In a monumental breakthrough, the Korean Fusion Energy Institute’s (KFE) Korea Tokamak Superconducting Advanced Research (KSTAR) fusion reactor reached a temperature of 100 million degrees Celsius for the first time. This remarkable achievement sets a new record for the project, and was accomplished during testing from December 2023 to February 2024. The reactor successfully maintained the high temperature for an impressive 48 seconds. By comparison, the Sun’s core temperature is only 15 million degrees Celsius.
In addition to reaching this impressive milestone, the KSTAR reactor also maintained high limit mode (H mode) for over 100 seconds. H-mode is an advanced operating mode in magnetically confined fusion that helps maintain a stable plasma state during the fusion process. Fusion reactions in the reactor simulate the production of light and heat from stars by fusing hydrogen nuclei and other light elements to release energy.
The success of KSTAR can be attributed in large part to a new tungsten diverter at the bottom of the vacuum tank in the reactor. The diverter played a crucial role in expelling exhaust gases and impurities while withstanding high surface heat loads. By switching from carbon to tungsten in the diverter, KSTAR scientists saw significant improvements in temperature management and operational efficiency, allowing for longer periods of H-mode operation.
The success of KSTAR’s tungsten diverter has far-reaching implications for fusion energy research worldwide, particularly for international collaborations like ITER (International Thermonuclear Experimental Reactor). Tungsten will also be used as a key component in ITER’s diverter, showcasing how advancements made by one nation can have global impact on fusion energy research as a whole.
