UAF Researcher Contributes to Fusion Energy
A technician works inside the reaction chamber of the DIII-D National Fusion Facility in San Diego, operated by General Atomics for the US Department of Energy.
When the UAF Geophysical Institute studies the behavior of ionized gasses, the subject is typically the aurora borealis. For one researcher, though, the study of electrically charged fluids is contributing to advances in nuclear fusion energy.
David Newman is a physicist specializing in plasma, a superheated state of matter where electrons tear away from their atoms. Plasmas in fusion energy research are millions of degrees, whereas auroras in the upper atmosphere might be no hotter than an oven.
Newman, a former chair of the American Physical Society’s Division of Plasma Physics, has been working in nuclear fusion research for decades. He has been at UAF since 1998 and was previously at Oak Ridge National Laboratory in Tennessee. The research has taken him overseas to work with colleagues in Spain, Japan, Germany, and the United Kingdom. In the United States, he has worked with researchers at the DIII-D National Fusion Facility in San Diego, the Princeton Plasma Physics Laboratory, the Massachusetts Institute of Technology, and elsewhere.
His latest research, funded by the US Department of Energy, is in magnetic confinement fusion, one of two major pathways in the nuclear fusion field.
Scientists at the National Ignition Facility at Lawrence Livermore National Laboratory in California achieved a breakthrough in December through the other of those two pathways: inertial confinement fusion. The world’s most energetic laser compressed a fuel pellet to fusion temperature, yielding more energy from nuclear reactions than ever before.
“What they achieved is a significant, incremental step,” Newman says. “There’s still a long way to go, probably several decades, before fusion energy can be created on a large and commercial scale.”
In Newman’s field, a doughnut-shaped chamber called a tokamak uses magnets to heat deuterium and tritium gas into plasma. Igniting a fusion reaction requires a high enough atomic density and a high enough temperature—270 million°F, or ten times hotter than the sun’s core. It also requires that the plasma be confined long enough to heat additional fuel gasses.
David Newman of the UAF Geophysical Institute.
Newman’s research is aimed at solving a problem that develops as plasma heats up. Turbulence causes heat to spread to plasma’s outer edges and the reactor wall, where it is lost. Uncontrolled particle transport can damage the tokamak’s internal lithium-based protective blanket. Controlling this turbulent transport is one of the big issues still facing fusion.
“This is increasingly important as more effort is made to pursue burning plasmas,” Newman says. “It’s one of the last remaining major problems in fusion energy research.”
The United States, China, the European Union, India, Japan, South Korea, and Russia are working together to build the International Thermonuclear Experimental Reactor, the world’s largest tokamak, in southern France.
“Over the last few decades enormous progress has been made on the path to magnetic confinement fusion,” Newman says. “I think it’s likely that within the next three to nine years a magnetic confinement experiment will exceed the break-even point and pave the way for putting fusion energy on the power grid, which I find to be a very exciting prospect.”