Superconducting magnetic coils inside of the compact fusion experiment. Courtesy Lockheed Martin
Yesterday, Lockheed Martin joined a long line of companies claiming to be hot on the trail of nuclear fusion, the long-promised savior of our energy economy. Unlike the atom-splitting fission reactions that run our submarines and nuclear power plants, fusion smashes atoms together at high temperatures, creating new particles in a reaction that emits massive amounts of emission-less, radiation-less energy.
With its drones circling the skies and the future locked up in space travel, Lockheed would love to get its hands on a fusion reactor just like the one that powered Star Trek’s Federation starships. And who wouldn’t? Fusion’s clean energy has the potential to power naval vessels and aircraft with effectively unlimited range using mere pounds of fuel. Of course, making perfect energy isn’t so easy: Companies and government labs have spent 60 years being just a decade away from nuclear fusion.
Lockheed is the latest to join that club, with a new concept for a magnetic confinement fusion reactor—one of the main fusion approaches, along with the laser fusion that the United States’ Lawrence Livermore National Ignition Facility is working on. Because of its small size—projected to fit into a tractor-trailer—Lockheed’s team thinks it can design, build, and test prototypes in year-long increments, so they can iterate to a functional reactor faster.
Those successive prototypes will try to solve the central problem of a magnetic confinement fusion reactor: “Plasma confinement is what has plagued all the previous teams,” says Tom McGuire, who is leading the project at Lockheed. Inside a reactor, high temperatures break atoms apart into electrons and ions, forming blazing-hot plasma that needs to be kept from the edges of the reactor. Magnetic fields do the trick, holding the electrically charged ions in place. The plasma heats and heats and heats until those ions fuse, creating new particles, including uncharged neutrons that fly past the magnetic encasement and transfer their energy to the walls of the reactor—energy that’s then used to drive generators.
But plasma is finicky, subject to unpredictable ripples that can bubble past that magnetic field at any moment. So far, then, most confinement reactors have used huge, heavy magnets to keep the plasma in check, and that means massive, building-sized reactors. Lockheed’s advance, along with its smaller, testable size, is adaptability. McGuire designed a magnetic container that shifts the strength of its magnetic field to match those plasma ripples. “If we have a perturbation or a ripple that sends it closer to the wall, the magnetic field gets stronger and stronger, so it has the right kind of feedback to keep it stable,” McGuire says.
The problem with that reactor? It doesn’t exist yet. “Some key parts of the prototype are theoretical and not yet proven,” says Nathan Gilliland, CEO of Canadian fusion company General Fusion. And it’s not as if Lockheed is the only one trying to crack fusion: While past efforts have been dominated by government labs, technological advances and venture capital are making for “a groundswell of ideas for more practical fusion technologies, mostly from the private sector,” says Gilliland. VC-backed companies like Tri Alpha, Helion, and Gilliland’s General Fusion are working on their own concepts and prototypes. So far McGuire’s team has built a structure—a few meters long by a meter in diameter—to test its plasma confinement claims. If they can iterate fast enough, they may just be the first to get to a functional nuclear reactor… probably in about 10 years.
Program manager Tom McGuire looks into the T-4 chamber, which is the fourth iteration of the Skunk Works’ compact fusion reactor experiment Courtesy Lockheed Martin
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