Lockheed Martin's Skunk Works is building a new, more capable test reactor as it continues to move ahead with its ambitious Compact Fusion Reactor program, or CFR. Despite slower than expected progress, the company remains confident the project can produce practical results, which would completely transform how power gets generated for both military and civilian purposes. Aviation Week was first to report the updates on the CFR program, including that Lockheed Martin is in the process of constructing its newest experimental reactor, known as the T5, on July 19, 2019. The company's legendary California-based Skunk Works advanced projects office is in charge of the effort and had already built four different test reactor designs, as well as a number of subvariants, since the program first became public knowledge in 2014. The War Zone has been following news of this potentially revolutionary program very closely in recent years.

"The work we have done today verifies our models and shows that the physics we are talking about – the basis of what we are trying to do – is sound," Jeff Babione, Skunk Works Vice President and General Manager, told Aviation Week. "This year we are constructing another reactor – T5 – which will be a significantly larger and more powerful reactor than our T4." The T5's main job will be to further test whether Skunk Work's basic reactor design can handle the heat and pressure from the highly energized plasma inside, which is central to how the system works. In a nuclear fusion reaction, a gaseous fuel gets heated up to a point where the pressure is so intense that its very atomic structure gets disrupted and certain particles fuse together into a heavier nucleus. This process also involves the release of a massive amount of energy, which, in principle, could be used to run a traditional thermal power generator.

Lockheed Martin via Stephen Trimble A Skunk Works briefing slide from 2017 on the CFR program outlining the goals for the T5, as well as three other planned future experimental reactors leading up to the first viable "TX" prototype.

“We are currently scheduled to have that [the T5] go online towards the end of this year," Babione said. "So that will be another significant leap in capability and towards demonstrating that the physics underlining our concept works." The CFR program is built around new patented reactor design, which The War Zone has explored in detail in the past, that uses superconducting coils to more effectively generate a magnetic field to contain the heat and pressure of the reaction. Lockheed Martin's hope is that this will overcome challenges that have relegated nuclear fusion power generation to the realm of experimentation since the first concepts emerged in the 1920s.

Lockheed Martin A diagram showing the basic reactor configuration Lockheed Martin is using in its CFR program.

Since then, teams in various countries have built functional fusion reactors, but they remain large, inefficient, and expensive. Last year, China touted progress on its Experimental Advanced Superconducting Tokamak (EAST), but without highlighting that this reactor is situated inside a two-story building within the Dongpu Science Island, a large research campus on a lakeshore peninsula in China’s Anhui Province. An international consortium also hopes to have construction of the International Thermonuclear Experimental Reactor (ITER) completed in France in 2025, but this reactor will weigh approximately 23,000 tons. Containing the reaction, the same one that occurs in our sun and other stars, and doing so for a protracted period of time, remains the biggest hurdle. Nuclear fusion creates temperatures of hundreds of millions of degrees Fahrenheit, which, in turn, also generate extremely high pressures inside the reactor vessel. The energy from fusion reactions can be so powerful that countries have already weaponized it in the form of hydrogen bombs. Using a powerful magnetic field remains the most viable means of keeping everything contained. Tokamaks such as EAST and ITER, a concept the Soviet Union first invented in the 1950s, which has become relatively common in fusion research, use a ring-shaped design, but remain inefficient. China says that its EAST now holds the world record for longest sustained fusion reaction at just 100 seconds. France's Tore Supra, another tokamak, holds the record for longest plasma discharge at just over six minutes. In 2014, Aviation Week, with the help of Dr. Thomas McGuire, head of the CFR program, explained Skunk Work's plan for getting past this issue:

“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.”