Investors are (quietly, says Scientific American) lining up support for companies figuring out the ins and outs of nuclear fusion:
…[T]he fragments of information that have filtered out make it clear that the building houses one of the largest fusion experiments now operating in the United States. It is also one of the most unconventional. Instead of using the doughnut-shaped ‘tokamak’ reactor that has dominated fusion-energy research for more than 40 years, Tri Alpha is testing a linear reactor that it claims will be smaller, simpler and cheaper — and will lead to commercial fusion power in little more than a decade, far ahead of the 30 to 50 years often quoted for tokamaks.
Over the past decade and a half, these mavericks have launched at least half a dozen companies to pursue alternative designs for fusion reactors. Some are reporting encouraging results, not to mention attracting sizeable investments. Tri Alpha itself has raised $150 million from the likes of Microsoft co-founder Paul Allen and the Russian government’s venture-capital firm, Rusnano.
[M]ost mainstream plasma physicists have simply left the practical engineering issues for later, assuming that fixes will emerge after the plasma physics has been worked out. The fusion mavericks are among the minority who argue that a more radical solution is needed: first get the engineering right, by designing a simple, cheap reactor that power companies might actually want to buy, and then try to make the plasmas behave.
One of those upstarts is Norman Rostoker, a physicist at the University of California, Irvine, who co-founded Tri Alpha in 1998 at the age of 72. He and his colleagues proposed ditching D–T fuel in favour of fusing protons with boron-11, a stable isotope that comprises about 80% of natural boron. Igniting this p–11B fuel would require temperatures of about a billion kelvin, almost 100 times as hot as the core of the Sun. And the energy created in each fusion event would be only about half that released by D–T. But the reaction products would be practically free of troublesome neutrons: the fusion would generate just three energetic helium nuclei, also known as ?-particles. These are charged, so they could be guided by magnetic fields into an ‘inverse cyclotron’ device that would convert their energy into an ordinary electric current with around 90% efficiency.