Scientists excited by cheaper, faster way to produce nuclear fusion energy

6 Nov 2018

A rendition of the Sparc high-field tokamak nuclear reactor experiment. Image: Ken Filar

MIT researchers working on an experimental nuclear fusion reactor believe they can make energy production faster and cheaper with new, powerful magnets.

Last month, we heard how scientists at MIT had found a way to shed excess heat in nuclear fusion reactors, something crucial when trying to reach temperatures of millions of degrees Celsius within the confines of a lab.

Now, another MIT team from its Plasma Science and Fusion Center and company Commonwealth Fusion Systems have revealed a breakthrough that they say could make future nuclear fusion energy production faster and cheaper than ever before.

Due to reveal their findings at the American Physical Society Division of Plasma Physics, the researchers described how their new high-temperature superconductors can be used to build magnets that produce stronger magnetic fields than ever before. The researchers plan to use this technology to build magnets at the scale required for fusion, followed by construction of what would be the world’s first fusion experiment to yield a net energy gain.

This fusion experiment is called Sparc, a tokamak fusion device with a configuration similar to many of the other experimental reactors out there already.

Net energy gain – where the reactor produces more energy than is put into it – is the end goal of nuclear fusion, with its advocates promising that such a breakthrough would allow for us to produce near-limitless, clean energy at very little cost.

Operational by 2025?

However, so far, we have been unable to find a way to stably keep the two elements created in the process –  deuterium and tritium – from not tearing apart from each other. While this has been overcome when placed in an environment as hot as the sun, achieving a stable plasma with net energy gain has not.

One potential solution to this is to create even stronger magnets that keep the hot ionised gases isolated and insulated from ordinary matter. Even the doubling of the magnetic field of a fusion device could help reduce the cost and size of the reactor by a factor of eight.

So, using superconductors – which allow for a current to pass through them without losing energy – the MIT researchers could facilitate operations at even higher temperatures with the new manufacturing process. This allows for the production of high-temperature superconductors in the form of ‘tapes’ or ‘ribbons’ that make magnets with unprecedented performance.

Unfortunately, it could be a while before this new technology is implemented because the design of these magnets is not suited to existing fusion machines. So, before Sparc is built, the team must find a way to incorporate the technology into the kind of large, strong magnets needed for fusion.

The researchers are working towards the goal of having Sparc operational by 2025, with an output of between 50MW and 100MW.

Colm Gorey was a senior journalist with Silicon Republic