OXFORD, U.K. — The U.K.-based Joint European Torus laboratory has broken its own world record for the largest amount of energy extracted from a nuclear fusion reaction, according to the BBC, more than doubling the previous record set in 1997.


The experiment was able to generate 59 megajoules of heat over five seconds by fusing two isotopes of hydrogen, known as deuterium and tritium, to form helium gas.


Though this is only about enough energy to boil 60 kettles’ worth of water, the project’s head of operations told the BBC that it demonstrates the ability to “create a mini star inside of our machine and hold it there for five seconds and get high performance,” and the BBC explains that, crucially, this “validates design choices” at the larger International Thermonuclear Experimental Reactor being built in France.


The massive ITER facility is supported by a number of governments across the world, including EU member states, the U.S., China and Russia, and is hoped to be the final step in proving nuclear fusion can become a reliable energy provider in the second half of this century. According to its CEO, if the Joint European Torus laboratory’s experiments hadn’t proved successful, there would have been major doubts about the chances of success at the ITER, so the new record represents a relief for many involved in both projects.