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China to Build World's First "Artificial Sun"
cletuii writes to tell us the People's Daily Online is reporting that China is planning on building the world's first "artificial sun" device. From the article: "The project, dubbed EAST (experimental advanced superconducting Tokamak), is being undertaken by the Hefei-based Institute of Plasma Physics under the Chinese Academy of Sciences. It will require a total investment of nearly 300 million yuan (37 million U.S. dollars), only one fifteenth to one twentieth the cost of similar devices being developed in the other parts of the world."
But Japan is land of the rising sun!
Isn't this how it works in the US too?
-Disgruntled Grad Student
"What could possibly go wrong?"
Dr. Otto Octavius recently filed suit against the government of China, damn USPTO lets you patent anything these days....
Wikipedia has some info about Tokamak reactors, and fusion power in general. I still don't get it ;)
The article says that the reactor "aims to generate infinite, clean nuclear-fusion-based energy".
.. anyone else a tinsy little bit worried about that word "infinite"?!
Infinite energy?
Uh
I don't know how much longer the real sun's going to last. I mean these days it seems like half the time it's not even up there.
My Greatest Heist - Muisc partly inspired by the unbeatable Qwantz
See also the Joint European Torus, the largest nuclear fusion reactor yet built, and ITER, the international attempt to build a much bigger one.
They are building an experimental fusion reactor, a Tokomak. While I suppose you could call it an artifical sun, I think a better choice of words would be tokomak or fusion reactor.
On another note, this is not a one of a kind device. Europe has one called JET, and is planning on making another, ITER.
If you are about to mod me down, keep in mind that this post was most likely sarcastic.
we have these already, they're called LIGHTBULBS.
When your dad was a kid the Soviets were still offering free delivery of their fusion devices to US cities. Nowadays fusion isn't as big a deal at the DoD, which means fewer resources and slipping goals.
Is China getting a civilization advance for this, or can they update all energy units for half the cost once this is complete? Mr. Chairman! We have completed a great wonder...Artifical Sun
Because there's no theoretical reason it can't work, and whoever doesn't need oil first wins?
Send lawyers, guns, and money!
No. The produced Helium in the Tritium-Deuterium reaction slows it down until it stops. In fact one of the problems of fusion with a tokamak is to get the helium-ash out of the plasma.
We can finally outsource global warming!
Since, with clean power, we wouldn't need oil from the Middle East, we could get out of there and terrorists would lose interest in the US.
Let's be clear about one thing: we already have a nearly unlimited supply of nearly waste-free nuclear power in the form of breeder reactors: they destroy most of the radioactive waste and are at least an order of magnitude more efficient than current nuclear power plants in using nuclear fuel.
Why aren't they being used? Hard to say. The US claims it's because of nuclear proliferation, but that doesn't seem like a particularly strong argument. In light of the hazards of current fission reactors, and the difficulties of achieving fusion, maybe that's the third option.
Of course, the best solution would be to stick with the fusion power plant in the sky: it provides more than enough energy for our needs, with current technologies, if we only made a concerted effort to capture it.
You're the asshole who starts talking politics in the middle of every discussion, aren't you?
Example from your life:
Coworker: So I started talking to this hot babe at the bar yesterday, and we were really hitting it off...
You, interupting: Bush wants to take away her voting rights and chain her to the stove!
Alcohol, Tobacco and Firearms should be the name of a store, not a government agency.
The article glosses over a few important details, such as the fact that it's highly unlikely it will be able to produce more energy than it consumes. Thus while it might be able to use seawater to produce 300 times the energy per volume of gasoline, it probably takes about 3,000 times as much energy to extract the deuterium and generate that energy (the bit about getting the core temperature up to 300 million degrees is telling).
Especially if they're only spending $37 million US. I'd expect research and development costs to be at least 1000 times that. Of course, the article is too light on details to even begin to understand what the hell they're talking about.
"No problem. I have the capacity to do infinite work so long as you don't mind that my quality approaches zero."-Dilbert
There are no free lunches especially when it comes to nuclear engineering/physics. The promising thing here is that you have the potential to have a much higher power density and cheaper fuel since deuterium, in the form of heavy water recovered from the ocean, is not exactly hard to come by. Desalinization followed by reduction of the water to hydrogen and oxygen and then just gather ye heavy hydrogen in the form of deuterium and tritium. Heck, if they don't use the tritium in the reactor, even though it is a fine lower temperature ignition source, they could always sell it on the open market. It's quite valuable on its own.
"[I]t is a wise man who admits the limits of his knowledge or skill, and that pretending either causes harm." --Terry Go
Worst cases I can think off. Mind you, I haven't studied fusion reactor disasters, yet. So I could be wide off. However, it is my impression that not many people are worried about this. And that what I write down here is the prevailing knowledge. I have a masters degree in physics and worked on a tokamak for my masters thesis. For my PhD, I will be working on plasma's within a few weeks. So, that you know, I am not a crackpot scientist. English is not my native language, have patience.
You fill the reactor with as much fuel as you can, and you keep the machine going (i.e. you keep the magnetic field lines on, so that the plasma is confined and fusion reactions are going on.). Once enough fuel is inserted and energy is build up, you get an hydrogen bomb. An hydrogen bomb requires a classical fission bomb to get temperatures high enough so that fusion starts. But this can not happen accidently. In other to use a fusion reactor as a bomb, you intentionally have to add fuel to get it that far that it will explode. Any fusion reactor will have safety mechanisms. Now such things can fail. But since the fuel is sitting outside, safety systems can be designed that no fuel is inserted unless the operator (assisted by a computer) authorises fuel injection.
