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

The nonlinear plasma physics

Magnetic self-organization in the lab magnetic fluctuations (reconnection) toroidal magnetic flux dynamo heat flux (MW/m2) energy transport rotation (km/s) momentum transport ion temperature (keV) ion heating 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 yields range of topologies and critical parameters Joint experiments and shared diagnostics

MST: Madison SymmetricTorus (Wisconsin) MRX: Magnetic Reconnection Experiment (Princeton) SSX: Swarthmore Spheromak Experiment MST: Madison SymmetricTorus (Wisconsin) SSPX: Sustained Spheromak Physics Experiment (LLNL)

MRX SSX 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 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 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)

v radius Linear theory for mode resonance in cylinder 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 multiple reconnections core core reconnection edge edge reconnection

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 0 10 f(MHz) Reconnection rate  turbulence amplitude; Instability theory developed, May explain anomalous resistivity

Lower hybrid turbulence Detected in MRX Similar to turbulence in magnetosphere (Cluster) Magnetic fluctuations E B 0 10 f(MHz) Reconnection rate ~ turbulence amplitude; Instability theory developed, May explain anomalous resistivity

Momentum Transport radial transport of toroidal momentum 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, V vq r --- Couette flow + diff. endcaps + end caps rotate with outer cyl. Couette flow Experiment (Princeton) hydrodynamically stable, ready for gallium V experiment radius Simulation (Chicago) underway

Combines idea from Princeton, code from SAIC 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 resonant surface quasilinear theory for one tearing mode computation for multiple, interacting modes 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 r/Rsun Strong perpendicular heating of high mass ions

Ion heating in lab plasma Observed during reconnection in all CMSO experiments Ti (eV) MST t = +0.50 ms t = -0.25 ms radius

Conversion of magnetic energy to ion thermal energy ~ 10 MW flows into the ions

change in ion thermal energy (J) MRX reconnected magnetic field energy (J)

Magnetic energy can be converted to Alfvenic jets SSX Energetic ion flux time (s)

Ions heated only with core and edge reconnection MST core reconnection core edge edge reconnection Ti (eV) 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 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 produced from transport Field sustained (the engine)

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 Magnetic field fluctuations generated by turbulent convection Large-scale field generation No dynamo via homogeneous turbulence, Large-scale flows sustains field Dynamo action driven by shear and magnetic buoyancy instabilities.

MHD computation of Jet production Magnetically formed jet |J| contours

MHD computation of Jet evolution Magnetically formed jet |J| contours helical fields develop in jet When kink unstable, flux conversion B -> Bz Similarities to experimental fields

Dynamo Effect in the Lab in experiment E|| j|| radius additional current drive mechanism (dynamo)

Hall dynamo is significant (theory significant)

Hall dynamo is significant experiment: 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 ~ 6 campus shows

Center Organization

Topical Coordinators each pair = 1 lab, 1 astro person Reconnection Yamada, Zweibel Momentum transport Craig, Li Dynamo Cattaneo, Prager Ion Heating Fiksel, Schnack Chaos and transport Malyshkin, Terry Helicity Ji, Kulsrud Educational outreach 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) UCLA P. Drake University of Michigan W. Gekelman UCLA R. Lin UC - Berkeley G. Navratil Columbia University E. Parker University of Chicago A. Pouquet NCAR, Boulder, CO D. Ryutov Lawrence Livermore National Lab

CMSO International Liaison Committee M. Berger University College, London, UK A. Burkert The University of Munich, Germany K. Kusano Hiroshima University, Japan P. Martin Consorzio RFX, Padua, Italy Y. Ono Tokyo University, Japan M. Velli Universita di Firenze, Italy N. Weiss 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,04 Hall 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 CMSO is a partnership between NSF and DOE 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 LANL ~$0.34M 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