SOURCE: Cray Inc.

January 02, 2007 07:30 ET

General Atomics Scientists Use Cray X1E Supercomputer at ORNL to Make Important Advance in Fusion Research

More Accurate Predictions of Plasma Turbulence in Reactors a Milestone on the Way to Clean, Abundant Power Based on Nuclear Fusion

SEATTLE, WA -- (MARKET WIRE) -- January 2, 2007 -- Global supercomputer leader Cray Inc. (NASDAQ: CRAY) today announced that General Atomics researchers using a Cray X1E™ supercomputer have made a significant breakthrough in their ability to predict what happens inside an experimental fusion reactor, a milestone on the way to developing a stable and efficient new power source. Fusion is the nuclear reaction that fuels stars like the sun and has the potential to produce clean, almost limitless power here on Earth.

The General Atomics scientists are employing a computer code they wrote called GYRO, scaled to the massive compute capabilities of a Cray X1E system located at Oak Ridge National Laboratory (ORNL), to simulate the complex behavior of the super-heated gaseous fuel called plasma as it roils within a reactor. Working under a grant of computer time from the Department of Energy's (DOE's) Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program, the researchers have for the first time been able to simulate both electron and ion plasma turbulence, a crucial step for eventually designing and building a full-scale, energy-producing fusion reactor.

"Approximation is the name of the game in physics," said Jeff Candy, principal scientist in the Energy Group at General Atomics. "GYRO performs a faithful gyrokinetic approximation of the fundamental physics that occurs when the nuclei of deuterium and tritium atoms fuse within a reactor's magnetic containment field. Normally researchers do smaller electron-scale simulations of the plasma. But the Cray X1E supercomputer at ORNL has allowed us to combine electron-scale and ion-scale simulations to produce a much closer approximation of turbulence fluxes for various temperatures and densities. Modeling these instabilities on the actual reactor would be very time-consuming and expensive."

"ORNL is the nation's largest computing resource for big, open science," said Doug Kothe, director of science for ORNL's National Center for Computational Sciences. "As part of DOE's recently expanded INCITE program, time on our Cray X1E 'Phoenix' and Cray XT3 'Jaguar' supercomputers is being allotted to scientists from General Atomics and other organizations doing challenging, high-impact research that requires leadership-class computing resources. Breakthrough science becomes possible because of the systems expertise provided by the collaboration between Cray and ORNL staff and researchers."

The National Center for Computational Sciences (NCCS) at the Oak Ridge National Laboratory is funded by the Department of Energy's Office of Science. The center was designated in 2004 by the Secretary of Energy as the Leadership Computing Facility for the nation.

Complex Calculations

A fusion reactor spins plasma at a high rate of speed, building up pressure and immense heat that can reach 200 million degrees Fahrenheit. Gyrokinetic physics is employed to study how these conditions cause instabilities that make the plasma slow down and cool. The equations involved in gyrokinetic calculations such as those performed by the General Atomics GYRO code were originally developed by researchers over 25 years ago. However, it has only been in the last few years that computers have become powerful enough to produce useful gyrokinetic simulations for fusion research.

To completely model the plasma in one of the donut-shaped reactors known as tokamaks where fusion research is conducted, the GYRO simulations will need to be included in still more complex models that take into account the engineering aspects of the reactors. General Atomics is also conducting fundamental research on the alpha particles produced by reactors that tend to slow down the plasma reaction. The ultimate goal is to design a much larger reactor that can confine the plasma in near-perfect thermal equilibrium and sustain the intense heat required for commercial power generation.

"Gryokinetic simulations place a tremendous amount of stress on a supercomputer's architecture," said Cray Chief Technology Officer Steve Scott. "The Cray X1E system at ORNL is built with powerful vector processors sharing a common global memory and fed by massive memory and interconnect bandwidth. We are delighted that the General Atomics team and other INCITE participants have been able to take advantage of this advanced architecture to do the sort of large-scale, computationally demanding scientific work that was not previously possible."

About General Atomics

Headquartered in San Diego, California, General Atomics was conceived in 1955 for the purpose of harnessing the power of nuclear technologies for the benefit of mankind. General Atomics' basic research into fission and fusion has matured into competence in many technologies, making the company and its affiliates one of the world's leading resources for high-technology systems development ranging from the nuclear fuel cycle to remotely operated surveillance aircraft, airborne sensors, and advanced electric, electronic, wireless and laser technologies. The General Atomics fusion program, which began over 40 years ago, is the largest such effort in private industry. Its long-term goal is the development of a fusion device that can produce electricity safely and economically. Go to for more information.

About Oak Ridge National Laboratory

Located in Oak Ridge, Tennessee, ORNL is the U.S. Department of Energy's largest science and energy laboratory, with over 4,000 researchers and support staff. ORNL is an international leader in research areas that include neutron science, new energy sources, high-performance computing, biological systems, nanoscale materials science and national security. The laboratory was selected as a DOE Office of Science National Leadership Computing Facility and is a key participant in the Office of Science's INCITE program, which is dedicated to supporting innovative, large-scale computational projects with the potential for high-impact scientific advances. Go to for more information.

About the Cray X1E Supercomputer

Combining the performance of traditional vector supercomputers with the scalability of microprocessor-based architectures, the Cray X1E supercomputer features the world's fastest processors and highest computing density. It is enabling scientists and industrial engineers to make breakthrough advances on a range of grand-challenge problems, including advanced aircraft design, weather forecasting and climate modeling, internal combustion simulation, plasma energy research, structural and fluid analysis, molecular dynamics and many others. Go to for more information.

About Cray Inc.

As a global leader in supercomputing, Cray provides highly advanced supercomputing systems and world-class services and support to government, industry and academia. Cray technology enables scientists and engineers to achieve remarkable breakthroughs by accelerating performance, improving efficiency and extending the capabilities of their most demanding applications. Cray's Adaptive Supercomputing vision will result in innovative next-generation products that integrate diverse processing technologies into a unified architecture, allowing customers to surpass today's limitations and meeting the market's continued demand for realized performance. Go to for more information.

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