1,337 seconds: that was how long WEST, a tokamak run from the CEA Cadarache site in southern France and one of the EUROfusion consortium medium size Tokamak facilities, was able to maintain a plasma for on 12 February. This was a 25% improvement on the previous record time achieved with EAST, in China, a few weeks previously.

Reaching durations such as these is a crucial milestone for machines like ITER, which will need to maintain fusion plasmas for several minutes. The end goal is to control the plasma, which is naturally unstable, while ensuring that all plasma-facing components are able to withstand its radiation without malfunctioning or polluting it.

This is what CEA researchers intend to achieve and what explains the current record. Over the coming months, the WEST team will double down on its efforts to achieve very long plasma durations—up to several hours combined—but also to heat the plasma to even higher temperatures with a view to approaching the conditions expected in fusion plasmas.