South Korea’s ‘Artificial Sun’ just sets a new world record for high temperature plasma

Scientists have just set a new world record for sustained high temperature plasma with the Korea Superconducting Tokamak Advanced Research (KSTAR) device and reach 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 a reality – a potentially unlimited source of clean energy. which can transform the way we drive our lives. , if we can make it work as intended.

Before this point, 100 million degrees had not been broken for more than ten seconds, so this is a significant improvement over previous attempts – even if there is still a long way to go before we can completely drain other energy sources. At this point, nuclear fusion power remains a possibility, not a certainty.

kstar 2The KSTAR. (Korean Institute of Fusion Energy)

“The technologies required for long-term operations of 100 million degrees Plasma are the key to realizing 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 KSTAR in maintaining the high temperature plasma for 20 seconds will be a major turning point in the race to secure the technologies for the long high performance plasma operation, which will be a critical component of is a commercial nuclear fusion reactor. “

The key to the jump after 20 seconds was an upgrade of the internal transport barrier (ITB) in the KSTAR. Scientists do not fully understand these ways, but at the simplest level it helps to control the confinement and stability of nuclear fusion reactions.

The KSTAR is a Tokamak-style reactor, similar to the one recently launched online in China, which combines atomic nuclei to create these large amounts of energy (as opposed to the nuclear fission used in power plants, which divide atomic nuclei apart).

Although the scientific work required to achieve this is complex, progress is steady. KSTAR first crossed the 100 million degree mark in 2018 and in 2019 managed to maintain the temperature for 8 seconds. It has now more than doubled.

“The success of the KSTAR experiment in the long, high temperature operation by overcoming some of the disadvantages of the ITB modes brings us one step closer to the development of technologies for the realization of nuclear fusion energy,” says nuclear physicist Yong -Su Na, from 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 – the same fusion reactions that happen on the sun, hence the nickname given to these reactors.

It has so far been a challenge to maintain high enough temperature for a long period of time so that the technology is viable. Scientists will have to break more records like this to make nuclear fusion work as a power source – which drains more than seawater (a source of hydrogen isotopes) and produces minimal waste.

Despite all the work that lies ahead to make these reactors produce more energy than they consume, progress is encouraging. By 2025, the engineers at KSTAR want to have exceeded the 100 million degree mark for a period of 300 seconds.

“The 100 million degree ion temperature obtained by enabling effective nuclear plasma heating for such a long time has demonstrated the unique capability of the superconducting KSTAR device, and will be recognized as a compelling basis for high performance, stable fusion plasmas, says core. physicist Young-Seok Park, of Columbia University.

Findings from the experiment are yet to be published in a paper report, but will be shared at the 2021 IAEA Fusion Energy Conference.