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"we could build one that generates net energy today". That's a pretty broad claim, considering the article linked itself notes that we've only hit a Q factor (
by araes 13y ago
"we could build one that generates net energy today". That's a pretty broad claim, considering the article linked itself notes that we've only hit a Q factor (output/input) of 0.7 with a test reactor measuring all the available energy. We still need a Q of 5, or a little under a factor of 10 (7.14) jump to be able to even have sustained fusion, as we specifically need the energy of the alpha particles, and need an estimated Q of 10 (factor of 14.3 jump, "Indispensable Truth") to be able to extract useful power. Any engineer will tell you jumping the efficiency of almost any system enough to get a 14.3x jump is not trivial.
We are making steady progress, and we're at least getting near break-even, but we're still a ways from rolling out Tokamak's as the one true solution. Frankly, I think the final solution may be a combination of strategies (magnetic confinement, inertial confinement, electrostatic confinement, and / or maybe one of the other ones, like sonofusion or the z-pinch).
- Retric 13y agoQ is only the first problem. Tokamak's are considered the front runner because they scale ridiculously well so getting something as small as JET to 0.7 briefly means something with 10x the volume is easy to hit a Q of 10. Jet's was design work started in 1973 we simply have never built another device that large again. However, the Tokamack confinement record is only 6 minutes 30 seconds. The neutron bombardment at scale is insane and grid power needs a steady and dependable energy supply, nobody has a ready supply of Tritium so they need to breed it somehow etc etc. Worse even if we built something that was clean and net energy positive so are windmills so the reactor also needs to be cheap. Also, while far safer and cleaner than fission fusion still generates a fair bit of radioactive waste due to all that neutron bombardment.