Nuclear Fusion Discovered 317
prostoalex writes "Both USA Today and The New York Times are reporting on research group from UCLA led by Seth J. Putterman which has discovered a form of nuclear fusion. The impact of the discovery? 'While the device is probably too inefficient to produce electricity or other forms of energy, the scientists say, egg-size fusion generators could someday find uses in spacecraft thrusters, medical treatments and scanners that search for bombs.' The findings are published in Nature magazine."
great result, but not really a "discovery" (Score:5, Informative)
First of all, humans "discovered" fusion in 1953 with the first fusion bomb, or "hydrogen" bomb. What this speaks of is controlled fusion.
Secondly, this isn't fusion on even a battery scale; this is a few thousand atoms per second or so. So unfortunately, it's not a matter of scaling up to produce a reactor. The amount of energy being put into the system dwarfs by thousands of times the energy from fusion being put out.
Third, this isn't even the discovery of table-top laboratory scale fusion. As an undergraduate, I worked on a muon catalyzed fusion [triumf.ca] experiment at TRIUMF [triumf.info] in Vancouver. By the time I was working on the experiment in 1994, the fusion reaction in the experiment was so well understood that it was being used to analyze other properties of solidified Hydrogen.
And I'm afraid it's a little bit of a dodge to say it's "at room temperature". The article doesn't say this, but presumably this takes place in a vaccum, where temperature is basically undefined in any conventional sense.
So a very nifty result, but not a discovery, I'm afraid. It will very likely be useful to study the fusion process, or perhaps other things as well.
Re:great result, but not really a "discovery" (Score:5, Insightful)
Just to be nit-picky: While the cell in which the muon catalyzed fusion takes place may fit on a normal table-top, it would take an awfully large table to hold the proton accelerator, the production target, and the system of vacuum pipes and magnets that decay the pions and select and degrade the muons.
Predictions, predictions..... why? (Score:3, Insightful)
Sure, superconductors have proven useful for a **few** niche uses, but the big hype was all about superconducting power lines etc... Twenty years on and the only place I've really seen superconductors has been in my flying car.
Why do scientists, supposedly conservative types, make these wild predictions? Is it to hype for funding?
Re:great result, but not really a "discovery" (Score:5, Informative)
Have a look at it here:
http://en.wikipedia.org/wiki/Farnsworth-Hirsch_Fu
It has since been abandoned as a potential fusion generator, since you still have to put in more energy than comes out of it (like every other fusion technology thus far). Some suggest this may be because it is too simple and offers less ways to spend lots of money on it (and acquire status and research grants by doing so).
And humans discovered fusion in the morning, when they opened their eyes and looked at the sun...
And humans discovered fusion in the morning, when (Score:5, Funny)
After patenting fusion, would you try to license or sue:
God, for infringing on your patent, with "billions and billions" of offending instances?
Everyone else on Earth, for receiving the benefits of the unlicensed fusion source?
Re:great result, but not really a "discovery" (Score:2)
Still smaller (Score:3, Interesting)
aparatus for identifying unknown substances non-invasively can now be made cheaper and more portable.
Make it smaller still, and perhaps you could swallow a radiation source to treat bowell cancer on the way through, instead of irradiating your whole body from the outside.
Re:great result, but not really a "discovery" (Score:3, Interesting)
The point now is to make a fusion reactor which can get that energy out safely in a useful form for less than $1 billion in hardware. Also, they do inject high temperature ions into the chamber, it would be silly not to.
Finally, if you think expensive and complicated are what get physicists prestige, you don't know enough about physicists.
Re:great result, but not really a "discovery" (Score:5, Informative)
This method of fusion has been known for at least a decade. But the energy efficiency is so low that it's just not a candidate for power generation. Like the article says, this is primarily targetted as a neutron source. It might be able to be scaled above the break even point, but not without some pretty innovative features.
The basic of it is you get a copper plate, attach it to a special crystal, heat it with a tungsten filament, and immerse it in deuterium gas. The heated crystal strips electrons from the deuterium gas, and the ions are accelerated towards an erbium-deuterium target.
I imagine most of your energy is lost as waste heat. And while this is cold fusion, this is not room temperature fusion. Cold fusion is any fusion that is not heat-pressure catalyzed. While heating is involved here, the energy from the heat pressure is not directly used to bring deuterium nuclei together...
