The institute, based at Daejeon, 160 km south of Seoul, said a fully non-inductive operation mode - called a "high poloidal beta scenario" - has been used to achieve this long and steady state of operation using high-power neutral beam. It said various techniques, including a rotating 3D field, have been applied to alleviate the accumulated heat fluxes on the plasma-facing components.

"The world record for high-performance plasma for more than a minute demonstrated that the KSTAR is the forefront in steady-state plasma operation technology in a superconducting device," NFRI said in a statement today. "This is a huge step forward for realization of the fusion reactor."

In addition, the institute said, KSTAR researchers also succeeded in achieving an alternative advanced plasma operation mode with the internal transport barrier (ITB).