UK-based energy technology startup First Light Fusion (First Light) has announced a breakthrough for its novel nuclear fusion technology. A spin-off from the University of Oxford, First Light has successfully tested its 'electric gun' to ignite fuel in its test reactor’s core.

This milestone, announced just weeks after another breakthrough at its American test facility, brings sustainable nuclear fusion closer to reality. By using this electric gun, the company has managed to increase the distance its reaction-starting projectile travels by a factor of 10. 

Previously the company used a pulsed power machine to electromagnetically launch projectiles. This allowed them to achieve a maximum stand-off distance of 1cm.

“The major milestone will help solve one of the key engineering challenges in designing a projectile fusion power plant. It forms part of the Oxford-based firm’s ongoing work to design a pilot power plant capable of producing commercial energy from fusion,” First Light explained in a press release

Image of First Light's test reactor at Oxford. Photo: First Light Fusion.

Another fusion milestone

First Light is exploring nuclear fusion using a unique method called inertial confinement fusion. This involves firing a high-speed projectile to create high temperatures and pressures, which trigger a fusion reaction.

This method generates the high temperatures and pressures required for fusion reactions by using a projectile to compress a target containing fusion fuel at an incredibly high speed. This process is similar to the firing of a spark plug in an internal combustion engine. 

“This creates the extreme temperatures and pressures required to achieve fusion by compressing a target containing fusion fuel using a projectile travelling at a tremendous speed. 

The ‘Stand-off’ distance is the distance between where the ‘projectile’ is launched and the ‘target’ – where the fusion implosion happens,” said First Light. 

First Light faced a significant challenge to increase the distance between the projectile and the target in its fusion reactor. Using the electric gun method, the start-up managed to increase the projectile distance to 10cm, ten times more than its previous record.

“The challenge is to be able to launch a projectile accurately, at velocities of several kilometres per second, while keeping it in a solid state when it hits the fusion fuel. This is a major challenge in First Light’s approach with its pilot power plant design requiring the projectile to be fired at very high speeds and accuracy,” First Light explained. 

Stand-off distance is the key

However, this is only part of the journey for First Light with its novel reactors. They need a distance of several meters to create a viable power plant. But, the technique promises to bring this 'Holy Grail' of energy production to life.

“First Light’s aim is to design the lowest risk and simplest, most scalable plant design possible. By increasing the energy per shot, and reducing the frequency, First Light aims to achieve a smaller overall plant size with a much lower risk,” said First Light.

“This is a milestone moment for First Light and the result of a huge amount of effort, time, and perseverance from the whole team,” explained Mila Fitzgerald, a Scientist at First Light Fusion.

“As we scale up our approach and look to design a pilot power plant based on First Light’s projectile approach – one of the key challenges is being able to fire a projectile at high speeds and from a further distance. That is the basis of our current pilot plant design,” she added.

“This experiment demonstrates a way for us to do that and is an exciting step in the right direction,” said Fitzgerald.