Commentary: Nuclear fusion may still be decades away, but the latest breakthrough could speed up its development

REASONS FOR HOPE

To produce a reactor for a working power station, you would need a laser that produced light energy at much greater efficiency (a few tens of percent) and shot targets successfully at 10 times per second, with each target costing a few pence or so. In addition, each laser shot would need to produce many times – perhaps 100 times – more energy out than was put in.

Very little research has actually been done on fusion “reactors”, where neutrons from the reactions would help drive a steam turbine to produce electricity. But there are other reasons for hope.

Firstly, while NIF has taken more than a decade to achieve ignition, during the same period, scientists have independently developed new lasers. These use electronic devices called diodes to transfer energy to the laser and are very, very efficient, converting a good fraction of the electricity from the grid into laser light.

Prototype versions of such lasers have been proven to work at the rates of 10 times per second, which would be required for them to be useful in fusion. These lasers are not yet of the size needed for fusion, but the technology is proven, and the UK leads in this type of research.

Also, the approach to fusion used by the scientists at NIF has some well-known, inherent inefficiencies, and there are several other ideas that could be much more effective.