It's not cold fusion (Score:5, Informative)
The original "cold fusion" apparatus (the one that didn't work, or at least no one was ever able to replicate the experiment) used an electrolytic cell with palladium electrodes in an electrolyte. Nowhere in the apparatus were the deuterium nuclei accelerated to high speed. The theory was that the current somehow induces the deuterium to infuse into the palladium electrode, where the deuterium nuclei get close enough to each other to fuse, without you having to clash them together at high energy.
That was the cool thing about it (pardon the pun). You didn't have to put much energy into the system, so you had more energy coming out than you had to put in, making it a feasable power source. If it worked:-).
Re:It's not cold fusion (Score:3, Informative)
Sonoluminescence was one of the holy grails of cold fusion that had a rough ride, yet that proposed that the collapsing bubble *did* accelerate the deuterium, and I've yet to be convinced by any that don't claim to accelerate the particles in some way.
Re:It's not cold fusion (Score:3, Informative)
In both cases, there is significant local heating. An atomic nucleus accelerated to relativistic speeds (article's example) can be considered to have an extremely high temperature.
In the case of sonoluminescence, the contents of the oscillating bubble become superheated due to adiabatic heating (If you compress a gas without energy loss to the outside, it will heat up. In the cas
Re:It's not cold fusion (Score:2)
Re:It's not cold fusion (Score:3, Informative)
A single particle doesn't really have a temperature, it has a kinetic energy. A mono-energetic beam of particles has a temeperature of 0 K, but what is usually referred to is the beam energy. The particles in a real beam don't have exactly the beam energy, but instead have a spread around it. A cold beam is a bea
Re:great result, but not really a "discovery" (Score:2)
Of course, we're all arguing over nothing. Nobody is saying that fusion has just been discovered. It's just the usual sloppy Slashdot headline.
Re:great result, but not really a "discovery" (Score:2, Interesting)
Muon catalysed cold fusion has looked like a good possibility for decades. However, as far as I'm aware, the problem is that the muons end up sticking to the fusion products too often rather than going on to catalyse the next fusion. As muons are short lived and "expensive" in terms of energy to produce this is not yet a practical source of power.
I seem to recall that in the forward to one of his books (probably 2010, or one of the other 2001 sequels) Arthur C Clarke talks about this as a possible source
Some corrections to the parent (Score:4, Informative)
They're not claiming it's self-sustaining. They're just claiming that it's novel, which it is, and that it's a neutron generator, which it is.
A commentary article in the current journal of Nature points out that "...portable neutron generators have found a wide range of applications, including welllogging for oil exploration, and the screening of baggage for airline security," but that "high-voltage power is required, and the apparatus is fairly complex."
This device is much simpler and more straightforward.
Third, this isn't even the discovery of table-top laboratory scale fusion.
True, but it is probably one of the simplest and most compact fusion/neutron generating techniques invented to date.
And I'm afraid it's a little bit of a dodge to say it's "at room temperature". The article doesn't say this, but presumably this takes place in a vaccum, where temperature is basically undefined in any conventional sense.
Please RTFA before you critique it. This method uses a pyroelectric crystal, heated presumably up to 100-200 Celsius or so, and a thin deuterium gas and a target made of erbium deuteride, both of which are presumably at or near room temperatures.
In any case, by "cold" fusion we typically mean "at temperatures easily maintainable in a lab," to distinguish from "hot" fusion which occurs at many thousands or millions of degrees.
Also, you should know that even in a "perfect" vacuum, temperature is and can be well-defined, usually by thermal radiation equilibrium with the enclosure. Even outer space has a well-defined thermal radiation background, which I think is within a couple degrees of absolute zero.
Actually (Score:2)
You can be a pendantic ass, so can I.
"but presumably this takes place in a vaccum,"
and if it doesn't?
Re:great result, but not really a "discovery" (Score:2)
Actually humans "discovered" fusion in prehistoric times when the first human looked up at the sun / stars. They may not have known what it was, but they discovered that there was something there and we now know it was a big fusion reactor.
Summary of the actual nature article (Score:5, Informative)
Their setup: The 'crystal' mentioned in the mainstream articles, is a z-cut lithium tantalate crystal (LiTaO3), with the negative axis facing outward onto a hollow copper block. A tiny tungsten probe (80 microns long and 100 nm wide) is then attached to the other crystal face. This probe acts as a tiny mast for the electric field so that there is a powerful electrical field at the tip of the probe. Then there were a bunch of fancy neutron-counters and single-photon counters bundled around it.
What they did: First they added deuterium gas (at 0.7 Pa) and then cooled the crystal down using liquid nitrogen (to 240 K). Then they used a little heater to increase the chamber temperature slowly.
