Fusion Reactor Smashes Energy Record

Environmental & Science Education, STEM, Energy, Sustainability, Science & Society, History of Science

Ed Hessler

I've previously reported on the development of practical nuclear fusion. You know, the energy that powers our sun...stars, through fusing together atoms. The scientific and engineering challenges in developing this technology are immense, to say the least.

In a short article in the British science journal Nature is reported the breaking of a 24-year-old nuclear fusion record. It was doubled. This new record requires a drum roll: 5s.

From the Nature article by Elizabeth Gibney. “JET (Joint European Torus) really achieved what was predicted. The same modelling now says ITER (ITER means "The Way, in Latin) will work,” says fusion physicist Josefine Proll at Eindhoven University of Technology in the Netherlands, who was not involved in JET’s research. “It’s a really, really good sign and I’m excited.”

Gibney attributes the following reporting to plasma scientist Fernanda Rimini "who oversaw the experiment when she reports that "in an experiment on 21 December 2021, JET’s tokamak produced 59 megajoules of energy over a fusion ‘pulse’ of five seconds, more than double the 21.7 megajoules released in 1997 over around four seconds. Although the 1997 experiment still retains the record for ‘peak power’, it was over a fraction of a second and its average power then was less than half that of today. ... The improvement took 20 years of experimental optimization, as well as hardware upgrades that included replacing the tokamak’s inner wall to waste less fuel.

"Producing the energy over a number of seconds is essential for understanding the heating, cooling and movement happening inside the plasma that will be crucial to run ITER." 

The story in Nature includes a still of the pulse light inside the JET reactor but Jonathan Amos' reporting for the BBC includes a video which captures the inside shortly before the light pulse, the full 5 second pulse of light and immediately following. In addition, there is a diagram of how fusion works. 

I like the way John Amos of the BBC described the energy output of these experiments.

"The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power).

"This is more than double what was achieved in similar tests back in 1997.

"It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France."

Interestingly, "the record-breaking run happened on the last day of a five month campaign. I bet you know what's next: analysis of data collected during this long experiment. 

Fusion energy is such an active area of research because of the amount energy it could provide--virtually limitless--that is both low-carbon and low-radiation.

There are more details in both articles if you are more technically minded.