Scientists have just set a new world record for high-temperature sustained plasma with the Korean superconducting device Tokamak Advanced Research (KSTAR), reaching an ion temperature of over 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 turning nuclear fusion power into a reality – a potentially unlimited source of clean energy that could transform the way we feed our lives. , if we manage to work according to the intention.
Prior to this point, 100 million degrees had not been violated for more than 10 seconds, so it is a substantial improvement over previous efforts – even if there is still a long way to go before we can completely eliminate other sources of energy. At this point, nuclear fusion power remains a possibility, not a certainty.
KSTAR. (Korean Fusion Energy Institute)
“The technologies needed for long 100 million-degree plasma operations are the key to achieving fusion energy,” says nuclear physicist Si-Woo Yoon, director of the KSTAR Research Center at the Korean Fusion Energy Institute (KFE).
“KSTAR’s success in keeping plasma at high temperatures for 20 seconds will be an important turning point in the race to ensure technologies for long-term operation with high-performance plasma, a critical component of a commercial nuclear fusion reactor in the future.”
The key to the 20-second jump was an update to KSTAR’s internal transport barrier (ITB) modes. These ways are not fully understood by scientists, 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 that recently entered China, fusing atomic nuclei to create these huge amounts of energy (unlike nuclear fission used in power plants, which separates atomic nuclei).
Although the scientific work required to achieve this is complex, progress has been steady. KSTAR first violated 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 long and high temperature operation by overcoming the disadvantages of ITB modes brings us one step closer to developing technologies for nuclear fusion energy,” says nuclear physicist Yong-Su Na of Seoul National University ( SNU).
Fusion devices, such as KSTAR, use hydrogen isotopes to create a plasma state in which ions and electrons are separated, ready for heating – the same fusion reactions that take place on the Sun, hence the nickname of these reactors.
So far, maintaining temperatures high enough for a long enough time for the technology to be viable has proven to be a challenge. Scientists will have to break several records like this for nuclear fusion to function as an energy source – leaking a little more than seawater (a source of hydrogen isotopes) and producing minimal waste.
Despite all the activities that are to be carried out to produce these reactors to produce more energy than they consume, progress has been encouraging. By 2025, KSTAR engineers want to exceed the 100 million degree mark for a period of 300 seconds.
“The ionic temperature of 100 million degrees obtained by activating the efficient core plasma heating for such a long time has demonstrated the unique capacity of the KSTAR superconducting device and will be recognized as a convincing basis for high-performance fusion plasmas, able to stable, ”says nuclear physicist Young-Seok Park of Columbia University.
The results of the experiment have not yet been published in a peer-reviewed paper, but are shared at the IAEA Fusion Energy Conference in 2021.