Ultra-Dense Deuterium

[sanman]

Has anybody ever heard of this stuff?

http://www.sciencedaily.com/releases/2009/05/090511181356.htm

So far, only microscopic amounts of the new material have been produced.

Okay, so that means it has at least been produced, so it exists. But is it stable once the confinement pressure has been removed, or is it just a fleeting substance? For it to be feasible as a fuel, I'd imagine it has to be a stable, persistent material.

Could it be useful for powering spacecraft one day? Presumably its compact mass density would allow for a lot of fuel within a small volume.

Is there any danger that such a high-density material could somehow chain-react, or spontaneously explode due to entropy pressures?

 

[Phrak]

Not a hint in that article as to how this dense deuterium was produced.

 

[Bob S]

Right now, it sounds like "cold fusion" deja vu. I once accidentally froze both the fill line and the vent line on a liquid deuterium target. It finally exploded, due to pressure build up, and filled the whole accelerator complex with about 2 torr of deuterium gas. So beware of frozen deuterium.

 

[Phrak]

Imagine a material so heavy that a cube with sides of length 10 cm weights 130 tonnes, a material whose density is significantly greater than the material in the core of the Sun.

The article doesn't make it sound like a Bose Einstein condensate.

Can diamond anvil cells achieve this density??

If so, how is could be a big item. Hasn't anyone bothered to stick some deuterium under an anvil until now?

If it's an anvil the diamond faces could aford a path to trigger a possible fusion reaction via laser. No need to remove the pressure for that.

Edit: Wikipedia quotes 25 x 10¹⁵ Pascals as the (calculated) pressure at the core of the sun.
Answers.com gives 300 gigaPascals as the pressure achievable by a daimond anvil.

 

[granpa]

the core of the sun is also a lot hotter.

somebody said that either metallic hydrogen or metallic helium might be a room temperature superconductor. cant remember which.

 

[alxm]

Supposedly it's 'Rydberg matter'. Which I haven't really heard about before, and which it seems few others have either, except this Holmlid guy. (who's Prof of Atmospheric Chemistry - what?)

And he, in turn, seems to have heard all about it in spades.

I'm skeptical. As I would be about any new state of matter only one guy has ever seen.

 

[granpa]

according to wikipedia:
A Rydberg atom is an excited atom with one or more electrons that have a very high principal quantum number...
Rydberg atoms are extremely large with loosely bound valence electrons, easily perturbed or ionized by collisions or external fields.

http://en.wikipedia.org/wiki/Rydberg_matter

http://en.wikipedia.org/wiki/Degenerate_matter

 

[alxm]

Yes granpa, but I've not seen any mention of this (or a the justification for why it's supposedly so stable) in established literature, and I've got a whole office full of chemical physics books.

A rather inordinate amount of references on the Wikipedia page are to articles by this very same Holmlid guy.

 

[granpa]

actually my point was that rydberg matter should be less dense than ordinary matter. not more dense.
(although, I guess its possible that the outer electrons could be both degenerate and in large-n orbitals at the same time).

editr maybe they are necessarily degenerate (metal-like) BECAUSE they are so large and diffuse. in which case Rydberg matter could be more dense than ordinary matter.

http://www2.chem.gu.se/staff/leif_holmlid.html [Broken]
In principle, Rydberg Matter is a condensed metallic phase formed from weakly interacting Rydberg species (Rydberg states).
The lowest state of Rydberg Matter in excitation state n = 1 can only be formed from hydrogen (protium and deuterium) atoms and is designated H(1) or D(1). This is dense or metallic hydrogen, which we have studied for a few years. The bond distance is 153 pm (1.53 angstroms) (picometer, one thousand times smaller than a nanometer), or 2.9 times the Bohr radius. It is a quantum fluid, with a density of approximately 0.6 kg / dm3. (0.6 grams/cc or 0.6 times as dense as water and 8.5 times as dense as liquid hydrogen which has a density of 0.071 g/cc)

