Fourth Generation Nuclear Weapons

[selfAdjoint]

See http://www.arxiv.org/abs/physics/0510071" excellent paper on the latest technology research on using tiny pellets of DT to yield explosions in the 100 ton range. Also includes brief but illuminating discussion of earlier nuclear weapons, from an international standpoint.

 

[theCandyman]

What is the Independent Scientific Research Institute? The paper seems like an interesting read, but I do not like the idea of research into more powerful nuclear weapons. The current ones are already so powerful, there is not a need to get greedy and make sommething that has the probability of having an effect on something other than a target if a bomb absolutely has to be used, Earth is a confined space after all.

 

[Lapin Dormant]

100 ton range is less then the KILOtonnes of an A bomb, and less moreso then the MEGAtonnes of the H bomb.

If I have the inference of "100 tons range" read properly. Smaller weapons of destrucive force from Nuclear sourcing.

 

[selfAdjoint]

100 ton range is less then the KILOtonnes of an A bomb, and less moreso then the MEGAtonnes of the H bomb.
If I have the inference of "100 tons range" read properly. Smaller weapons of destrucive force from Nuclear sourcing.

Yes. And with only a tiny, very thin shell of actinide, so minimal radiation signature. DT is a clean reaction, and they only need milligrams of it per weapon, so "safe for battlefield use"!

 

[hitssquad]

with [...] a [...] thin shell of actinide

What are you referring to? I only skimmed the article, but it seemed to be saying that the trigger would be non-fission. Are you referring to a U-238 blanket? I didn't see the article mention a U-238 blanket.

 

[sharmans]

wow...Great

 

[selfAdjoint]

What are you referring to? I only skimmed the article, but it seemed to be saying that the trigger would be non-fission. Are you referring to a U-238 blanket? I didn't see the article mention a U-238 blanket.

I thought I saw a reference to a thin shell of Uranium or Plutonium surrounding the pellet, but maybe this was in the "sparkplug" pellets used in H-bombs.

 

[hitssquad]

I thought I saw a reference to a thin shell of Uranium or Plutonium surrounding the pellet, but maybe this was in the "sparkplug" pellets used in H-bombs.

I think that was part of the section discussing older-generation devices:

2.2 Two-stage thermonuclear weapons

In two-stage thermonuclear weapons, the fusion material(i.e., lithium-deuteride, LiD) is generally packaged as a cylindrical or spherical shell sandwiched between an outer-shell of heavy material (the pusher/tamper) and an inner-shell of fissile material. This inner-shell (the spark-plug) is generally boosted with some DT gas. As suggested by its name, the purpose of the spark-plug is to ignite the fusion material at the appropriate time, i.e, once it has been sufficiently compressed. This whole package is called the "secondary" of the thermonuclear weapon, and is enclosed together with the "primary" in a thick and heavy "radiation case" which is designed to contain the soft-X-rays from the primary as long as possible.

 

[theCandyman]

100 ton range is less then the KILOtonnes of an A bomb, and less moreso then the MEGAtonnes of the H bomb.

I did read it wrongly. I still do not agree with it, using smaller weapons like this would only encourage using larger ones.

 

[Pengwuino]

I did read it wrongly. I still do not agree with it, using smaller weapons like this would only encourage using larger ones.

That is if we actually ever use the smaller ones. Maybe there are actual applications for something like that (mining for example) although I wonder what kind fo radiation levels it creates. And I also believe the belief that using smaller will result in bigger is as baseless as when they started saying the cheaper/cleaner you can make them, the more people will start using them.

 

[theCandyman]

The machine gun comes to mind, the inventor wanted to make something so horrible that war would no longer be something humanity wanted. In the present, they are common place and unlike defending trenches in the world wars, they are mounted onto helicopters and vehicles.

Of course there are other applications for this, but they are looking into the "military effectiveness".

 

[Pengwuino]

I never really liked his reasoning for the machine gun. I don't see how he could have thought "humanity wants war" at the time and that the machine gun would have made people "not want it".

 

[sid_galt]

There is one weapon so horrible that humanity does not engage in major wars - the nuclear bomb.

Anyway, it's a pretty cool idea. I wonder how large they'll be. Could one for instance fit in a small UAV?

 

[Grogs]

That is if we actually ever use the smaller ones. Maybe there are actual applications for something like that (mining for example) although I wonder what kind fo radiation levels it creates. And I also believe the belief that using smaller will result in bigger is as baseless as when they started saying the cheaper/cleaner you can make them, the more people will start using them.

