What laudable task can one do in the span of 22 minutes? Neaten a desk, tend to emails and other correspondence — or set a record for fusion plasma longevity in a tokamak.

The WEST tokamak operated by the French Alternative Energies and Atomic Energy Commission (CEA) set this 1,337-second time record for plasma duration in February 2025. The milestone was achieved at a plasma temperature of 50 million degrees C by maintaining hydrogen plasma for the test duration through the injection of 2 MW of heating power.

According to CEA, “This leap forward demonstrates how our knowledge of plasmas and technological control of them over longer periods is becoming more mature, and offers hope that fusion plasmas can be stabilized for greater amounts of time in machines such as ITER (International Thermonuclear Experimental Reactor).”

The plasma chamber of the WEST reactor. Source: CEA

The goal is to manage the unstable plasma while ensuring that any component in contact with it can tolerate the radiation without becoming contaminated or degrading. Researchers will next focus on intensifying efforts to demonstrate longer plasma durations — up to several hours combined — and to heat the plasma to even greater temperatures.