Scientists have just set a new world record for high-temperature sustained plasma with Korea’s Tokamak Advanced Research (KSTAR) superconducting device, which reaches an ion temperature of more than 100 million degrees Celsius (180 million degrees). Fahrenheit) for a period of 20 seconds.
Known as Korea’s “artificial sun,” KSTAR uses magnetic fields to generate and stabilize ultra-hot plasma, with the ultimate goal of making nuclear fusion energy a potentially unlimited source of clean energy that can transform. our way of empowering our lives. , if we can get it to work the way we wanted.
Prior to this point, the 100 million degrees had not been breached for more than 10 seconds, so it represents a substantial improvement on previous efforts, even if much remains to be done to be able to completely abandon other sources of energy. At this point, nuclear fusion energy remains a possibility, not a certainty.
The KSTAR. (Korea Institute of Fusion Energy)
“The technologies needed for long 100 million-degree plasma operations are the key to realizing fusion energy,” says nuclear physicist Si-Woo Yoon, director of the KSTAR Research Center at the Institute of Korea Fusion Energy (KFE).
“KSTAR’s success in keeping plasma high temperature for 20 seconds will be a major turning point in the race to ensure technologies for the long-term operation of high-performance plasma, a critical component of a high-performance reactor. commercial nuclear fusion in the future “.
The key to the 20-second jump was an upgrade to the Internal Transport Barrier (ITB) modes within KSTAR. Scientists do not fully understand these modes, but at the simplest level they help control the confinement and stability of nuclear fusion reactions.
KSTAR is a tokamak-style reactor, similar to the one recently connected to China, fusing atomic nuclei to create these huge amounts of energy (unlike nuclear fission used in power plants, which divides atomic nuclei). ).
Although the scientific work required to achieve this is complex, progress has been steady. KSTAR first breached the 100 million degree limit in 2018 and in 2019 managed to maintain the temperature for 8 seconds. Now, that has more than doubled.
“The success of the KSTAR experiment in the long operation at high temperature by overcoming some drawbacks of ITB modes brings us one step closer to the development of technologies for the realization of nuclear fusion energy,” says the physicist Yong-Su Na nuclear, Seoul National University (SNU).
Fusion devices like KSTAR use hydrogen isotopes to create a plasma state where ions and electrons are separated, ready to heat up, the same fusion reactions that take place in the Sun, hence the nickname they have been given. these reactors.
So far, maintaining temperatures high enough for a period of time long enough for the technology to be viable has proven to be a challenge. Scientists will have to break more records like this for nuclear fusion to function as an energy source: little more than seawater (a source of hydrogen isotopes) will escape and produce minimal waste.
Despite all the work left to get these reactors to produce more energy than they consume, progress has been encouraging. By 2025, KSTAR engineers want to have surpassed 100 million degrees over a 300-second period.
“The ion temperature of 100 million degrees achieved by allowing efficient core plasma heating for such a long time demonstrated the unique capability of the KSTAR superconducting device and will be recognized as a compelling basis for high-performance fusion plasmas and steady state, “says Columbia University physicist Young-Seok Park.
The results of the experiment have not yet been published in a peer-reviewed paper, but are being shared at the IAEA 2021 Fusion Energy Conference