China's Fusion Reactor Reaches 100 Million Degrees Celsius (abc.net.au) 261
hackingbear shares a report from the Australian Broadcasting Corporation: The team of scientists from China's Institute of Plasma Physics announced this week that plasma in their Experimental Advanced Superconducting Tokamak (EAST) -- dubbed the 'artificial sun' -- reached a whopping 100 million degrees Celsius which is six times hotter than the core of the Sun. This temperature is the minimum required to maintain a fusion reaction that produces more power than it takes to run. The Chinese research team said they were able to achieve the record temperature through the use of various new techniques in heating and controlling the plasma, but could only maintain the state for around 10 seconds. The latest breakthrough provided experimental evidence that reaching the 100 million degrees Celsius mark is possible, according to China's Institute of Plasma Physics. "While the U.S. is putting new restrictions on nuclear technology exports to China, inventions and findings of EAST will be important contributions to the development of the International Thermonuclear Experimental Reactor (ITER)," writes Slashdot reader hackingbear. The reactor is currently being built in southern France with collaboration from 35 nations. According to the Australian Broadcasting Corporation, it is expected to be "the first device to consistently produce net energy, producing 500 megawatts of clean and sustainable power."
could only maintain the state for 10 seconds (Score:5, Funny)
Re:could only maintain the state for 10 seconds (Score:5, Informative)
You joke, but actually plasma fusion reactors are quite safe -- far safer than their fission counterparts.
Even if all of the matter inside a fusion reactor were to fuse simultaneously -- a physical impossibility -- the worst that would happen is significant damage to the reactor building. There simply isn't enough matter inside the reactor at any time to do worse.
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Even if all of the matter inside a fusion reactor were to fuse simultaneously -- a physical impossibility -- the worst that would happen is significant damage to the reactor building. There simply isn't enough matter inside the reactor at any time to do worse.
Fusion reactors are still generating neutrons.. activation is still a problem. There must be at least some radioactive crap that can leak out and make the evening news.
Re: could only maintain the state for 10 seconds (Score:5, Interesting)
Not really. The only direct products you make will be Helium-4 (stable), Helium-5 and Helium-6. You could smash up or change isotope a carbon, nitrogen or oxygen atom, I suppose. But you're talking very short half-lives.
The concrete is a problem. Fortunately, the Iranians have a recipe that is less likely to powder or fail. So, with trade restored under the joint agreement, we're ok.
Oh.
Re:could only maintain the state for 10 seconds (Score:5, Informative)
Fusion reactors are still generating neutrons.. activation is still a problem.
Most of the neutrons are absorbed by the lithium blanket. The lithium splits into helium-4 and tritium. The tritium is collected and fed back into the reactor.
Most structural parts exposed to thermal neutrons are made of zirconium, which has a very small neutron cross-section.
There is some problems with neutron activation from a fusion reactor, but way less than with fission reactors. There is no danger of a "meltdown" or any other catastrophic failure. The biggest concern is a tritium leak, but tritium isn't very dangerous, dissipates rapidly, doesn't bioaccumulate, and has a half-life of only 12 years.
Would I be willing to live next to a fusion reactor? Sure.
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Most structural parts exposed to thermal neutrons are made of zirconium
I couldn't find anything: do you have any info on that (the structural metal part)? Zirconium isn't a common structural metal. Presumably it would have to be alloyed, but then you have to concern yourself with the cross section of the alloying parts as well.
All in all a very interestig engineering problem.
Re:could only maintain the state for 10 seconds (Score:5, Informative)
Zirconium isn't a common structural metal.
Of course not. It is heavy and expensive. It is only used where low neutron cross section is important.
Presumably it would have to be alloyed
Yes, most commonly with tin and niobium. Sometimes with chromium, nickel, or iron.
then you have to concern yourself with the cross section of the alloying parts as well.
Indeed. Most zirconium alloys are 95% or more zirconium for this reason.
