Overview of CMSO Center for Magnetic Self-Organization in

Overview of CMSO Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas S. Prager May, 2006 Outline • Physics topics • Participants • Physics goals and highlights • Educational outreach • Management structure • Funding Magnetic self-organization nonlinear plasma phy sics se lf-o r g aniz at io n energy source large-scale st ruct ure magnet ic inst abilit ies The nonlinear plasma physics dy namo magnet ic reconnect ion angular moment um t ransport magnet ic chaos and t ransport magnet ic helicit y conserv at ion ion heat ing se lf-o r g aniz at io n energy source large-scale st ruct ure magnet ic inst abilit ies Magnetic self-organization in the lab ˜ B~ b B(a) B (T) .04 .02 0 magnetic fluctuations (reconnection) dynamo energy transport momentum transport C4+ toroidal magnetic a2 .07  flux  heat flux Q .06 1.5 1.0 0 30 20 10 0 0.4 0.2 0 –2 –1 0 Time (ms) 1 (MW/m2) (MW/m2) 0.5 rotation V (km/s) (km/s) ion temperature Tion (keV) (KeV) ion heating 2 time (ms) CMSO goal: understand plasma physics needed to solve key laboratory and astrophysical problems • linking laboratory and astrophysical scientists • linking experiment, theory, computation Original Institutional Members Princeton University The University of Chicago The University of Wisconsin Science Applications International Corp Swarthmore College Lawrence Livermore National Laboratory ~25 investigators, ~similar number of postdocs and students ~ equal number of lab and astrophysicists With New Funded Members Princeton University The University of Chicago The University of Wisconsin Science Applications International Corp Swarthmore College Lawrence Livermore National Laboratory Los Alamos National Laboratory (05) University of New Hampshire (05) ~30 investigators, ~similar number of postdocs and students ~ equal number of lab and astrophysicists Cooperative Agreements (International) Ruhr University/Julich Center, Germany(04) Torino Jet Consortium, Italy (05) Experimental facilities Facilit y MST ( Madison Symme tr ic Torus) Inst it ution Universit y of Wisco nsin Princet on Universit y Lawrence Livermore Nat ional Lab Swart hmore College Princet on Universit y Descript ion Reversed Field Pinch Merging Plasmas Sphero mak Merging Plasmas Flow ing liquid gallium MRX ( Magnet ic Reconnect ion Exp t ) SSPX ( St eady St at e Spheromak Exp t ) SSX ( Swa rth more Spheromak Exp t ) MRI experime nt •yields range of topologies and critical parameters •Joint experiments and shared diagnostics MRX: Magnetic Reconnection Experiment (Princeton) SSX: Swarthmore Spheromak Experiment SSPX: Sustained Spheromak Physics Experiment (LLNL) MST: Madison SymmetricTorus (Wisconsin) MRX Inductively produced plasmas, Spheromak or annular plasmas Locailzed reconnection at merger SSX Electrostatically - produced spheromaks (by plasma guns) Two spheromaks reconnect and merge SSPX Electrostatically - produced spheromak MST Reversed field pinch Liquid gallium MRI experiment (Princeton) To study the magnetorotational instability Major Computational Tools Code NEK 5000 Li2 Inst it ution Universit y of Chicago Descript ion Spect ral f init e elements incomp ressible resistiv e MHD ( Any geomet ry ) Nonlinear, 3 D, ideal HD/ MHD, Cart esian, Cylind rical, Spherical Third ord er hyb rid, essenti ally nonoscillat ory ( ENO) isoth erm al code f or comp ressible MHD Fully spect ral, incomp ressible, resistiv e MHD ( slab or t riply periodic) Nonlinear, 3 D, resistiv e MHD , cyl ind rical geo met ry Nonlinear, 3 D, resistiv e, t wo -f luid , t oro idal g eomet ry Nonlinear, 3 D relat ivi sti c PIC Los A lamos Universit y of Wisconsin Universit y of Chicago DEBS NIMROD VPIC SAIC, U. Wisconsin Multi -instit uti onal (W isconsin, SAIC, Los A lamos) Los A lamos •Not an exhaustive list •Codes built largely outside of CMSO •Complemented by equal amount of analytic theory Sample Physics Highlights • New or emerging results • Mostly where center approach is critical We are pursuing much of the original plans, but new investigations have also arisen (plans for next 2 years discussed later) Reconnection • Two-fluid Hall effects • Reconnection with line tying • Effects of coupled reconnection sites • Effects of lower hybrid turbulence not foreseen in proposal Hall effects on reconnection • Identified on 3 CMSO experiments (MRX, SSX, MST) • Performed quasilinear theory • Will study via two-fluid codes (NIMROD, UNH) and possibly via LANL PIC code Observation of Hall effects Observed quadrupole B component, MRX SSX QuickTime™ and a TIFF (LZW) decompressor are neede d to see this picture. radius also observed in magnetosphere Reconnection with line-tying • Studied analytically (UW, LANL) and computationally(UW) • Compare to non-CMSO linear experiments • Features of periodic systems survive (e.g.,large, localized currents) Linear theory for mode resonance in cylinder v periodic line-tied radius radius Effects of multiple, coupled reconnections Many self-organizing effects in MST occur ONLY with multiple reconnections Effects of multiple, coupled reconnections Many self-organizing effects in MST occur ONLY with multiple reconnections core reconnection only core reconnection multiple reconnections core edge reconnection edge •Applies to magnetic energy release, dynamo, momentum transport, ion heating •Related to nonlinear mode coupling •Might be important in astrophysics where multiple reconnections may occur (e.g., solar flare simulations of Kusano) Lower hybrid turbulence Detected in MRX Magnetic fluctuations QuickTime™ an d a TIFF (LZW) decomp resso r are need ed to see this picture. 