Korean nuclear fusion reactor achieves 100 million°C for 30 seconds

 

The Korea Superconducting Tokamak Advanced Research experiment

A nuclear fusion reaction has continued for 30 seconds at temperatures in excess of 100 million°C. While the duration and temperature alone aren’t record, the simultaneous achievement of heat and stability brings us a step closer to a feasible fusion reactor – as long as the technique used can be scaled up. 

Most of the scientists agree that viable fusion power is still decades away, but the incremental advances in understanding and outcomes keep coming. A test conducted in 2021 created a reaction energetic enough to be self-sustaining, suppositional designs for a commercial reactor are being drawn up, while work continues on the large ITER experimental fusion reactor in France. 

Now Yong-Su Na at Seoul National University in South Korea and his teammates have succeeded in running an experiment at the extremely high temperatures that will be required for a viable reactor, and keeping the hot, ionized state of matter that is formed within the device stable for 30 seconds. 

Na’s team make used of a modified ITB technique at the Korea Superconducting Tokamak Advanced Research (KSTAR) device, attaining a much lower plasma density. Their approach seems to raise temperatures at the core of the plasma and lower them at the edge, which will probably increase the lifespan of reactor components. 

“It’s not physics, it’s engineering,” Lee Margetts speaks. “If you just ponder about this from the point of view of a gas-fired or a coal-fired power station, if you do not have anything to take the heat away, then the people running it would say ‘we have to switch it off because it gets too much hot and it will melt the power station’, and that’s exactly the situation here.” 

“The magnetic confinement fusion approach has got a very long history of evolving to solve the next problem that it comes up against,”Brian Appelbe speaks. “But the point that makes me kind of nervous, or uncertain, is the engineering challenges of actually building an economical power plant based on this.” 

Journal reference: Nature, DOI: 10.1038/s41586-022-05008-1