3 ms·

There really are physics that only work at very large scale, such as stars and black holes. It may be that we can only get fusion power generation working in h

by zlynx 9y ago

There really are physics that only work at very large scale, such as stars and black holes. It may be that we can only get fusion power generation working in huge reactors like ITER. It's also a good attempt at getting many countries working together. Ideally, more big brains working together will have better ideas and results. There's downsides to ITER too of course. But I think it's worth working on.

Yizahi 9y ago
ITER is actually a small scale model. Full scale would be DEMO, a few decades in the future :) .
candiodari 9y ago
There are fusion reactors that are 5 cm diameter. Total size less than a microwave. They're very useful but not energy-positive, though there are reports of one that was Q=0.2, which given that that one was fridge sized was pretty good. They're the only practical way we have of producing fast neutrons. They are critical in physics research, some medical treatments, fusion research, ... their is absolutely no even remotely practical alternative to them (they're microwave sized devices, using 4-10kw of power that replace synchotrons. Small synchotrons are basketball-field sized and need their own power station) (replace should be taken with a grain of salt since most places that have IEC fusors had no way in hell to afford a synchotron, so they are democratizing fast neutrons. Okay, that's perhaps a strong word but if you have a use for them, there's no reason why you couldn't operate one of these devices in any regular office) (ps: given how easy, hard to detect, and deadly mistakes with fast neutrons are, please do do it in an office building at least 100m away from me. As it stands though, they're completely unregulated) The reason we scale up is roughly: 1) Scaling laws work in favor of Q. Q should scale with something like the 3rd power of the size of the reactor. So it's much easier to build a huge Q>1 reactor. 2) Where to stick parts ? Fusion reactors require strong magnetic fields and the only real way we knew of doing that 20 years ago when these were designed was cyronically frozen. That means we need sections inside the reactor for superconductors, for crygenic cooling equipment (mostly piping). Even disregarding that, fast neutrons will destroy any material they touch, making it brittle and crumble. Aside from bigger reactors making sure more material can get destroyed without failure, one thing that they interact with well is large volumes of water. So if at all possible, we'd like large volumes of water inside the reactor too (for other reasons too, like one strategy for extracting power). That needs space, obviously. 3) It is much easier to keep things stable if their scale is larger. There is more reaction time for the control equipment, the fields involved are larger and move slower, ...

by zlynx 9y ago

Yizahi 9y ago

ITER is actually a small scale model. Full scale would be DEMO, a few decades in the future :) .

candiodari 9y ago

There are fusion reactors that are 5 cm diameter. Total size less than a microwave. They're very useful but not energy-positive, though there are reports of one that was Q=0.2, which given that that one was fridge sized was pretty good. They're the only practical way we have of producing fast neutrons. They are critical in physics research, some medical treatments, fusion research, ... their is absolutely no even remotely practical alternative to them (they're microwave sized devices, using 4-10kw of power that replace synchotrons. Small synchotrons are basketball-field sized and need their own power station) (replace should be taken with a grain of salt since most places that have IEC fusors had no way in hell to afford a synchotron, so they are democratizing fast neutrons. Okay, that's perhaps a strong word but if you have a use for them, there's no reason why you couldn't operate one of these devices in any regular office) (ps: given how easy, hard to detect, and deadly mistakes with fast neutrons are, please do do it in an office building at least 100m away from me. As it stands though, they're completely unregulated) The reason we scale up is roughly: 1) Scaling laws work in favor of Q. Q should scale with something like the 3rd power of the size of the reactor. So it's much easier to build a huge Q>1 reactor. 2) Where to stick parts ? Fusion reactors require strong magnetic fields and the only real way we knew of doing that 20 years ago when these were designed was cyronically frozen. That means we need sections inside the reactor for superconductors, for crygenic cooling equipment (mostly piping). Even disregarding that, fast neutrons will destroy any material they touch, making it brittle and crumble. Aside from bigger reactors making sure more material can get destroyed without failure, one thing that they interact with well is large volumes of water. So if at all possible, we'd like large volumes of water inside the reactor too (for other reasons too, like one strategy for extracting power). That needs space, obviously. 3) It is much easier to keep things stable if their scale is larger. There is more reaction time for the control equipment, the fields involved are larger and move slower, ...