Scientists in South Korea have made a breakthrough in nuclear fusion research, achieving a stable plasma reaction at a temperature of over 100 million degrees Celsius for 30 seconds.
This is the longest duration of such a high-temperature fusion reaction ever recorded, and it brings humanity one step closer to harnessing the power of the stars.
Nuclear fusion is the process that fuels the Sun and other stars, where lighter atoms fuse together to form heavier ones, releasing enormous amounts of energy in the process.
If humans can replicate this process on Earth, it could provide a virtually limitless source of clean and carbon-free energy.
However, achieving nuclear fusion is extremely difficult, as it requires creating and sustaining a plasma state of matter, where atoms are stripped of their electrons and form a hot and dense soup of ions and electrons.
To initiate and maintain a fusion reaction, the plasma has to be heated to temperatures of over 100 million degrees Celsius, which is hotter than the core of the Sun.
It also has to be confined and controlled by powerful magnetic fields, preventing it from touching the walls of the reactor and cooling down.
The Korea Superconducting Tokamak Advanced Research (KSTAR) facility, also known as the Korean artificial sun, is one of the world’s leading fusion reactors, using superconducting magnets to create a doughnut-shaped plasma chamber.
In December 2020, KSTAR achieved a plasma operation at 100 million degrees Celsius for 20 seconds, setting a new world record at the time.
Now, the researchers have extended that record to 30 seconds, demonstrating a sustained and stable fusion reaction.
‘This is an important milestone that proves KSTAR’s ability to operate high-temperature plasma for a long time,’ said Si-Woo Yoon, director of KSTAR Research Center at Korea Institute of Fusion Energy (KFE), in a statement.
‘We will continue our research to extend the duration to 300 seconds by 2025.’
The researchers also conducted experiments on plasma turbulence, edge-localized modes (ELMs), and disruption mitigation during their latest campaign.
These are some of the key challenges that face fusion reactors, as they can affect the stability and efficiency of the plasma confinement.
The results of these experiments will be shared with other fusion research facilities around the world, such as ITER in France, which is expected to be completed by 2025 and become the world’s largest fusion reactor.
‘The success of KSTAR’s high-temperature plasma operation will be a solid foundation for ITER’s successful operation,’ said Yong-Su Na, professor at Seoul National University who participated in the KSTAR experiment.
