World record for nuclear fusion smashed by MIT team

17 Oct 2016

The interior of the MIT nuclear fusion reactor. Image: Bob Mumgaard/Plasma Science and Fusion Center

In its final send off, a highly experimental nuclear fusion reactor at MIT has smashed the world record for plasma pressure, the key ingredient to making clean, near-limitless energy.

Despite the prophesied potential of nuclear fusion technology, it remains one of the most controversial in science, with many taking the decision to dismiss it as a modern form of alchemy.

So, for every Wendelstein 7-X (W7-X) stellerator that shows signs of promise, there is an E-Cat ‘portable cold fusion’ reactor that is derided as a hoax by nuclear physicists.

Two-thirds of the challenge

If it were to be achieved, a nuclear fusion reactor would be able to replicate our own sun whereby the energy released in a reactor would exceed the energy required to keep the reaction going.

Aside from being a nearly limitless and potentially cheap form of energy, any harmful waste produced by nuclear fusion would only last for a very short space of time, compared with nuclear fusion waste that will be harmful for millennia.

This doesn’t mean that all research into the technology is wasted however, as the latest news from MIT in the US reveals it has broken yet another record, this time with the the amount of plasma pressure the reactor has generated.

According to MIT News, for the first time ever, the team of scientists and engineers achieved 2 atmospheres of plasma pressure with its Alcator C-Mod tokamak reactor.

This will be crucial to any future breakthroughs in fusion energy, as the greater the pressure within the reactor, the better the chance of the plasma reaching the necessary temperatures of more than 50m degrees Celsius.

While the plasma being contained in a fixed volume is also crucial in creating a working reactor, it is believed that achieving the highest pressure possible accounts for two-thirds of the overall challenge.

Staggering numbers

By doubling the amount of pressure within the reactor, the resulting energy generated is four times greater. In this experiment, the plasma generated 300trn fusion reactions per second at a temperature of 35m degrees Celsius.

To put this into perspective, this made the reactor twice as hot as the centre of the sun within the volume of just one cubic metre for two whole seconds, which is a long time compared with other nuclear fusion experiments so far.

“This is a remarkable achievement that highlights the highly successful Alcator C-Mod program at MIT,” said Dale Meade, former deputy director at the Princeton Plasma Physics Laboratory (who was not directly involved in the experiments).

“The record plasma pressure validates the high-magnetic-field approach as an attractive path to practical fusion energy.”

In what was a fitting send off, MIT’s reactor will now be taken offline. This means the record will likely remain unbroken until IETR in France build its new reactor that contains 800 times the volume of MIT’s.

When it is fully operational in 2032, it hopes to achieve a plasma pressure of 2.6 atmospheres.

Colm Gorey was a senior journalist with Silicon Republic