Slashdot Mirror
Room-Temperature, Small-Scale Fusion at UCLA
gnuman99 writes "A UCLA collaboration (Seth Putterman, Brian Naranjo and Jim Gimzewski) appear to have developed a fusion device powered by a pyroelectric crystal, a type of crystal used in cell phones to filter signals. When heated, such a crystal produces a large electric charge on its surface. The UCLA researchers placed a lithium tantalate (LiTaO3) pyroelectric crystal so that one side touches a copper disc. A tiny tungsten probe is then placed at the center of the copper disc. When the crystal is subsequently heated, a very large large electric field is produced at the end of the tugsten tip, ~25 billion volts per meter. This field gradient is so high that it strips the electrons from nearby deuterium atoms. The ionized deuterium atoms then accelerated by this field towards a solid target of erbium deuteride (ErD2). They collide with it at such high energies that some fuse with the target. A measurement of almost 900 neutrons per second was observed. This is 400 times the background! Although the amount of energy produced in this initial experiment was miniscule (~1E-8 jules), this technology could be used for things like microthrusters. There are pictures and movies on the UCLA's physics site." Reader richmlpdx adds a link to coverage at MSNBC.
Submitter is confusing "pyroelectric" with "piezoelectric." Crystals used for oscillators, filters, and speakers use the piezoelectric effect.
Yes, they are fusing particles, but this is not power-producing fusion. To call it fusion will mislead a general audience.
What it is -- which is still very cool -- is a particle accellerator the size of a toaster. High energy accerators fuse atoms, but we don't usually call them fusion reactors.
So, we should be talking about a small particle accelrator that could be used for medical imaging and treatment, sensing, or spacecraft propulsion.
They call the study "Observation of nuclear fusion driven by a pyroelectric crystal".
Unless the submitter is one of the researchers, the submitter was correct.
Thanks for making me learn about those electric characteristics of chrystals though.
Irene KHAAAAAAN!
I just think it's funny that they try to limit the applications.
That's kinda like saying "The 'Internet' could have potential uses in communications, biomedical research and remote sensing."
If small-scale fusion that produces more power than it consumes is indeed possible, it could have implications everywhere in everything. Portable, standalone fusion power sources could (in time) change everything. ((Note to self: do not mention phasers and lose all credibility....))
In 2002 there was a report claiming fusion due to cavitation. The article appeared in Science:
Science, Vol 295, Issue 5561, 1868-1873 , 8 March 2002 [DOI: 10.1126/science.1067589]
The method involves irradiating a liquid with sound. The acoustic waves can cause microscopic bubbles to form in solution (cavitation). When these bubbles collapse, their temperatures can become quite high. Done properly, in fact, these cavitations can lead to sonoluminescence (creation of light from sound). The creation of a plasma under these conditions has been confirmed. The Science article further claimed that neutrons were measured, indicating that fusion temperatures had been achieved. They were certainly not claiming this as a power source (yet), since energy input was much greater than output.
The interesting thing is the controversy that resulted, and, as far as I know, is still not resolved. Scientists worldwide are still split on whether or not fusion has really been achieved. It will take some time longer before we know for sure (altough the most recent reports I've read lean towards this really being fusion).
I'm bringing this up because it seems rather similar to what we have here. It is a high-profile announcement of fusion in a rather unusual setup. I anticipate that this will be met with much skepticism (rightly), and that it will take some time before we know "for sure" that it's really fusion.
Anyways, highly interesting results, and I'm looking forward for future confirmation/elaboration of these experiments. But I wouldn't get too excited, since these kinds of discoveries sometimes have subtle flaws (or mis-interpretations) that only become revealled when the full scrutiny of the scientific process is applied to them.
... as was I.
Certainly, the research is about using the pyroelectric effect. The submitter was right about that.
What the submitter was wrong about was this:
"a type of crystal used in cell phones to filter signals."
That is, as the parent post correctly points out, using the piezoelectric effect. So it is informative, although it should have pointed out exactly in what part of the write-up was wrong.
