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First Plasma on the Levitated Dipole Experiment
deglr6328 writes "In light of recent, somewhat disappointing news in the world of nuclear fusion research, it is worth noting that there are still reasons to keep up hope that some breakthroughs are yet to be made. At 12:53 pm on the 13th. of this month the Levitated Dipole Experiment achieved its first plasma. The Levitated Dipole Experiment(LDX), built at MIT's Plasma Science and Fusion Center as a joint project of Columbia University and MIT, is a magnetic confinement fusion research device, that unlike all previous stellarator, reverse-field pinch and tokamak like experiments, uses a superconducting levitated torus to confine its plasma. The LDX's achievement of first plasma is, in a way, about 17 years in the making even though it has only been in construction since 1999. The concept for LDX was first considered by Akira Hasegawa as he was studying the data coming in from the Voyager missions which flew through the (dipole) magnetospheres of the outer planets. He noticed that unlike laboratory confined fusion plasmas which tended to be unstable, difficult to control, and which lost energy quickly, the plasma of a magnetosphere is intrinsically more quiescent, stable and actually reacts favorably (increases its density/temperature) to outside perturbations such as ie. bombardment by a solar storm. A highly informative and interesting video of operations on the day of first shot can be found here. Congratulations to the scientists and engineers who have worked very hard on getting the project to this point and here's looking forward to the possibility that LDX will reveal fundamentally new physics in the arduous quest for clean fusion energy."
-- Still waiting for the Nike endorsement
Exactly. Groups like Greenpeace are so informed and ignorant they are hindering clean cheap energy. The amount of radioactive waste put into the atmosphere by coal is much greater than nuclear fission. Fission is clean and a lot more abundant than coal or oil. It will take some time but we should be gearing up for a hydrogen economy where hydrogen gas is used in everything from cars to cell phones. The hydrogen can come from nuclear power plants.
Call me crazy, but I think this is a good solution.
So we don't turn the server into plasma, here's a mirror of the video:
http://razor.csbnet.se/First_LDX_Plasma2.mov
Thank you for seeing that. Uranium is in the coal and it goes into the atmosphere when it's burned. I didn't know this was such a "secret".
Absolutely arrangement is important. If it wasn't, nobody would ever die. But it being important doesn't mean it's the sole distinction between living and non living matter.
I are winner
So then the phenomenon of life is merely a complex arrangement of atoms and nothing more?
We have no reason to believe otherwise.
Fission itself isn't bad, but you have to trust the people designing it handling it, and that is where the problem lies. The Soviet reactors used a bad design and the population suffered for it.
Also, fusion isn't totally radiation free. Disposing of the liners for the current fusion reactors is expensive because they got charged with neutrons that escaped the reaction. This radiation is part of the problems that ITER tries to solve with different choices in liner materials and other shield materials.
Ever heard of muon catalysed fusion?
They've actually got it working. They just can't get breakeven yet.
Many people fail to realise that the 'laws of entropy' aren't laws, they're statements of statistical likelihoods. Entryopy can spontaneously decrease, its just incredibly incredibly incredibly unlikely to do so by any statistically significant amount. ... jump one foot to the left.
But in this case entropy isnt realy relevent.
If you want every partical in your body to simultaneously 'jump' one foot to the left. All you have to do is
Sigs are for wimps. I am proud to be one.
In the case of LDX, however, tritium is completely unnecessary for operation, as it makes use of the Deuterium-Deuterium reaction.
And there's a lot of Deuterium in the oceans. I believe the estimate is that we could run our entire civilization off of the Deuterium present in just the first centimeter of the oceans for one or more years. And we'd put most of that water back, so you don't even have to worry about the oceans being taken away from all the little fishies. :-)
You would be referring to the David-Besse plant, not the Perry plant.
