AIP Scitation Steven T. Corneliussen, October 2014
“The old promise of atoms for peace was a noble one, but ultimately flawed because the technology wasn’t right for it,” declares Thomas McGuire in a 4-minute public relations video. He leads a fusion energy project at Lockheed Martin’s Skunk Works, famous for originating, among other things, the U-2 spy plane and the F-117 stealth warplane. He finishes his confident thought: “We can achieve that grand vision and bring clean power to the world. The true atomic age can start.”
An accompanying press release asserts that the Skunk Works, using iterative design-build-test cycles, can develop and deploy a new compact fusion reactor (CFR) in as little as 10 years. It quotes McGuire: “Our . . . concept combines several alternative magnetic confinement approaches, taking the best parts of each, and offers a 90 percent size reduction over previous concepts. The smaller size will allow us to design, build and test the CFR in less than a year.”
So what are the technical facts? Within the abundant skepticism seen in the media coverage, a big component is the complaint that not enough facts have been made public. A Guardian article reports that despite all of the publicity, “experts point to the lack of details or results.” It ends by observing that Lockheed has “come up with an idea and they want someone to give them some money so they can develop it”—and by adding that although investment in fusion “is exciting and potentially world-changing,” the “real breakthroughs occur when experiments actually take place.” Aviation Week and Space Technology, which was granted special access, noted that “Lockheed has made public its project with the aim of attracting partners, resources and additional researchers.”
At MIT Technology Review, the skepticism shone through in a headline and subhead: “Does Lockheed Martin really have a breakthrough fusion machine? Lockheed Martin says it will have a small fusion reactor prototype in five years but offers no data.” There are “huge obstacles,” the article notes, “and no hard evidence that Lockheed has overcome them.” The article quotes MIT professor of nuclear science and engineering Ian H. Hutchinson: “[A]s far as I can tell, they aren’t paying attention to the basic physics of magnetic-confinement fusion energy. And so I’m highly skeptical that they have anything interesting to offer.”
At the Huffington Post, one article even yoked the Lockheed news with cold fusion, discussed both in some detail, and ended by promising to continue to monitor them, since at “the very least, they are certain to make an interesting chapter in the sociology of science.” But another Huffington Post piece quoted Mike Zarnstorff, deputy director for research at the Princeton Plasma Physics Laboratory: “We don’t know what the promise of this experiment is—these type of ideas have been explored in the past—but maybe there are new ideas here that will somehow address the previously found challenges.”
In any case, some of the technical details have been reported. At the Engineer—founded in 1856 and calling itself “the UK’s leading online resource for the engineering industry”—Stuart Nathan published technical commentaries on 17 and 22 October. He included links to the three patents Lockheed has applied for:
And Science magazine has offered something like a technical summary:
[McGuire] said that [his group’s] magnetic confinement concept combined elements from several earlier approaches. The core of the device uses cusp confinement, a sort of magnetic trap in which particles that try to escape are pushed back by rounded, pillowlike magnetic fields. Cusp devices were investigated in the 1960s and 1970s but were largely abandoned because particles leak out through gaps between the various magnetic fields leading to a loss of temperature. McGuire says they get around this problem by encapsulating the cusp device inside a magnetic mirror device, a different sort of confinement technique. Cylindrical in shape, it uses a magnetic field to restrict particles to movement along its axis. Extra-strong fields at the ends of the machine—magnetic mirrors—prevent the particles from escaping. Mirror devices were also extensively studied last century, culminating in the 54-meter-long Mirror Fusion Test Facility B (MFTF-B) at Lawrence Livermore National Laboratory in California. In 1986, MFTF-B was completed at a cost of $372 million but, for budgetary reasons, was never turned on.
Another technique the team is using to counter particle losses from cusp confinement is recirculation. “We recapture the flow of particles and route it back into the device,” McGuire said. The team has built its first machine and has carried out 200 shots during commissioning and applied up to 1 kilowatt of heating, but McGuire declined to detail any measurements of plasma temperature, density, or confinement time—the key parameters for a fusion plasma—but said the plasma appeared very stable. He said they would be ramping up heating over the coming months and would publish results next year.
McGuire acknowledged the need for shielding against neutrons for the magnet coils positioned inside the reactor vessel. He estimates that between 80 and 150 centimeters of shielding would be needed, but this can be accommodated in their compact design. Researchers . . . say that it is difficult to estimate the final size of the machine without more knowledge of its design. Lockheed has said its goal is a machine 7 meters across, but some estimates had suggested that the required shielding would make it considerably larger.
Steven T. Corneliussen, a media analyst for the American Institute of Physics, monitors three national newspapers, the weeklies Nature and Science, and occasionally other publications. He has published op-eds in the Washington Post and other newspapers, has written for NASA’s history program, and is a science writer at a particle-accelerator laboratory.