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 (0.023 angstroms). Its density is extremely large, >130 kg / cm3 (130,000 times as dense as water), 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.


edit:he just seems to be calling 'degenerate matter' 'rydberg matter'. which in a sense, if all rydberg matter is metal-like, it is.

http://www.sciencedirect.com/scienc...serid=10&md5=ec9093be8b72a328c121a8092c95ac67
This material is probably an inverted metal with the deuterons moving in the field from the stationary electrons, which gives a predicted interatomic distance of 2.5 pm, close to the measured value. Thus, we prove that an ultra-dense deuterium material exists.


edit:why would the electrons be stationary?

 

[granpa]

http://nextbigfuture.com/2009/05/university-of-gothenberg-making.html
"The photograph shows an experiment in which dense deuterium is irradiated by a laser. The white glow in the container in the centre of the photograph is from deuterium."


the deuterium in the photo doesnt seem to be under any great amount of pressure.

 

[granpa]

if hydrogen excited to a Rydberg state naturally forms metallic hydrogen then I wonder if we could use that to make metallic hydrogen commercially? (didnt they use a laser to make super dense silane? https://www.physicsforums.com/showthread.php?t=228682)

http://en.wikipedia.org/wiki/Metallic_hydrogen
A theory has been put forward by Neil Ashcroft that metallic hydrogen may be a superconductor as high as room temperature (290 K)

 

[Bob S]

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 (0.023 angstroms). Its density is extremely large, >130 kg / cm3 (130,000 times as dense as water), 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.

Why not put negative muons in it. They will pull the deuterium nuclei close enough together to catalyze fusion before the muon decays. Multiple muon catalysis by a single muon has been observed in deuterium bubble chambers, density 0.16 grams per cc. Maybe muons could catalyze 100's? or 1000s? in this ultradense phase before the muon decays. See
http://en.wikipedia.org/wiki/Muon-catalyzed_fusion
http://prola.aps.org/abstract/PR/v106/i2/p330_1
Uploaded photo (jpg) of two catalysis D-D fusions by single muon in bubble chamber.

 

[sanman]

Yes, but this ultra-dense deuterium is said to be Rydberg Matter, with unique electronic orbitals. Who knows if muons and muonic orbitals are compatible with this?

The other thing, is that they're comparing this matter to water droplets in a cloud, and saying that it's not stable for very large crystal sizes, and that the largest cluster of such matter has been counted at 91 atoms. That's too low for muon-catalyzed fusion breakeven.

 

[granpa]

the reason its unstable might just be charge. the nuclei are close together but the eletrons are in very large orbits. too many nuclei and they start repelling one another electrically.

but I'm just guessing.

 

[Phrak]

granpa's wikipedia link, http://en.wikipedia.org/wiki/Rydberg_matter, claims that Rydberg matter is formed in small hexagonal, planar units of a few atoms and would occur as a condensate within the gases state of the material.

Maybe a substrate could encourage its formation under different conditions.But it would take a heck of a lot of muons, all in the same place, to the exclusion of electrons to get a muon structure to form instead.

 

[sanman]

So something I need to understand here -- the nuclei are closer to each other, but the electrons have a large-radius planetary-style orbit, which means that the atoms are roughly pancake-shaped? And so these atoms stack like pancakes to achieve the high density, or do they attach in some different way, like flat floor tiles?

 

[granpa]

the nuclei are within the orbits of each others electrons. (like in a metal)

a whole cluster might be smaller than the orbit of one of its atoms outer electron. thats why I think electronic repulsion might be the limiting factor in how big it gets.

 

[Bob S]

granpa's wikipedia link, Maybe a substrate could encourage i...wo catalytic fusions in about 2 microseconds.

 

[granpa]

http://www.sciencedirect.com/scienc...serid=10&md5=ec9093be8b72a328c121a8092c95ac67

This material is probably an inverted metal with the deuterons moving in the field from the stationary electrons,

not sure what hes talking about but it sounds similar to the impression that a supersolid would give.