I think it's just the opposite really. I think most sane (ok, at least a little bit sane) world leaders realize that tossing ICBM's around will cause serious fallout in the international community. These seem to be an attempt to subvert that. It's seems like sort of an 'if we use a bunch of smaller nukes, maybe they won't mind so much' theory.

As for the long-term radiation effects on the landscape, it doesn't look like they'd be too bad. Of course the immediate effects for those near the weapon would be pretty horrible. The LD50/30 range for a 1-ton device would be about 300m and for a 100-ton one it would be around 1000m. This means that a person standing 1000m from a 100-ton detonation would have a 50% chance of dying (painfully!) from acute radiation sickness in the next 30 days. Of course people farther out still have a chance of dying either from ARS or from a cancer induced by the radiation. Closer in, people would literally drop dead in their tracks.

 

[Lapin Dormant]

What about the simplistic idea that the main reason is a manner of disposing of all {of some} of that nuclear waste, as this is seen as a Practical application for it's disposal?

Personally I don't think we need any more explosive devices as we already have enough to 'face off' the planet.

 

[Grogs]

What about the simplistic idea that the main reason is a manner of disposing of all {of some} of that nuclear waste, as this is seen as a Practical application for it's disposal?

I'm not sure I follow you. Was this something discussed in the paper? I don't see how these weapons could in any way help with waste disposal. The only radioactive isotope it would contain would be tritium (H-3). As radioactive substances go, Tritium is pretty benign, releasing only an 18.6 keV electron and no gammas whatsoever when it decays. We're also only talking about a few grams, so even if tritium *were* a serious disposal problem, it would take a *lot* of these bombs to make even a sizable dent in our inventory.

 

[Lapin Dormant]

Probably my error, as I did NOT read the paper, but in the manufacture of tritium, isn't that done by nuclear bombardment using radioactive isotopes?
Hence a 'use' for some of the waste?

 

[Grogs]

Probably my error, as I did NOT read the paper, but in the manufacture of tritium, isn't that done by nuclear bombardment using radioactive isotopes?
Hence a 'use' for some of the waste?

To the best of my knowledge, the easiest way to produce Tritium is to put some Li-6 inside of a reactor. The high-neutron flux in the reactor will produce Tritium using the reaction: Li-6 + n -> He4 + H-3. In spent fuel rods, there will be some residual neutron flux, but it's going to be considerably less than what you'd get inside of a reactor.

In an operating nuclear reactor, only about 0.7% of the neutron flux come from sources other than the fissions (we call these delayed neutrons and they're actually critical to our ability to control fission reactors.) Most of these delayed neutron sources have quite short half-lives though, typically less than 1 minute, so in spent fuel the neutron flux would fall off significantly after only a short period of time.

This isn't to say there aren't uses for nuclear waste though. We could pull about 99% of the material from spent fuel rods (the Uranium and Plutonium) plus a few other select isotopes which are useful for medical or commercial purposes (radioisotopic tracing and food irradiation for example.) Unfortunately, in order to do that we'd have to reprocess the waste and our current policy in the U.S. is that we don't recycle our fuel.


Back to the initial article, I noticed one item that I missed on my first initial skim. It completely ignores the problems associated with storing tritium-deuterium gas in a warhead. First, by it's very nature tritium is difficult to store as a pure gas. It tends to escape through the walls of most common storage materials (glass, steel) over a period of time. It's also radioactive, with a half-life of 12.3 years. The result is that after a period of time, your weapon will have considerably less yield than it did when it was first produced, giving it a fairly short shelf-life.

In the earliest thermonuclear weapons, they had to periodically disassemble the warhead, remove the pit, and refill it with tritium. This was less than desirable, so a solution was devised to use Li-D, which is stable, in the pit instead of D-T. When the first-stage (fission) trigger was ignited, it would provide the neutron flux to produce tritium from the Li to be used in the reaction. In the case of a conventional trigger, like the FGNW's, you wouldn't have the neutron flux so you'd have to use D-T gas in the pit. Has our technology improved enough that this is no longer a significant obstacle?

 

[hitssquad]

tritium [...] tends to escape through the walls of most common storage materials (glass

Glass is tritium-permeable?

 

[Grogs]

Glass is tritium-permeable?

No, actually that should be plastic, not glass.