More info here: Zirconium Alloys [wikipedia.org]
Zirconium sits right below titanium in the periodic table, and shares many properties, including high strength and resistance to corrosion.
Just below Zirconium is Hafnium, which has one of the biggest neutron cross sections. Hafnium is used as a neutron absorber, and hafnium salts can be used as a neutron poison to quickly shutdown thorium salt reactors in an emergency.
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I had done some design work on a nuclear fusion reactor, we mainly used common alloys like stainless steel (with special control over cobalt content), aluminum, titanium, etc. Aluminum alloys are great as they don't activate and self anneal radiation damage. The zirconium you mention might be more towards the intense plasma facing components. I've seen tungsten, carbon-carbon, and beryllium used in this area - particularly in the diverter area.
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Most structural parts exposed to thermal neutrons are made of zirconium
I couldn't find anything: do you have any info on that (the structural metal part)? Zirconium isn't a common structural metal.
Zr is currently used as the cladding on fission fuel rods because it lets most of the neutrons through.
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Neutron activation and a melt down have nothing to do with each other.
Would I be willing to live next to a fusion reactor? Sure.
Current technology? No. You can't. They are far away from habitated areas for a reason: neutron flux.
There is a reason why the reactor gets evacuated and the scientists are underground during experiments: neutron flux.
The biggest concern is a tritium leak, but tritium isn't very dangerous, dissipates rapidly, doesn't bioaccumulate
No it is not. It is a GAS. It is more or less the w
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Add to this the half lives of neutron activated materials are all short. They are mostly measured in days and hours. It's not like fission where many of the half lives are measured in centuries and millennia. Basically decommissioning for a fusion power station is turn it off, wait say 20 years and dismantle like anything else with no precautions.
So with the chance of anything going wrong leading to external contamination somewhere around Ä, other than I expect a fusion power station to be nosy like an
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Until someone actually builds the first fusion plant. Then the flat-earth lobby will find reasons why this tech is the most horrible idea since Jenner invented vaccines.
Fortunately these will be built in China, so there will be nothing the hippies can do about them.
Minimal dangers (Score:2)
Fusion reactors are still generating neutrons.. activation is still a problem. There must be at least some radioactive crap that can leak out and make the evening news.
There is some but it's far less of a problem [wikipedia.org] than with fission reactors. The half lives of the waste products are short and there isn't much high level waste to begin with. In the event of problems the reactor shuts down almost immediately and there is no residual heat to cause the sorts of problems we see with fission reactor failures. Additionally fusion reactors do not contribute to weapons proliferation either. Basically fusion power is pretty much the holy grail of power generation if we can figure
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There must be at least some radioactive crap that can leak out and make the evening news.
Then here come the hippies.....
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Office Temp (Score:5, Funny)
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Some of the researchers still felt it was too cold in the office and would prefer to bump up the thermostat a little more
Actually they tried to make it too cold, but the temperature was an unsigned int and it wrapped.
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You could do that with early PC flight simulators. Get a fast enough clockwise roll on your fighter plane, and after a while, it would start rolling anti-clockwise. Always wondered if that would happen in real life.
Sun's core too cold for fusion, sort of (Score:5, Informative)
The protons in the core of the sun are in a temperature distribution, like a bell curve, and the average of this bell curve is way to cold for fusion. The only reason fusion happens is there are so many protons, a very few have freakishly high temperature way up the high end of the bell curve. Only those statistical outliers are fusing.
Re:Sun's core too cold for fusion, sort of (Score:5, Interesting)
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Similar in that statistically unlikely things happen quite often with enough time or space.
The mean free path of a neutrino is calculated to be several light years through solid lead before hitting a particle.
However neutrinos are emitted by the sun so frequently and neutrino detectors are so large that we can detect them reasonably frequently.
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You could see that in the harbours close to the Arctic. The air would be below zero, but the water was still liquid. Little clouds of water vapour would form and float around the surface, looking like ghosts.
