Oct
16
Lockheed Martin’s Skunk Works Builds a Fusion Reactor
October 16, 2014 | 4 Comments
The Lockheed Martin Skunk Works has built and tested a new lab sized “compact fusion reactor” (CFR). The Skunk Works has built on more than 60 years of fusion research and investment to develop an approach that offers a significant reduction in size compared to government sponsored efforts such as the ITER multinational effort based in France.
Tom McGuire, compact fusion lead for the Skunk Works’ Revolutionary Technology Programs said, “Our compact fusion 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.”
Currently in design-build-test cycles, with more cycles to go, the team anticipates being able to produce a prototype in five years. With each experiment they gain confidence and progress technically. The team will also be searching for partners to help further the technology.
Compact Fusion Reactor Diagram. Click image for the largest view. Image Credit: Lockheed Martin.
Lockheed believes its scalable compact concept will also be small and practical enough for applications ranging from interplanetary spacecraft and commercial ships to city power stations, perhaps even bring back the nuclear-powered aircraft.
Research institutions, laboratories, privateers and companies around the world are also pursuing ideas for fusion power, but no one has graduated from the experimental stage. Lockheed believes it has a concept to get past the formidable “breakeven” line of producing more power than used. The firm also knows the knowledge and intellectual prowess to solve the oncoming problems is beyond its staff expertise. They’re going public its project with the aim of attracting partners, resources and additional researchers. A very smart management move and realistic self assessment.
The young team is led by the youthful Thomas McGuire, an aeronautical engineer in the Skunk Work’s Revolutionary Technology Programs unit. The current experiments use a stainless steel container for a containment vessel roughly the size of a business-jet engine that’s connected to sensors, injectors, a turbopump to generate an internal vacuum and a huge array of batteries.
To understand the Lockheed position for backing the team the fusion basics need covered. Fusion fuel destined for reactors that produce heat as the primary energy almost always make use of the hydrogen isotopes deuterium and tritium. The isotope gas is injected into an evacuated containment vessel where energy is added, usually by radio-frequency heating breaking it into ions and electrons, forming very hot plasma.
Plasma, like an electric arc or lightning is too hot for physical containment necessitating strong magnetic fields that prevent it from touching the sides of the vessel. When the confinement is sufficiently heated and pressurized the ions overcome their mutual repulsion, collide and fuse. The fusion creates helium-4, releasing a neutron per atom that carries the released energy kinetically through the confining magnetic fields. These neutrons along with the radiant energy heat the reactor wall where conventional heat exchange technology can be used to drive turbine electricity generators.
Lockheed CFR Inside. Click image for the largest view. Image Credit: Eric Schulzinger Lockheed Martin.
The CFR presents a new version of confinement, something like 20 times more effective than the tokamak used at ITER. The Lockheed CFR has a series of superconducting coils generating a new magnetic-field geometry in which the plasma is held within the broader confines of the entire reaction chamber. Superconducting magnets within the coils will generate a magnetic field around the outer border of the chamber.
McGuire explains, “So for us, instead of a bike tire expanding into air, we have something more like a tube that expands into an ever-stronger wall.” The system is therefore regulated by a self-tuning feedback mechanism, whereby the farther out the plasma goes, the stronger the magnetic field pushes back to contain it. The CFR is expected to have a beta limit ratio of one. “We should be able to go to 100% or beyond.”
Containment efficiency is key. The Lockheed CFR generates more power than a tokamak by a factor of 10, which in turn means for the same power output, the CFR can be 10 times smaller.
McGuire takes up this point with, “It’s one of the reasons we think it is feasible for development and future economics. Ten times smaller is the key. But on the physics side, it still has to work, and one of the reasons we think our physics will work is that we’ve been able to make an inherently stable configuration.” One of the main reasons for this stability is the positioning of the superconductor coils and shape of the magnetic field lines. “In our case, it is always in balance. So if you have less pressure, the plasma will be smaller and will always sit in this magnetic well.”