:) Try to remember that dying from a nuclear plant accident is orders of magnitude less likely for anyone on the planet than even dying from lightning - even if you are a golfer :)
It wasn't a "hole" it was a crater and pitting from boric acid leakage that damaged the reactor vessel. According to some other articles I saw in a quick Google search, they have a emergency sump system that would recirculate any coolant that leaked thru that hole back into the reactor - there would have been no meltdown *
The boric acid was stopped by a stainless steel outer layer that was another of the layers of defense. It could have eaten thru that, too, but it would have taken many years, many more than elapse between the regular inspections (AMAF it was when the plant was taken down for refueling - which happens pretty seldom - that they discovered the damage) and this was a *very* unusual accident, one which has prompted a considerable amount of redesign. Note that David-Besse and similar plants are also very old designs.
*NO* power production system is safe. NOT EVER. But fission plants have a much better safety record than any of the others do, which was drinkypoo's point. Look at the coalmine disasters, natural gas production facility disasters, and other dangers we face from "conventional" energy production. Even including Chernobyl fission has killed or injured FAR fewer people and environments than any of the other technologies.
Anyway, try to make an effort to get your facts straight and read about the events you describe before fear-mongering. If nothing else it helps other people take you seriously.
BTW, I lived near and got power from a fission reactor for twelve years out of my life. Never bothered me nor any of the people who lived there, either. Of course we Minnesotans know that our winters are much more likely to kill us than a power generation plant is
* Although there is a question of whether the filters in the emergency coolant containment system could have clogged, this problem is being addressed and has already been fixed in many plants - this according to info that's already fairly old and fixes have been implemented.
Cheers,
SB
It's old. The more humans I meet, the more I like my cats. At least they are honest.
OK, I'll bite (I am a chemist :-).
Those guys indeed knew how to use their calorimeter, but they did not concern themselves with any other part of science, and, hence, in the interpretation of their measurements (not in the measurement results per se) they have made several trivial mistakes. Sadly, that is the way many scientists who are in possession of some exotic/expensive piece of equipment behave. I've seen it many times.
Now about cold fusion... Unfortunately, it is physically impossible, and for a reason. The Coulomb barrier to bring together 2 hydrogen nuclei is enormous, and it is the reason why 10^6 K (or maybe even hotter) temperature is normally needed to start the reaction. At more human conditions, nuclei could, of course, tunnel through the Coulomb barrier and fuse as much as they want. Problem is, this tunnelling is extremely slow (rate is actually easy to calculate - I think it will be in any college radiochemistry course), and it won't be sufficient to sustain the reaction, or even measure its heat on the macroscopic scale.
The mechanism proposed by Fleischmann did not take into account the extremely high activation energy for fusion. They did have a vague concept that there should be an activation energy, and that it is probably high, but they did not realize how high it is...
Actually, they typically do the opposite: they have the cadmium "control" rods get lowered DOWN into the reactor. Cadmium absorbs neutrons, so if something goes wrong, they just drop them and the reaction stops in a fraction of a second.
Not that this makes everything safe. Read the report on Three Mile Island sometime. It's long, but it's a fascinating read.
http://www.fas.org/man/dod-101/sys/missile/row/shk val.htm
Here's a review of the most recent book I've read on the matter, and it hammers rather hard on Pons, Fleischmann, and particularly Bockris at Texas A&M: http://www.findarticles.com/p/articles/mi_m2843/is _n3_v18/ai_15383317
Got mead?
Without a plentiful source of water, there wouldn't be a good way to cool a power plant in the desert. That's why so many of them are built on prime real estate on lake shores or rivers.
IANANP, BIWARPFMEAC*. I'd like to elaborate a little bit on this point:
Fission occurs when a heavy radioactive nucleus (in the control rods) absorbs a neutron and splits into two smaller nuclei and a few extra neutrons. These new neutrons can be absorbed by other heavy nucli, and more fission occurs.
Now most of the neutrons released move too fast to be absorbed by a nucleus; instead, they just bounce off. In order for a sustainable reaction to take place, a material - called the moderator - is required to slow down the neutrons so that they can be absorbed.
Most modern** nuclear reactors are pressure-water reactors. This means that they use water as both a coolant and as a moderator. If the water excapes, then the reaction fissles out.
However, Chernobyl was initially designed with a solid moderator built into the reactor vessel. (I think it was graphite, if I remember correctly.) It used water purely as a coolant. So when the coolant leaked, the reactor kept on fissing atoms and the reaction got out of control (although not fast enough for a thermonuclear reaction).