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The thermal energy produced per cubic meter in the core of the sun is comparable to a compost pile and less than per volume heat produced by a human. The Sun is just really, really big, so emitted light gets re-absorbed as heat, and even a relatively conductive material makes a decent insulator if thick enough. The slow fusion process of the Sun can get as hot as it does just because the heat is so well trapped.
On Earth, we are limited to only a couple meters of insulation, instead of 100,000s of km. The
Celsius? (Score:5, Funny)
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Real scientists use Kelvins, not C. But I can't be bothered doing the conversion right now.
Re: Celsius? (Score:2)
*replaces battery in your hp48*
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Re:Celsius? (Score:5, Funny)
You are quite right. 100 deg C = 212 deg F, therefore 100 mil deg C = 212 mil deg F. I salute your intelligence!
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You are quite right. 100 deg C = 212 deg F, therefore 100 mil deg C = 212 mil deg F. I salute your intelligence!
"mil deg"? Why do Americans have to invent new units/prefixes everyday? Now how do I know if "mil" stands for one thousandth or for one million? :)
I know, nobody uses the SI prefixes for high temperatures (have you ever heard of a kK or of a GK>), and we all like shorthands, that's why the scientific community prefers to use the electron-Volt. 100 million degrees (C or K) is about 8.6keV.
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You, sir, are no Farenheit:
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You failed basic science, physics and chemistry.
Caution: Urge to "Whooosh" rising!
Still useless for energy production (Score:2, Interesting)
I'm afraid that all deuteriam and tritium based fusion reactors rely on fuel that is in extremely limited supply, especially tritium. Since the main source of tritium on Earth is nuclear decay from fission reactors, if there are enough fission reactors to generate enough of the very inefficiently used fusion fuel to generate significant, they can generate many times more energy from the fission reactors without having to engage in dangerous refinement of the tritium.
It's theoretically possible that thallium
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Energy generation is not the point at this time. The point is creating and maintaining the plasma and 10 seconds is pretty impressive at this stage for Tokamak.
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I agree that the physics is interesting. But the eagerness, and much of the fiscal support for fusion, has been based on the expectation to produce energy with it. There are some more viable approaches. Thallium fusion at least makes more economic and therdynamic sense: it seems possible to recover more energy than is used to create the reaction, and the fuel is far more plentiful. And technologies such as orbital mirrors seem viable to harvest similarly or even larger supplies of energy with less concentra
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What is this "thallium fusion" of which you speak? Or was that a typo, like the word "therdynamic" in your post?
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Oh, my. That _was_ a mistake. I meant boron.
A fusion reactor will generate its own Tritium (Score:3)
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Umm.. if you get a fusion power plant going, that's a great achievement. You can then look for one that runs on easily available fuel.
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The possibilities already exist, in physics and in resources, for thallium to provide fusion power. I was quite startled to learn this, it gets little attention compared to hydrogen fusion.
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You can get all the tritium you need by capturing Spider-man alive and giving him to Harry Osbourne.
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I'm afraid that all deuteriam and tritium based fusion reactors rely on fuel that is in extremely limited supply, especially tritium. Since the main source of tritium on Earth is nuclear decay from fission reactors, if there are enough fission reactors to generate enough of the very inefficiently used fusion fuel to generate significant, they can generate many times more energy from the fission reactors without having to engage in dangerous refinement of the tritium.
The plan is for tritium to be bred from fusion reactors when they are actually working in a commercially useful manner.
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One can, indeed, buy heavy water, the economic and thermodynamic cost of refining it is large: it takes more power than the fusion reactions produce until and unless they become _profoundly_ more efficient, and the energy cost of refining deuterium is rarely factored into the "break-even" point of fusion power. The cost of refining the tritium, and the economic costs of refining a toxic, very radiuctive, chemically reactive gas is also not factored in.
