Startup makes tiny 'benchtop' fusion devices for more efficient reactors

Nuclear fusion is how stars (including our own Sun) create their energy, and scientists are hopeful it could one day be used as a clean, abundant energy solution here on Earth.

There are no carbon emissions, most of the fuel required is widely available, and it's safe: if the reaction goes wrong, it simply peters out and stops.

You might have spotted the big challenge, which is trying to fit an entire star's worth of energy production inside a power plant.

Two main approaches are being explored, one using magnets to create the incredibly high temperatures and pressures required, and one using lasers — which is where the startup Cambridge Heavy Industries comes in.

As TechCrunch reports, the company is currently operating in 'stealth mode' from a lab attached to the Massachusetts Institute of Technology (MIT), but now seems ready to share some details about the technology it's developing.

The main innovations: fusion that's more efficient and needs less room than conventional reactors.

Nuclear fusion on a tabletop The focus is on fusion fuel first (Image credit: Cambridge Heavy Industries) Yun Kai, co-founder and CEO of Cambridge Heavy Industries, describes the company's fusion device as "tiny" and "benchtop" sized, which means experiments can be carried out and improved upon quickly.

The technology will eventually be scaled up, but the aim is to build something smaller than conventional reactor designs — the size of two basketball courts approximately, rather than a full power plant complex.

What makes the approach of Cambridge Heavy Industries different is the dual laser setup.

The first laser delivers its light as concentric rings that hit the block of fuel, designed to create shock waves traveling inward that create an accelerating compression effect; the second laser then hits the wave at the perfect spot to produce the super-high pressure required for ignition and nuclear fusion.

The enclosed system effectively acts as its own self-contained, compact fuel factory, because everything is moving inwards.

It's also designed around a 2D rather than a 3D setup, which means fewer angles to cover — the laser fusion setup at the National Ignition Facility (NIF) in the US uses an array of 192 lasers in three dimensions to compress its own fuel blocks, for example.

As it's smaller and more efficient, the Cambridge Heavy Industries benchtop device can get through 50–80 laser shots per day — at the NIF, it's just a handful.

A relatively low amount of laser power is required, says Kai, and as dozens of experiments are being done every 24 hours, the system can be quickly analyzed and iterated over time.