ITER’s project, which won’t be ready for nearly 30 years, is so expensive because it uses pricey superconducting magnets (tokamaks) and lasers to contain plasma for a fusion reaction. General Fusion takes a different tactic: the company plans to create a fusion reaction that gives off more energy than is required to sustain it by using low-tech brute force.
More specifically, General Fusion plans to make a metal sphere reactor that spins a liquid mixture of lithium and lead to create a vortex inside the sphere. Two spheromaks, or plasma rings kept together by a self-contained magnetic field, are injected into the sphere to create a target. At the same time, 220 pistons hit the outside surface of the sphere to create a shock wave that hits the plasma, compresses it, fuses the isotopes into helium, and releases energy-filled neutrons captured by the liquid mixture. The energy is extracted from the liquid with a heat exchanger to create steam to spin a power-generating turbine and to continue to run the reactor.
It sounds good on paper, but General Fusion has yet to develop 3-D simulations or build a test reactor. If the company can raise another $37 million, it hopes to have a prototype reactor ready in five years. With $500 million more in funding, the company will have a grid-ready reactor four years after that. These are a lot of “ifs”, and we probably won’t know the fate of General Fusion for at least half a decade. But if it does succeed, the startup could bring the sky-high price of nuclear fusion–the holy grail of energy–back down to earth.
[Via MIT Technology Review]