|Carbon deposition studies on the DIII-D Tokamak.|
- FESP makes leading contributions in MFE science experiments at the DIII-D tokamak at General Atomics in San Diego and the National Spherical Torus Experiment at Princeton in toroidal magnetic confinement research. These are the experimental elements for FESP's research in boundary physics, one that is ideally situated for FESP's theory and simulation research that is supported by OFES in this arena.
- The strong coupling between experiment and theory makes LLNL ideally suited to be leading contributors to developing predictive tools and divertor design efforts that draw upon our boundary physics understanding.
- The work extends to diagnostics not only of the plasma boundary but of the core current density as well, and has formed the basis for diagnostic studies that have been performed for major diagnostic systems for the ITER project.
Magnetic Fusion — Tokamak
LLNL Collaboration focuses on tasks
- Use of a Multiple Discipline Team, focused on tasks
— Physicists, engineers, technicians, and computational staff are part of the team (as needed).
- Strong On-site Presence of Personnel at DIII–D
— Over 3/4 of FTE are on site, rest are “in sight”
— Includes on-site diagnostic technician, as needed E-Tech
- Use of Institutional Strengths of LLNL, as needed
— Edge Modeling from LLNL theory (separate funding)
— Engineering support (optical design, engineering design)
- Participation in International Collaborations
— ITPA, ASDEX-U, JT-60U, TEXTOR (IRTV)
Pedestal, Boundary, and Divertor
- ITER research and Fusion Science
— Edge & Divertor measurements and modeling
– Heat Flux, impurity emissions, recycling
— Tritium & H2 Retention & Removal
– SOL drifts (transport), impurity sources
— Validated edge model development
– (UEDGE, BOUT, TEMPEST)
— Diagnostic Development (IRTV)
- Scenario Development
— Current profile measurement and control - Motional Stark Effect - Measure angle of polarized light from D 2 Stark Spectrum in plasma
— ITER Scenario Development (CORSICA equilibrium & transport code)
US ITER diagnostics provide important control and science tools
Current MFE experimental Staff
- S. Allen - Associate Program Leader for the FESP/DIIID collaboration
- D. Hill - Deputy Director of DIII-D national program
- M. Groth - Spectroscopist
- C. Lasnier - IRTV, ITER WFO
- M. Makowski - Edge Modeling, Mathematica, MSE
- C. Holcomb-FL - MSE Lead
- M. Fenstermacher - Campaign Leader, TV spec
- T. Casper - Core modeling, fluctuations (on assignment at ITER)
- Vlad Soukhanovskii - Edge physics on NSTX at PPPL
- B. Meyer - UNIX, Image Reconstructions, controls
- Gary Porter, Marv Rensink - UEDGE Fluid Modeling
- R. Ellis (ME), B. Geer (EE), D. Behne(ME), S. Lerner (ITER optics), K. Morris (ITER CAD)
The figure above shows the comparison of predicted ELM structure and measured light from carbon ions during an ELM: (a) calculated 3D profile of the distortion due to an ELM; (b) blow-up of the region that would be seen by the camera; (c) measured 3D profile of light emitted by carbon atoms during the ELM.
A team of scientists has opened a new window into the complex behavior that occurs at the edge of a 100‑million-degree fusion plasma. Using advanced high-speed cameras, the team obtained very detailed, three-dimensional images of plasma instabilities known as Edge Localized Modes (ELMs). Understanding the mechanism that lead to these instabilities will have important implications for the performance of the next generation of fusion devices, such as the International Thermonuclear Experimental Reactor (ITER), a major international project with significant U.S. participation. The team, which included researchers from Lawrence Livermore, General Atomics, Oak Ridge National Laboratory, and the University of California, San Diego, performed the experiments at the DIII-D tokamak at General Atomics in La Jolla, California.