That wasn't the only problem. The reactor's personal paniced and tried to send the control rods in too quickly. While the control rods were halfway in, neutrons bounced into the bottom of the reactor and formed a critical amount for a chain reaction. At the same time, the heat of the reaction and loss of pressure from the origional malfunction turned the leftover water into steam pockets also in the bottom of the reactor. Soon after, an explosion ruptured the reaction vessel.
Perhaps the primary cause of the accident (and of TMI) was the confusing interface to the equipment! Some devices used red lights to signify emergency conditions, while others used green or another color. Instruments were hard to read and slow to respond. An ergonomical failure contributed to the accident.
Today, most control rooms have learned from the mistakes at TMI and Chernobyl. They are easier and more consistant to use. However, even more improvements are possible with new designs. It is a pity that nobody will allow the old workhorses ot be retired.
* I am not a nuclear physicist, but I wrote a research paper for my Engineering Analysis class.
** "Modern Nuclear Reactor" is somewhat of an oxymoron. Due to NIMBY feelings among the general public, most commercial nuclear reactors are old (60s-70s era) and modern designs are never given a chance despite the improvements in efficiency, safety, and (less) waste production. :-(
It is impossible to enjoy idling thoroughly unless one has plenty of work to do.
- Jerome Klapka Jerome
After producing two rings at the opposite end of a vacuum tube, they were guided by a magnetic field until they collided. At collision they repelled each other, and then were compressed. The rings heated up and stayed stable for 30 microseconds under compression ( which by plasma standards is a long time). The funding was cut off in 1978 because the concept was too far from the mainstream.
In 1999 John Brandenburg received a grant from NASA to move the experiment from Miami to Lanham MD (near NASA Goddard). He moved it and reassembled it, but never received an money to operate it. It stands gathering dust.
Right now, Paul Koloc is doing something similar in his garage, producing ball lightning ( a stable plasma structure that has been documented since Roman times). His project, Plasmak, has received some sbir funding. For more details on the Plasmak, look here.
From reading the white paper, I do not think the Trisops plasma is the same configuration as in the levitated dipole experiment. I do not have a clear idea of the structure of the Plasmak.
I list the Trisops papers below for anyone who wants to follow up.
Daniel R. Wells, Paul Edward Ziajka, and Jack L. Tunstall. Hydrodynamic confinement of thermonuclear plasmas TRISOPS VIII (plasma liner confinement). Fusion Tech., 9:83, 1986.
Winston H. Bostick and Daniel R. Wells. Azimuthal magnetic field in the conical theta pinch. Phys. Fluids, 6(9):1325, 1963.
"Simultaneous Electron Density and Ion Temperature Measurements of a Moderately Dense Plasma Using Doppler and Stark Broadened He-II Lines" (with others), Applied Optics (Letters) v 17, p1481, 1978.
"High Temperature, High Density Plasma Production by Vortex Ring Compression" (with others), Physical Review Letters, v 41 #3, p166, 1978. "
The Interaction between Two Force Free Plasma Vortices in the TRISOPS III Machine" (with others), Physics of Fluids, v 22, p379, 1979.
Tritium is rare, in the sense that it makes up 1 ppm of the hydrogen in the oceans. This has however proven to be a self-sustaining solar-powered equilibrium, ie. sea water will always reorganize itself to contain 1/1000 deuterium and 1/1000000 tritium. Which means we would have to use more power than the amount of solar power absorbed by the earth's entire ocean before we would even begin to see "squandered resources". So "artificial" fusion energy is in fact indirect solar energy.
"And you are dying so slowly, you believe to be living" - Bertrand Besigye
The problem with that is that muons are expensive to get, and the muons often end up stuck to the ash, so it's hard to recycle them.
I rarely criticize things I don't care about.
Generally speaking, catalysts might act in two ways:
*by lowering the activation barrier for the original reaction mechanism through selective stabilization of the corresponding rate limiting transition state
*by changing the nature of the rate limiting step (changing the reaction mechanism to something else).
In the case of a fusion reaction the presumed mechanism is very simple: two nuclei are being brought together, and once they are sufficiently close, we've got our product.
