The Korea Superconducting Tokamak Advanced Research (KSTAR) device at the Korea Institute of Fusion Energy (KFE) sustained a 100-million-degree-Celsius ion-temperature plasma for 102 seconds, extending the device's 2024 record of 48 seconds and validating performance after last year's full tungsten divertor upgrade.

100 million °C — roughly seven times the temperature of the solar core — is the empirical threshold for economically meaningful deuterium-tritium fusion. KSTAR is the first tokamak to sustain that temperature in a fully tungsten-walled configuration, eliminating the carbon plasma-facing tiles used in earlier campaigns and removing a key tritium retention concern.

100 million °C — roughly seven times the temperature of the solar core — is the empirical threshold for economically meaningful deuterium-tritium fusion.

KFE president Suk Jae Yoo said the result accelerates Korea's K-DEMO program, which targets a 200 MWe demonstration reactor in the late 2030s. KSTAR data is also fed into the ITER tungsten divertor design, which was confirmed by the ITER Council in 2024 as the baseline plasma-facing surface for D-T operations.