this fusion ain't cold
For the past 25 years, fusion research has focused almost exclusively on the tokamak reactor - a giant donut that holds 200-million-degree deuterium-tritium plasma suspended in a magnetic field and uses it to produce heat and drive a turbine. This process uses the same heat-engine based approach to power generation as coal - it just replaces a coal furnace with a fusion plant. The deuterium-tritium reaction also produces high-energy neutrons, which leave the plant radioactive. Not to mention that the fuel, tritium, is the same stuff used in H-bombs.
The focus fusion reactor uses a very different approach. The details are on the website, and they explain it much more fully than I can here. But the gist of it is that they fuse Boron-11 and a hydrogen atom using a device called a plasma focus, leaving 3 helium atoms and no radioactive by-products. Rather than letting these atoms collide with a tank of water to produce steam, they are directed in a beam to a sort of reverse particle accelerator that converts the fusion energy directly to electricity. If you've taken any thermodynamics, you know that heat engines are inefficient by nature. Bypassing the steam-turbine cycle not only reduces cost, it makes for a much more efficient process.
Perhaps the best thing about the idea is that power plants based on the plasma focus would be small and cheap - $500,000 and the size of a two-car garage. These small plants could be built in a much more distributed way than current power stations, helping to avoid things like the blackout of two years ago. It would also enable developing countries to generate significant amounts of power relatively cheaply. The project is still in the R&D phase and has yet to produce a break-even prototype. But their proof-of-concept is quite impressive. Take a look.