So our rate-determining transition state in this case will happen at the point of the reaction coordinate (in thisi case, our coordinate will conveniently be internuclear distance) where E=(E coulombic)-(E weak) has the highest value.
So, we might try to imagine a catalyst that stabilizes such a transition state sufficiently for the reaction to go at room temperature... And, unfortunately, such a chemical catalyst is impossible. And here is why. In order for the chemical reaction to proceed at room temperature at all, its energy of activation needs to be of the order of 30-50 kcal/mol at most (I could look up some of my old lecture notes for exact figures, but what's important here is the order of magnitude). Now, the activation energy for the hypothetical fusion process would be on the order of some 10^7-10^8 kkcal/mol (you can come to this number in two ways - either by calculating the molar coulomb repulsion energy, or from a simple Arrhenius equation and the plasma temperatures commonly found in tokamak experiments and on the Sun). So your pure chemical interaction free energy between your hypothetical catalyst and the transition state has to be of the order of 10^7-10^8 kkcal/mol! And this is just not possible with chemical interactions (i.e. those interatomic/intermolacular interactions that are only concerning the outer electron shells). For example, a very strong covalent bond might have an energy of about 200 kcal/mol - and that is as strong as it gets! A typical hydrogen bond is 5 kcal/mol.
Now, you might think of a catalyst that changes the mechanism of the reaction... But in case of fusion, no matter what you do, you have to bring your nuclei together. And there is no chemical force that is going to come to your rescue with 10^7 kcals/mol of free energy.
Those considerations (which I have simplified a bit since I hate long typing) are exactly the ones that were overlooked by the authors of the original cold fusion paper. Indeed, they have claimed that "strained" surface of their electrode was catalyzing fusion, but they had a very faint idea of the magnitude of the activation energy of the process and of the rate of tunneling through such a barrier. Any competent chemist or physicist, though, would be well aware of this - and that is why nobody wants to publish or finance cold fusion research. Just like you might have troubles to get a grant for a research program to disprove the atomic theory :-)
I have seen other reports of cold fusion based on cavitation experiments, and, IMHO, those are somewhat more credible at least in principle (since their authors do not claim any miracle catalysis, but "just" suggest that they are able to generate an appropriate local temperature for a short time). Of course, even if those experiments will ever reach reproducibility (so far noone has obtained reliable and beleivable results), they will have only a limited practical value...
For decades the threat considered most viable in the transportation of nuclear waste has been the green movement, not handling accidents, not terrorists, not even traffic accidents. Understand that greenpeace is a hinderance to clean energy and perhaps you might start helping to resolve the problem. Coal plants put out more radiation every day than three mile island ever did. We have coal power plants because it isn't feasible to build nuclear power plants (no plant has been built in the US since three mile island).
The hard reality is greenpeace is opposed to nuclear energy because it puts a positive spin on the word "nuclear" and greenpeace is vehemently anti-military. They would rather seen tons of radiation pumped out worldwide from coal power plants than to allow the word nuclear to lose it's negative connotation. It's a power trip on the part of greenpeace, nothing more, nothing less.
Fools
Greenies don't object to nuclear power on principle - the problem is safe transport and storage of fuel and waste.
Oh, that's just something they say to sound more rational. Now if you compare risks and accidents with conventional fossile fuel transportation such as oil tankers and gas pipes.. Suddenly carting around rather modest amounts of nuclear fuel/waste isn't such a big problem.
Don't forget that the amount of uranium required to produce equivalent energy as coal is less than 1/1000.
As for storage. those "rational" fears are that the containers buried into bedrock (done here in Europe) may be damaged by geological activity sometime in far future. And the waste might come into contact with water supply or return to surface.
All I can say to that is: Radon.
Somehow we can deal with naturally occurring radiation..
The sun is a very large fusion reactor and has no containment whatsoever, other than its own gravity. Magnetic shielding of a sort occurs due to our magnetosphere, and physical shielding occurs because of our atmosphere (IIRC, the ionosphere and ozone layers are crucial in this point).
Most of the fusion designs I've read about (I"m a computer guy, but physics interests me) use magnetic containment in addition to physical shielding. They're also a lot smaller than the sun. The pysical shielding does get bombarded by radiation, but that's what it's there for, really - it gets bombarded instead of the operators.