It is, possible to for neutrons from fusion reactions t
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This would also keep thallium out of the hands of serial killers:
https://www.theledger.com/arti... [theledger.com]
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What about H3? I've been hearing for years that we can get that from the moon. Where the stuff is supposed to be just laying around by the truck load tor the taking?
Not hot enough (Score:2)
One fusion dirty secret is that it produces neutrons that cannot be confined by electromagnetic fields, because they have no charge. They will damage the reactor, and the only way to get rid of them is to use some a-neutronic fusion reaction such as hydrogen+boron.
But hydrogen+boron fusion require much more input energy than hydrogen+hydrogen. Is 100 million degrees hot enough?
Aneutronic fusion may be impossible to sustain (Score:3)
Proton-boron fusion requires temperatures 10x higher than D-T.
What's more, because of the higher atomic number for boron, Bremsstrahlung radiation will cool the plasma (if it's thermal) faster than the fusion reactions heat it.
If the plasma isn't thermal, it's actually really hard to keep it nonthermal (entropy tends to win very quickly.) So it seems to me that aneutronic fusion reactions are hopeless for a plasma where losses due to Bremsstrahlung are larger than the fusion power will be.
--PeterM
No bias here (Score:5, Funny)
While the U.S. is putting new restrictions on nuclear technology exports to China
How about instead, saying "While China is repeatedly caught attempting to steal nuclear technology from the United States"...
OK, and a linked article bashing Trump admin policies based on testimony of officials who briefed New York Times journalists under condition of anonymity? Yep, this is without question legit and unbiased.
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How does putting export restrictions on nuclear technology to China prevent China from stealing it?
Aide from anything else if they were minded to steal it they could just get it from the US direct or from other countries it gets exported to.
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How does putting export restrictions on nuclear technology to China prevent China from stealing it?
It'a not stealing if they use technology that we have no interest in developing.
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How about instead, saying "While China is repeatedly caught attempting to steal nuclear technology from the United States"...
But what would the point be? I mean industrial espionage has been a core part of every major nation since industrialisation. What purpose does it serve to point out the obvious?
But since we're talking nuclear I have a better question for you: What's the purpose of nuclear technology for a nation if all you do is build weapons with it. Knowledge doesn't benefit you without the application of that knowledge. And in other news the world's first Westinghouse AP1000 reactor is now online ... in China.
But how much is that in electron volts? (Score:4, Interesting)
China's Fusion Reactor Reaches 100 Million Degrees Celsius
Plasma energy sounds really large when you express it in temperature. But a more convenient gauge may be the voltage needed to accelerate the particles to velocity magnitudes correspondng to that sort of energy. This is also directly applicable to fusion systems, such as the Farnsworth-Hirsch or Bussard's Polywell, which use electric fields to accelerate the particles into the reaction volume.
Both electrons and hydrogen nuclei have a charge magnitude of 1, so dropping them across a potential difference of N volts adds N electron volts of energy to each particle. Then, if you let the plasma thermalize to a Maxwellâ"Boltzmann distribution, the electron temperature will be (by definition) the temperature of the distribution is about 2/3 that corresponding to the average electron energy.
So to go from degrees Celsius degrees (of a thermalized plasma) to electron volts: .003% drop in the bucket. (Kelvin step sizes are the same but Celsius starts at 273.15 Kelvin.)
- Subtract 273.15 - a
- Divide by 11,605 to get electron volts.
- Multiply by 2/3 to get the average energy of the electrons and ions.
That's an acceleration voltage of 6,025 volts (or 9,037 if you're going to react them before they thermalize). That's right in the ballpark for high-end vacuum tube technology - like the second anode on a CRT. (Those ran about 3000 to 6000 V in the 1940s, and about 25,000 V when modern color tubes were being replaced by flat panels.)
You can see why we all had high hopes for things like Polywell, where (if it worked as expected) a "gassy vacuum tube" that would fit in a strip-mall store's back room, with all supporting equipment (mostly mid-20th-century style electronics), and provide 100 MW of DC at cross-country power line voltages.
