Lockheed Martin Compact Nuclear Fusion Reactor Concept will have 20 times more plasma is ten times smaller and targets a 100 MW prototype in 2019

The Lockheed Martin Skunk Works® team is working on a new compact fusion reactor (CFR) that can be developed and deployed in as little as ten years. Currently, there are several patents pending that cover their approach.

“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,” said Tom McGuire, compact fusion lead for the Skunk Works’ Revolutionary Technology Programs. “The smaller size will allow us to design, build and test the CFR in less than a year.”

After completing several of these design-build-test cycles, the team anticipates being able to produce a prototype in five years. As they gain confidence and progress technically with each experiment, they will also be searching for partners to help further the technology.

Aviation Week has some technical details

Superconductors inside magnetic rings will contain the plasma.Credit : Lockheed Martin

Initial work demonstrated the feasibility of building a 100-megawatt reactor measuring seven feet by 10 feet, which could fit on the back of a large truck, and is about 10 times smaller than current reactors.

The Lockheed 100MW compact fusion reactor would run on deuterium and tritium (isotopes of hydrogen).

Instead of the large tokomaks which will take until the mid-2040s or 2050s for the first one and which will be large (30,000 tons) and expensive have one that fit on a truck. Build on a production line like jet engines.

Aviation Week was given exclusive access to view the Skunk Works experiment, dubbed “T4,” first hand. Led by Thomas McGuire, an aeronautical engineer in the Skunk Work’s aptly named Revolutionary Technology Programs unit, the current experiments are focused on a containment vessel roughly the size of a business-jet engine. Connected to sensors, injectors, a turbopump to generate an internal vacuum and a huge array of batteries, the stainless steel container seems an unlikely first step toward solving a conundrum that has defeated generations of nuclear physicists—namely finding an effective way to control the fusion reaction.

The problem with tokamaks is that “they can only hold so much plasma, and we call that the beta limit,” McGuire says. Measured as the ratio of plasma pressure to the magnetic pressure, the beta limit of the average tokamak is low, or about “5% or so of the confining pressure,” he says. Comparing the torus to a bicycle tire, McGuire adds, “if they put too much in, eventually their confining tire will fail and burst—so to operate safely, they don’t go too close to that.”

The CFR will avoid these issues by tackling plasma confinement in a radically different way. Instead of constraining the plasma within tubular rings, a series of superconducting coils will generate 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. “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,” McGuire says. 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,” he adds.

he Lockheed design “takes the good parts of a lot of designs.” It includes the 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,” he says. 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 adds, referring to another promising avenue of fusion power research. A Polywell fusion reactor uses electromagnets to generate a magnetic field that traps electrons, creating a negative voltage, which then attract positive ions. The resulting acceleration of the ions toward the negative center results in a collision and fusion.

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Neutrons released from plasma (colored purple in the picture) will transfer heat through the reactor walls. Credit : Lockheed Martin

Breakthrough technology: Charles Chase and his team at Lockheed have developed a High Beta configuration, which allows a compact reactor design and speedier development timeline (5 years instead of 30).

* The magnetic field increases the farther that you go out, which pushes the plasma back in.
* It also has very few open field lines (very few paths for the plasma to leak out)
* Very good arch curvature of the field lines
* The Lockheed system has a beta of about 1.
* This system is DT (deuterium – tritium)

Credit : Lockheed Martin and Google Solve for X

McGuire said the company had several patents pending for the work and was looking for partners in academia, industry and among government laboratories to advance the work.

Currently a cylinder 1 meter wide and 2 meters tall. The 100 MW version would be about twice the dimensions.

Credit : Lockheed Martin and Google Solve for X

Credit : Lockheed Martin and Google Solve for X

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