Issue link: https://cp.revolio.com/i/5219
62 winter 2009 WhaT IT IS Nuclear fusion is the process where multiple like-charged atomic nuclei come together, or "fuse," to create a heavier nucleus. Once this happens, energy is released. Sounds simple, but like forces repulse each other, and in order for nuclei to fuse, they have to smash through substantial electrostatic forces known as the Coulomb barrier. The smallest Coulomb barrier occurs in hydrogen, which only has a single positive charge in its nucleus. But bi-protons aren't stable, so fusion also uses neutrons, ideally from a helium nucleus. As a result, deuterium, also known as "heavy water" and which contains helium, makes an ideal fusion fuel. Richardson explains, "The problem is that heating things up is how you get energy, but nature doesn't like things to be hot. Nature always tries to bring everything to equilibrium, and the sun is only able to sustain fusion because it is isolated in a vacuum." Once you've started firing pellets of hydrogen at deuterium, you need someplace to contain the resulting release in energy in order to avoid the inevitable drift towards equilibrium and dissipation. Gravity makes an excellent containment field, but the only objects capable of generating that level of gravity are stars — and stars, obviously, are not an ideal environment for humans. Ions can be used to create a magnetic field, which keeps the resulting energy release from escaping. liquid metal can also be used as a containment layer. "Think of a smoke ring," Richardson explains. "If you squish that smoke ring fast enough, the energy can't escape." a SlaB In The laB At one point in our conversation, Richardson leads me to the back room where all the real work at General Fusion takes place. In the middle of the room, surrounded by large batteries and intense looking technicians, we are staring at the beginnings of a fusion reactor. The device measures about three meters end to end, and most closely resembles two oversized steel traffic pylons lying on their sides and pointing at each other. Eventually these pylons will be joined in the middle by a spherical chamber. I'm struck by both the small size of the prototype and the DIY aesthetic of the whole operation. Is this the energy source of the future, resting on wooden blocks? When the general public thinks of fusion, giant donut-shaped devices commonly spring to mind. These devices, known as tokamaks, are essentially giant magnets built to contain high-speed fusion reactions. These magnets and all the associated staff, equipment and maintenance are astronomically expensive. The usefulness of this kind of magnetic fusion is limited, since it can't be easily adapted for use in power plants. lasers can also be used to generate an implosion, but that's an equally expensive proposition. Richardson: "lasers are high tech, and the magnetic guys are even more high tech. But high tech is expensive. What we want to do is take old stuff and put it together." General Fusion's reactor is a metal sphere surrounded by pneumatic pistons. The pistons create an acoustic wave that travels through a liquid metal containment layer, hitting the center with a shock wave. In the center of the sphere, a plasma target should then — in theory — implode and create fusion energy, which is then extracted with a heat exchanger. From there, steam is released to create electricity. For the reactor to have any practical purpose, it has to repeat this process every second. General Fusion is currently in the first stage of the project, building all the components including the sphere that will eventually contain a magnetized ball of plasma. During the second stage, due to start in 2011, they'll build the actual reactor. Richardson isn't talking about incrementally lowering the cost of fusion. He's talking about a quantum leap downward in price. The company hasn't yet reached their stated goal of raising $50 million, a pittance compared to the money spent on government funded fusion projects, but has succeeded in raising over $9 million from private investors and $12.9 million from Sustainable Technology Development Canada, a Canadian government agency. Where GF innovates is in adapting today's technology to improve an old design. Fusion energy is generated in miniscule amounts of time, and thirty years ago the technology simply wasn't available to control instruments fast enough to take control during the crucial moment when fusion energy is released. IMAgES COURTESy Of gEnERAL fUSIOn