The Korea Fusion Energy Institute has installed a new converter on the KSTAR tokamak, allowing the artificial sun to maintain high ion temperatures exceeding 100 million degrees Celsius for a longer period.
KSTAR — called an artificial sun because it carries out nuclear fusion, the same reaction that fuels our star — was completed in 2007 and generated its first plasma in 2008. It is about a third the size of ITER, the massive experimental reactor being built in France. . Both reactors are tokamak types: “circuit”-shaped devices that carry out nuclear fusion with plasma, or electrically charged gases that are brought to extremely high temperatures and pressures.
KSTAR uses a converter located at the bottom of the tokamak that controls the exhaust of waste gases and impurities from the reactor. The converter is a plasma facing component, meaning it is placed inside the tokamak and bears the full weight of the heat from the inner surface. Currently, KSTAR is able to operate on plasma for approximately 30 seconds; Scientists hope the new converter will enable 300-second plasma operations by the end of 2026.
KSTAR tokamak in Daejeon, South Korea, Photo: Korea Fusion Energy Institute (KFE)
KSTAR originally had a carbon converter, but in 2018 scientists began working on a tungsten tokamak converter. Tungsten has a higher melting point than carbon and improves the reactor heat flow limit by two times, according to a recent statement from the Korea National Science and Technology Research Council. A prototype of the new transformer was completed in 2021 and installation was completed last year.
Workers inside the unloaded container of a KSTAR tokamak. Image: Korea Fusion Energy Institute (KFE)
“At KSTAR, we implemented a converter using tungsten material, which is also the choice made at ITER,” KFE President Suk Jae Yoo said in the statement. “We will do our best to contribute our best efforts to obtaining the necessary data for ITER through the KSTAR experiments.”
Nuclear fusion research may have made slow but important progress; In 2022, scientists at Lawrence Livermore National Laboratory achieved a net energy increase in a fusion reaction for the first time. We are still very (read: very) Far from the vaunted goal of a reliable, carbon-free energy source, the achievement came with caveats, but even so it showed that the field is moving forward with difficulty.
ITER’s first plasma is expected to be produced in 2025, and the first fusion is expected to take place in 2035. But the reactor’s timelines have shrunk while its costs have risen, from about 5 billion euros in 2006 to more than 20 billion euros, according to Scientific magazine. American, so we may be waiting longer than that.
However, these are still difficult times for tokamak reactors. Last month, the six-story JT-60SA reactor was opened in Japan; Researchers affiliated with the project estimate that it will take two years for the reactor to develop the plasma needed for experiments. There are more than 50 tokamaks in operation worldwide, according to the International Atomic Energy Agency.
Plasma experiments using KSTAR’s new tungsten converter will continue until February, according to the National Science and Technology Research Council, while tokamak scientists ensure the environment for the experiments is stable and can reproduce 100 million degree plasma.
Published no Gizmodo
