Ultra-Dense Deuterium Produced 355
Omomyid was among several readers writing in about the production of microscopic amounts of ultra-dense deuterium by scientists at the University of Gothenberg, in Sweden. A cubic centimeter of the stuff would weigh 287 lbs. (130 kg). UDD is 100,000 times more dense than water, and a million times more dense than deuterium ice, which is a common fuel in laser-ignited fusion projects. The researchers say that, if (big if) the material can be produced in large quantities, it would vastly improve the chances of starting a fusion reaction, as the atoms are much closer together. Such a D-D fusion reaction would be cleaner than one involving highly radioactive tritium. Many outlets have picked up the same press release that Science Daily printed pretty much verbatim (as is their wont); there doesn't seem to be much else about this on the Web. Here's the home page of one of the researchers. The press release gives no hint as to how the UDD was produced. Reader wisebabo asks: "I can easily imagine a material being compressed by some heavy duty diamond anvil to reach this density, the question is: what happens when you let the pressure off? Will it expand (explosively one would presume) back to its original volume?"
What the heck passes for editing these days??? (Score:4, Informative)
"Highly Radioactive Tritium" - I'm assuming they meant something concerning the very energetic neutrons produced in D-T fusion. Tritium by itself can't be considered highly radioactive by any stretch of the imagination. They put the stuff in my watch with thin glass for a shield, for Pete's sake!
LOTS of missing details from TFA: (Score:5, Informative)
FIRST - there is no claim for an observable amount of matter in the D(-1) state. It isn't "microscopic amounts" - for "microscopic" means "visible in a microscope". Do the math, fellow NBF visionaries: 2.3 picometers ... if it were a lattice compound ... would be about 440^3 units per cubic nanometer, or 440,000^3 (about 85E15 or 85 quadrillion atoms in a cubic micrometer box. Nothing doing. They're measuring the energy (~600eV) spectroscopically, from the FRAGMENTS of the supposed union. This is not a union-of-deuterons lasting nanoseconds, or microseconds, or milliseconds, or seconds. No, these are the fragments that lasted just long enough for the D(-1) state to hold together in a laser beam for ATTOSECONDS. (That's what those little "as" annotations are on their viewgraph).
SECOND, while it is nice to foster the conjecture that such matter IF microscopically attainable, IF stable enought to survives the time-of-flight from source to fusion reactor, IF the energy-cost-of-production is far less than the increased odds (and useful energy return) of the attendant fusion exists ... THEN it is a great and wonderful thing.
THIRD, single D(-1) pseudonucleons may well exist for nanoseconds per KURT9's thesis, but again ... nanoseconds is very much too short for deeply sub-relativistic ballistic particles to traverse a source (the laser-and-"compression" chamber) to the fusion reaction chamber. Even if they only exist as single diatomic particles, lifetimes have to be raised at least into the microseconds. For practical energy production in the reactor proper (let's say, 250 MW thermal), 4.88E20 diatomic Rydberg nucleons would have to be created (assuming 3.23MeV per fusion of D(-1) to get to 4He) ... and remembering that 4He is the least likely product produced.
FOURTH (per last part of Third), the 2D + 2D = 4He reaction is well known to be very improbable in a single step, since there are LOWER ENERGY intermediate products that bleed off the excited spin-state fusion reaction (one of the key 'first principles' of fusion physics). Per the excellent if brief article in WikiPedia,
50% ... D + D = T + p ... D + D = 3He + n
50%
Researching further, D + D = 4He occurs about one in a dozen million fusion reactions nominally.
FIFTH, summing goatse.cx guy's "facts" together and this looks like yet another fruitless (for fusion) avenues of research. There is only hope, and not a shred of evidence that the D(-1) Rydberg CAN be made in 1E20 nucleons/second quantities, no reference to the overall energy-of-formation, no evidence that the diatoms can exist for more than attoseconds, nothing but speculative wishes that such a material holds promise to D+D=4He reactions (which is just an uber-popular topic, anyway). Therefore, it gets a 3 star SnakeOil award, coupled with 2 stars for the actual science, the novelty of the discovery, and the fine department of Physics at Gothenberg for letting these two obviously talented, and quite frankly queer, researchers have their limelight.
So, in summary, I have to say: "Sorry, dude, I just don't think it'll work."
=smudge=
Not a cubic centimetre... (Score:3, Informative)
The FA says a 10cm cube, i.e. 1000 cubic centimetres, would weigh 130 tonnes.
Re:how does this not spontaneously fuse (Score:5, Informative)
Re:how does this not spontaneously fuse (Score:5, Informative)
The centre of the sun is less dense than you might think, owing to thermal and radiation pressure.