 

[sanman]

So you're saying that the electronic shells are tightly locked together in stationary positions, so that the nuclei inside are the ones which are vibrating instead? Is that even possible? Isn't that like the tail wagging the dog?

 

[granpa]

the article states that the nuclei are flowing while the electrons are locked into a lattice. what I'm saying is that maybe its just a supersolid instead. in effect the 'effective mass' of the solid is less than its normal mass. maybe zero, who knows.

 

[granpa]

would that mean that ultradense deuterium (and possibly therefore metallic hydrogen) is a perfect supersolid?

 

[mheslep]

Actually not. A single negative muon quickly penetrates the electron cloud and forms a muonic deuterium atom, with a Bohr radius about 206 times smaller than the normal deuterium atom. This neutral atom then goes around inside the electrons and bumps into another deuterium nucleus, and forms a deuterium molecular ion. The separation of deuterium neuclei in this ion is then close enough to produce fusion within several microseconds. The bubble chamber photo I posted above shows two catalytic fusions in about 2 microseconds.

Yes but to what end, given the 6GeV required to create the muon?

 

[granpa]

actually my point was that rydberg matter should be less dense than ordinary matter. not more dense.
(although, I guess its possible that the outer electrons could be both degenerate and in large-n orbitals at the same time).

editr maybe they are necessarily degenerate (metal-like) BECAUSE they are so large and diffuse. in which case Rydberg matter could be more dense than ordinary matter.

http://www2.chem.gu.se/staff/leif_holmlid.html [Broken]
In principle, Rydberg Matter is a condensed metallic phase formed from weakly interacting Rydberg species (Rydberg states).
The lowest state of Rydberg Matter in excitation state n = 1 can only be formed from hydrogen (protium and deuterium) atoms and is designated H(1) or D(1). This is dense or metallic hydrogen, which we have studied for a few years. The bond distance is 153 pm (1.53 angstroms) (picometer, one thousand times smaller than a nanometer), or 2.9 times the Bohr radius. It is a quantum fluid, with a density of approximately 0.6 kg / dm3. (0.6 grams/cc or 0.6 times as dense as water and 8.5 times as dense as liquid hydrogen which has a density of 0.071 g/cc)

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 (0.023 angstroms). Its density is extremely large, >130 kg / cm3 (130,000 times as dense as water), 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.


edit:he just seems to be calling 'degenerate matter' 'rydberg matter'. which in a sense, if all rydberg matter is metal-like, it is.

http://www.sciencedirect.com/scienc...serid=10&md5=ec9093be8b72a328c121a8092c95ac67
This material is probably an inverted metal with the deuterons moving in the field from the stationary electrons, which gives a predicted interatomic distance of 2.5 pm, close to the measured value. Thus, we prove that an ultra-dense deuterium material exists.

A single negative muon quickly penetrates the electron cloud and forms a muonic deuterium atom, with a Bohr radius about 206 times smaller than the normal deuterium atom

ultradense deuterium is 209 (incorrect. I goofed) times smaller than normal deuterium (which I assume to be the same size as hydrogen) according to my calculations and the rounded numbers given in the article.

density of deuterium=2 * density of hydrogen= 0.142
density of ultradense deuterium=130,000
density of ultradense deuterium/density of deuterium=130,000/0.142=915,492.95
radius of deuterium/radius of ultradense deuterium=cube root of 915,492.95=97.1

whoops. I entered 9,000,000 instead of 900,000

 

[Bob S]

Yes but to what end, given the 6GeV required to create the muon?

It takes about 6 GeV minimum to produce an antiproton. Muons come from pion decay (as well as from other sources), and pions can be produced by about (I forget exactly) about 300 MeV protons. I mentioned muons because thay can catalyze d-d fusion by getting the two deuterons roughly 10 times closer (hence 100 times volumetrically) than ultra-dense deuterium. Muon-catalyzed fusion is "exothermic" (energy out > energy in) only if a single muon can catalyze 100's (1000's?) of fusions.