Of course many of the other methods for directly heating plasma heat the electrons much more than the ions. So the average energy of the plasma may be substantially lower.
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It is around 2 electron volts.
No, it's in the 6 thousand to 9 thousand eV range. See the end of the grandfather post.
General Fusion - Liquid Metal Containment (Score:2)
There is a company called General Fusion http://generalfusion.com/ [generalfusion.com] that is attempting to use liquid metal fusion containment. Sounds very cool, in an almost steampunk sort of way. Being a physics noob, I'm wondering if anybody who actually knows this stuff can comment on whether or not their idea makes any sense?
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The one run by a guy who used to make bits for laser printers?
Yeah, I wouldn't hold much hope.
He may be way more qualified than I could ever be, but it just sounds like a PhD with an idea to me. There are literally millions of those kinds of people round the globe, and he hasn't really shown anything special or different.
Hell, his Wiki article still harps on about some amazing micromirror thing that would revolutionise the telecoms industry which he seems to have just... done nothing about.
Would trust this
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ITER wont produce power (Score:5, Interesting)
It will run at 400 - 600 seconds and will produce more energy than it consumes, that is all. There is no power plant attached nor will there ever be: https://www.iter.org/sci/Goals [iter.org]
And the power production is not clean as long as we use deuterium + tritium, the reactor vessel will have to be replaced around every 10 years and discarded as highly radioactive waste.
Regarding sustainability: ITER will attempt to breed tritium ... lets see how good that works. Otherwise we had to farm tritium from the sea, which is energy intensive and causes another spot in the chain to work with an radioactive element.
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Well duh ITER is not a power plant that is DEMO.
Sure the lining of the reactor vessel might need replacing depending on what ITER is able to determine (one of it's goals is investigation of the lining for the reactor). However once it is taken out it can be stuck in a warehouse for ~20 years then recycled. Sure it might be highly radioactive but the half lives are basically all short on a human time scale unlike fission reactor waste.
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Yeah but we have... Clean Coal! Take that... (Score:3, Funny)
Pleased (Score:2)
Pleased to observe that I am not on the opposite side of the planet to China if that stuff gets out of control.
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Re:Really hot! (Score:5, Informative)
To sustain enough steam to power the world you would need, not unsurprisingly, the entire world's current supply of oil, gas, nuclear fission, solar, wind, hydro, etc. Because... that's pretty much what we use it to do (I'm excluding all losses here, for simplicity).
One you achieve fusion, you can literally power the entire world from 867 tonnes of hydrogen per year. That's maybe a shipping container full of hydrogen. Something we can pull out of the ocean.
For reference, we would need to burn 12 billion tonnes of oil, 10.4 billion tonnes of gas or even 7000 tonnes of uranium to do the same.
Pretty much the only thing more powerful is complete utilisation of E=mc^2 - merging antimatter and matter and capturing the blast. You'd only need 3 tonnes of antimatter to power the world in that instance.
https://www.forbes.com/sites/s... [forbes.com]
Fusion, if it can be made to work, could power the entire world from one power station. Of course, that's not what would happen - we'd just end up USING UP all that energy and every country would have half a dozen of them. We'd end up synthesising rare materials and doing all the things we can't currently do because of the sheer amount of energy they require, rather than actually just settle on current usage coming from one place.
But it literally is an order of magnitude more energy than the nuclear reactors we have now, which are orders of magnitude more energy than even coal and oil, which are orders of magnitude more energy than anything else.
And it looks like we could viably do it inside the next century or so.
With that amount of energy, you could easily obliterate the planet, or fire things into space like they were paper planes.
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Not the first to reach that temperature (Score:3)
100 million degrees is a record for plasma, perhaps. If it proved that reaching 100mK was possible, it's only in the tokomak design, because the Z Pulsed Power Facility achieved 1 billion K in 2006!
it's not about temperature but how long (Score:2)
It's a great achievement, not doubts, however the problem with fusion is to control plasma long enough to have sustained reaction, thus getting netto energy surplus.