 

[Lapin Dormant]

Nice answer Grogs

Had some experience at this have you?

(it shows)

 

[Grogs]

Nice answer Grogs
Had some experience at this have you?
(it shows)

Thanks. It's education rather than experience actually. My minor as an undergrad was nuclear engineering and I'm getting ready to start on a Master's degree in NE this spring. Sometimes what you learn in the classroom is quite a bit different than how things are actually done though, so it's nice to have folks like Astronuc and Morbius who have years of experience working in the field for sanity checking.

 

[Lapin Dormant]

Fooled me you did

Thanks. It's education rather than experience actually. My minor as an undergrad was nuclear engineering and I'm getting ready to start on a Master's degree in NE this spring. Sometimes what you learn in the classroom is quite a bit different than how things are actually done though, so it's nice to have folks like Astronuc and Morbius who have years of experience working in the field for sanity checking.

It is probably the usage of the "We" thing cause you make it sound like you have done it.

Fun stuff itsn't it, complex, yet simple, yet mightly Complex.

Potent.

 

[Morbius]

There is one weapon so horrible that humanity does not engage in major wars - the nuclear bomb.
Anyway, it's a pretty cool idea. I wonder how large they'll be. Could one for instance fit in a small UAV?

sid_galt,

We have had nuclear artillery shells!

No secret there.

Dr. Gregory Greenman
Physicist

 

[NavyMan]

Gotta love atomic annie.

 

[Morbius]

Gotta love atomic annie.

NavyMan,
Yes - but what I actually had in mind were regular 8" and 155mm shells.
For example, the W-79 was an 8 inch projectile:
http://nuclearweaponarchive.org/Usa/Weapons/W79.jpg
and the W-48 was a 155mm [ 6.1 inch ] projectile:
http://nuclearweaponarchive.org/Usa/Weapons/Mk48.jpg
"Atomic Annie" was the W-9 and was a 280 mm shell:
http://nuclearweaponarchive.org/Usa/Weapons/Mk9.jpg
Later designs like the W-48 were almost half the diameter of "Atomic Annie"
Dr. Gregory Greenman
Physicist

 

[theCandyman]

Yes - but what I actually had in mind were regular 8" and 155mm shells.
For example, the W-79 was an 8 inch projectile:
http://nuclearweaponarchive.org/Usa/Weapons/W79.jpg

I thought the bombs were big because a critical mass is needed, so what are the dimensions of the smallest critical mass?

 

[Astronuc]

I thought the bombs were big because a critical mass is needed, so what are the dimensions of the smallest critical mass?

That's a secret.

The smallest critical mass depends on how well one can compress a mass of fissile material (i.e. depends on max density achieveable) and on the purity of the fissile material. One certainly needs less Pu239 than U235.

 

[NavyMan]

I read recently it was possible to get the critical mass documents due to the freedom of information act, they are supposedly available from the National Archives and cost about $20. Scary thought

 

[Pengwuino]

I read recently it was possible to get the critical mass documents due to the freedom of information act, they are supposedly available from the National Archives and cost about $20. Scary thought

Well then go buy it :P

You'd think thatd be one of the things that were exempt from FOIA... unless the information is less useful then it seems.

 

[Astronuc]

I read recently it was possible to get the critical mass documents due to the freedom of information act, they are supposedly available from the National Archives and cost about $20. Scary thought

Unless they have been declassified, I doubt that key critical mass calculations are available. The details of nuclear weapons are not in the public domain, and are not available under FOIA.

There was a move during the Clinton administration to declassify some DOE records. IIRC, that program was suspended.

 

[Morbius]

I read recently it was possible to get the critical mass documents due to the freedom of information act, they are supposedly available from the National Archives and cost about $20. Scary thought

NavyMan,

NO - anything that is classified by the Atomic Energy Act of 1954 is IMMUNE from the
Freedom of Information Act.

In addition to my job as a physicist, I am also an Authorized Derivative Classifier. That
is, with published guidance from DOE, I decide if a document is classified or not.

In that capacity, I also handle Freedom of Information Act requests. There is a check
box on the FOIA form which states that the information is covered by the Atomic Energy
Act. If I check that box, then the FOIA request is automatically DENIED.

Dr. Gregory Greenman
Physicist

 

[Morbius]

Unless they have been declassified, I doubt that key critical mass calculations are available. The details of nuclear weapons are not in the public domain, and are not available under FOIA.
There was a move during the Clinton administration to declassify some DOE records. IIRC, that program was suspended.

