Fusion reactors have been a dream since the 1950’s. Creating a nearly inexhaustible power source and finding a way to harness the same sort of energy production as our nearest neighborhood star has been an enigma to scientists for years. A running joke amongst those in the know says that fusion power plants are a mere 30 years away – and have been 30 years away anytime anyone has been asked for roughly the last 60 years. Researchers at MIT have made a few key changes to the established design used in most theoretical fusion reactors that they say would increase the potential power output as much as 10 times.
While MIT’s design still uses the same Tokamak (donut-shaped) reactor schematic that’s been studied and used in fusion experiments since it was invented by Russian physicists in the 1950’s, the main difference comes in the magnetic field they’re using to hold the fusion reaction in place. Since the ultimate result of a fusion reaction creates something very, very hot – it’s modeled after the sun, after all – it is very important for the longevity of the reactor itself that the reaction is held away from any solid materials using a magnetic field. In this instance, MIT is using rare-earth barium copper oxide superconducting tape to create a stronger magnetic field in a smaller overall footprint. MIT explains:
The stronger magnetic field makes it possible to produce the required magnetic confinement of the superhot plasma — that is, the working material of a fusion reaction — but in a much smaller device than those previously envisioned. The reduction in size, in turn, makes the whole system less expensive and faster to build, and also allows for some ingenious new features in the power plant design.
One of the main ingenious new features they’ve envisioned includes a design where the fusion core can be removed without dismantling the reactor. This will speed research and help improve the design more quickly since researchers can more easily try new materials or tweak performance quickly.
If successful, MIT researchers estimate that the current improvements to the design will allow for their fusion reactor to create three times as much energy as it needs to run with hopes to ramp that up to 5 or 6 times. That’s certainly an impressive estimate considering that no fusion reactor has ever created more energy than it’s consumed. Even creating any energy above what it takes to start the reaction would be a major accomplishment.
Even if these new ideas and benefits come to fruition, their belief is that a practical nuclear fusion reactor using this design is still at least a decade away. Better than 30 years, certainly, but who knows if that target will be reached or if we will just change the joke from “30 years away” to “10 years away.”Source: MIT