Brian LaBombard
Senior Research Scientist
175 Albany St., Cambridge, MA 02139, USA
TEL.: 617-253-7264 FAX: 617-253-0627
Research Interests
Brian has been a leader in the area of experimental plasma boundary and divertor physics in magnetic fusion devices since joining that nascent field as a graduate student in 1978. Boundary plasma physics plays a critical role in the performance of magnetic fusion devices – setting the power and particle flux densities to first wall surfaces, determining impurity levels in the plasma core, imposing boundary conditions for plasma flow and rotation, and participating in the formation of edge transport barriers, all of which ultimately determine the level of plasma energy confinement.
The scientific feasibility of energy production from plasma fusion will soon be demonstrated in ITER, yielding 10 times more power out than in. Yet, much more research is needed to identify robust solutions to power exhaust and plasma-material interaction challenges for electricity-producing fusion reactors. Ultimately, the success of these devices will come from assembling the knowledge base, developing the first-principles understanding and demonstrating the means to control boundary plasma phenomena.
Education
U. Lowell, Lowell, Massachusetts, B.S., summa cum laude (1978) Nuclear Engineering
Biographical Sketch
Brian has made seminal contributions to boundary plasma physics: uncovering ‘main-chamber recycling’ phenomenon in C-Mod’s diverted plasmas and revealing intermittent, non-diffusive transport in the scrape-off layer as the underlying cause; identifying edge plasma transport and its scaling with collisionality as a key physics ingredient in the empirical tokamak density limit; demonstrating that ballooning-like transport asymmetries drive near-sonic parallel plasma flows in the plasma edge and that such transport-driven flows impose a toroidal rotation boundary condition for the confined plasma; uncovering evidence that pressure gradients are constrained near the last-closed flux surface, being clamped at a ‘critical value’ that scales with poloidal magnetic field squared and varies with plasma collisionality. These observations broadly connect with results from state-of-the-art numerical simulations of electromagnetic plasma turbulence, pointing toward a first-principles understanding of the underlying transport physics, including the physics of the tokamak density limit. Two of Brian's first-authored papers [Nuclear Fusion 44 (2004) 1047 and Nuclear Fusion 45 (2005) 1658] were nominated for the 2007 and 2008 Nuclear Fusion awards – one of the ten “very best papers published” in 2004 and 2005, respectively.
Brian is a fellow of the American Physical Society, a key contributor to the ITER physics basis and a research supervisor for graduate and undergraduate students. He has served as external examiner for numerous graduate theses and mentor for the national undergraduate fellowship program in fusion.
Presentation to DoE at Alcator C-Mod Quarterly Revew, March 7, 2013
Alcator_DX: Oral Presentation
White Paper submitted to FESAC subcommittee on future facilities, Feb. 14, 2013
Alcator_DX: High Power Density Advanced Divertor Test Facility
X-point Target Divertor in Alcator DX
Presentation at MIT PSFC, Feb. 4, 2013
X-point Target Divertor Concept
TTF2013, Santa Rosa, CA: "Mirror Langmuir Probe observations of edge plasma turbulence and the Quasi-Coherent Mode in Alcator C-Mod"
The QCM is unambiguously identified as an electron drift-Alfven wave.
Oral Presentation
Poster Presentation
Transport and drift-driven plasma flow components in the Alcator C-Mod boundary plasma
N. Smick, Nuclear Fusion 53 (2013) 023001
Divertor ‘death-ray’ explained: An artifact of a Langmuir probe operating at negative bias in a high-recycling divertor
D. Brunner, J. Nucl. Mater. 2013
APS 2012, Providence, RI: "Mirror Langmuir Probe measurements of fluctuation-induced heat and particle transport in the Alcator C-Mod boundary plasma
Oral Presentation
APS 2011, Salt Lake City, UT: "Shoelace' Antenna System for Direct Excitation of C-Mod's Quasi-Coherent Mode (QCM) and Boundary Layer Turbulence"
Poster_Presentation
APS 2010, Chicago, IL - Scaling of the power exhaust channel in Alcator C-Mod
Invited Paper, Phys. Plasmas 18 (2011) 056104
APS 2010, Chicago, IL - Scaling of the power exhaust channel in Alcator C-Mod
Invited Talk
Press Release from APS Meeting
Joint Research Target - Heat flux 'footprints' in the boundary plasmas of Alcator C-Mod, DIII-D and NSTX
FY2010 Annual Performance Target Final Report
Boundary Layer Heat Transport Experiments in Alcator C-Mod in Support of the FY2010 US DoE Joint Research Target
PSFC Internal Report
PSI 2010, San Diego, CA - Divertor heat flux footprints in EDA H-mode discharges on Alcator C-Mod
Poster Presentation
Paper (published in J. Nucl. Mater.)