At the moment the biggest problem is that plasma leaks through magnetic confinement dropping temperature and shutting down fusion, and short bursts of fusion require more energy for heating plasma than one gets back.
The ITER (international tokamak project) aims at breaking even, there are also other approaches, for which major players are:
- s
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Myself, if I had to make a guess, I'd pick something like the Polywell design: https://en.wikipedia.org/wiki/... [wikipedia.org]
But then, I was largely persuaded by some snark from Bussard: https://www.youtube.com/watch?... [youtube.com]
Paraphrasing from memory, his line goes something like: "We've spent billions of dollars researching Tokamaks and what we've learned is that Tokamaks are no damn good. Even the people working on them will tell you that they're never going to work, but they say the physics is really good. They're l
Re:Apparently not (Score:4, Funny)
Also I'm pretty sure the Sun, which is considerably cooler than this, is producing more power than it absorbs.
Gravitational plasma confinement/optical density (Score:5, Informative)
The Sun can be cooler because it has a couple of things going for it: it's optically dense and gravitationally confined. That is, the core is SO big and SO dense that radiation doesn't just leak heat out into space. So the plasma doesn't cool down immediately. Also, the plasma density is maintained by the weight of all the mass of the rest of the star.
Lab experiments, and in fact any plasma on earth, have neither of these advantages going for them.
That is why the Sun can maintain its fusion reaction and why it is so hard to create fusion on earth.
Re:Gravitational plasma confinement/optical densit (Score:4, Interesting)
My understanding is that the energy output, per cubic meter, is about the same as the human body, 50-100 watts or whatever. Just that there are a lot of cubic meters in the core of the Sun, so it adds up. As the AC says, proton-proton fusion is slow, even at the pressures and temperatures at the core.
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My understanding is that the energy output, per cubic meter, is about the same as the human body, 50-100 watts or whatever.
Humans output around 100 watts abut are somewhat less than a meter cubed (we'd weigh about a ton at that size). Human power density is more like 1000-1500W/m^3, so we have about 10x the power density of the sun.
Re: Gravitational plasma confinement/optical densi (Score:2)
Humans... are somewhat less than a meter cubed
This confirms why Oklahoma always felt like The Twilight Zone: most of 'em aren't human.
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Even better, the GP's values are wrong. The sun has a power density of around (3.846E26 Watts / 1.4E27 m^3) = 0.27W/m^3. Humans are thus nearly 10,000x more energetic than the sun per cubic metre
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Generally when people are talking about the Sun's power density, they are talking about the region where fusion actually occurs, in the core, not the entire visible sphere, which is the number you are using. That would be a bit like talking about the energy density in a tokamak by averaging the power output over the volume of the entire tokamak structure rather than just the actual fuel confined in the magnetic field.
The Solar core is 19% of the Solar radius, and thus the energy density in the core, where f
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Also you are rating the human metabolic rate about a factor of 3 too high, is is about 1000 W/m^3, so the ratio of heat output per unit volume is 25 times higher for humans. But the density of the solar core is 160 g/cm^3, so the energy output per unit mass in the Sun is 6 times higher than in humans.
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They achieved the temperature required to maintain a reaction above energy break-even, but likely they could not maintain it because of instabilities.
As an AC poster suggested, there is more than one criterion for maintaining a fusion reaction.
Re:Apparently not (Score:5, Informative)
Not just instabilities, but lack of a mechanism to capture and feed the excess energy back into the device, which was not a goal of the experiment.
Re:Apparently not (Score:5, Funny)
Advice: don't study science. With your deep, keen insight you'll a be natural for sanitary management.
