Humanity probably isn’t on the cusp of a nuclear fusion revolution just yet. But along the way, we are getting some peeks at mind-blowing fusion experiments, so what’s the big rush?
We submit this new footage from the British fusion firm Tokamak Energy, which captures physics so extreme that they almost doesn’t look real.
Shot with a high speed color camera, the video shows a donut-shaped chamber called a tokamak — the company’s namesake — swirling with a pink cloud of glowing hydrogen plasma as it reaches temperatures hotter than the core of the Sun, all imprisoned in an unbelievably powerful magnetic field. What we’re seeing is only the visible light from the plasma’s edge, because the core of the plasma is so hot that it doesn’t emit visible light at all.
In the top right corner, you can also witness a dazzling spectacle of lithium grains being injected into the chamber. At first a brilliant red, the lithium grains fall deeper into the plasma, while ionization turns it into a blurred halo of bright green.
Plasma is better in colour! Watch one of our latest #plasma pulses in our ST40 tokamak, filmed using our new high-speed colour camera at an incredible 16,000 frames per second.
Each pulse lasts around a fifth of a second. What you’re seeing is mostly visible light from the… pic.twitter.com/jWKmcl0tEx — Tokamak Energy (@TokamakEnergy) October 15, 2025
Nuclear fusion is the same process that powers stars for billions of years, including our own Sun. In the core of a star, the immense gravity smashes small atoms hydrogen atoms together in a superheated soup of plasma, releasing more heat when they combine.
Recreating this on Earth is tricky, since we don’t have the absurd gravity of a star to effortlessly smash atoms together. A tokamak is one way of doing it, though: it uses superconductor magnets to create a powerful magnetic field that traps the plasma, which is so hot that no solid material can contain it.
The fuel source, hydrogen atoms, also come with drawbacks. Though it’s the most abundant atom in the universe, they’re trickier to come by on Earth, especially the specific isotopes needed for fusion. Naturally occurring deuterium is somewhat rare and can be extracted from seawater, but another popular isotope, tritium, is so scare that scientists have to “breed” it by irradiating lithium, itself a metal in short supply. But in theory, they’re much safer fuel sources than the atoms used in nuclear fission, like plutonium and uranium, with the radiation it releases during fusion having a very short half life.
Right now, our puny human attempts at kickstarting fusion demands putting in more energy than it puts out. It’s still far from being practical, but the cool footage we’re witnessing is actually a boon to scientists.
“The color camera is especially helpful for experiments like these,” Tokamak Energy physicist Laura Zhang said in a statement. “It helps us immediately identify whether the gaseous impurities we’re introducing are radiating at the expected place, and whether lithium powders are penetrating to the plasma core.”
More on fusion: Fusion Startup Says It’s Figured Out How to Turn Mercury Into Gold