Scientists have been working on nuclear fusion technology in earnest since the 1950s, an approach which entails combining the sub-atomic particles of lighter elements into more stable permutations, thus unleashing considerable amounts of energy.
Experts have long considered it a potential panacea for the twin dilemmas of sating the world economy’s insatiable appetite for energy while keeping greenhouse gas emissions beneath a reasonable threshold in order to forestall worsening climate change.
Aerospace and defence giant Lockheed Martin now claims to have achieved a major breakthrough in nuclear fusion technology which could soon pave the way for the development of portable, small-scale reactors.
While Lockheed released limited information on its fusion research efforts in 2013, Tom McGuire, head of fusion energy at the company’s secretive Skunk Works research unit, said that following four years of work, he and his team were now ready to go public with details on their breakthrough development in hopes of finding partners in both the private and government sectors.
The Compact Fusion Reactor (CFR) device developed by McGuire and his team marks a radical departure from prior efforts to generate fusion energy in its approach to the containment of the superheated plasma that lies at the core of the process.
The conventional method for producing fusion energy involves injecting a gaseous fusion fuel, comprised of the hydrogen isotopes deuterium and tritium, into an evacuated containment chamber. This fuel is then transformed into a super-hot plasma of ions and electrons, usually by means of radio-frequency heating.
The critical part of the process lies in confining this superheated plasma in place by means of a magnetic field and preventing it from coming into contact with the sides of the containment vessel. If the confinement force is strong enough, the ions will fuse together in spite of their mutual repulsion.
The fusion of the ions results in the creation of helium-4 as well as free neutrons that raise the temperature of the reactor walls, generating heat which can used to power turbine generators.
Since the 1950s, the primary means of containing and controlling this superheated plasma has been the tokamak – a ring-shaped device developed by Soviet physicists which uses a magnetic field to contain the plasma. The tokamak’s magnetic field forces the plasma into a doughnut-shape called a torus, while a second set of magnets maintains the reaction process by producing a current within the plasma itself.
The tokamak suffers from debilitating flaws, however. The device consumes copious amounts of energy – often almost the same amount that the fusion process itself is capable of generating, while they also are restricted in the amount of plasma they can contain, a threshold referred to as the “beta limit.” The devices must also be built in an immense scale, which in turn entails huge expenditures.
McGuire and his team have developed a disparate approach to plasma confinement with the CFR. In lieu of the tubular tokamak, the reactor uses a series of coils containing superconductive magnets. The coils generate a magnetic field around the external border of the chamber, permitting heightened efficiency and an increased beta limit.
McGuire is confident that the physics of the approach will work given the success of the researchers in producing an inherently stable configuration. This was achieved through the positioning of the superconductor coils in order to precisely mould the shape of the magnetic field lines and achieve the right amount of pressure for confining the plasma.
The CFR is expected to have a beta limit of 100 per cent, as compared to the average of five per cent for existing tokamaks, and researchers believe it will generate roughly 10 times more power than the long-standing method.
This heightened generation capacity in turn translates into the ability to dramatically reduce the scale of reactors, potentially making their usage practical for a greater range of purposes, including as engines on seafaring vessels and interplanetary spaceships.
According to their initial results the new approach developed by Skunk Works should make it possible to build a 100-megawatt fusion reactor measuring just 23 feet by 43 feet, a mere tenth the size of existing power facilities of commensurate power. A reactor of that size would be small enough to fit on the back of large truck.
McGuire expects progress on the device to advance swiftly, foreseeing the development of a prototype within five years to demonstrate that the physics is workable, and the development of an initial production model in as soon as a decade.
“What makes our project really interesting and feasible is that timeline as a potential solution,” he said.