The energy from the aforementioned fusion counteracts the pressure from the outer layers pushing in. This state is one of equilibrium; reduce the rate of reaction and the core contracts, speeding fusion, increase the rate of reaction and the core expands, slowing the fusion back down again. The estimated density of the sun is much, much lower than the density would be for a non-fusing body of the same mass. If anything, this discrepancy will be more noticeable in the core, where the temperature is highest.
If no fusion reactions were occurring, which is what will happen when the fuel runs out, the core would contract until it became electron-degenerate matter, the material of a white dwarf star. With a more massive star, the contraction would continue past that point until neutron degeneracy took over (leading to a neutron star), or it passed the Swartzchild radius (leading to a black hole).
From TFA and Researcher's home page (Score:3, Informative)
No clue here as to production, but possibly in the references below. Anyone have access to these?
"A much denser state exists for deuterium, named D(-1). We call it ultra-dense deuterium. This is the inverse of D(1), and the bond distance is very small, equal to 2.3 pm. Its density is extremely large, >130 kg / cm3, if it can exist as a dense phase. Due to the short bond distance, D-D fusion is expected to take place easily in this material. See Ref. 179 below!"
183. S. Badiei, P. U. Andersson and L. Holmlid, "High-energy Coulomb explosions in ultra-dense deuterium: time-of-flight mass spectrometry with variable energy and flight length". Int. J. Mass Spectrom. 282 (2009) 70-76.
179. S. Badiei, P. U. Andersson and L. Holmlid, "Fusion reactions in high-density hydrogen: a fast route to small-scale fusion?" Int. J. Hydr. Energy 34 (2009) 487-495.
178. L. Holmlid, "Clusters HN+ (N = 4, 6, 12) from condensed atomic hydrogen and deuterium indicating close-packed structures in the desorbed phase at an active catalyst surface". Surf. Sci. 602 (2008) 3381â"3387.
176. S. Badiei and L. Holmlid, "Condensed atomic hydrogen as a possible target in inertial confinement fusion (ICF)". J. Fusion Energ. 27 (2008) 296â"300.
I don't see the necessity for brute force compression. H can be highly compressed while trapped in metal crystal lattice, such as in H saturated palladium. The individual energies are still high but due to being already in close proximity much of the squeezing has already been done. Such a lattice that can then be removed, dissolved, etc. might leave high density H droppings.
Re:Not a cubic centimetre... (Score:5, Informative)
The FA says a 10cm cube, i.e. 1000 cubic centimetres, would weigh 130 tonnes.
Metric isn't that hard.
If 10 cm * 10 cm * 10 cm = 1000 cm^3 weighs 130 000 kg, then 1 cm * 1 cm * 1 cm = 1 cm^3 weighs 130 kg.
Re:Metallic Deuterium ? (Score:3, Informative)
> I have to wonder if they haven't made metallic deuterium.
No. This is something quite different (if it exists at all).
Re:Not necessarily a gas! (Score:2, Informative)
In short, deuterium is a gas at STP.
That's not to say they can't make UDD, but the pressure/temperature stability of the material is suspect.
Re:What the heck passes for editing these days??? (Score:5, Informative)
Still, relative to deuterium, it's much more radioactive.
Deuterium doesn't decay, at least not on any observable time scale. So "relative to deuterium", anything that does decay is much more radioactive. This includes such notable elements as Bismuth, used in Pepto-Bismol, and Tungsten, used in lightbulb filaments. Nevermind such notables as Americium in smoke detectors.
Re:LOTS of missing details from TFA: (Score:5, Informative)
Queer has more definitions than gay.
Peculiar, eccentric, those are more probable. Fake is also a valid definition but that probably doesn't apply. (Queer fiver as opposed to a queer scientist)
Re:Not necessarily a gas! (Score:3, Informative)
Leif Holmid's page claims this material has a bond length of 2.3pm. Picometers. 10^-12 meter. Now, the normal bond length of dihydrogen is about 74pm, so if these claims are true, the spacing between atoms has been squashed down by about a factor of 30. This distance is still too small for the strong interaction to pull the nuclei together- the effective range of the strong force is on the order of a femtometer, or 10^-15 meters. If you do happen to get the nuclei closer (by dumping in more energy), fusion would be expected to occur. Absent that, this means the predominant force at 2.3pm is going to be electrostatic repulsion between protons, which would only presumably be countered by applied force, like pressure from a diamond anvil cell. Take the pressure off, and the deuterium atoms should energetically move to increase their distances.
Re:how does this not spontaneously fuse (Score:3, Informative)
So my question then became how does this not spontaneously fuse?