(My other reply down as -1 Wrong. Sorry, Anonymous Coward.)
Irene KHAAAAAAN!
The reason these devices are interesting is the flow of Neutrons.
There are several applications in materials science where you want neutrons, but you don't want to send your sample off to Oak Ridge, and wait, or go through the paperwork to try to build a research reactor. This device would allow, for instance, in-house Neutron Diffraction experiments, which is similar to X-ray diffraction except that Hydrogens show up. You can see hydrogen loading in containment materials, migration in batteries, and other minor structural changes which are invisible to other analytic techniques.
The fact that they use fusion is nifty, but it's the neutron flux in a convenient package that makes this a way cool experiment.
the more accurate the calculations became, the more the concepts tended to vanish into thin air. R. S. Mulliken
New Scientist has a right up as well. The seemed to have written off the whole idea of using it to produce energy. http://www.newscientist.com/article.ns?id=dn7315
The Farnsworth-Hirsch Fusor has been around since the 1960's, and is so easy to build that it is sometimes seen in high school science fairs. It is commonly available as a neutron source.
What would be "new" would be a net gain in energy, but like the fusor, that doesn't seem to be happening with this new device.
-- Insert witty one-liner here. --
What these guys have done is found a novel application of a relatively well-known means of generating extremely high electric fields. This is good, and may produce more compact, robust neutron generators than we currently have.
But it is clear from the article--and the basic physics--that this isn't a practical means of generating fusion power. This is just another hot fusion mechanism--it isn't "room temperature". The deuterium ions from the gas discharge are accelerated by the field and smash into the ErD surface with high energies.
The interaction cross-sections are such that virtually all of the D ions will slow down without fusing, and the energy that went into accelerating them will be only recoverable as heat, with the usual thermodynamic (in)efficiencies. The DD fusion cross-section just isn't high enough to overcome those losses.
Cool experiment, though.
--Tom
Blasphemy is a human right. Blasphemophobia kills.
Although this research is not going to give us energy production, it is the smallest neutron source I've heard of (palm-sized according to article). This in and of itself is quite exciting, and it would have numerous applications in industry. Neutron sources right now are used to image industrial materials (it can be used to map the internal stress distribution in pipes, aircraft components, etc... and it can get images through materials that would block x-rays). Having portable neutron-imagers would be useful to industry for doing stress analysis/imaging on components while they are in actual use. I can think of lots more applications, but I'll leave it at that.
For those interested, here is the abstract of the Nature article in question (the article is already available online, to subscribers, even though it officially releases in tomorrow's issue of Nature):
Nature 434, 1115-1117 (28 April 2005) | doi: 10.1038/nature03575
Deuterium is hardly specialized. The hydrogen in sea water is 1/6000 D. It is easily separated, and it's readily available by the truckload.
Any practical fusion process is likely to use deuterium rather than ordinary hydrogen because it's plentiful and far easier to fuse.
Physicists look to crystal device for future of fusion
muon-catalyzed fusion would only viably occur in a particle accelerator setup, which I already mentioned (where else are you getting the muons from). In any case (as far as I know) no such thing is actually used today at neutron facilities.
For examples of neutron-beamline research facilities that exist today, I refer you to NIST, HMI, and the Spallation Neutron Source (still being built).
You would be right, if there weren't already other ways of doing fusion without a tokamak or simlar devices.
Philo Farnsworth was doing table top fusion back in the 60's using tube techniques that were part of the outgrowth of his pioneering work in Television.
Check out fusor.net for details on the technique.
Look around on the Net, and you can find more articles on the device in question, including people who have built them to play around with. To the best of my knowledge, there is no practical appliction for a Farnsworth device, except the not-inconsiderable bragging rights that you have built your own fusion reactor (a line sure to have the babes just lining up).
7. What we cannot speak about we must pass over in silence.
... this one looks legit. The big indicator is that neutrons are given off.