What happened: Less than 3 minutes later, and still below 273 K (0 degrees Celcius), the neutron signal rose above the background level. There were x-rays coming from the probe tip, and a whole bunch of neutrons. After a few more minutes, the electric field was so strong that it caused arcing between the probe tip and the enclosure (because they kept heatingthe crystal, and the field thus kept getting stronger). The arcing stopped the process (and I'd guess it damages the crystal?).
They added a few links in the article to previous papers: a pdf [ucla.edu] describing the concept they are trying to harness, another pdf [binghamton.edu] with more about how they use the crystals with the deuterium gas, and a brief abstract [inel.gov].
I think this is pretty cool. I bet/hope that before long (within 10 years), this will be powering small extrasolar probes.
Pretty neat stuff. I don't even mind dupe posts when they're on such important stuff.
Re:great result, but not really a "discovery" (Score:2, Informative)
Re:great result, but not really a "discovery" (Score:3, Funny)
Re:great result, but not really a "discovery" (Score:3, Insightful)
Since you're a knowledgeable physics guy, would you take a moment and respond to my question?
Is there any way to create a Bose-Einstein Condensate of 'fuseable' gas such that the density of the gas is so high that quickly transitioning the gas out of the condensate state would result in fusion?
I.e., if two tritium molecules occupy the same location in a quantum state and are quickly transitioned from that state could their 'proximity' to each other be enough to induce the fusion process withou
Re:great result, but not really a "discovery" (Score:3, Informative)
Yup, a dupe from a post not 24 hours old.
Apparently Zonk is shooting for some sort of record.
Re:great result, but not really a "discovery" (Score:2)
The sun also has its own atmosphere. The temperature of that atmosphere (5000-ish degrees F) is what gives the sun its color.
In any case, my beef isn't with the scienists. They did something very useful and cool, which I expect will be very useful in the very near future. My beef is with the Times and other papers like it, which post headlines of "s
Re:great result, but not really a "discovery" (Score:2)
Get real work done, or argue physics on Slashdot. Something like that.
Re:great result, but not really a "discovery" (Score:2)
Would "human tolerable temperatures" be a better phrase to use? Yes. Will life go on? Yes.
Re:great result, but not really a "discovery" (Score:2)
Slashdot: Nuclear Fusion Dupe Discovered (Score:5, Funny)
Re:Slashdot: Nuclear Fusion Dupe Discovered (Score:5, Insightful)
This was 'supposed' to help them clean up dupes, yet we find that they are not only failing to check dupes, tehy are also failing to check the account so that those of us (that are paying, not being paid) can help out...
Re:Slashdot: Nuclear Fusion Dupe Discovered (Score:2)
E-mail for those nonbelievers:
Mark:
Sharp eye! Thanks for noting that one.
Tim
On 4/27/05, Mark Owen wrote:
> A measurement of almost 900 neutrons per second was *observer*.
>
> Should be *observed*
>
--
Re:Slashdot: Nuclear Fusion Dupe Discovered (Score:2)
This was 'supposed' to help them clean up dupes, yet we find that they are not only failing to check dupes, tehy are also failing to check the account so that those of us (that are paying, not being paid) can help out...
That's because you're doing it all wrong. The staff doesn't care. But there is a solution; you mention that we're paying for this "service." Gentlemen, I give you the contact information for the Open Source Technology Group, Slashdot's parent company:
Re:Slashdot: Nuclear Fusion Dupe Discovered (Score:2)
I would say it's still worth pinging him about it, particularly if the daddypants account is being ignored. My impression of Jeff is that although he's wierd in innumerable ways, he cares a lot about what slashdot is and what it stands for, and would be very annoyed about an editor who ignored a message about a duplicate post and posted it anyway.
PT Barnum (Score:2)
Re:Slashdot: Nuclear Fusion Dupe Discovered (Score:2)
Now THAT is funny! (Score:2)
Dupe (Score:5, Funny)
but (Score:2)
Re:Dupe (Score:2, Funny)
Sad to see scientists stoop so low (Score:4, Insightful)
Heh. It's kind of a funny to watch us scientists who're interested in some particular natural phenonmenon to come up with the weirdest reasons why further research on the subject might help in the WAR AGAINST TERRORISM(!!1!one!).
No, actually it's not funny. It's sad.
homeland security applicatins (Score:5, Interesting)
You irradiate the baggage/cargo (or whatever) with neutrons, and check the outgoing neutron flux with a geigerzahler or some other neutron detector. If there is fissile material in the baggage, some of it would split, generating detectably more neutrons.