It would... given enough time. The rate of fusion in the solar core is quite sedate. The vast majority of hydrogen or deuterium in the solar core won't fuse for some billions of years to come.
This stuff will have a huge spontaneous fusion cross-section, relatively speaking, but that could still be vastly lower than anything practically interesting. During the cold fusion flap Koonin and collaborators did a careful recalculation of the "standard" spontaneous fusion cross-section (which depends sensitively on the details of the asymptotic wavefunction) and found that the accepted value was many orders of magnitude too small. But the corrected value was still many orders of magnitude smaller than that required to make any of the cold fusion claims plausible.
Re:Energy is not a Technical problem, one of Will (Score:5, Informative)
Recycle what's still usable. The USA doesn't do this because of an ill advised cold war ban on reprocessing technology, but Japan and France both do.
Separate the remainder and pitch the low level stuff. Vitrify it, bury it, forget about it. As long as it doesn't get into the water table in large quantity, we're safe. In small quantities, it's negligible. Worst case, we're the only ones who pay the price; low level radioactives aren't a threat to the ecology, especially not when the only water irradiated is in aquifers (we're pretty much the only species that has any reason to fear deep water contamination).
For evidence of the low impact of radiation, witness the resurgent wildlife at Chernobyl - plant and animal life is more loss-tolerant when radiation is concerned than human culture. A 5% increase in cancer rates terrifies us, yet impacts animals little (far less than human activity). This means the minor radioactives are far more a health concern than an environmental one.
What's left after the low level crud is separated, the really nasty stuff, is something like 1% of the total waste. This is the stuff we don't want leaking into the environment, for our sakes or the rest of the high order life on this planet. You're left with 90% of the problem condensed down to 1% of the mass. What you do with that is up to you; cart it offworld, bury it at a subduction zone, build a huge RTG and use it for power - there are several options.
Re:It's also good for practical jokes (Score:5, Informative)
Interesting idea. I found this terminal velocity calculator [nasa.gov].
A 1 cm^3 cube of UDD has a surface area of 0.00107639104 sq feet [google.com]. (Actually, it would be a little more as it rotates in the air.) Unfortunately, the above calculator rounds values off too much to handle this. In fact, it can't really handle it because it isn't able to compensate for compressibility effects and shock waves as we exceed the speed of sound. (Using the Eiffel Tower's height of 1063 ft., it is returning a value of a little over a mile per second!)
So let's try dropping a big piece, say a sphere with a cross sectional area of 1 sq. ft. This will have a radius of sqrt(1 / pi), and hence a volume of (4/3) * pi * (sqrt( 1 / pi))^3, or about 0.75225 [google.com] cubic feet. This yields an impressive weight of 6,113,486 pounds [google.com].
The terminal velocity calculator is cutting us off at 10,000 pounds, but we can punch this out ourselves to get an answer. We just need a reasonable value for the atmospheric density. Through a little trial and error, I found that a value of .001697 gives about the same results as what the terminal velocity calculator returns for 10,000 pound weights. Running the calculation for our weight yields 101,000 ft/sec. [google.com], or about 19.2 miles/second.
This is surely a ridiculous result, since we're still disregarding compressibility effects, and using dodgy math. Still, it was interesting, and this sort of speed is not impossible. The fastest man made space probe, Helios, traveled at over twice this speed, albeit in a vacuum.
Let's accept the result for now, and compare this to the Chicxulub impact [wikipedia.org], which is "one of the largest confirmed impact structures in the world; the impacting bolide that formed the crater was at least 10 km (6 mi) in diameter." I don't see any estimates of the bolide's mass or impact velocity. However, we know the impact released 400 zettajoules of energy, or 4x10^23 joules.
Our object would have a kinetic energy [wikipedia.org] of merely 1.3x10^15 joules [google.com], so it probably won't be destroying the earth. Still, with the force all directed at such a tiny area, something dramatic is bound to happen. I imagine it would burrow quite deeply, and then release energy upward and outward somehow.
I have no idea how to estimate the hole's depth. If anyone thinks this ludicrous math is enjoyable, feel free to add your own calculations!
Re:LOTS of missing details from TFA: (Score:4, Informative)
No, these are the fragments that lasted just long enough for the D(-1) state to hold together in a laser beam for ATTOSECONDS. (That's what those little "as" annotations are on their viewgraph).
