Developing Clean Renewable Power Understanding and predicting plasma behavior in fusion devices
	DOE Program Managers
	John Mandrekas DOE Office of Fusion Energy Sciences	Lali Chatterjee DOE Office of Advanced Scientific Computing Research

Fusion has the potential to provide a long-term, environmentally-acceptable source of energy for the future. While research during the past 20 years indicates that it will likely be possible to design and build a fusion power plant, the major challenge of making fusion energy economical remains. Improved simulation and modeling of fusion systems using terascale computers is essential to achieving the predictive scientific understanding needed to make fusion practical. Answers to several long-standing questions could give the United States a competitive edge in the design of future fusion power plants. Magnetized fusion plasmas contain electrons and the fusion fuel -- ions of deuterium and tritium. Plasma contained within a fusion device behaves very differently depending on the shape of the magnetic field and distribution of the electric current. Because no material can withstand the 100 million degree temperature of the plasma, it is the magnetic field that actually contains the plasma. Being able to control the plasma is critical to the success of fusion as a source of energy.

Integrated simulation of magnetic fusion systems involves the simultaneous modeling of the core plasma, the edge plasma, and the plasma-wall interactions. In each region of the plasma, there is anomalous transport driven by turbulence, there are abrupt rearrangements of the plasma caused by large-scale instabilities, and there are interactions with neutral atoms and electromagnetic waves. Many of these processes must be computed on short time and space scales, while the results of integrated modeling are needed for the whole device on long time scales. The mix of complexity and widely differing scales in integrated modeling results in a unique computational challenge

At present our understanding of the small-scale ("micro") instabilities that degrade plasma confinement by causing the turbulent transport of energy and particles and the large-scale ("macro") instabilities that can produce rapid topological changes in the confining magnetic field are too incomplete to begin developing integrated models. Similarly our understanding of plasma-material interactions and the propagation of electromagnetic waves are also too primitive to begin to develop integrated models. Thus, the first phase of SciDAC activities in fusion energy sciences focuses on the development of improved physics models of each of these elements.

Fusion Projects Announced in September 2006

Petaflops for Gigawatts
Framework Application for Core-Edge Transport Simulations (FACETS)
Full-scale reactor modeling for the U.S. fusion program and ITER, the next step fusion confinement device
    Principal Investigator: J.R. Cary (cary@txcorp.com)
    Tech-X Corporation
Includes a Scientific Application Partnership — Steady State Gyrokinetic Transport Code

Continuing Projects

Simulation of Wave Interactions with Magnetohydrodynamics
Coupling radio-frequency waves (an essential plasma control technique) with the magnetohydrodynamics of the plasma
    Principal Investigator: Don Batchelor (batchelordb@ornl.gov)
    Oak Ridge National Laboratory

Center for Plasma Edge Simulation
Developing a new integrated predictive plasma edge simulation package applicable to next generation experiments
    Principal Investigator: C. S. Chang (cschang@cims.nyu.edu)
    Courant Institute of Mathematical Sciences, New York University

Center for Gyrokinetic Particle Simulations of Turbulent Transport in Burning Plasmas
Simulating of turbulent transport to investigate plasma confinement properties
    Principal Investigator: W.W. Lee (wwlee@pppl.gov)
    Princeton Plasma Physics Laboratory

Center for Extended Magnetohydrodynamic Modeling
Assessing the mechanisms that lead to disruptive and other stability limits in present and next generation fusion devices
    Principal Investigator: Steve Jardin (jardin@pppl.gov)
    Princeton Plasma Physics Laboratory

Numerical Computation of Wave-Plasma Interactions in Multi-dimensional Systems
Understanding and predicting electromagnetic wave processess in fusion-relevant plasmas
    Principal Investigator: Paul Bonoli (bonoli@psfc.mit.edu)
    Massachusetts Institute of Technology