0 10 f(MHz) •Reconnection rate  turbulence amplitude; •Instability theory developed, •May explain anomalous resistivity Lower hybrid turbulence Detected in MRX Magnetic fluctuations QuickTime™ an d a TIFF (LZW) decomp resso r are need ed to see this picture. Similar to turbulence in magnetosphere (Cluster) E B QuickTime™ and a TIFF (LZW) decompressor are neede d to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 10 f(MHz) •Reconnection rate ~ turbulence amplitude; •Instability theory developed, •May explain anomalous resistivity Momentum Transport radial transport of toroidal momentum rotation momentum transport In accretion disks, solar interior, jets, lab experiments, classical viscosity fails to explain momentum transport Leading explanation in astrophysics MHD instability Flow-driven (magnetorotational instability) momentum transported by j x b and v.v Leading explanation in lab plasma resistive MHD instability  current-driven (tearing instability) momentum transported by j x b and v.v Momentum Transport Highlights • MRI in Gallium: experiment and theory • MRI in disk corona: computation • Momentum transport from current-driven reconnection MRI in Gallium • Experiment (Princeton) hydrodynamically stable, ready for gallium V v --- Couette flow + diff. endcaps flow Couette + end caps rotate with outer cyl. experiment r radius •Simulation (Chicago) underway QuickTime™ and a TIFF (LZW) decompressor are neede d to see this picture. MRI in disk corona • Investigate effects of disk corona on momentum transport; possible strong effect • Combines idea from Princeton, code from SAIC initial state: flux dipole ...after a few rotations Momentum transport from current-driven reconnection experiment Requires multiple tearing modes (nonlinear coupling) Theory and computation of Maxwell stress in MHD quasilinear theory for one tearing mode computation for multiple, interacting modes ˜B j ˜ resonant surface ˜B j ˜ r   An effect in astrophysical plasmas? reconnection and flow is ubiquitous raises some important theoretical questions (e.g., effect of nonlinear coupling on spatial structure) Ion Heating Ion heating in solar wind thermal speed km/s QuickTime™ an d a TIFF (LZW) decompressor are need ed to see this p icture. r/Rsun Strong perpendicular heating of high mass ions Ion heating in lab plasma Observed during reconnection in all CMSO experiments Ti (eV) t = +0.50 ms MST QuickTime™ and a TIFF (LZW) decompressor are neede d to see this picture. t = -0.25 ms radius Conversion of magnetic energy to ion thermal energy ~ 10 MW flows into the ions change in thermal energy ion (J) MRX reconnected magnetic field energy (J) Magnetic energy can be converted to Alfvenic jets magnetic energy QuickTime™ and a TIFF (LZW) deco mpressor are neede d to se e this picture. SSX Energetic ion flux time (s) Ions heated only with core and edge reconnection MST ˜ B Ti (eV) core QuickTime™ anedge da TIFF (LZW) decompressor are need ed to see this p icture . core reconnection edge reconnection QuickTime™ an d a TIFF (LZW) decompressor are need ed to see this picture. time (ms) What is mechanism for ion heating? • Still a puzzle • Theory of viscous damping of magnetic fluctuations has been developed Magnetic chaos and transport Magnetic turbulence Transport in chaotic magnetic field Magnetic chaos and transport Magnetic turbulence • Star formation • Heating via cascades • Scattering of radiation • Underlies other CMSO topics Transport in chaotic magnetic field • Heat conduction in galaxy clusters (condensation) • Cosmic ray scattering Magnetic turbulence • Properties of Alfvenic turbulence • Intermittency in magnetic turbulence • Comparisons with turbulence in experiments Sample results: Intermittency explains pulsar pulse width broadening, Observed in kinetic Alfven wave turbulence QuickTime™ an d a TIFF (LZW) decompressor are need ed to see this p icture . computation Measurements underway in experiment for comparison Transport in chaotic field Experiment measure transport vs gyroradius in chaotic field Transport in chaotic field Experiment measure transport vs gyroradius in chaotic field Result Small gyroradius (electrons): large transport Large gyroradius (energetic ions): small transport Ion orbits well-ordered Transport measured via neutron emission from energetic ions produced by neutral beam