You didn't specify what viewgraph you were referring to (there are none in the links in the summary). Presumably you are looking at one of their papers. E.g. Figure 2 from:
S. Badiei, P. U. Andersson and L. Holmlid, "High-energy Coulomb explosions in ultra-dense deuterium: time-of-flight mass spectrometry with variable energy and flight length". Int. J. Mass Spectrom. 282 (2009) 70-76. doi:10.1016/j.ijms.2009.02.014 [doi.org]
Yes, that graph marks points along the curve with "as" meaning "attoseconds", but that doesn't mean that the UDD has a lifetime of attoseconds. That graph is describing the "Coulomb explosion" technique they are using to measure the bond distances in UDD. Briefly, they excite the ultra-dense deuterium with a laser pulse that ionizes some of the atoms, which causes them to fly apart (due to Coulomb repulsion) with great energy. By measuring the ions that result from this explosion they can calculate the bond distances. This high-speed explosion, however, was artificially induced to make it possible to measure the inter-atomic distances. If they had not purposefully excited the UDD with a laser it would have lasted longer.
I'm not sure how much longer that would be, mind you. As far as I can tell from their papers, they have not yet measured the lifetime. So it may very well be a rather low lifetime. (Though some forms of Rydberg matter can have appreciable lifetimes [wikipedia.org].) If anyone has any actual data (with link) for the lifetime, I'd love to see it.
IF stable enought to survives the time-of-flight from source to fusion reactor
For Intertially-Confined Fusion, which typically uses lasers to compress the target matter, one could design a system where the UDD state is produced in-situ and immediately laser-compressed.
single D(-1) pseudonucleons may well exist for nanoseconds per KURT9's thesis
This is another statement whose source is unclear. Who or what is "KURT9"?
There is only hope ... nothing but speculative wishes that such a material holds promise to D+D=4He reactions ...
From the above-cited paper:
"Due to the high density of the D(1) material, a factor of 2×10^5 higher than for H(1), the transport of energetic particles through the material is strongly impeded. In fact, the deuterons at 2.3pm bond distance are close to the nuclear barrier, and a kinetic energy of 630 eV may be sufficient to give d-d fusion by tunneling."
I haven't looked into the theory enough yet to say whether their suggestion of tunneling [wikipedia.org] is correct or not... but if true this would indeed vastly increase the rate of fusion reactions. If nothing else, the extremely high density of the nucleons will make all kinds of many-body and multi-step reactions much more viable.
he fine department of Physics at Gothenberg for letting these two obviously talented, and quite frankly queer, researchers have their limelight.
Umm... what?
=smudge=
I guess you're trolling.
Re:What the heck passes for editing these days??? (Score:3, Informative)
This includes such notable elements as Bismuth, used in Pepto-Bismol, and Tungsten, used in lightbulb filaments.
I had missed the memo that bismuth-209 decays very slowly (half life of approximately ~10^19 years, which is stable for all practical purposes). Most naturally occurring tungsten is stable, though, at least as far as human observation goes (Wikipedia says that about 0.1% of natural tungsten is tungsten-180, which has a half-life of ~10^18 years, which is as practically stable as bismuth-209).
Re:That's "dilithium" (Score:5, Informative)
Vitamin A - Apricots.
Vitamin D - UV irradiated mushrooms.
Vitamin E - Nuts, Seeds, Asparagus, lots of others.
Vitamin K - Kiwi, Avocado, Spinach, lots of others.
Plus Vitamin D is naturally synthesized by the human body when exposed to UV radiation.
Even if you were right, though, your original statement would still be stupid. Vitamins clearly DO grow on trees.
If you had stated that SOME vitamins don't grow on trees, I probably wouldn't have bothered responding. I'm not an expert, so I would have assumed that you were probably right. However, after researching your claims about Vitamins A, D, E, and K, it's become apparent that you have no clue what you're talking about.
Re:That's "dilithium" (Score:5, Informative)
Just because a vitamin is capable of dissolving in fat does not mean that it only comes from animal sources. Many plants produce fats (vegetable oils) and are rich in these vitamins. For example, vitamin A is found in carrots and peaches; D is processed from mushrooms; E comes from nuts and leafy veggies, and so does K.
Re:That's "dilithium" (Score:5, Informative)
Vitamin A:
Carrots, broccoli, sweet potatoes, kale, spinach, pumpkin, cantaloupe, apricots, papaya, mangoes, peas, squash.
Vitamin D:
Generated within the human body on contact with sunlight (UV light). Can also be produced in mushrooms grown under UV light.
Vitamin E:
Avocado, spinach, asparagus, wheat germ, wholegrain foods, most nuts, seeds, and palm & vegetable oils.
Vitamin K:
Spinach, cabbage, kale, cauliflower, broccoli, avocado, kiwi, parsley.
