Scientists in South Korea have announced a new world record for the length of time temperatures have been maintained 100 million degrees Celsius – seven times higher than the core of the sun – during a nuclear fusion experiment, in what they called a major step forward for this futuristic energy technology.

Nuclear fusion seeks to reproduce the reaction that makes the sun and other stars shineby fusing two atoms to release massive amounts of energy. It is often referred to as the “holy grail” of solutions for the climate, as clean energy, fusion has the potential to provide unlimited energy without the planet-warming carbon pollution. But controlling the process is extremely difficult. The most common way to achieve fusion energy involves a donut-shaped reactor called a tokamak in which hydrogen variants are heated to extremely high temperatures to create plasma. High-temperature, high-density creatures in which reactions can occur for long durationsis crucial to the future of nuclear fusion reactors, said Si-Woo Yoon, director of the KSTAR Research Center at the Korea Fusion Energy Institute (KFE) where the new record was achieved.

The maintenance of these high temperatures “it was not easy because of the unstable nature of high temperature plasma”he told the CNNwhich is why this recent record is so important.

KSTAR, KFE’s research fusion device, referred to as “artificial sun”, managed to maintain plasma with temperatures of 100 million degrees for 48 seconds during tests between December 2023 and February 2024, beating the previous record of 30 seconds set in 2021. KFE scientists said they managed to extend the time by tweaking the process, including using tungsten instead of carbon in the “deflectors”, the which extract the heat and waste produced by the fusion reaction.

The ultimate goal is for KSTAR to be able to sustain plasma temperatures of 100 million degrees for 300 seconds by 2026, a “tipping point” to be able to scale fusion operations, commented Si-Woo Yoon. Research by scientists in South Korea will feed into the development of the International Thermonuclear Experimental Reactor in southern France, known as ITER, the world’s largest tokamak that aims to prove fusion is possible. KSTAR’s work “will go a long way in ensuring the predicted performance of ITER’s operation in a timely manner and promoting the commercialization of fusion energy,” said Si-Woo Yoon.