The Korean artificial sun — the Korea Superconducting Tokamak Advanced Research (KSTAR) reactor — has set a new fusion record after superheating a plasma loop to 180 million° F (100 million° C) for 48 seconds. The system also sustained high confinement mode for over 100 seconds.

The Korea Institute of Fusion Energy reports that this surpasses the record set in 2023 of tokamak device operation at these temperatures for 30 seconds.

This advance in extending the duration of high-temperature and high-density plasmas required for fusion energy production stemmed from improvements in the performance of the plasma heating systems, high-temperature plasma operation and control techniques. The plasma duration resulted in a new record in the field of ion temperatures beyond 100 million° C.

The high confinement mode was maintained for a continuous duration of 102 seconds, considered the baseline operation mode for sustaining a high-temperature, high-density plasma state. Researchers attribute this progress to the installation of new tungsten divertors in 2023. These demonstrated only a 25% increase in surface temperature relative to the previously deployed carbon-based components under similar heat loads.

The target is the attainment of 300 seconds of plasma operation with ion temperatures over 100 million° C. KSTAR performance improvements implemented or planned to reach this goal include installing additional tungsten plasma-facing components and securing real-time feedback control utilizing artificial intelligence technology.