Last month, the Korea Superconducting Tokamak Advanced Research (KSTAR) device, a nuclear fusion reactor known as an ‘artificial sun’, broke the world record by maintaining a plasma for an incredible 20 seconds at an ion temperature of more than 100 million degrees Celsius (180 million degrees Fahrenheit), which is one of the core conditions for nuclear fusion of such a device.
KSTAR’s progress is staggering. It only reached 100 million degrees Celsius in 2018, but only for 1.5 seconds. In 2019, it was extended to 8 seconds. It has now more than doubled. No other device that can produce this hot (or hotter) plasma could sustain it for longer than ten seconds.
The record performance was possible thanks to a newly developed internal transport barrier mode. The researchers believe that they will be able to achieve 300 seconds with an ionic temperature that is higher than what is achieved here over the next five years. An important goal in the future development of commercial nuclear fusion reactors.
“The technologies required for long-term operations of 100 million degrees Plasma are the key to realizing fusion energy,” said Si-Woo Yoon, director of the KSTAR research center at the Korea Institute of Fusion Energy, in a statement said. “[T]he KSTAR’s success in maintaining the high temperature plasma for 20 seconds will be an important turning point in the fight to secure the technologies for the long high performance plasma operation, which in the future will be a critical part of a commercial nuclear fusion reactor. ‘
This KSTAR run started in August and lasted until December 10th. The team conducted a total of 110 plasma experiments to test the capabilities of the device, as well as methods and techniques to inject and stabilize the plasma. The experiments were conducted in collaboration with local and international partners.
South Korea is one of the members of ITER (originally the International Thermonuclear Experimental Reactor), the engineering mega-project that will be the largest nuclear fusion reactors ever built. Its purpose is to show that it is possible to build a device that can release more energy through nuclear fusion (in a controlled way) than is necessary to create in the first place the state of fusion of ligatoms .
The experiments conducted with KSTAR are crucial to inform the development of ITER, which is due to take effect in 2025. The results of the KSTAR run in 2020 are expected to be presented at the IAEA Fusion Energy Conference in May 2021.
While the joke is that nuclear fusion is always 20 years away, developments like this over the last decade really show how far this field has come.