APS 2008, Dallas, TX - Relationship between Edge Gradients and Plasma Flows in Alcator C-Mod
Contributed Oral
TTF 2008, Boulder, CO - Scrape-off layer flows, toroidal rotation and critical gradient phenomena in the tokamak edge
Plenary Invited Talk
APS 2007, Orlando, FL - Critical gradients and plasma flows in the edge of Alcator C-Mod
Invited Paper, Phys. Plasmas 15 (2008) 056106.
APS 2007, Orlando, FL - Critical gradients and plasma flows in the edge of Alcator C-Mod
Invited Talk
Press Release from APS Meeting
APS 2006, Philadelphia, PA - Critical edge gradients and flows with reversed magnetic field in Alcator C-Mod
Contributed Oral
PSI 2006, Hefei, Anhui, China - Operational Phase Space of the Edge Plasma and Its Sensitivity to Magnetic Topology in Alcator C-Mod
Contributed Talk
Paper - J, Nucl. Mater. 363-365 (2007) 517.
Edge and Pedestal Physics ITPA Group Meeting at MIT, April 10-12, 2006 - Plasma flows and critical gradient phenomena near the last-closed flux surface
Workshop Talk
APS 2005, Denver, CO - Operational Phase Space of the Edge Plasma in Alcator C-Mod
Contributed Oral
Evidence for electromagnetic fluid drift turbulence controlling the edge plasma state in the Alcator C-Mod tokamak
Nuclear Fusion 45 (2005) 1658
EPS 2005, Tarragona, Spain - Transport-driven scrape-off layer flows and the role of the x-point
Invited Talk
Sherwood 2005, Stateline, Nevada - Scrape-off layer flows, magnetic topology, and the boundary conditions imposed at the separatrix in a tokamak plasma
Review Talk
APS 2004, Savannah, GA - Transport-driven scrape-off layer flows and the x-point dependence of the L-H power threshold in Alcator C-Mod
Invited Talk
Press Release from APS Meeting
APS 2004, Savannah, GA - Transport-driven scrape-off layer flows and the x-point dependence of the L-H power threshold in Alcator C-Mod
Invited Paper, Phys. Plasmas 12 (2005) 056111
PSI 2004, Portland, ME - Poloidal Transport Asymmetries, Edge Plasma Flows and Toroidal Rotation in Alcator C-Mod
Invited Talk
PSI 2004, Portland, ME - Plasma Profiles and Flows in the High-Field Side Scrape-off Layer in Alcator C-Mod
Contributed Poster
Transport-Driven Scrape-off Layer Flows and the Boundary Conditions Imposed at the Magnetic Separatrix in a Tokamak Plasma
Nucl. Fusion 44 (2004) 1047 (http://www.psfc.mit.edu/library/04ja/04JA017/04JA017_abs.html)
Scrape-off layer flows, magnetic topology and influence on the L-H threshold in a tokamak
Submitted to PRL January 21, 2004, rejected by PRL June 2, 2004 (http://www.psfc.mit.edu/library/04ja/04JA016/04JA016_abs.html)
ITERPhysics Basis Contribution - Cross-field Particle Transportin the Edge Plasma of Tokamak Experiments and Implications for ITER Operation
Report (http://www.psfc.mit.edu/library/03rr/03RR008/03RR008_abs.html)
APS 2003, Albuquerque, NM - Evidence for Electromagnetic Fluid Drift Turbulence Controlling the Edge Plasma State in Alcator C-Mod
Contributed Oral
APS 2003, Albuquerque, NM - Plasma Profiles and Flows in the High-Field Scrape-off Layer in Alcator C-Mod
Contributed Poster
In-Situ Gas Conductance and Flow Measurements Through Alcator C-Mod Divertor Structures With and Without Plasma Present
Report (http://www.psfc.mit.edu/library/03rr/03RR006/03RR006_abs.html)
IAEA2002, Lyon, France - Density Limit and Cross-Field Edge Transport Scaling in Alcator C-Mod
Talk - short version
Talk - full version
Paper (also see: http://www.iaea.org/programmes/ripc/physics/fec2002/html/fec2002.htm)
PSI 2002,Gifu, Japan - Toroidal rotation as an explanation for plasmaflow observations in the Alcator C-Mod scrape-off layer
Poster Presentation
Paper (published in J. Nucl. Mater.)