If you want to get cute about it, note that fission neutrons have lower energy than fusion neutrons. Then use a neutron detector that can differentiate neutrons by energy.
Now, you can probably detect neutron flux from spontaneous fission without any irradiation, but depending on type of fissile material and amount of shielding that flux might be too low to detect reliably. And you wouldn't be able to tell an isotopic neutron source from fissile materials. Not that isotopic neutron sources shouldn't raise suspicion if found in cargo/baggage.
The only real problem with a detector based on neutron irradiation is that you have to keep people the hell away from it:-).
Re:homeland security applicatins (Score:3, Informative)
The difference is enough to tell the difference between a CD player boom-box, and a bomb inside a boom-box even when the explosive are hidden inside the batteries or capacitors.
A far as detecting fissile material I do
Ob. Snoop Dawg (Score:3, Funny)
Are you fo shizzle about the fissile?
Sorry:)
Re:homeland security applicatins (Score:3, Interesting)
For a few decades, Cornell University ran a low-power fission reactor (unpressurized, approx. 100-200KW output power), and neutron generation for just such imagi
Re:Sad to see scientists stoop so low (Score:2)
Really..
Re:Sad to see scientists stoop so low (Score:2)
So, being able to detect WMD materials being smuggled through ports or airports fails to help stop terrorists how? What part of guys who want to kill you smuggling in, say, refined uranium, is it not useful to stop? How is it not helping a scientist, or his institution, to point out something that obvious, and to benefit from having more people and resources interested in his research?
So, l
Egg sized thrusters (Score:4, Funny)
Terms, conditions and Homeland Security restrictions may apply.
Re:Egg sized thrusters (Score:4, Funny)
Wait a second... (Score:2, Funny)
Re:Wait a second... (Score:2)
Isn't this the same as.... (Score:2)
Again? (Score:5, Funny)
"My god, that discovery is even better than it was yesterday! I'm glad we discovered it again. Let's discover pepperoni pizza next!"
Only on Slashdot
Repost (Score:5, Funny)
From the wrms-your-heart dept. (Score:4, Informative)
Pyoelectric != Piezoelectric (Score:2, Informative)
Weird (Score:5, Informative)
What this device really is, is not so much of a fusion generator as it is a neutron source. Nuclear physicists use sources such as these for processes such as starting atomic reactions and changing elements. (e.g. You can make lead into gold with enough radiation. Although plutonium production is a far more useful change.)
A nuclear physicist I know suggested that the Sonofusion concept might be useful for the same reasons. Unfortuntely, we are quickly piling up ways of using fusion as neutron sources, but have yet to come up with a single one to produce energy.
Lead into gold ??? (Score:3, Interesting)
Gold having an atomic number 79 compared to 82 of lead. Isn't it easier to fuse on extra protons and neutrons with an accelerator than it is to split off just a few. With the atomic weights 197 (Gold) and 207(Lead) You'll need to hit the gold with a hydrogen, a helium, and some extra nuetrons to turn it into lead.
To turn lead into gold, you need a way to strip off this little bit, or split, split, fuse, fuse, and pull out the extra in the middle step.
Just
Re:Lead into gold ??? (Score:2)
BTW, I dug up an article [about.com] on the process. Here's a more technical explanation. [tased.edu.au]
Re:Lead into gold ??? (Score:2)
Time travel? (Score:3, Funny)
Obviously this discovery can also allow previously posted articles to Travel Through Time and appear a day later.
Wow.
Bombs (Score:2)
Re:Bombs (Score:2)
You can use it to calibrate a neutron detector to sniff out radioactive materials that way. Or you can use it in an x-ray machine type format; not many materials are good neutron shields; any nuclear weapon that passes the neutron leakage test would have to include pretty good neutron shielding, not to mention that nuclear materials themselves tend to absorb neutrons; but they emit more than they absorb (it is this reaction that
Seriously now, let's do something about this... (Score:5, Insightful)
Re:Seriously now, let's do something about this... (Score:5, Insightful)
Re:Seriously now, let's do something about this... (Score:2)
That they post duplicate stories to get a rise out of us slashizens?
That poor spelling is just them thumbing their noses at our poorly spelled comments?
That inserting opinions into the articles will sucker people into flamebait?
That not rendering correctly on firefox is really them buckling down to Microsoft advertising on their site?
