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Germany Fires Up Bizarre New Fusion Reactor (sciencemag.org)
New submitter insitus writes: On 10 December, Germany's new Wendelstein 7-X stellarator was fired up for the first time, rounding off a construction effort that took nearly 2 decades and cost €1 billion. Initially and for the first couple of months, the reactor will be filled with helium—an unreactive gas—so that operators can make sure that they can control and heat the gas effectively. At the end of January, experiments will begin with hydrogen in an effort to show that fusing hydrogen isotopes can be a viable source of clean and virtually limitless energy.
great Jazz Fusion band name.
Is this a story from Futurama?
Is that a problem? We already nuked the crap out of space with the rainbow bombs back in the 60s.
Minimum threshold fixed. Thanks!
FTA: "This story was originally published online on 21 October and in the 23 October issue of Science. It has been updated with new information."
And yes, this story was on Slashdot then.
Lawrence Person (lawrencepersonh@gmailh.com (remove all "h"s to mail)
http://www.lawrenceperson.com/
Same as a fission reactor?
The cooling system powers steam turbines
It's bizarre because the story isn't quite a dupe.
The Bizarre Reactor Scientists Hope Will Save Fusion Research
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Heat. Thermal transfer to steam turbines. It would be sweet if we could directly extract the energy, but there's no known way of doing that yet. The turbine method is decently efficient, though.
Germany Fires Up Bizarre New Fusion Reactor
Could at least give a hint as to what's so bizarre about it in the summary.
Y'know, as opposed to all those boring run-of-the-mill fusion reactors...
Possibly the headline writer meant to say "Germany Fires Up Weird New Fusion Reactor" and forgot to add "Guess what happens next!"
Yes, it is click-baitism infesting the summary.
What is really interesting about this is that the stellerator is the oldest fusion reactor design approach, being given a new trial with 21st Century design techniques.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Everyone's going to say that it's finally the Mr Fusion from Back to the Future. Noooo. It's Das Mister Fusion. It's German.
The bizarre part is that the reactor is at the German army base on the Moon and they're using only moon helium.
You are welcome on my lawn.
You don't have to "draw off" energy - the plasma is more than happy to lose heat to its surroundings. The biggest challenge with fusion is to stop the plasma from giving up its energy too fast!
That said, for continuously operating toruses you do have to "draw off" the "ash" (helium) by means of an "exhaust" system that juts up into the outer reaches of the plasma stream (where the heavier helium concentrates), which is "a" challenge (the component is subject to a very hostile environment and faces huge thermal loads), but it's not a showstopper challenge by any means.
Nothing says 'welcome to the neighborhood' like a gunny sack full of dead squirrels.
Heat. Thermal transfer to steam turbines.
Standard PWR fission reactors use a 2 stage liquid/steam system to move energy from the core to the turbines. The first stage is flowing the liquid directly over the core inside the reactor vessel, which in turn keeps the reactor vessel at a decent temperature. But you can't do this with a fusion set up due to not being able to get to the inside of the (in this case) toroid. Thus all of the produced energy seems like it has to flow through the toroid walls in order to escape the reactor vessel - which would be rather nasty for any systems in close proximity to that reactor vessel (EG control systems that operate the magnetics and keep the plasma bottled up). So It seems to me that the only practical way of extracting the energy is by dunking the entire reactor vessel in the first stage liquid - and that seems impractical.
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Regular fusion reactors are either spherical or toroidal. The stellerator is more like a helical shape twisted round so that it forms a continuous loop. Words alone don't do it justice:
http://www.fusion-eur.org/fusi...
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I should have wikied before I posted:
https://en.wikipedia.org/wiki/...
if you haven't heard much about the "stellarator", the twisted design is actually a resulting design from an evolutionary algorithm.
robotic evolution will happen quickly.
Anons need not reply. Questions end with a question mark.
Take a look at the specs in TFA. The magnets in this system are cooled with liquid helium to -270 deg C. The plasma sits inside the magnets. Thus any energy extracted from the plasma has to cross the boundary of the magnets, while at the same time not upsetting the magnets themselves.. What I want is an explanation of how this aspect is being considered. Once you have the energy out of the core you can pipe it into turbines to produce electricity. But that part is easily done.
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Instead of an easily-described geometry like "spherical" or "toroidal", this has a Lovecraftian "unnameable" geometry.
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"So long and thanks for all the fish."
Wrong.
All Impulse based (yes, that means stellarators) fusion reactors produce huge magnetic flux changes during the superheat fusion cycle.
AC coupling this is power to the intermediate storage, which so far does not exist.
Nothing new, and nothing will work.
Sounds ripe for a typical heat pump system using the liquid helium as the refrigerant.
Nothing says success like the juxtaposition of "Germany" and "technological innovation involving a hydrogen filled container".
Who cares. If they start using this they might be able to cut back on all those coal burning plants. Good for their smog levels good for everyone's environment.
I think that the best option would probably be a helium heat jacket between the plasma and the rest of the structure. The helium becomes super-heated by transitioning the structure, then is piped to the turbines.
By utilizing helium you can utilize a much wider temperature range(for efficiency) without crazy-high pressures.
I don't read AC A human right
First of all, this reactor, like all current fusion reactors does not create excess energy.