Astronuc,

You are correct about FOIA.

The Clinton Administration did seek to declassify a lot of information. Most classified
information is defined by an Executive Order - so the President has a lot of latitude in
the determination of classified information.

http://www.fas.org/sgp/clinton/eo12958.html


However, nuclear information is classified by the Atomic Energy Act of 1954 - which is
an Act of Congress - i.e. a Law. It takes another Act of Congress to change its provisions.

https://www.osti.gov/opennet/forms.jsp?formurl=od/rdfrdhtm.html


Specifically, the Clinton Administration stated that for "borderline" cases, the
determination should favor a finding that the information is unclassified.
However, the Atomic Energy Act, with its "born secret" provisions, states that the
determination should favor classified, not unclassified in borderline cases.


In order to overule the "born secret" provisions, it would take an Act of Congress, as I
stated above; which the Clinton Administration did not pursue.

Dr. Gregory Greenman
Physicist

 

[James Essig]

Hi Folks;

I can imagine the potential for shaped charged nuclear devices able to produce enough heat and pressure to induce fusion in a limited subset of or throughout entire body of water. Note that shaped charge nuclear devices may be able to produce a concentrated jet of plasma and thermalized gamma rays with a blackbody temperature of about 10 EXP 14 K to 10 EXP 15K and pressures of perhaps 100,000,000 million atmospheres based on the estimate that the device could concentrate the reaction energy/plasma as much as 6 orders of magnitude above that of a spherically symmetric nuclear explosion. Nested shaped charges wherein a shape charge jet would be formed from a multitude of primary shaped charge jets could probably best this figure by several orders of magnitude.

Such a device might be detonated in a small pond or lake in an enemies territory thus roasting the enemies whole country in one feld-swoop. The danger is that it could be detonated in the ocean causing a chain fusion reaction to propagate through the entire Earth's ocean in a fraction of a second thus vaporizing the Earth with an effective 10 EXP 18.5 metric ton fusion bomb.

At a temperature of 10 EXP 15 K, it might be possible to create a macroscopic aggregate of Higg's Bosons thus causing a type of energy release that might be associated with such a large concentration of Higg's Bosons. Perhaps such a device could be used to alter the zero point energy state of the space within with the device is set off perhaps leading to a Higg's field imbalance and a limited release of zero point energy which is estimated by some physics theories to have a density 120 orders of magnitude greater than that of the average mattergy density of the obsevable universe. One cubic meter of space might have the latent energy of 10 EXP 41 times that of the mattergy within the observable within the universe. The danger here obviously is that a runaway phase change might ensue to envelope the whole universe. The worst possible scenario would be that the phase change might effect the whole multiverse or omniverse if such exist or the entire fractal verse proposed to exist within the theory of chaotic inflation due to any weak causal coupling between our Big Bang and any others in any form of causal coupling with our universe.

The message is that we had better be careful with our nuclear weapons experiments. No doubt, improvements in our ability to produce ever greater amount of liberated energy will continue, but let's be careful.

Regards;

Jim

 

[GammaScanner]

Hi Folks;

... thermalized gamma rays ...

Hadn't heard of these.

All mine sort of fade out once they've been comptonized a bit and then photoelectronized.

A particular spectrum of gamma rays?
Photoneutron production maybe?
Gamma rays produced by thermal sources? (not just really high energy x-rays)

I've not thought of gamma rays being in equilibrium, they just go down in energy.
Inverse Compton scattering?

Are we talking such density of gamma rays, the most likely thing they might collide with is each other? That would have to be like 10 EXP zillion or so, at which point my puzzler gets sore and goes to sleep.

Interesting to think of though, Thanks!

- Ed

 

[James Essig]

Hi GammaScanner;

I was sort of thinking gamma rays produced with an energy of rough order of magnitude of the temperature of the plasma in the form of black body radiation. The temperature of the plasma with nucleon/proton/other charged particles of about 10 EXP 15 K might very briefly radiate gamma rays on the order of 10 EXP 12 to 10 EXP 13 eV extrapolated from 1million to 10 million eV gamma rays from the initial plasma produced in the nanoseconds after the fusion sequence of a thermonuclear device is complete. A more realistic model might be the gamma ray energies that exist within the fission component just after the chain reaction has effectively ended. The maximum temperature of the fission reaction is about 100 million K at fission completion. For the fusion sequence, the maximum temperature reaches about 300 million to 400 million K although these temperatures are probably at locations well within the fusion stage where pressures and temperatures can be compounded by the compressive effects of the overlayers of fusioning material. At gamma ray energies approaching 1 TeV, interaction with quarks composing the nucleons no doubt becomes important.

