China’s "artificial sun" fusion tokamak has just broken the world record for the longest period of time achieving a plasma temperature, maintaining an intense 120 million degrees Celsius (216 million degrees Fahrenheit) for 101 seconds, as well as a whopping 160 million degrees Celsius for 20 seconds. Although nuclear fusion reactors are still in their infancy, maintaining these temperatures for increasing lengths of time pushes the field further into its eventual goal of near-unlimited energy.
The announcement was made by China's state-affiliated media outlet the Global Times, revealing the Experimental Advanced Superconducting Tokamak (EAST) had broken the fusion record, which was originally held by the Korean KSTAR fusion device back in December 2020 achieving 100 million degrees Celsius for 20 seconds. Holding this level of heat for five times the duration is a massive milestone, which the EAST researchers now hope to further extend.
"The breakthrough is significant progress, and the ultimate goal should be keeping the temperature at a stable level for a long time," said Li Miao, director of the physics department of the Southern University of Science and Technology, Shenzhen, in a statement to the Global Times.
A tokamak is a device that utilizes powerful magnets to create a magnetic field capable of confining plasma. Often in the shape of a ringed donut, a tokamak heats deuterium and tritium within the magnetic field to plasma temperatures, which can be over six times hotter than the core of the Sun. Intense energy is required to maintain this magnetic prison that holds the plasma in place, meaning current iterations are far too inefficient and short-lived to be a viable fusion reactor, but tokamaks currently represent our best option for a working fusion reactor in the future.
To achieve fusion, temperatures must breach 100 million degrees Celsius and remain there, a point at which deuterium and tritium atoms begin to combine. In this process, immense amounts of energy are released, which it is hoped can be harnessed to power the world’s electricity grid once the reactors become viable. Some scientists even wish to forgo the intense heat required for "hot fusion" and are attempting to create "cold fusion" – that is, a nuclear reaction happening near room temperature – although this is just a hypothetical idea that has not proved realistic yet.
EAST has been in operation since 2006, and followed the construction of China’s first superconducting tokamak device called HT-7. Since then, EAST has continued to impress by generating hotter and hotter plasma for longer periods of time. It aims to create pulses of plasma that last 1,000 seconds, which may still be many years off with just 101 seconds currently achieved. EAST now joins five other tokamaks in China attempting to control plasma into a usable energy source.