Princeton Plasma Physics Laboratory
This cross section of ITER shows the inner walls of the fusion system. New experimental results suggest that sprinkling boron powder into the vessel could protect the inner walls from the plasma’s heat. Additionally, a new computer modeling framework shows the powder may only need to be sprinkled from one location. (Image credit: ITER Organization)
Fusion researchers are increasingly turning to the element tungsten when looking for an ideal material for components that will directly face the plasma inside fusion reactors known as tokamaks and stellarators. But under the intense heat of fusion plasma, tungsten atoms from the wall can sputter off and enter the plasma. Too much tungsten in the plasma would substantially cool it, which would make sustaining fusion reactions very challenging. Now, researchers at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) have experimental results suggesting that sprinkling boron powder into the tokamak could solve the problem. Boron partly shields the reactor wall from the plasma and prevents atoms from the wall from getting into the plasma. A new computer modeling framework, also led by PPPL researchers, shows the powder may only need to be sprinkled from one location. The experimental results and computer modeling framework will be presented this week at the 66th Annual Meeting of the American Physical Society Division of Plasma Physics in Atlanta.
Joseph Snipes, deputy head for Tokamak Experimental Science, is optimistic about the solid boron injection system based on experiments that demonstrated reduced tungsten sputtering after a solid boron injection. The experiments were conducted in three tungsten-walled tokamaks worldwide: one in Germany, one in China and one in the U.S.
