Pistol Shrimp meets Nuclear Fusion

Using shockwave techniques inspired by the pistol shrimp, a new fusion startup has demonstrated a practical way to produce nuclear fusion.

This technique, says First Light, is inspired by the pistol shrimp, and its famous underwater bubble-shooting weapon. These little fellas snap their claws together at incredible speed, creating a shockwave and squirting a jet of water forward at up to 60 mph (96 km/h). That's so fast that the water itself gets vaporized as it shears against the still water around it, creating tiny bubble cavities. The bubble cavities interact with the shockwave, and collapse in an infinitesimally short period of time – but for the briefest of moments, the vapor in those bubbles is heated to tens of thousands of degrees, and even emits a bright flash of light.

irst Light took this as a starting point and began designing ways to amplify this effect well beyond what the shrimp's claw can achieve, to a point where it can create fusion-friendly conditions. It has created and refined a series of small targets, some in cubic form with sides of about 1 cm (0.4 inches) that are designed to create a series of interacting shockwaves and bubble cavities when they're hit with coin-shaped projectiles at super-high velocities. These shockwaves intersect at planned moments to supercharge the pistol shrimp's cavitation effects, greatly multiplying the pressure around a small, precisely positioned fuel pellet in the middle.

The target design uses interacting cavity collapses and pressure waves to amplify that pressure up to around one terapascal, and when the fuel pellet implodes just as massive pressure waves bear down on it from all sides, the final pressure can get as high as 100 terapascals, with the fuel accelerating to more than 70 km/sec (252,000 km/h, 157,000 mph), or Mach 204, as it implodes.

At this instant, says First Light, the fuel becomes the fastest-moving object on Earth, and the pressure and temperature that fuel pellet generates as it's compressed from several millimeters down to less than 100 microns is enough to trigger fusion reactions. These release impressive amounts of heat energy and neutrons, which are absorbed by 1-meter-thick (3.3-ft) curtains of liquid lithium metal flowing within the chamber.

As the pellet splashes down into a pool of liquid lithium, a heat exchanger transfers the heat to water, generating steam that turns a turbine and produces electricity in the final commercial reactor design.

Each target, says First Light, would produce enough energy to power an average UK home for two years. According to Energy UK, that equates to about 6.2 megawatt-hours. In a commercial power plant, this would happen once every 30 seconds, giving the plant an effective output around 744 MW – a little under the 1 GW of the average US nuclear fission plant, but without any nuclear waste or potential of meltdown.

The company says this relatively simple technique (well, certainly simple when compared to tokamak and stellarator designs) "offers a pathway to a very competitive Levelised Cost Of Energy ("LCOE") of under US$50/MWh." That's only a little pricier than the LCOE of current solar and wind energy – but of course it can be produced on demand, making it an excellent base load generator for a power grid, or a good option to ramp up and down to keep up with the demand curve.