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Piston-Powered Nuclear Fusion
katarn writes "General Fusion is a startup proposing they can create commercially viable fusion using acoustic shock waves, triggered by 220 precisely controlled pneumatic pistons. Their approach is based on a US Naval research concept called 'Linus' and old research done by General Atomics. They feel we now have the high-speed, digital processing capable of pulling off this feat, where decades ago the technology was not available. I think we can hold off on the 'vaporware' claims for a bit; everyone is aware of the horrible track record for turning fusion concepts into reality, but they don't claim to be the first with the idea or that there are not substantial challenges in the way. If nothing else, it is a fascinating concept."
Los Alamos National Laboratory has further details on this type of fusion, and longtime LANL researcher Ronald Kirkpatrick did an external assessment (PDF) of General Fusion's plans. Popular Science had a lengthy story about the company a while back. The reason they're back in the headlines now is that they've secured enough funding to begin work on a prototype reactor.
I mean, come on, this is just begging for some steam punk artwork!
There's been some modest interest in actively stabilized fusion for a while, but this is the first mechanical scheme.
The basic problem with fusion reactors is that the plasmas aren't stable. Most work to date involves trying to come up with some geometry that produces an inherently stable plasma. So far, nothing works, although some geometries almost work. But it's not that hard to build a small machine that has an unstable plasma. The original Stellerator, in 1951, did that.
The instabilities occur on the order of milliseconds, not microseconds or nanoseconds. That's slow enough that some kind of active stabilization scheme to nudge the instabilities back in line might work. Something with a large number of sensors and actuators. But I'd been expecting electrostatic deflection plates or magnets, not physical pistons.
You could attach four smart mechanical arms to someone's brain stem (with an inhibitor chip of course). Those extra arms could make the millisecond adjustments to keep the instabilities in check. I have to admit this sounds familiar ...
Startups, by their very nature, do not succeed on a bet that the technology will be invented. Venture capitalists do not support fairytale wishes.
Startups use existing, proven technology and package it in new ways to serve a need of the consumer. Startups are about commercializing a technology, not inventing it.
What startup does breakthrough research? None.
Research is the luxury of universities (with infinite time horizons) and monopolists like Microsoft .
There's a reason fifties novels sound like that. It has to do with art imitating life, not the other way around. General Atomics was real. So were General Dynamics and General Electric. So were companies like North American Aviation and The Aerospace Corporation. Some of them even still exist.
Only in the vaguest sense. The secondary stage in a thermonuclear bomb is triggered by a fission primary, however the secondary stage in a thermonuclear bomb is not a purely fusion weapon. It's a multilayer sandwich. The secondary starts off with another fission reaction (the plutonium spark-plug), which helps trigger the fusion reaction (lithium deuteride), which in turn boosts the ongoing fission reaction in the spark plug, which in turn boosts the ongoing fusion reaction. Finally it produces a neutron flux which detonates and consumes the secondary casing (depleted uranium, U-238). Most of the energy in a thermonuclear bomb comes from the fission of the depleted uranium protective casing. Thermonuclear bombs do fission 'better' than purely fission bombs. For the record, this was discovered accidentally when Castle Bravo was a much bigger bang than the designers expected.