Scientists have just set a new world record for sustained high-temperature plasma with the Korea Superconducting Tokamak Advanced Research (KSTAR) device, reaching an ion temperature of over 100 million degrees Celsius (180 million degrees Fahrenheit) for 20 seconds.
Known as Korea’s “artificial sun,” the KSTAR uses magnetic fields to generate and stabilize ultra-hot plasma, with the ultimate goal of making nuclear fusion power a reality – a potentially limitless source of clean energy that will alter the way we live our lives. energy supply could change, if we can make it work as intended.
Before this point, 100 million degrees had not been exceeded for more than 10 seconds, so it’s a significant improvement over previous efforts – even if there’s still a long way to go before we can completely dump other energy sources. At this point, fusion energy remains a possibility, not a certainty.
The KSTAR. (Korea Institute of Fusion Energy)
“The technologies required for long-term operations of 100 million degrees of plasma are key to the realization of fusion energy,” said nuclear physicist Si-Woo Yoon, a director of the KSTAR Research Center at the Korea Institute of Fusion Energy (KFE) .
“The success of the KSTAR in maintaining the plasma at high temperature for 20 seconds will be a major turning point in the race to secure the technologies for the long-term high-performance plasma control, a critical part of a commercial fusion reactor in the future.”
The key to the jump to 20 seconds was an upgrade to the Internal Transport Barrier (ITB) modes in the KSTAR. These modes are not fully understood by scientists, but at the simplest level, they help to control the confinement and stability of the nuclear fusion reactions.
The KSTAR is a tokamak-style reactor, similar to the one that recently went online in China, where atomic nuclei are joined together to create these enormous amounts of energy (unlike nuclear fission used in power plants, which split atomic nuclei apart).
While the scientific work required to achieve this is complex, progress has been steady. KSTAR first exceeded the 100 million degree limit in 2018 and managed to hold the temperature for 8 seconds in 2019. Now, that’s more than doubled.
“The success of the KSTAR experiment in long operation at high temperatures by overcoming some of the drawbacks of the ITB modes takes us one step closer to developing technologies for realizing nuclear fusion energy,” said nuclear physicist Yong-Su Na, from Seoul National University (SNU).
Fusion devices like KSTAR use hydrogen isotopes to create a plasma state in which ions and electrons separate, ready to heat – the same fusion reactions that take place on the sun, hence the nickname these reactors have been given.
So far it has proven challenging to keep the temperature long enough to make the technology viable. Scientists will have to break more records of this kind in order for nuclear fusion to act as an energy source – draining little more than seawater (a source of hydrogen isotopes) and producing as little waste as possible.
Despite all the work that remains to be done to make these reactors produce more energy than they consume, progress is encouraging. By 2025, KSTAR engineers aim to exceed 100 million degrees for a period of 300 seconds.
“The ion temperature of 100 million degrees achieved by enabling efficient nuclear plasma heating for such a long duration has demonstrated the unique capability of the superconducting KSTAR device and will be recognized as a compelling foundation for high quality, stable fusion plas” says nuclear physicist Young-Seok Park, of Columbia University.
The experiment’s findings have yet to be published in a peer-reviewed paper, but will be shared at the IAEA Fusion Energy Conference 2021.