The engineer in charge of the most audacious fusion power program yet tells us how it will happen.
Lockheed Martin’s secret fusion power program came out of hiding last week. This week, the Skunk Works engineer in charge of the ambitious effort met with reporters to explain just how the defense giant plans to make fusion the real deal within five to 10 years.
The key to practical fusion power—which has eluded scientists trying to crack the problem for more than 60 years—is to go small. So says Tom McGuire, program manager for the compact fusion program at the Revolutionary Technology Programs group at Lockheed’s Skunk Works.
“We think we’ve invented something that’s inherently stable and it’s ten times smaller than the mainstream approaches,” he told reporters on Monday. “What’s really exciting about that is we can develop it more quickly because of its scale.” McGuire said he and his team completed much of the theoretical work behind their system over the last four years, and have begun the first experiments.
“We don’t have any results that we would want to publicly call out quantitatively,” he said. “[But] we know we can heat and ignite the plasma with under a kilowatt of power and get it lit.”
In other words, he’s saying the team has created and magnetically contained the superheated gas that would be required to eventually get atoms to overcome their natural repulsion and fuse to release energy—for about a second at a time. He said the team would publish their results in a formal paper in the coming year.
Still, McGuire and his team are a long way from the practical power plants he has said could be in operation within the next 10 years. So why is he so confident they’ll succeed where so many others have failed? It comes down to pressure
Getting fusion power to work is a matter of not only creating the plasma in which the atoms of a deuterium and tritium (isotopes of hydrogen) will fuse, but confining the plasma within a magnetic field. If the plasma were to touch the physical walls of the reactor, so much heat would transfer to the walls that the gas inside could not remain a plasma, says Princeton Plasma Physics Laboratory director Stewart Prager. Bottling up that plasma has been a major challenge that typically requires expensive superconducting magnets.
The second part of the problem, Prager tells PM, is that mainstream fusion power projects now at work, such as the multibillion-dollar ITER project under construction in France, rely on a torus-shaped magnetic field generated in a device known as a tokamak. This setup requires a magnetic field that creates many times the pressure of the plasma it contains.
By contrast, the Lockheed compact fusion reactor project is aiming for a system in which the magnetic field pressure and the plasma pressure are more or less the same. McGuire proposes to achieve this by using a differently shaped magnetic field, generated by less powerful magnets that can be much smaller and cheaper. Such a system could be so small that it could be delivered by truck.
“We see a lot of different applications for this technology, said McGuire. “[For] some of the early-on developments, we think we can get it light enough to be useful for some mobile applications such as ships. Looking down the road, it’s within the realm of possibility for airplanes. We’re very focused on the plasma physics and the early stages of it at this point. We’ll be developing the concepts more and more with continued success as we go forward.
The biggest use for these small fusion systems would be power plants that could roll out of factories and go wherever they are needed.
The Proof Is in the Plasma
Prager said that while such concepts sound great, the Lockheed team still hasn’t released enough details to make them credible.
“If there’s a great idea out there to do this where you can put it on a truck,” he says, “that would be absolutely remarkable and fantastic. But from the information they released, there’s just no evidence to conclude that that’s the case. They really have to release exactly what the idea is for anybody to really have a conclusion on it.”
McGuire acknowledged that his group’s concept for mobile fusion plants “does go in the face of a lot of established research and entrenched research.” However, he said, “we think we have the best concept that we can see at this moment.”