Fusion reactors are thought of as being very expensive, and are believed through theoretical calculations to be very efficient energy generators. Still, nuclear fusion is still a dream and many projects are being started, among which it is the ITER project, that has been estimated to a rough $14 billion. The ITER relies on expensive superconducting magnets, called “tokamaks”, to contain the superheated plasma necessary to achieve and sustain a nuclear fusion.
Meanwhile, General Fusion, a small startup company from Canada, claims they can build a new type of a fusion power plant in the next ten years, and build it a lot cheaper than ITER – for less than a billion dollars. They have already gathered $13.5 million from various private and public investors, who understood their technology would work and want some share of the eventual profit.
General Fusion’s nuclear reactor is made of a metal sphere, filled with a liquid mixture of lithium and lead. The liquid is spun to create a vortex inside the sphere that forms a vertical cavity in the middle. At this point, two donut-shaped plasma rings held together by self-generated magnetic fields, called spheromaks, are injected into the cavity from the top and bottom of the sphere and come together to create a target in the center. “Think about it as blowing smoke rings at each other,” says Doug Richardson, chief executive of General Fusion. The entire sphere is surrounded by 220 pneumatic pistons, programmed to hit it simultaneously at 100 meters/second and create an acoustic shock wave.
The wave compressed a plasma target, called “spheromak”, and triggers a fusion burst. Thermal energy is then collected with a heat exchanger, used to create steam, and generate electricity through a turbine. They would have to repeat the process every second to produce usable power. It all sounds simple and dandy, but it isn’t quite like that.
This kind of approach has already been experimented in the 80’s, but they didn’t have the proper control equipment to perform the simultaneous hit of the sphere with the 220 pneumatic pistons. Nowadays, thanks to high performance DSPs, they can do it properly.
Los Alamos and General Fusion are collaborating as part of a recently signed research agreement. “The project has many risks,” says Richardson, “and we expect most of it to not perform exactly as expected.” However, General Fusion can make its test reactor work, it hopes to attract enough attention to easily raise the $500 million for a demonstrative nuclear fusion power plant.