injection Possible implications for relativistic cosmic ray ions The Dynamo Why is the universe magnetized? • Growth of magnetic field from a seed • Sustainment of magnetic field • Redistribution of magnetic field Why is the universe magnetized? • Growth of magnetic field from a seed primordial plasma • Sustainment of magnetic field e.g., in solar interior in accretion disk • Redistribution of magnetic field e.g., solar coronal field extra-galactic jets The disk-jet system Field sustained (the engine) Field produced from transport CMSO Activity • Theoretical work on all problems the role of turbulence on the dynamo, flux conversion in jets, • Lab plasma dynamo effect: field transport, with physics connections to growth and sustainment Abstract dynamo theory Small-scale field generation (via turbulence) Computation: dynamo absent at low / Theory: dynamo present at high Rm Large-scale field generation No dynamo via homogeneous turbulence, Large-scale flows sustains field Magnetic field fluctuations generated by turbulent convection Dynamo action driven by shear and magnetic buoyancy instabilities. MHD computation of Jet production Magnetically formed jet |J| contours QuickTime™ and a TIFF (LZW) decompressor are neede d to see this picture. MHD computation of Jet evolution Magnetically formed jet |J| contours QuickTime™ and a TIFF (LZW) decompressor are neede d to see this picture. helical fields develop in jet QuickTime™ and a TIFF (LZW) decomp resso r are need ed to see this picture. When kink unstable, flux conversion B -> Bz Similarities to experimental fields Dynamo Effect in the Lab in experiment 2.0 E  j E || 1.5  V/m E|| 1.0 0.5 neo j|| J|| (Zeff = 2) 0.0 -0.5 0.0 0.2 0.4 radius additional current drive mechanism (dynamo) /a 0.6 0.8 1.0 Hall dynamo is significant ˜ ˜ E ||  v  B ||  ˜B j ˜ ne ||  j || Hall dynamo  (theory significant) Hall dynamo is significant ˜ ˜ E ||  v  B ||  experiment: ˜B j ˜ ne ||  j || Hall dynamo  ˜B j ˜ ne || Laser Faraday rotation Questions for the lab plasma, relevant to astrophysics • At what conditions (and locations) do two-fluid and MHD dynamos dominate? • Is the final plasma state determined by MHD, with mechanism of arrival influenced by two-fluid effects? • Is the lab alpha effect, based on quasi-laminar flows, a basis for field sustainment (possibly similar to conclusion from computation for astrophysics) CMSO Educational Outreach •Highlight is Wonders of Physics program •Supported by CMSO and DOE (50/50) •Established before CMSO, expanded in quantity and quality ~ 150 traveling shows/yr all 72 Wisconsin counties, plus selected other states QuickTime™ and a TIFF (LZW) decomp resso r are need ed to see this picture. ~ 6 campus shows Center Organization Topical Coordinators each pair = 1 lab, 1 astro person • Reconnection • Momentum transport • Dynamo • Ion Heating • Chaos and transport • Helicity • Educational outreach Yamada, Zweibel Craig, Li Cattaneo, Prager Fiksel, Schnack Malyshkin, Terry Ji, Kulsrud Reardon, Sprott CMSO Steering Committee F. Cattaneo H. Ji S. Prager D. Schnack C. Sprott P. Terry M. Yamada E. Zweibel meets weekly by teleconference CMSO Program Advisory Committee S. Cowley (Chair) P. Drake UCLA University of Michigan W. Gekelman R. Lin G. Navratil E. Parker A. Pouquet UCLA UC - Berkeley Columbia University University of Chicago NCAR, Boulder, CO D. Ryutov Lawrence Livermore National Lab CMSO International Liaison Committee M. Berger A. Burkert K. Kusano P. Martin University College, London, UK The University of Munich, Germany Hiroshima University, Japan Consorzio RFX, Padua, Italy Y. Ono M. Velli N. Weiss Tokyo University, Japan Universita di Firenze, Italy Cambridge University, UK CMSO Meetings Sept, 03 Ion heating/chaos (Chicago) Sept, 03 Reconnection/momentum (Princeton) Oct, 03 Dynamo (Chicago) Nov, 03 General meeting (Chicago) June,04Hall dynamo and relaxation (Princeton) Aug, 04 General meeting (Madison) Sept, 04 PAC meeting (Madison) Oct, 04 Reconnection (Princeton) Jan, 05 Video conference of task leaders March, 05 General meeting (San Diego) April, 05 Dynamo/helicity meeting (Princeton) June, 05 Intermittency and turbulence (Madison) June, 05 Experimental meeting (Madison) Oct, 05 General meeting (Princeton) Nov, 05 PAC meeting (Madison) Jan, 06 Winter school on reconnection (Los Angeles, w/CMPD) March, 06 Line-tied reconnection (Los Alamos) June, 06 Workshop on MSO (Aspen, with CMPD)) Aug, 06 General meeting (Chicago) Budget • NSF $2.25M/yr for five years • DOE ~$0.4M to PPPL ~$0.1M to LLNL ~$0.15M to UNH all facility and base program support ~$0.34M • LANL CMSO is a partnership between NSF and DOE Summary •CMSO has enabled many new, cross-disciplinary physics activities (and been a learning experience) •New linkages have been established (lab/astro, expt/theory, expt/expt) •Many physics investigations completed, many new starts •The linkages are strong, but still increasing, the full potential is a longer-term process than 2.5 years