The Experimental Advanced Superconducting Tokamak (EAST), known as the “Artificial Sun”, is China’s cutting-edge fusion reactor. Over the last several years, it has consistently broken fusion records, and it can now add a new one to its collection: the longest sustained ultra-hot plasma. They kept it going for 1,066 seconds – that’s 17 minutes and 46 seconds of plasma well beyond 100 million degrees.
As reported by Xinhua, the Chinese state media agency, the achievement happened on Monday, January 20, 2025, led by researchers from the Institute of Plasma Physics under the Chinese Academy of Sciences. Back in May 2023, EAST had achieved its previous record of 403 seconds for its ultra-hot plasma. The temperature of this was in the past defined as over 160 million degrees Celsius (288 million degrees Fahrenheit), although if this was the temperature achieved this time it has not yet been disclosed.
EAST previously sustained a plasma of 120 million degrees Celsius (216 million degrees Fahrenheit) for an incredible 1,056 seconds back on December 30, 2021, so no matter which temperature was reached above the 100 million degree mark, the new record is the officially longest sustained ultra-hot plasma. This demonstration is an important step forward in fusion reactors becoming a consistent energy source.
These temperatures are much higher than the cores of stars where fusion is constantly happening. Stars can count on the pressure to hold hydrogen (usually) together so it can fuse at a lower temperature. The hydrogen or helium in reactors has a much lower density, so the plasma needs higher temperatures and it needs to be kept going for a long time – otherwise, you are not going to get the consistent output you’d want from a commercial power plant.
“A fusion device must achieve stable operation at high efficiency for thousands of seconds to enable the self-sustaining circulation of plasma, which is critical for the continuous power generation of future fusion plants,” Song Yuntao, ASIPP director, told Xinhua.
China is a member of the ITER collaboration, together with the European Union, India, Japan, Russia, South Korea, and the United States. The full-scale nuclear fusion power plant was expected to see its first plasma later this year, but it is now expected for 2034. Experimental reactors such as EAST, as well as many others across the world, are constantly refining what ITER is going to be like when it opens.
[H/T: Xinhua]