Re:From TFA and Researcher's home page (Score:3, Informative)
That (RM) there is for Rydberg matter, the exotic state of matter the hydrogen or deuterium is found in. Rydberg matter [wikipedia.org] is a metastable state where atoms (or molecules) cluster together, not forming covalent or ionic bonds, but rather sharing a system of delocalized electrons, similar to pi-bonding in organic aromatic systems. It's also similar to the excited state of phosphorescent materials; as with phosphorescent materials, quantum mechanical considerations allow the material to maintain this excited state for a short interval before decaying to the ground state. The catalyst used apparently desorbs hydrogen atoms (or deuterium) in this excited Rydberg state into an ultrahigh vacuum chamber, where some will cluster together to form metastable Rydberg matter clusters. Yes, the clusters are apparently stable at room temp and without a diamond anvil; it's the relaxation of their electronic state which determines their lifetime.
In this experiment, the separation between atoms in the cluster is tested by using laser pulses to essentially blow away the electrons, leaving only a cloud of positively charged protons or deuterium nuclei. The rapid repulsion of all of these particles from each other is called a Coulomb explosion, and via Coulomb's law, the energy released by this repulsion is inversely proportional to the square of the initial separation distance of the particles, which it stands to reason is the distance they had as Rydberg matter.
For hydrogen, the results indicate that the atoms were 150pm apart, which is very impressive; it implies hydrogen atoms were together in a metallic state that was thought to require pressures like those in the interior of Jupiter. What's really wild though is the "inverted metal" state of "ultra-dense deuterium." By their calculations, the deuterium atoms were 2.3pm apart. Which is about 1/10 of the radius of a single ground state hydrogen atom. This is pretty much a dense state of matter that you'd expect inside a neutron star, and apparently you can make it with a vacuum chamber, a laser, and a hydride donor. What they're proposing:
I think there's more information on the process in one of the citations: S. Badiei, L. Holmlid, J. Phys. B: At. Mol. Opt. Phys. 39 (2006) 4191., but someone else will need to look that that one up.
Re:That's "dilithium" (Score:3, Informative)
If you get enough sunlight (or artificial equivalent), you can produce all the vitamin D you need yourself. So this basically boils down to "energy" again. In fact, AFAIK, you basically can't get enough vitamin D from your diet alone unless the foods or drinks you consume have been artificially enriched (e.g. milk). Even if you could get enough from your diet, you'd probably end up massively overdosing on other vitamins. :-)
Re:It's also good for practical jokes (Score:2, Informative)
Women walk around in high heels causing that kind of pressure all over the place...
Re:That's "dilithium" (Score:1, Informative)
Re:Muon catalysis? (Score:3, Informative)
> You need a stable muon first.
Actually, you don't. All you need is for the muon to live long enough for the fusion to take place. And, as it happens, muons live long enough to catalyze many fusion events.
Muon-catalyzed fusion is a well-studied problem, and one on which I did a graduate term project many years ago. The big problem isn't the muon lifetime -- everything works pretty well, you can get the muons to replace electrons in singly-ionized D-D or D-T molecules, and they even ratchet themselves down to the lowest-energy muonic states quite quickly, and after that, the fusion happens more than fast enough. When I did my project, the big problem was with muon recycling -- once the fusion event occurs, the muon might be ejected, or it might be bound to the He fusion product for the high-energy D-T case.
Binding to the He (called "alpha-sticking" in the jargon) is very bad, it makes the muon unavailable to catalyze more reactions, no matter how long the damn thing lives. As of about 1993, the state of the art was, you needed to use D-T fusion to have any hope of achieving energetic break-even, but D-T fusion was plagued by alpha-sticking, so break-even wasn't happening.
A longer-lived muon would help, obviously, since they're energetically expensive to produce, but the muon lifetime is far from the limiting factor in this process.
Re:That's "dilithium" (Score:3, Informative)
There are just a slew of "buts" coming. First off is as Holmlid notes, just making the deuterium so dense in any volume is an issue and must be worked quite cold. Next, the matter of stability comes to mind, as in the paper’s graphs the time to live is short, shorter than even nanoseconds. That makes the foreseeable production essentially within a laser fusion reactor. Making the ultra dense deuterium and moving it seems out of the question for now. The time of life seems impractical for any laser ignition anytime soon. Finally, the fusion reaction would have to be rather, well, counter intuitive, yielding harmless helium and hydrogen. One would expect a wider range of new materials from the fusion including tritium, which can be nasty radioactive stuff. Lots of supposition, but experimentation is in order.
All that said, it is by every objective view - a great success. Metallic hydrogen has been worked on for several years with less than useful results. The heavier ultra dense deuterium with the atoms already very close might just spark some engineering to see if the new fuel candidate has potential. But it’s a long climb up a tall mountain.