Neutron radiation is very hazardous. One of the problems with the Utah cold fusion fiasco was the "dead graduate student" problem. Given the amount of fusion that was allegedly occuring, a lot of neutrons should be given off, so many that given the lack of radiation shielding, there should have been a lot of dead graduate students.
Since there were no dead graduate students, it was likely that no fusion was occuring.
Indeed. A lucky break for them. It's an amazing coincidence that I just finished reading "Bad Science : The Short Life and Weird Times of Cold Fusion" by Gary Taubes last night. It's a fast paced, light, extremely well-written book that'll put most thriller/mystery type books to shame. Especially for anybody remotely connected wth academia. He describes the events leading up to and following the great cold fusion sham in the late 80s and early 90s out of Utah U and BYU and quickly picked up by a bunch of people all around the world. It seems that 400 time background is peanuts. And that's an understatement. Any fusion reaction would be giving out about 20-40 orders more. Yes, thats 10^(20-40). 400 times is easily accounted for by cosmic radiation unless GREAT precautions are taken in measurement, by noise in the instrumentation. I have of course not broken tradition and RTFA. -mp-
-mp-
you'd think people would stop confusing Jules with Joules
Instructions for building your own electrostatic confinement fusion device (aka fusor) are here.
The point is that they can maintain the whole system at room temperature, instead of conventional fusion system that require a massive coil to contain the superheated plasma.
In US, you can easily buy enough major firearms to wipe out your neighbourhood but a few little fireworks are banned.
One good nitpick deserves another!.
It's not wasting time, I'm educating myself.
An atom is atomic (i.e. the gold nuclei that they accelerate at BNL are high energy atomic particles). Subatomic paricles make up atoms (protons, neutrons, and electrons).
You know, that's pretty simple-minded thinking. And the direct causes of native peoples' subjugation at the hands of marauding, murderous Europeans were swords, guns and terrible diseases.
But what made us turn from wild near-apes with rather large foreheads into what we are now was farming, which led to writing, political centralization, and the rest of civilization.
So, our ancestors (culturally, if not genetically) beat up everyone else's ancestors because, at the start of it all, they were better farmers.
And we're not even really evolved from predators! We evolved from small, squirrelish lemurs who, if I remember right, were pretty much omnivorous, certainly not anything like the species of Carnivora. More recently, some of the Australopithecus apes were even vegetarian. Even when they hunted, our ancestors were much better gatherers than hunters, no matter what those cave paintings would have you believe.
But I suppose you were just making a point off the top of your head, which sounded good at first blush.
--grendel drago
Laws do not persuade just because they threaten. --Seneca
But seriously, doesn't filling a chamber with something sort of nullify the whole vacuum thing?
Sure. But I suspect the important part was that the equipment could remove all the gasses (read, "impurities") from the chamber before they let in the deuterium gas. And provide a controlled method for disposing of the products (still nearly all deuterium) of the experiment afterward.
For chemical reactions, deuterium is identical to hydrogen. So it's something whose disposal has to be controlled, not merely dumped into the lab. Don't want someone's flipping a light switch to cause a fire.
tasks(723) drafts(105) languages(484) examples(29106)
Because this development was featured in prestigious Nature, the world is taking notice. An Associate Press story is receiving widespread coverage by mainstream news organizations. Google News is showing major coverage by a wide range of news organizations worldwide. http://pesn.com/2005/04/28/6900088_UCLA_Cold_Fusio n/
UCLA website http://rodan.physics.ucla.edu/pyrofusion/ credits SlashDot for overwhelming their server.
Also worth note: Cold Fusion Goes Back to School at MIT - Colloquium to be held on Massachusetts Institute of Technology campus May 21, 2005. http://pesn.com/2005/04/20/6900085_Cold_Fusion_MIT /
Tomorrow's news yesterday -- the bleeding, visionary edge.
No. AFAIK, vacuum is defined as a gas pressure less than atmospheric pressure. There are several degrees of vacuum, low vacuum to ultra-high vacuum and whatever.