There are two ways to energy transferred out, one is to utilize the so called MHD effect (was in favour the last century), now people say that you need to breed tritium from lithium, so the have a shell of lithium around the reactor core. That core is heating up by hits of neutrons. From that core you can extract heat ... as some other poster said: like in an fission reactor to drive turbines.
However: I doubt anyone ever did the math, you have "inside" a hot core that needs to get heat to the "outside" to drive a steam engine. "In-between" you have super conducting cooled coils (close to absolute zero) which generate the magnetic containment field.
But I guess, you can insulate the cooled coils good enough to bypass the heat transfer in a way that it is not disturbing the cooling of the coils.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
For Tokamaks, the energy-generation method involves catching high-energy particles emitted from the fusion reaction using a system on the outer shell of the containment vessel. This implies that the shell will degrade over time and need replacement, and that the containment vessel must be transparent to those particles. I'm going to assume that for an actual power-generating Stellarator design, there'd be a similar set-up -- unless there's some method by which the oddly-shaped magnetic field causes controlled amounts of particles to escape at well-defined points.
You're quite right in asking how the energy comes out. This is indeed one of the major challenges of fusion energy.
"how do you say "D'oh!" in German?"
Deuterium Hydroxide, also known as 'slightly heavy water'
What I don't understand is how they plan to heat a gas to 100 million degrees centigrade.. or what materials they're using to contain it. Most metals have a melting point of between 2500 and 3500 degrees centigrade. Even assuming the superheated gas doesn't directly touch the structural components, convection would surely still heat any containing material to its melting point. What are they using to contain it?
So what are the conceptual ideas for taking the energy out from a fusion reactor?
They have a FAQ which includes an answer to your question.
"how do you say "D'oh!" in German?"
Deuterium Hydroxide, also known as 'slightly heavy water'
It's just BIG BONED!
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
It's similar but almost completely unlike the twisting in twisted pair.
A normal toroidal tokomak has the magnets closer together and the centre than at the outside, and the variation in the resulting magnetic field leads to instabilities. The twist in the stellerator is supposed to ensure that the variations in magnetic field all get cancelled out as the plasma circulates.
> A completely new class of nuclear energy is not a project that a single nation, or a handful thereof, could hope to accomplish.
It's interesting you would say that. One country developed the first class of nuclear energy (kaboom), then developed "a completely new class of nuclear energy" again when they built the first nuclear power plants (1951), then miniaturized them to fit in submarines (1958), then created a whole new class again for space probes, etc. What makes it impossible for the country that has achieved most of the nuclear breakthroughs to achieve the next one?
Sure, the US has declined vis-a-vis other nations in the last few years, but I don't see any reason that must be either permanent or mean that they can no longer lead in -any- area. One strong leader like Kennedy or Reagan could make a huge difference, you know, someone who would actually LEAD.
Reading the article, it seems the US was on its way to building one like this, but ran out of money. Kinda par for the course with public-funded projects in the US these days.
It is by my will alone my thoughts acquire motion; it is by the juice of the coffee bean that the thoughts acquire speed
i hate these baby steps. they should have gone straight for dilithium crystals.
> Am I understanding correctly in likening the twisted plasma flow in this reactor design to how a twisted-pair cable works?
No.
Consider the fuel in a steady state. What we call heat is microscopically speed, and in this case all the ions are circulating around the torus very rapidly. Now think about the way the magnets are placed around the torus, as a series of rings. Because the rings are closer together on the inside radius, that means there is a stronger field on the inside of the torus than the outside. So that means an ion circulating on the inside radius sees more force than the ones on the outside, and they begin to move in different directions. That is bad.
The idea of the stelerator is to shape the reactor so ions that find themselves on the outside of the torus will find themselves on the inside somewhere else, and that will average out the magnetic force so everyone sees the same results over an extended period. The simplest way to do this is to place two straight sections in the torus to extend it into a racetrack shape, and then take one end and rotate it 180 degrees. The result is a figure-8 shape. Now just trace a line starting on the outside of one of the round ends and you'll see that by the time it gets to the other end its now on the inside.
The X-7 is simply a modification on that basic concept. Instead of a single twist, the magnets are arranged to continually twist the field through the entire reactor. The resulting pattern looks like the stripes on a candy cane. So the ions are constantly circulating from the inside to the outside. This motion also has the very desirable side-effect that it constantly mixes the fuel, which reduces problems with hot spots and areas of higher density that plagued early designs.
Does any of this make a difference? No. There is exactly zero chance this design will result in a practical, economic power producing design. It's science fair all the way. That's fine, but that's not really what they say about these things, is it?
"construction effort that took nearly 2 decades and cost â1 billion"
So...a tiny fraction of a percent of what's currently being spent on political wars, on a technology that could save the planet (instead of just creating more enemies and terrorists).
Business as usual, then.
No sig today...
...and opened up a gateway to hell!
Yes I'm sure all those physicists have not "done the math" on how to get power out of a reactor. I mean it's just this big important aspect of reactor design which you could get a Ph. D in by running simulations and doing the math, so I'm sure no one anywhere is looking at it.
"....on a technology that could save the planet..."
And which, if it should ever prove practical and buildable, will be banned in Germany.