The KSTAR tokamak and some of its auxiliary systems, seen from the entrance to the hall.

KSTAR is considerably smaller than ITER (with a 1.8-metre major radius as compared to 6.2 metres) and it differs in many design details. The machine achieved high-performance operation mode (H-mode) in 2010 and reached an ion temperature of 100 million °C in 2018. KSTAR has proved especially efficient in suppressing edge localized modes ( ELMs ), a phenomenon that can occur during H-mode during which bursts of energy and particles are expelled from the plasma.