DIII-D tokamak used to test spacecraft heat shield materials

November 16, 2021, 3:00PMNuclear News
A set of graphite rods was exposed to hot plasma in the DIII-D tokamak. Researchers measured the ablation behavior under extreme heat and particle flow to simulate conditions experienced by spacecraft heat shields during atmospheric entry. (Image: General Atomics)

As a spacecraft on a research mission hurtles at up to 100,000 miles per hour toward the surface of a gas giant like Jupiter, the atmospheric gases surrounding the spacecraft turn to plasma, and spacecraft temperatures increase to more than 10,000 °F.

General Atomics’ compact fusion design shows net-electric potential

April 6, 2021, 12:00PMNuclear News
The outside of the DIII-D tokamak, where testing that supports the development of the Compact Advanced Tokamak has been performed. Photo: General Atomics

Scientists at the DIII-D National Fusion Facility have published research on a compact fusion reactor design they say could be used to develop a pilot-scale fusion power plant. According to General Atomics (GA), which operates DIII-D as a national user facility for the Department of Energy’s Office of Science, the Compact Advanced Tokamak (CAT) concept uses a self-sustaining configuration that can hold energy more efficiently than in typical pulsed configurations, allowing the plant to be built at a reduced scale and cost.

New model stretches the limits of fusion torus control

August 17, 2020, 7:37AMNuclear News

PPPL physicists Raffi Nazikian (left) and Qiming Hu, with a figure from their research. Photo: PPPL/Elle Starkman

Stars contain their plasma with the force of gravity, but here on earth, plasma in fusion tokamaks must be magnetically confined. That confinement is tenuous, because tokamaks are subject to edge localized modes (ELM)—intense bursts of heat and particles that must be controlled to prevent instabilities and damage to the fusion reactor.

Researchers at the Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) and at General Atomics (GA) recently published a paper in Physical Review Letters explaining this tokamak restriction and a potential path to overcome it. They have developed a new model for ELM suppression in the DIII-D National Fusion Facility, which is operated by GA for the DOE. PPPL physicists Qiming Hu and Raffi Nazikian are the lead authors of the paper, which was announced on August 10 by PPPL.