Generally your worries with radiation are alpha, beta, and gamma rays. Alpha and beta are both stopped easily (paper will stop alpha rays, and tin foil will stop beta rays). I'm not sure how much gamma radiation gets put off by fusion, but we've dealt with that at fission plants and can shield it relatively easily (think concrete and lead - gamma rays are essentially extremely short-wavelength light, and they interact with atomic nuclei). A properly built fusion plant (once we build them) will be perfectly fine to be around during normal operation.
As far as clean and safe, most people are talking about waste products and the possible consequences of accidents. As far as waste, only the containment vessels are dangerous - the metal absorbes neutrons and whatnot and becomes radioactive. So, we have to find a place to bury some steel plates every now and again - not a big deal, unless you're an extreme environmentalist. The fuel waste is helium, which is only dangerous if you try to substitute it for air. With fission, of course, the waste is highly radioactive and there's a lot more of it than there would be with fusion, but not as much as people think - nuclear reactors don't need very much fuel when compared to say, coal or gas plants.
As far as accidents, all designs for fusion reactors I'm aware of are incapable of an explosion. If any factor of the reaction goes wrong - too much fuel, too little fuel, wrong temperature, etc. - the reaction stops. With a fission reactor, the worst case scenario is a meltdown (like chernobyl) or a gas release (can't remember the plant name offhand - it was in the pacific northwest).
We know fusion would be clean and safe because even though we haven't produced any working plants, we know the physics behind it very well. Fusion bombs require fission bombs to start the reaction (thermonuclear bombs are designed this way), so explosions are impossible (although, even fission plants are incapable of exploding like a nuclear bomb - bomb design is very, very different). The waste products from fusion reactors are harmless, except for the shielding, and the shielding isn't going anywhere - unlike the possibility of gas release with archaic fission reactor designs.
Fission is safe - for certain quantities of safe, anyway. Disasters are very unlikely and usually of limited scope - but of course, theoretically it can be extremely nasty when stuff goes wrong. It's certainly cleaner than most of our current technologies and has less environmental impact. But fission can't shake the stigma it has, so we'll likely not develop it much more than we have now. Fusion will be safer and cleaner, but it's not quite here yet so we have to make do.
Those who can't do, teach. Those who can't teach either, do tech support.
FYI, the most complete reference for my research paper was the Ph.D. Thesis for Dr. Alexander Roman Sich when at MIT:
It is impossible to enjoy idling thoroughly unless one has plenty of work to do.
- Jerome Klapka Jerome
Check out the phenomena known as emergence. For example, ants find the shortest route to a food source through clever use of their pheromones. Clever in the sense that the system is ingenious, however the ants do not consciously do anything except mark their trails as they randomly run about and follow other pheromone trails. The pheromone path-creation is not programmed into the ants. They just follow a couple of simple rules.
The result is very ingenious: the shortest route will eventually have the strongest pheromones. As the pheromones vaporize over time, the less used paths die away, and the most used paths (which are also shorter as distance equals time spent in this case) will rule.
That's the organizing principle (or at least one of them). Emergence through synergy. Great complexity comes from the interaction of very small agents (particles, molecules, whatever). Check out the authors Holland, Wolfram and Flake, to name just some from the top of my head.
It's like putting a bunch of threads into a bag and rolling them around with your hands in the bags. You end up with knots.
We didn't become humans at once. What happens in micro level also exhibits emergence upwards up to the macro level. Eventually there's a clump called a human. Humans then form societies, come up with culture and build houses which are emergent properties of humans. Houses clump together into cities, and cities into a metropolis, everytime giving birth to new kind of complexity and new kind of things. And so on. We don't have to consciously "build a city". All it takes is for many people to build houses next to a nice river where lots of fish can be found. In time, there will be a city there, although nobody "built the city" per se.
Also, if the "organizing principle" was broken somehow, there would have appeared no intelligent life, and we would not be observing all this, thus we would not know that the organizing principle was broken!
I do not moderate.
If this is the case, then Palladium is not acting as a catalyst.
Catalysts are, by definition, not consumed as part of the reactions they help enable.