Now hold on... my tin hat isn't strapped on correctly.
Re:Seriously now, let's do something about this... (Score:3, Insightful)
Re:Seriously now, let's do something about this... (Score:2)
Then again... the editors might not care.. people are still viewing the duped article, and therefore, people are still (mostly) looking at ads
Re:Seriously now, let's do something about this... (Score:2)
I quiver in anticipation.
The next story will be available soon... (Score:5, Funny)
Unsubscribers can get a chance to read it yesterday!
Re:The next story will be available soon... (Score:2)
Unsubscribers in the meantime can get a chance to re-read yesterdays posts as new, waiting for the next real story!
i don't mind all of the dupes (Score:5, Insightful)
the only thing that puzzles me about dupes though is how it is possible that me, a very casual reader, is easily struck by their appearance, when an editor, supposedly editting their own website, fails to be struck by the duplication
i don't understand the mechanism by which that works
Re:i don't mind all of the dupes (Score:2, Insightful)
Re:i don't mind all of the dupes (Score:2)
For more information (Score:2, Interesting)
Let's see (Score:5, Informative)
Secondly, they haven't discovered fusion, they have invented a new type of fusion-based neutron generator. Several types of neutron generators are commonly known, and some [wikipedia.org]are simple enough that you could build a working one in your garage. All of them use the same principle, more or less - high voltage, on the order of 100kV, accelerates deuterium ions into a deuterium (or tritium) containing target. So does this one.
The novelty is that they used a pyroelectric crystal to generate the high voltage. This makes the device small and self-contained, with no need for high-voltage electric machinery. All you do is heat-cycle the crystal with some 50 degree C temperature span, and you get fusion neutrons.
Note that like all fusion devices to date (other than bombs), this gadget produces a lot less fusion energy than is put in, and brings us no closer to having a fusion-based power source.
But it's a neat idea. And it makes a neat cheap laboratory neutron source.
Sweet! (Score:2)
10 Print "Story from Yesterday"
20 Goto 10
30 REM back to WoW
Yay for sarcasm!
Wow... (Score:5, Funny)
It seems like somebody's discovering cold fusion just about every day now. .
Let me see if I got this right.... (Score:2)
comment postings saying its a dup...... well certainly a WHOLE LOT MORE than 2
C'mon guys, anymore than 10 comments saying it's a dup is not just redundant, it's redundant, overrated and annyoing.
I need a dup filter.
Re:Let me see if I got this right.... (Score:2)
It's almost like a self sustaing chain reaction. Oh wait, that's fission.
You mean they did it again, today!? (Score:2)
Comment removed (Score:4, Funny)
And... (Score:2)
And bombs.
Sorry. Had to be said.
Re:And... (Score:2)
neutrons and cells (Score:2, Interesting)
1) as a propulsion source, ion emitters are cheaper/safer
2) from a safety PoV, neutrons don't interact too well with living cells (in any amount) - producing free radicals - almost impossible to shield against
not only a dupe (Score:2)
/. is just now something to check when eating lunch or dinner
sad
Karma whoring (Score:3, Funny)
I'll be right back.
Re:Karma whoring (Score:2)
Useful for neutrons, not power (and it's hot) (Score:3, Funny)
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 "
well (Score:2)
Damn lazy scientist, another 10 years without a discovery like this I would of had to do it myself.
I wish Slashdot would discover "fusion" (Score:2, Funny)
I mean, come on, Slashdot editors - if you don't even read your own website, why would you expect anyone else to? At least I don't feel guilty about adblocking ads.odsn.com.
Wow (Score:3, Insightful)
If someone claims two applications of a new technology that are so exteremly unrelated to each other in one sentence I find it hard to take him/her serious. But hey, maybe it can be used to propel a car, cheaply and environmentally friendly.
True enough (Score:2)
Take the "penny" for instance. You can use it to buy items with (used to be easier, now you need a huge sack of them) as well as bridge the gap on a circuit box! Two very unrelated uses of the penny.
YEEEHAW (Score:2)
Eat THAT Hammurabi.
wow (Score:3, Funny)
Re:The impact of the discovery? (Score:5, Funny)
Re:Dupe (Score:2)
Re:First Dupe! (Score:2, Funny)
That's why the editors can't see the dupes.
Re:Fusion, time travel... (Score:5, Funny)
Thats what usually happens when they get Slashdot up to 88 miles per hour.
Re:OT: Slashdot index page screwed up? (Score:2)
Re:Mumbo Jumbo (Score:3, Funny)