4 ms·
> But how much of that G > 1 energy has ever been harvested? None, because we haven't achieved G > 1 yet. :) Per https://physics.stackexchange.com/questions/7
by PhasmaFelis 10y ago
> But how much of that G > 1 energy has ever been harvested?
None, because we haven't achieved G > 1 yet. :)
Per https://physics.stackexchange.com/questions/70209/how-is-energy-extracted-from-fusion https://physics.stackexchange.com/questions/70209/how-is-ene..., hydrogen fusion produces helium and neutrons; neutrons are unaffected by magnetic fields, so they escape confinement and impact the reactor walls, heating them. The heat is simply vented in current test rigs, but in a working model it can be used to produce steam to power generators. That's specifically for tokamaks, but I would guess the process is similar for stellarators.
- wyager 10y agoIt's great how even our most advanced energy generation technologies are still just steam boilers at heart. That hasn't changed in 305 years.
- djsumdog 10y agoSteam initially, but effect ways of converting all that heat to electricity are pretty limited at the moment. One way to convert the heat from radioactive decay into electricity is through thermocouples (typically found in RTGs used on deep space probes and Mars exploration craft). They're incredibly inefficient though, less efficient than simply turning steam turbines.
- zlynx 10y agoI've read about some theoretical designs that would open the field to allow all negative charged particles out and use these electrons as power directly. But first, designs would have to be able to keep the containment pressure/temperature much higher than it currently is. https://en.wikipedia.org/wiki/Aneutronic_fusion#Energy_capture https://en.wikipedia.org/wiki/Aneutronic_fusion#Energy_captu...
- boznz 10y agoThe Focus Fusion http://lppfusion.com/ http://lppfusion.com/ reactor does direct conversion to electricity. A Shame these guys are the least funded contender in this race and could do their research on a rounding error from ITAR.
- sandworm101 10y agoSo if the neutrons are untouched by magnetic fields, don't they also heat the magnets? I can see them passing through walls to boil water, but any heat created in the magnets would be very difficult to harvest given the temperatures involved. How much energy would it take to keep the magnets cool in the presence of a sustained (ie days) fusion reaction nearby? Generating such a flux in a bottle surrounded by things that need to be kept so cool sounds a bit of a fool's errand... but I really want practical fusion to be a thing.
- madengr 10y agoWater is a good neutron absorber. Maybe the water is in front of the magnets.