In a reactor at the National Fusion Research Institute (NFRI) in South Korea, a team managed to keep superheated plasma – one of the four states of matter – in a steady state for more than a minute, a new record.
The Korean Superconducting Tokamak Advanced Research (KSTAR) tokamak-type nuclear fusion reactor has achieved a world record of 70 seconds in high-performance plasma operation.
The new record marks another step towards nuclear fusion as a potentially limitless source of energy.
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. Various techniques, including a rotating 3D field, have been applied to alleviate the accumulated heat fluxes on the plasma-facing components.
NFRI president Keeman Kim said: "We will exert efforts for KSTAR to continuously produce world-class results, and to promote international joint research among nuclear fusion researchers."
Construction of KSTAR, a tokamak-typed nuclear fusion reactor, began in December 1995 and it was completed in August 2007. The first experiment was conducted in KSTAR in 2009. It was the first in the world to feature a fully superconducting magnet system with a central solenoid, toroidal and poloidal field coils. It measures 8.6 m high, and 8.8 m in diameter.
Tokomak-design reactors like KSTAR use magnetism to contain a toroidal-shaped plasma at temperatures of up to 300 million °C. Despite this temperature, it is necessary to cool superconducting magnets to -269°C. Inside the plasma, a few grams of deuterium and tritium atoms are stripped to the nuclei, which fuse to release energy. It is hoped that this form of nuclear energy could one day be used to generate electricity, but maintaining a steady plasma has proven very difficult.
This world record brings us one step closer to the reality of limitless energy created from plasma.