Fusion Energy Sciences

Sandia's Fusion Energy Sciences Program is developing a technology base for the design of in-vessel components that will perform satisfactorily in fusion plasma environments.   We study the interactions of plasmas and materials, the behavior of materials exposed to high-heat fluxes, and the interfaces of plasmas and fusion reactor walls.   Extensive analyses of prototypes are required before components can be qualified for operation in fusion machines.  The process involves selecting, specifying, and developing materials for components exposed to high-heat and particle fluxes   Materials samples and prototype components are tested in Sandia's Plasma Materials Test Facility, which uses high-power electron beams to generate high-heat fluxes that simulate fusion reactor environments. Materials and components are also exposed to tritium plasmas in Sandia's Tritium Plasma Experiment, located at Los Alamos National Laboratory.   Materials from these tests are characterized using Sandia's accelerator facilities for ion beam analysis.

Sandia directly supports US and international fusion machines.  This support includes tritium removal inventory support and materials postmortem analysis for the recently closed Princeton tokamak fusion test reactor; materials analysis and diagnostic development for the General Atomics DIII-D Advanced Divertor Project; and measurements of plasma/wall interaction in the C-Mod tokamak at the Massachusetts Institute of Technology and the National Spherical Torus Experiment at the Princeton Plasma Physics Laboratory.   We participate in collaborative experiments on the Joint European Torus in the United Kingdom, the JT-60 tokamak in Japan, the Large Helical Device in Japan, and the KSTAR device in Korea.

In all these experiments, Sandia participates in machine operation and provides specialized diagnostics and data analysis for evaluating plasma/material interactions, boundary layer plasma control, and plasma-facing components.  We also continue to collaborate on plasma/ material interaction and high-heat-flux issues with colleagues in Europe and Japan.  At the DOE's direction, Sandia has entered into cooperative exchanges on plasmafacing component development with several laboratories in Russia.   We just completed a successful six-year collaboration on the design of the International Thermonuclear Experimental Reactor as part of the US team collaborating with Europe, Japan, and Russia.

In 1999, the DOE started two new projects to find innovative solutions for plasma-facing components:  the Advanced Limiter/Divertor Plasma-Facing Surfaces program and the Advanced Power Extraction study.  These projects use liquid surfaces facing the plasma (examples of liquids being studied are lithium, tin/lithium alloy, and lithium beryllium fluoride).  These studies are a joint effort among Argonne National Laboratory, General Atomics, Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, Sandia National Laboratories, the University of Illinois, the University of California at Los Angeles, and the University of California at San Diego.

Sandia is using our unique test facilities and analysis capabilities to determine the heat-flux capability, particle pumping and retention characteristics, erosion rates, and design features of liquid walls in a fusion device.  We are developing the diagnostics to measure heat flux on a flowing liquid and the effect of extremely intense, short-duration heat pulses on a liquid surface.  We are working with other institutions to design and construct a proof-of-principle liquid surface device that can be tested in a US fusion machine.

Because of the increased focus in US fusion energy sciences on more compact, alternative concepts to the conventional tokamak, the issues of plasma/material interactions will be of greater importance in the future.  Sandia is acting as a central resource for using alternative concepts to resolve these problems with plasma-facing components. We also have started discussions with the inertial fusion energy community on future collaborations related to reactor chamber technology development.   The liquid wall research is directly related to many concepts for inertial fusion reactors.

Contact: Mike Ulrickson
Sandia National Laboratories
P.O. Box 5800, MS-1129
Albuquerque, NM 87185-1129
Phone: 505-845-3020, Fax: 505-845-3130
Email:maulric@sandia.gov