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am_Unition  ·  996 days ago  ·  link  ·    ·  parent  ·  post: Rotamaks: Yet another ignored fusion technology

Bro this did not deserve a badge, but thank you!

    a similar effect with with a laser

In theory, you should be able to heat whatever-mak plasma with photons, certainly. (for posterity) Inertial confinement fusion uses lasers to fuse. I would guess that the reason the magnetic confinement folks don't really rely on lasers for heating is that whatever particles are bouncing around the vacuum chamber will go into the beam source and fairly quickly ruin whatever material you're using to lase? Honestly, I'm not sure why an energetic neutral beam source would be superior, except for something to do with component degradation being more easily/cheaply dealt with. People are working on the laser'ing method. And of course, if you're using UV or anything shorter wavelength, if you put the laser outside the chamber, behind a glass flange thick enough to hold up under the pressure differential, you're gonna lose a lotttttt of photons inside the glass.

Very related, and not mentioned in the blog: Plasma-chamber material considerations are serious business. So even if you've got an infinitely stable confinement, you will still eventually have to cease your fusing mode for a mode of operation that reliably restores the intended coating(s) inside the chamber and sweeps away the large "dust" molecules.

It's disheartening that it's 2022 and we're still at "Well we can't really simulate this until we have quantum computing clusters, probably, but we'll do the best we can, and if it seems like a new configuration or approach could work, maybe we'll get the money to build it. Maybe it will even kinda work!". But such is plasma confinement. One of my profs, very candidly one day went into a rant that started with: "Look... Look. Plasma... is.. not your friend."

I have been wondering if there's a very different approach from all of this that might be superior. Instead of using the energy from fusion to boil water and going through turbines to generate electricity, if you're clever enough, you might be able to go straight to generating a voltage across the chamber (edit: Yes, I know, a chamber with a potential across it sounds like a nightmare, if not impossible, not sure how you'd have anything, like instruments, sources, the beloved tinfoil sheet barely obscuring some glass, etc., hooked up to it :(. That problem aside, you could have some periphery electronics to siphon off (or in) charge however you need, the same sort of idea as a Marx generator, but maybe in reverse?). Then, instead of aiming for loooooong confinements, engineer the thing to lose confinement (albeit in a controlled manner) every 1/60th of a second. Of course, that's still a long time, as far as the plasma's concerned (typical ion gyrofrequencies for magnetic confinement fusion plasmas are ≳ 1E7 Hz, with electrons ≳ 1E10 Hz). Still shaves off a couple or several orders of magnitude from your targeted confinement time. I kinda doubt either of these directions would work out, ultimately. 'nother edit: Yeah, it'd be.. even harder, I think, to make anything close to a sine wave shape, you'd need something inherently lossy to shape fusion-outputted waveforms back to sine-like. Unless. you had a large array of units that you could use systematically...

'nother 'nother edit: Also I think it is loss of confinement that is to blame for the most egregious dusting/doping events, so maybe planned, routine loss of confinement is just plain stupid.

In general, I'm loathe to search the literature outside of my current regime. I'd much rather show up at a conference, find some experts, and ask my foolish questions. I don't care if I look stupid if it saves me huge amounts of time.