IHS Global Spec Roger Pink, Ph.D., 16 December 2014
A Lockheed Martin Skunk Works team is working on a compact fusion reactor (CFR) that could be developed and deployed in as little as 10 years. The lead scientist on the project, Thomas McGuire, said in an October 15 press release that the company’s compact fusion concept “combines several alternative magnetic confinement approaches, taking the best parts of each, and offers a 90% size reduction over previous concepts.”
McGuire says the team is working on producing a 100 megawatt (MW) prototype in five years. He says this should be possible because of the small scale design of the reactor, which makes it possible to redesign, build and test reactors quickly. The prototype reactor should be capable of sustaining short-term reactions (up to 10 seconds). If the prototype is successful, he estimates a production version would be available in 10 years. Lockheed Martin says it has gone public with the research in an effort to attract partners to help develop the reactor and supporting technology.
Skunk Works exists within Lockheed Martin to create breakthrough technologies, usually with a focus in aeronautics and in sync with the company’s defense industry work. Skunk Works’ successes include the U-2 reconnaissance aircraft, the SR-71 Blackbird reconnaissance aircraft, the F-117 Nighthawk ground-attack aircraft with stealth technology and the F-22 Raptor fighter aircraft. A compact fusion reactor could enable future aircraft designs with greater ranges and endurance.
Reactor Design
McGuire received his doctorate from Massachusetts Institute of Technology (MIT) in 2007 and wrote a thesis entitled “Improved Lifetimes and Synchronization Behavior in Multi-grid Inertial Electrostatic Confinement Fusion Devices.” In his thesis, McGuire examined inertial electrostatic confinement (IEC) for fusion, a design that allows for much smaller fusion reactors. McGuire joined Lockheed Martin in November 2007.
The compact fusion reactor McGuire’s team is developing is not an IEC. According to recent patent filings and quotes McGuire has made publicly, the design uses magnetic field oscillation to heat the plasma. The reactor combines several magnetic confinement techniques such as cusp confinement to magnetically trap the fusing plasma and magnetic mirrors to reflect leaking particles, a critical flaw of cusp confinement devices developed in the 1960’s and 1970’s.
It’s hard to know how much and which parts of his thesis work has played a role at Skunk Works. There haven’t been any papers related to this reactor published yet, though McGuire indicated he expects to publish next year. There have been three patent filings that offer clues. They are “Heating Plasma for Fusion Power Using Magnetic Field Oscillation,” “Magnetic Field Plasma Confinement for Compact Fusion Power,” and “Active Cooling of Structures Immersed in Plasma.” All three patent applications list McGuire as applicant and inventor and were filed in April 2014.
Why Fusion Power Matters
Fusion has always held the promise of nearly limitless power (as compared to today’s power requirements). That’s because fusion reactions are nuclear reactions, not chemical reactions. Chemical reactions (like burning fossil fuels) work because electrons essentially are being reorganized around nuclei in such a way as to save energy. The saved energy is then released as heat that is used to power turbines. Nuclear reactions such as fission and fusion work by reorganizing the protons and neutrons inside nuclei, where the energies are must higher. The energy savings produced are much greater and thus more heat is produced.
There are two ways to rearrange the protons and neutrons in nuclei. One way is to take really big, inefficient nuclei like uranium or plutonium and refine them enough so they are likely to split into more stable, smaller nuclei. Once started, the resulting splitting (known as a fission reaction) produces heat and radioactive waste. Fission reactions must be constantly monitored because if they were left on their own the fissionable material would consume itself as fast as possible. The heat produced in such a scenario would destroy the plant around it in a meltdown.
In a fusion reaction, by contrast, two stable small atoms are smashed together to form a slightly bigger, even more stable larger atom. Since the larger atom is a more efficient configuration of the protons and neutrons than what was found in the smaller atoms, excess energy is given off as heat.
The problem with fusion reactions is keeping them going. This is because nuclei generally don’t like to get close enough to each other to fuse. There is a potential barrier that must be overcome to get to the energy savings. The only way to get the atoms close enough to fuse is at extremely high temperatures where the kinetic energies of the nuclei are large enough to overcome the repulsive force between them.
The most common approach until now for achieving plasma hot enough to fuse has been tokamak nuclear fusion reactors. These use magnetic fields to confine plasma in the shape of the torus. These tokamaks are mega-projects, like ITER in Europe, and involve multinational cooperation and tens of billions of dollars in investment. Given their size and complexity, these projects have tended to move slowly and have not had much success to date.
Skepticism and Hope
The general sentiment since the Lockheed Martin announcement has been caution and skepticism. This of course is an understandable reaction, especially since there isn’t any data available for scientists to analyze. Still, it seems unlikely that a highly regarded company like Lockheed Martin would make a public announcement without a belief that fusion was within reach.
Project lead McGuire has the background and pedigree to know what he’s talking about. This likely will not be a replay of the incident in 1989 where two chemists found themselves outside of their area of expertise, rushed to publish claims of cold fusion and were later discredited. McGuire has been studying fusion for almost 15 years at institutions like MIT and Lockheed Martin. It is conceivable that he was able to expand upon his thesis work at Skunk Works over the past seven years and achieve a workable design.
Based on Lockheed Martin’s timeline, the compact fusion prototype could be ready by early 2020. By 2025, a 100 MW compact fusion reactor, small enough to fit on a truck, could be in production.