[HN Gopher] Spherical tokamak achieves crucial plasma temperatures
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Spherical tokamak achieves crucial plasma temperatures
Author : rajnathani
Score : 84 points
Date : 2023-04-09 18:49 UTC (4 hours ago)
(HTM) web link (www.eetimes.com)
(TXT) w3m dump (www.eetimes.com)
| RangerScience wrote:
| One thing I've never figured out about fusion - how do you get
| the heat _out_ and turned into electricity?
|
| (Presumably, water to steam then turbines, like everything, but
| how do you get the heat out from the reaction?)
| apendleton wrote:
| Depends on the reaction. Most efforts are around deuterium-
| tritium fusion (that's the pair that's easiest to make fuse),
| which emits most of its energy as high-energy neutrons. So for
| these, yes, like the peer comment said, the neutrons are
| hitting something that heats up (that's the "blanket," which
| might be made of molten salt or metal), and then you can get
| the heat out of that with a heat exchanger. The company
| described in this article is aiming for D-T fusion.
|
| There are other reactions one can pursue that produce charged
| particles instead of neutrons. With these reactions, there are
| alternative energy conversion pathways that turn the kinetic
| energy of these charged particles directly into voltage, and
| you can skip the turbine. Of the fusion startups, Helion is
| probably the most prominent pursuing this kind of approach,
| with a D-He3 reaction. See
| https://en.wikipedia.org/wiki/Direct_energy_conversion for more
| info on this general approach.
| jamiek88 wrote:
| That's kinda on the 'we'll figure it out later' track.
|
| Materials are being investigated that can withstand the heat
| and neutron bombardment to attach a steam turbine the old
| fashioned way.
|
| But we ain't there yet, not without having to constantly change
| the 'walls'.
|
| > Most of the energy produced inside a fusion reactor is
| emitted in the form of neutrons, which heat a material
| surrounding the fusing plasma, called a blanket. In a power-
| producing plant, that heated blanket would in turn be used to
| drive a generating turbine
| Tuna-Fish wrote:
| The simplest answer that's part of the plan for most DT
| reactors is "as neutrons".
|
| The fraction of the energy that is retained as velocity of
| particles with a charge vs that is lost as the velocity of
| neutrons turns out to be conveniently just about where you'd
| want it to be. So, to capture the energy you need to surround
| your reactor with something that effectively converts fast
| neutrons to heat, such as a blanket of molten lithium, which
| you then use as a heat source. Lithium is proposed because it
| would also breed the necessary tritium.
| nelox wrote:
| This podcast covers the state of the art, including the spherical
| tokamak: https://podcasts.apple.com/au/podcast/babbage-from-the-
| econo...
| dejv wrote:
| They used to produce great Youtube channel:
| https://www.youtube.com/@tokamakenergy6400
| robocat wrote:
| One video that shows two guys inside the tokamak, installing a
| diverter, which gives you an idea of the internal dimensions of
| the toroid - 10 minutes into
| https://www.youtube.com/watch?v=YkkeCjgrG-0
| fandorin wrote:
| if you want to understand fusion and what the heck tokamak is - I
| can highly recommend Lex Friedman conversation with Dennis Whyte
| [1]. It's a great source of info not only about the fusion energy
| - Dennis describes so much more there! Amazing guy.
|
| [1]
| https://open.spotify.com/episode/5X1TXNQ9zIo5PGJe80xtpv?si=Z...
| xqcgrek2 wrote:
| Marketing hype. This is very far from being useful.
| lallysingh wrote:
| Nobody said it would be. Did your RTFA? It's just a milestone
| crossed.
| gus_massa wrote:
| I had to search it:
| https://en.wikipedia.org/wiki/Spherical_tokamak
|
| > _A traditional tokamak has a toroidal confinement area that
| gives it an overall shape similar to a donut, complete with a
| large hole in the middle. The spherical tokamak reduces the size
| of the hole as much as possible, resulting in a plasma shape that
| is almost spherical, often compared with a cored apple._
| [deleted]
| trebligdivad wrote:
| I love the picture; HUGE bus bars at the top; stuff held together
| with random metal framing, and a couple of dangling UK 13A plugs!
| post-it wrote:
| I love the wooden ceiling above.
| tyingq wrote:
| That L-shaped piece of t-slot aluminum that's dead center in
| the picture looks especially janky. Like sort of a quick and
| dirty friction fit brace.
| lostlogin wrote:
| It looks like the inside of The Millennium Falcon, but with
| more duct tape.
| thriftwy wrote:
| Tokamak cannot be spherical since To stand for Toroidal.
|
| How about Sphekamak?
| adastra22 wrote:
| It is toroidal, just compressed so small that the packaging is
| spherical.
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