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 plasma’s edge, glowing pink. The core is simply too hot to emit visible light. In this footage, lithium is dropped into the plasma. As it interacts, it glows red when excited, then turns green as it becomes ionised, losing an electron. From there, it traces the magnetic field lines, revealing the plasma’s path around the tokamak. Lithium is the focus of our $52 million ST40 upgrade programme, in partnership with @ENERGY and @energygovuk. This builds on pioneering work at @PPPLab and others that has shown that lithium can significantly improve plasma performance. This video comes from ongoing research into X-point radiator (XPR) regimes, a promising operating mode for future #fusion power plants that aims to cool the plasma before it reaches plasma-facing components (PFCs), helping to reduce wear without compromising performance. Fusion research just got a lot more colourful! 👇 tokamakenergy.com/2025/10/15… #Fusion #FusionEnergy #EnergyTransition #Innovation