to magnetic pressure), to allow for possible advanced fuel cycle _ Operate at intermediate density (between magnetic fusion and inertial fusion) e.g. SM 2002 and IPPA - “The ICC experiments address several programmatic and fusion energy science objectives [Flowchart diagram illustrating integration between Base Plasma Physics (Theory & Simulation, ST/stellarator/RFP/other ICCs, Tokamak physics), Major Facilities (ITER, 14-MeV neutron source, Component Test Facility, Innovative Configuration ETR, DEMO / Tokamak DEMO), and Base Technologies (Fusion power technologies, Plasma support technologies)]. e.g. SM 2002 and IPPA 1999 Words relating to the ICCs: The Innovative Confinement Concepts are a core part of the US base Fusion Energy Sciences Program, along with the Advanced Tokamak (AT) program and the theory and computational modeling program. The ICC program responds to Goal 2 of the Integrated Program Planning Activity: Resolve outstanding scientific issues and establish reduced-cost paths to more attractive fusion energy systems by investigating a broad range of innovative magnetic confinement configurations. Skunkworks: opportunity to think quite outside the box, and so some talks are quite controversial. The subject is novel ideas for fusion reactors -- physics and/or technology -- and not reporting on existing alternate concept research. Novel ideas include significant new twists on old ideas, combinations of ideas that together offer a qualitative advantage, or completely new concepts and new opportunities created by technology advances, e.g. fast ignition in ICF. Some suggested constraints on skunkworks: (a) conservation of energy and momentum (b) 2nd law of thermodynamics (c) no low temperature fusion unless you can demonstrate either unambiguous results or plausible barrier penetration schemes! ICC Workshop Purpose This workshop is for presentation of results and ideas about concepts that might make large steps towards practical fusion power, complementing the important feasibility steps of the International Tokamak Experimental Reactor (ITER), and the National (laser) Ignition Facility (NIF). The ICC experiments also complement the mainline concepts in the advancement of plasma science. These experiments test the general validity of plasma physics and technology in wider parameter regimes, develop new fusion plasma physics, and cross-fertilize with other fields of plasma science.