Tungsten is emerging as a crucial material for next-generation fusion reactors due to its ability to withstand extreme heat and reduce fuel retention, reports Darren Orf of Popular Mechanics. In 2024, Korea’s KSTAR reactor sustained plasma at 100 million °C using a tungsten divertor, while France’s WEST reactor achieved a six-minute fusion reaction at 50 million °C with higher energy and density than carbon-based designs. Although tungsten presents challenges because it can cool plasma if it enters the reaction, advances in diagnostics—such as WEST’s multi-energy soft X-ray camera—are helping scientists manage these risks. The results support ITER’s decision to use tungsten walls and strengthen its role in the future of commercial fusion energy. Orf writes:
Tungsten, represented unexpectedly by the letter W on the periodic table of elements (for wolframite, an ore where tungsten is often found), is proving to be quite the wonder material for fusion reactors. In April 2024, the Korea Institute of Fusion Energy announced that its KSTAR fusion reactor successfully sustained plasma at 100 million degrees Celsius thanks in large part to its Tungsten divertor (basically a tokamak exhaust port). […]
While carbon has many benefits—chief among them being its high melting point—it may not be the best go-to material of choice for commercial reactors. That’s because carbon can retain fuel in the wall because of its relatively high atomic mass compared to tungsten. This doesn’t work because reactors also need to breed tritium from these reactions to create a sustainable fuel supply. […]
“The tungsten-wall environment is far more challenging than using carbon,” Luis Delgado-Aparicio, the head of advanced projects at the Princeton Plasma Physics Laboratory that is a partner on the WEST project, said in a press statement. “This is, simply, the difference between trying to grab your kitten at home versus trying to pet the wildest lion.”
Like KSTAR in Korea, the WEST reactor’s primary goal is to lay the groundwork for the International Thermonuclear Experimental Reactor (ITER), another nearby fusion reactor in France.
In 2023, ITER decided to switch the material of the reactor’s inner wall from beryllium to, you guessed it, tungsten. ITER’s fusion neighbor, WEST, will hopefully have lots of Tungsten data to provide once ITER is fully operational.
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