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I once did an internship at the MPI in Garching and had the opportunity to visit the Stellarator. Although it looks much less spectacular with all the coils hid
by ThePhysicist 11y ago
I once did an internship at the MPI in Garching and had the opportunity to visit the Stellarator. Although it looks much less spectacular with all the coils hidden in their housing it is still an incredibly impressive machine with an audacious design.
Today the numerical effort required for realizing it might seem not very impressive given the technological capabilities that we have, but you have to take into account that the first version (Wendelstein 7-AS) was built in the 1980s already.
That said I really hope that the experiment confirms the viability of this design and its (potential) superiority compared to the classical Tokamak fusion chamber.
- zamalek 11y agoI have no doubt that a design that goes with the physics (instead of going against it like Tokamaks do) is going to yield great results, however I hope something comes out if it that will also allow for viable Tokamaks. Stellarators are hellishly complex and expensive.
- drjesusphd 11y agoCan you explain what you mean by tokamaks "going against the physics"?
- kuschku 11y agoTokamaks need, to contain the plasma, a continuously changing magnetic field. To create a continuously changing magnetic field, you need to continuously increase or decrease the current. The issue is that you can not turn up the current more than a maximum level, and you have to keep the direction the same (so you can’t switch between turning off and on). Stellerators instead solve this with complex geometry and the plasma creating its own continously changing magnetic field.
- drjesusphd 11y ago> Tokamaks need, to contain the plasma, a continuously changing magnetic field Do you have a citation for this claim?
- kuschku 11y agoI could source one from German Wikipedia, but english wikipedia does not seem to have that information. You might be able to find some sources when you search for the reasons of Tokamaks pulsed usage.
- fanf2 11y agoA tokamak is basically an AC transformer, with the plasma acting as one of the windings.
- zamalek 11y agoSo far as I understand it (arm chair physicist), Stellerators "shape" the plasma in a "natural" way, Tokamaks force it into a more "unnatural" shape - like trying to put a beach ball [plasma] into a box [torus]. If I misunderstand it disregard my comment entirely, although I'd like to know why.
- drjesusphd 11y agoHere's how I understand it: - The simplest closed magnetic configuration is a torus. You can't smoothly "comb a hairy ball", but you can comb a hairy torus. - For a toroidal plasma to be stable, it needs magnetic field components both the "long way" around (toroidal), and the "short way" around (poloidal). - The tokamak generates the poloidal field from a current within the plasma, whereas the stellerator imposes that component with external magnets. So you could make a "natural" argument either way, and I was asking the grandparent in what sense the stellerator is more "natural".
- noir_lord 11y ago> Stellarators are hellishly complex and expensive. True but that is largely true of the first of anything complex and expensive since it's Development Costs + Construction costs / 1 until they build another.
- ant6n 11y agoWell, if this one works, they just need to copy, it, right? I mean in the end, you really only need one viable design.