Fusion Magnets

Fusion technology has long been regarded as the best path to limitless, clean energy. Much of the research todate has been confined to tabletop scale models, but new developments in magnet design could propel the industry forward.

In a nutshell, a fusion reactor works by heating hydrogen under extremely high pressures to hundreds of millions of degrees, forming plasma – a superheated state in which electrons are stripped away from the atoms, allowing them to fuse together and form helium. In the fusion process, some of the mass is transformed into heat, which can be used to generate electricity. Powerful magnets are needed to contain the plasma, and they need to be designed so that they don’t consume more power than the reactor can produce.

The new magnet design utilizes 300 kilometers (185 miles) of a special electromagnetic tape comprised of thin layers of super-conducting rare earth barium copper oxide (ReBCO). The tape is wrapped around a 10-ton, D-shaped magnet and supercooled to -253 degrees Celsius (-423 degrees Fahrenheit), at which point it can conduct up to 40,000 amps of electricity – enough to power a small town. Eighteen of the magnets will be placed in a spherical tokamak. At full power, it’s estimated that the forces generated by the magnets will be twice that of the pressure at the bottom of the deepest ocean trench.

The first demonstration device – known as SPARC – will be constructed in collaboration with the Massachusetts Institute for Technology (MIT).