Analysis of fluctuation-driven particle fluxes measured by probes
Paper - Physics of Plasmas 9 (2002)
APS 2001, Long Beach, CA - Phenomenology and Scaling of Cross-Field Plasma Transport in the Alcator C-Mod Edge Plasma
Contributed poster
IAEATechnical Committee Meeting on DIVERTOR CONCEPTS September 11-14,2001, Aix-en-Provence, France: - Cross-field Plasma Transport inthe Scrape-off Layer: A key physics issue for SOL, divertor and coreplasma
Invited_Review Talk
Plasma Fluctuations in the 'Far SOL'
Paper - Physics of Plasmas 8 (2001) 3702
Workshop on Plasma Turbulence and Transport in Edge/SOL Regions 14-15 May, 2001, Fairbanks, Alaska - Particle Transport in the Alcator C-ModScrape-off Layer
Talk
APS 2000, Quebec City, Canada - Particle transport in the scrape-off layer and relationship to discharge density limit in Alcator C-Mod
Invited Talk
Paper - Physics of Plasmas 8 (2001) 2107
Press Release
PSI 2000, Rosenhiem, Germany - Cross-Field Plasma Transport and Main Chamber Recycling in Diverted Plasmas on Alcator C-Mod
Invited Talk
Paper - Nuclear Fusion 40 (2000)
APS 1999, Seattle, WA - Cross-Field Particle Transport through the Separatrix and Scrape-off Layer in Alcator C-Mod
Contributed Oral
Initial Results of the Alcator C-Mod Quasi-Coherent Mode Antenna
T. Golfinopolous, APS2012 Poster.
A 'Shoelace' Antenna System for Direct Excitation of C-Mod's Quasi-Coherent Mode (QCM) and Boundary Layer Turbulence
B. LaBombard, APS2011 Poster.
Electrical Characteristics and Performance of the Alcator C-Mod Quasi-Coherent Mode Antenna System
T. Golfinopolous, APS2011 Poster.
Mirror Langmuir Probe Development
A "Mirror Langmuir Probe" is Being Developed -- A Powerful New Technique to Measure Boundary n, Te, Phi Profiles and Turbulence
APS2012 Contributed Oral.
Mirror Langmuir probe: A technique for real-time measurement of magnetized plasma conditions using a single Langmuir electrode
Rev. Sci. Instrum. 78 (2007) 073501.
Construction and operation of a Mirror Langmuir Probe Diagnostic for the Alcator C-Mod Tokamak
L. Lyons Master's Thesis, 2007.
Edge Plasma Flow Diagnostic Development
Plasma Flows in the Alcator C-Mod Scrape-off Layer.
N. Smick Doctoral Thesis, 2009.
(WASP) Wall scanning probe for high-field side plasma measurements on Alcator C-Mod.
Rev. Sci. Instrum. 80, 023502 (2009).
Verification of Plasma-Sheath Heat Transfer Physics using Surface Thermocouple Diagnostic
Surface thermocouples for measurement of pulsed heat flux in the divertor of the Alcator C-Mod tokamak
Rev. Sci. Instrum. 83 (2012) 033501
Edge Plasma Ion Mass Spectroscopy
Omegatron Ion Mass Spectrometer - Review of Scientific Instruments 71 (2000) 4107:
Omegatron Ion Mass Spectrometer for the Alcator C-Mod Tokamak
Helium-3 Transport Experiments with Omegatron - Physics of Plasmas 7 (2000) 4573:
Impurity Dispersal 'Plume' Experiments
Impurity Plume Experiments: physics and detailed modeling - Plasma Phys. Control. Fusion 46 (2004) 1617.
Impurity plume experiments in the edge plasma of the Alcator C-Mod Tokamak
Impurity Dispersal 'Plumes' - Journal of Nuclear Materials 290-2939 (2001) 598
Impurity Transport Experiments in the Edge Plasmaof Alcator C-Mod using Gas Injection Plumes
Novel Tracer Gas Injecting Probe System - Journal of Nuclear Materials 266-269 (1999) 571
Alcator C-Mod Cryopump Development
Design, installation and commissioning of the upper divertor cryopump system in Alcator C-Mod
PSFC/RR-08-06-
APS 2007, Orlando, FL - Design and operation of a novel cryopumping system in Alcator C-Mod
Contributed Poster
1-D Space,2-D Velocity Kinetic Neutral Transport Code written in IDL*
PSFC Research Report: PSFC/RR-01-9 (KN1D.pro)
KN1D source code can be found here
PSFC Research Report: PSFC/RR-00-9 (Kinetic_Neutrals.pro)
A 1-D Space, 2-D Velocity, Kinetic Neutral Transport Algorithm
* IDL is a trademark of Research Systems, Inc., Boulder, CO
Last Revised: 4/4/2013