Meet the BFG – that’s Big Friendly Gun, though the original word probably wasn’t “friendly” – a 22-meter (72-foot) prototype steel gun that fires a projectile at an astronomical speed towards a fuel pellet to create nuclear fusion reactions. Designed by UK startup First Light Fusion, the gun is designed to achieve fusion without using magnets or lasers, which soak up a huge amount of energy and make fusion remarkably inefficient in current iterations.
First reported by Newsweek, the startup is testing a radical new approach to nuclear fusion in its projectile-based system, which it claims is more efficient and less complex than laser-based methodologies.
Currently, fusion reactors use a large laser to spark the first reaction. The high-energy beams heat the outer layer of the targets filled with thermonuclear fuel, which explode outward and compress the fuel within. Shockwaves produced in the reaction combine with this compression to put the fuel under enough pressure to create nuclear fusion, beginning the process of generating immense heat.
First Light’s approach is altogether simpler, though that doesn’t detract from the incredible engineering. A large steel gun containing gunpowder and a piston is fired, accelerating the piston down the barrel and compressing hydrogen gas in front of it as it goes. Entering a cone-shaped area, the gas is compressed down into a tiny area and meets the projectile, which then shoots out of the gun at 7 kilometers per second (4.3 miles per second) into the fusion target. At this impact point, the pressure is sufficient to begin nuclear fusion.
It is the highest energy projectile launcher in the UK and the company has raised significant funding for the venture, funding both the BFG and their conceptual fusion machines.
Projectile fusion isn’t a new concept, but their design could be a game-changer for the fusion industry.
"Net energy gain has been demonstrated with inertial fusion, but the driver, instead of being a laser, was an underground weapons test," CEO Nick Hawker told Newsweek.
"So there is that empirical proof there that you can get to high energy gain with inertial fusion.
"I feel a bit unfair giving this as a criticism of magnetic fusion because the challenges we know about are because of the work done in magnetic fusion, and that's what has allowed us to come up with an approach that sidesteps them."
The company has already tested their massive gun, and tests will continue to gather data on the viability of the approach. In the meantime, the team is already hard at work building the next iteration, which will remove the crude gunpowder solution and instead use electric currents to accelerate the piston initially.
If all goes well, Hawker expects the reactor to be producing usable energy in the next decade, and to be putting it into the grid the decade after that. In short, they believe they are on the cusp of almost unlimited energy.