May 20, 2026 - Business
Inside San Diego's fusion lab creating a tiny sun
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Behold the DIII-D tokamak. Photo: Courtesy of General Atomics
General Atomics can create quite literally a small sun in Sorrento Valley.
The big picture: The defense contractor operates what's called a tokamak that can get 100 times hotter than the sun. When it's on, the machine is the hottest thing in the entire solar system.
Toka-what? A tokamak is a doughnut-shaped machine that creates powerful magnetic fields used for fusion.
- It heats up plasma fuel super-duper hot.
- Then the doughnut shape forces it to move in circles until it fuses, which creates tons of energy.
- "The sun is this giant ball of gas, it gets very hot and then it fuses, and that's what makes all the energy from the sun," Richard Buttery, director of the U.S. Department of Energy's DIII-D National Fusion Facility, told Axios. "And we do the same thing."
Inside the fusion room: This technology is the largest operational magnetic fusion device in the country, so it's a big draw, Buttery said.
- Scientists and engineers from all over the world want to use the facility for their experiments, so they bid for time with the DIII-D.
- "Maybe they want to bring a material in and see how it goes under those kinds of temperatures, or have some clever idea as to how to make plasma get a little hotter," Buttery said.
- They currently have more than 800 users.
The big goal is to make a fully fusion pilot plant by 2030, he said.
- "It's not just that we make this ball of gas and it's hot and wasn't that fun, it's how do I make it really hot? And how do I make something that's going to work that when I build a little bit bigger one with a bit stronger magnetic fields," he said.