McGuire credits his predecessors saying the Lockheed design “takes the good parts of a lot of designs.” It includes the (efficient confinement of) high beta configuration, the use of magnetic field lines arranged into linear ring “cusps” to confine the plasma and “the engineering simplicity of an axisymmetric mirror.” The “axisymmetric mirror” is created by positioning zones of high magnetic field near each end of the vessel so that they reflect a significant fraction of plasma particles escaping along the axis of the CFR. “We also have a recirculation that is very similar to a Polywell concept,” he added, referring to another promising avenue of fusion power research.
The Lockheed group is well aware the CFR is barely out of the concept phase, and many key challenges remain before a viable prototype can be built. “We would like to get to a prototype in five generations. If we can meet our plan of doing a design-build-test generation every year, that will put us at about five years, and we’ve already shown we can do that in the lab, McGuire said.
If that works out as expected a prototype would demonstrate ignition conditions and the ability to run for upward of 10 sec. in a steady state after the injectors, which will be used to ignite the plasma, are turned off. “So it wouldn’t be at full power, like a working concept reactor, but basically just showing that all the physics work,” McGuire said.
So far the preliminary simulations and experimental results “have been very promising and positive,” McGuire said. “The latest is a magnetized ion confinement experiment, and preliminary measurements show the behavior looks like it is working correctly. We are starting with the plasma confinement, and that’s where we are putting most of our effort. One of the reasons we are becoming more vocal with our project is that we are building up our team as we start to tackle the other big problems. We need help and we want other people involved. It’s a global enterprise, and we are happy to be leaders in it.”
Like the other leaders such as EMC2, Tri-Alpha and Lawrenceville Plasma Physics the theory should work – if the materials science and the engineering can get to the pressure heat and ion velocity to fuse and release more energy than used.
Give Lockheed credit for staying with the hydrogen fuels, lighting off Boron aka Pb11 fuel will be much harder, and integrating into the existing grid and power generating field. Small and simple has its attractions and a practical realistic sense.
Lockheed also has a steel cable connection to military and congressional funding, suggesting that this project will go. It will also, unintended, generate intense interest and confidence in the theories and efforts of the technologies McGuire cherry picked to build his concept. These groups are going for Pb11 fueling as best can be seen so far because that fuel’s fusion main product of electrons can go directly to electricity.
Hot fusion could have two major breakthroughs in hydrogen isotope fuel and again in Pb11. All before ITER even powers up.
Comments
4 Comments so far
Feedburner
Reddit
Stumbleupon
Hope it works.
Looks like standard fusion to me – which means turbines must be present to turn excess heat (as steam) into power. So, the reactor might fit on a tractor trailer – but it will require several more trailer’s worth of turbine equipment.
Reply to [Matt Musson on October 17, 2014 7:38 AM]:
The idea is to truck the trailer to CURRENT turbine facilities, so that those current facilities can use the heat from the CFR–instead of from current methods of heat generation–to power their conventional turbines that make electricity. Nice idea, eh?
It’s a snazzy design but I still see major milestones to fulfill.
1. Demonstration of actual high temperature and high density plasma confinement using this magnetic bottle arrangement. This will mean scale-up and dollars.
2. Finding new high temperature superconducting materials (required for the electro magnet). Otherwise the design will require a sophisticated cryogenic system for cooling the superconducting wires.
3. The need to engineer an efficient primary cooling system to absorb the liberated heat and efficiently transfer this heat to a secondary loop to power a Brayton (?) cycle turbine. (non-moderating halide salts or molten lead are candidate fluids.)
4. If Skunkworks is demonstrating this device by burning D + T, the device will produce large amounts of high energy neutrons which will create a highly activated containment. This will generate high rates of dpa damage in the vessel and will require the kind of refractory materials or alloys considered for ITER’s first wall.