Contrast this to a fission reactor (the ones in operation now). All the fuel is present inside the reactor. The only thing operators can do is manipulate the burning rate. When something fails here all the fuel just keeps burning.
If something goes wrong in a fusion reactor, the reactor simply has to burn out. This happens rather quickly. there is no need to keep fuel inside that is needed more than for a minute or so. (Don't know how much or how long, just below the critical value for a explosion.) Fission reactors have fuel rods inside that lasted for years. Fusion reactors can be designed that fail safe means that no fuel is injected. You have to override such systems just to inject fuel, just to keep it going. In fission, fail save means that carbon rods are inserted between the fuel rods and you hope/pray that the fission reactions stop.
Okay, so what happens when everything goes wrong. No extra fuel is injected and the operators are no longer in control of the machine. It can not explode because there is not enough fuel inside. So forget Chernobyl and TMI. This means that everything outside the building is safe.
So, it can not explode. That leaves radiation. These are neutrons, gamma's (high energy light waves), high energy particles (alpha's mostly). There are other particle inside a reactor than alpha particles. Alpha particles (20% of the energy of a fusion reaction, 80% goes into the neutrons) are needed to keep temperaturs high. But this needs to be supplemented by external energy sources (another fail save, stop injecting energy.) Now these other particles, such as helium (this is the waste from fusion reactors. Even the waste has high economical value ! ) and carbon (eroded from the wall) have to be continually extracted from the reactor because the are bad for maintaining the required temperatures and energy levels. Alpha particles are stopped by a piece a paper. Don't worry about them. The neutrons are needed to generate tritium (tritium is radioactive, I think it has a 20 minute halve life inside the human body). But tritium will only be needed in the first few generations. Because using tritium is the easiest way to get towards a working fusion reactor. So the neutrons activate the reactor and the reactor will be stored for 50-100 years as high radioactive waste. Strontium, as you mentioned, although present in carbon and a waste product of coal plants is not present in fusion reactors. So these neutrons hit the wall, generate tritium and heat the wall/water in pipes and exit the chamber. (the water inside the chamber wall is the first water pipe system and generates steam in a secondary pipe system. From here you have a classical power plant of any kind.) Blocking those neutrons coming from the reactor chamb
Councilor Hart, it is posts like yours that have kept me reading slashdot, and enduring (and eventually coming to cherish, to a degree) it's many and various quirks.
I don't really have any way of knowing that you are who you say you are, or verifying that you know what you say you know, but assuming that you are and you can (respectively), I'd like to tell you that you rock! That was the best explanation of a complex subject to a mostly layman audience I've read in a long time.
[Posted AC so I don't get a reputation for being complimentary to people]
if a fusion reactor lost containment and went kaboom
What do you mean by losing containment?
If the chamber bursts, the plasma comes into contact with the outside world. Everything in reach of the plasma is going to have a lousy day, but there isn't an explosion. Also, such an environment isn't exactly beneficiary to fusion reactions.
If the magnetic fields disappear, the plasma comes into contact with the wall. Again not very positive, for the wall and potentially for everything outside. Again, something which doesn't exactly promotes fusion reactions.
The only way, as I see it, for such a reactor to explode is to maintain confinement and keep adding fuel and fuel until it explodes.
An explosion is a lose of containment, but lose of containment doesn't imply an explosion.
In my other post, I did forgot to mention x-rays. But I have no idea about the amount of x-rays produced in a tokamak or in case of failure or the effect of it on humans, so I won't comment on that.
As to the radioactive particles from fission. It's the short lived ones that are dangerous, not the ones that are stable for a few billion years. Heck, we are living in a world filled with particles that have a 4+ billion years half live. Everything else has mostly decayed and disappeared since Earth's formation.
A magnetically confined fusion plasma is a very tenuous beast. If all operating conditions are not satisfied, the background plasma requisite for fusion will not be created -- and if you go from 'good' to 'bad' operating conditions, the plasma snuffs itself out on the order of a confinement time (several milliseconds depending on device parameters).
has any scientist working on such a reactor deliberately simulated a total containment field failure?
Sure -- in modern research devices these failures happen for a myriad of reasons. Disruptions have happened a lot in the course of this research. On current devices, a disruption can be a 'no big deal' operation or force repairs; on a fusion reactor they really need to be avoided. Fortunately, the cause of showstopper disruption events are well known and techniques exist to stay away from the region of parameter space that causes them! There are also techniques to mitigate disruptions from unexpected failures (PDF warning).
think a popcorn kernel what happens when it reaches the right temperature? *pop*
There's a difference between temperature and energy density. For instance, if you blow out a candle you can snuff out the glowing wick with your fingers without burning them -- despite the wick being around 1000 K. The reason is that the candle wick doesn't have much energy stored inside. The same goes for a magnetically confined plasma. While the plasma has a very small tail in its energy distribution which allows thermonuclear fusion, the stored energy in the plasma itself is insufficient to, say, melt a building and set off an incindeary firestorm.
Disclaimer: I am a plasma physicist working in the magnetic fusion arena.
I do not think this word means what you think it means.
"Disclaimer" here means "take this with a grain of salt; I might be biased." Now, if you weren't actually a plasma physicist--say, if you were a gardener--I could see adding a disclaimer. But since you are a plasma physicist...
i'd hit it so hard, if you pulled me out you'd be the king of britain [bash.org]