How a shrimp inspired nuclear fusion technology

Fusion power, a long sought-after solution to the world’s energy needs, offers effectively unlimited, clean and safe electricity generation that could stay on when the Sun goes down and the wind stops blowing. After many decades of international projects, in recent years dozens of startup companies have raised billions of dollars of private funding in the race to reach what sometimes seems like gold at the end of the rainbow. One of those companies is First Light Fusion (FLF), which has set its sights on using a novel approach to create energy by the fusion of atoms of deuterium (D) and tritium (T), the two isotopes of hydrogen favoured as fuel by fusion engineers. 

The venture grew out of research by Dr Nicholas Hawker and Professor Yiannis Ventikos FREng at the University of Oxford. Hawker worked on hydrodynamic simulations of “shock-driven cavity collapse” – what happens when an external shock compresses a target. This laid the foundations for computer modelling to see if that shock-driven collapse would work as inertial confinement fusion (ICF). 

Hawker took inspiration from the pistol shrimp. This small creature has a large claw that can click shut so quickly that the underwater movement creates a bubble and a shockwave in the water. As the bubble collapses, the shock wave heats the vapour in the bubble to tens of thousands of degrees, emitting a brief flash of light. The shrimp’s aim is that the loud noise from the shockwave will kill its prey.

When modelling the shrimp’s trick, and the interaction of the bubble and shockwave, Hawker decided to apply the computer simulations to a pellet of fusion fuel. Could a similar process to that clicked claw create a shockwave to heat fusion fuel to temperatures and pressures needed for nuclear fusion?

Fusion with impact

Set up in 2011, FLF is one of a handful of companies using a process known as ICF. FLF describes its variation of ICF as impact fusion. It starts with a small pellet of DT fuel embedded in a target, which implodes when it is smashed with enough energy. In the process, FLF’s targets are designed to work as amplifiers and to compress the fuel pellet from all sides until it reaches temperatures and pressures higher than those in the Sun. 

The best-known example of ICF is the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in California. Funded by the US Department of Energy and built at a cost $3.5 billion, the NIF – the world’s largest laser – officially opened in May 2009. It made headlines in 2022 when it reported that fusion reactions there had produced more energy than it took to heat and compress the fuel targets, one of the major benchmarks for ICF. The NIF uses 192 powerful laser beams as drivers, housed in a 10-storey building the size of three football fields, to blast tiny pellets of DT. 

This was good news for FLF. As Hawker puts it: “Our approach leverages the same physics now proven by NIF but combines it with a unique approach that gets to a competitive cost point in a truly scalable manner.” FLF’s system doesn’t need a large array of lasers, just a single fast-moving projectile, launched by a driver at a carefully designed target.

FLF had already built two machines to test its target designs. One, dubbed the big friendly gun (BFG), uses gunpowder to aim a projectile at fuel targets. The second driver, called Machine 3, uses electromagnetic forces to launch a projectile at the fuel.

In November 2021, FLF achieved fusion on its BFG machine. To confirm that FLF had created genuine thermonuclear fusion, it enlisted the help of the UK Atomic Energy Authority (UKAEA). The UKAEA’s Culham Laboratory is the home of the Joint European Torus (JET), the best-known example of magnetic confinement fusion. It has a long history of diagnosing what goes on in fusion projects. Its researchers pored over FLF’s diagnostic systems and confirmed its claims. 

FLF had planned to build an even bigger driver, but the positive results from NIF were a cue to change direction. Ryan Ramsey, Chief Operating Officer, says that as more results came in from NIF they asked themselves “Why are we doing this?”. FLF decided to concentrate on developing its ‘shock amplification’ approach to ICF. 

The NIF concept isn’t practical for a power plant, says Ramsey. “You can’t have 192 penetrations into a reactor chamber.” Instead, FLF hits targets on just one side. The target itself then creates a shockwave that compresses the fuel from all sides. “The convergence is created completely within the amplifier,” says Hawker. On impact, the pellet itself pushes the fuel to fusion conditions. 

When it comes to getting fuel into its targets, the company can draw on the previous experience with ICF. FLF can then put that inside its own amplifiers. 

“The key technology for us is the target design,” says Hawker. It is, he says, “the secret sauce”. When it comes to building a power station, Hawker has compared ICF to an internal combustion engine: drop in a fuel target, hit it with a projectile, recover the energy, and keep repeating the process.

Test and amplify

Machine operated by Sandia National Laboratories in New Mexico in the US. The most powerful pulsed power facility in the world, the Z Machine can electromagnetically launch projectiles to higher velocities than any other facility. 

FLF describes its approach to ICF as being “driver agnostic”. The driver just has to hit the target (and therefore the amplifier) hard enough. 

Ramsey says with five different ICF driver technologies under development around the world, FLF’s approach could be relevant to all of them. Each driver will need different target designs, which is where the company’s expertise in accelerator modelling, computer simulations and target manufacturing come into play.

The modelling proved its power in February 2024 when measurements on the Z Machine broke the pressure record. FLF’s simulation predicted the pressure to within 2% of the measured result.
After keeping its computer modelling and simulation in house, mostly to protect this intellectual property, says Ramsey, the company is now preparing a cloud option to see if this can speed up the development and simulation of new drivers. “The cloud will give us significantly more computer power. We think this will make us quicker,” he adds. 

For Ramsey, computing has been the game changer in amplifier design. Add machine learning and FLF can devise new amplifiers and analyse how they are likely to amplify the driver’s impact force.

FLF’s current business plan is to focus on designing amplifiers that others can use in their ICF reactors. To this end, the company is building a portfolio of patents on the design and production of amplifiers. 

FLF’s amplifiers, cubes of about four centimetres, are made of “normal materials,” says Hawker. With model amplifiers to hand, the in-house precision manufacturing team can assess how easy it is to make new amplifier designs. As Ramsey puts it, there is no point in designing a great amplifier if you can’t make it. 

The company’s idea is to design and validate amplifiers and licence production to specialist manufacturers who could make targets in the large numbers, perhaps thousands a day, that a reactor would need. To this end, FLF is investigating the manufacture of amplifiers with the support of the Advanced Manufacturing Research Centre in Sheffield.