Re:Apparently not (Score:4, Interesting)
They keep running into problems. I've read a few papers, and they would hit problems such as the metals used weren't strong enough to withstand the magnetic fields they were generating. That was fixed. Then the plasma rings would start to twist, buckle, warp and pinch into singularities. Stellerators fixed that problem by putting some torsion into the plasma rings. Tokamaks fixed that problem by adding extra magnetic field randomness or something to break up the standing waves. That fixed that problem. Then the neutron bombardment started poking holes in the metal structure, which weakens it over time. Maybe that has been fixed, but it keeps going round and round.
Re:Apparently not (Score:5, Insightful)
It isn't going "round and round" it is going forward, step by step. Each issue that is solved is one less issue. There have been at least 226 tokamaks built to date, and each one advances knowledge about some aspect of design and operation. That is how extremely complex systems are developed. There is a lot of work to be done to build and operate the first true break-even tokamak -- about 20 years and $20 billion worth.
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So what you are saying is sustainable fusion energy is about 20 years away? Wait...I feel like I've heard that before...
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My point is not that I would expect a fusion experiment to instantly produce viable energy output... if they haven't gotten it to self-sustaining levels yet, that's to be expected. I would, however, think that would still be the entire initial goal, and I would have expected that right out of the starting gate they'd be siphoning off as much power as they could into keeping the reaction going until they were able to get enough to keep the reaction going, and anything over and above that, if and when the
Re: Apparently not (Score:2)
Plasma is unstable. If it's not held at suitable density under suitable conditions, it will tend to pinch off. That is the problem. Nothing to do with energy.
Re: Apparently not (Score:2)
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Projects like ITER exist primarily as a bypass of NPT restrictions. They were never about producing electric power or seriously advancing technology to eventually enable that outcome. It's an expensive tax payer funded scam.
Because the people who dispense multibillion dollar research grants are more easily scammed than some random Internet AC.
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Great! So soon I can get my Chinese takeout much faster, right?
I'm thinking a really fast pizza oven. Why settle for dirty old coal-fired pizza, when you can have fusion pizza!
Re:Great! (Score:5, Informative)
So serious question: how many oceans will that boil? It's one thing to have the moon that hot, it's another to have the head of a pin that hot. Or are the just going after temperature quantity rather than size/mass?
You're on the right track. Temperature != Heat. The plasma in the outer magnetosphere of the earth has a temperature of thousands of degrees kelvin, but it doesn't melt a spacecraft that's in it. Why? It's sparse. The average kinetic energy of particles in the plasma is high (i.e., high temperature) but the power per unit area that strikes the spacecraft is very low.
That being said, the plasma inside a Tokomak can certainly melt something. That's (part of) why there is so much effort put into magnetic confinement.
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Correct. Temperature != Heat Capacity. Thanks for the improvement.
Re: Great! (Score:2)
They're trying several methods. Laser fusion is one, the Chinese reactor is another.
Find out the specific heat of materials to calculate temperature of one given the temperature of the other.
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They're trying several methods. Laser fusion is one, the Chinese reactor is another.
"Laser fusion" is dead. The actual general technology is properly known as inertial confinement fusion (ICF) and lasers are only one possible method of providing the driving energy.
The original ICF idea of direct drive laser fusion is completely dead - it does not work. All ICF schemes now use indirect drive, using an external energy pulse to create thermal X-rays inside a little metal capsule (hohlraum) which then drives the implosion. You don't necessarily need lasers to provide that energy pulse, particl
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Yes,the catch is:
they want american funding and like to attract european and american PhD students to their facilities (*facepalm*)
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Sigh.
It's to do with the bonds between the parts of the nucleus, and the conversion of mass to energy.
If you take a bunch of 1 proton (Hydrogen) atoms which have
one or two extra neutrons (Deuterium, Triterium) and smash them together you will form an atom with more protons (Helium) and no neutrons, and get a bunch of "spare" neutrons which are either a) obliterated or b) ejected.
E=mc^2. A neutron worth of mass converted to energy is an awful lot.
In fission, you do something different. You take U2
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