Collisions of gamma rays among nucleons might produce some of the desired gamma rays through compton scattering, charged particle collisions might produce additional gamma rays, and other exotic reactions that produce extremely hard gamma rays such as those that occur in 1 TeV accellerators and soon, the 14 TeV accellator at the upgraded CERN may be gamma ray components. Although I would say that some way of producing a high enough plasma density would be required to allow for gamma ray interactions before the gamma rays would escape for compton scattering to work at these extreme energies.

Thanks for the insights and questions!

Regards;

Jim

 

[vanesch]

Hi GammaScanner;

I was sort of thinking gamma rays produced with an energy of rough order of magnitude of the temperature of the plasma in the form of black body radiation. The temperature of the plasma with nucleon/proton/other charged particles of about 10 EXP 15 K might very briefly radiate gamma rays on the order of 10 EXP 12 to 10 EXP 13 eV extrapolated from 1million to 10 million eV gamma rays from the initial plasma produced in the nanoseconds after the fusion sequence of a thermonuclear device is complete.

I honestly doubt that you could get to TeV energies with nuclear explosions, even with very special ones. After all, individual processes start out at the 200 MeV range (fission energy, or of the order of 14 MeV fusion energy), and thermodynamics will normally make it such that this energy gets distributed over more and more degrees of freedom.

 

[James Essig]

Hi vanesch;

Thanks very much for the insights and comments.

It will be interesting to see what sort of particles and interactions can and will occur when the upgraded Large Hadron Collider goes on line at CERN this May. Perhaps more particles and decay sequences will be discovered adding to the great number of Feyman diagrams for which we would have discovered real particle interaction sequences thereby allowing even more degrees of freedom thus really putting the kobash on the concept that TeV energies could be generated by any realistically sized nuclear device.

Regards;

Jim

 

[James Essig]

Cluster Nuclear Devices

Hi Folks;

I once, and I believe only once, read of the concept of cluster bomblet nuclear munitions back in the very late 1970s in a public dailly news paper. I believe it was either the Washington Post or some other newspaper of the Washington D.C. metro area.

I have often wondered how effective such a device could be, say perhaps on the battlefield, or for use in a counter strike on populated areas if the U.S. were to suffer a very unfortunate first strike.

My idea is that the device could contain 100 or perhaps even 1,000 bomblets each of the mass of the "Davy Crockett" warhead which as a very low mass nuclear device with a yield of between 10 and 20 tons of TNT, as small of a yield for which nuclear devices have been produced. I hear that 2,100 of the "Davy Crockett" devices were produced but that they were retired in the early 1970s.

The device reportedly would produce a near instantly fatal dose or ionizing radiation at a range of about 500 feet and a most probably lethal dose at a range of 1/4 mile. I can imagine if the yield were to be boosted to 1 kiloton in the form of a neutron bomb, a similarly compact device would have great deterent value in the form of a neutron cluster bomb.

A fourth generation nuclear device utilizing pure fusion bomblets within a cluster bomb might have even greater deterent value. If a kilogram of hydrogen were to undergo complete nuclear fusion, then the resulting yield would be about 225 Kt/Kg. Now obviously, a pure fusion bomb would probably not have all of its fusion fuel fused simply because some of it would be blasted away by the explosion before it would fuse. But my God, could you imagine a pure fusion cluster bomb utilizing 100 or even 1,000 225 kiloton yield bomblets! Talk about deterence!

Just a thought.

Regards;

Jim

 

[JeffKoch]

Keep in mind that anyone really familiar with this stuff can't talk about it on forums, much less publish papers about new "fourth generation" concepts in apparently unrefereed unclassified online journals. I'd take any information stated in this article with many grains of salt.

 

[James Essig]

Hi Folks;

Bear in mind that the same laws of physics that the folks at LLNL and other nuclear weapons R&D labs are bound by are the same laws that all other physiciists are bound by. The U.S. government is not bound by Divine providence to have an absolute monopoly on all possible nuclear weapons designs that have not been realized. I am sure there are workable nuclear weapons configurations that have not been tested and perhaps not even thought about by the folks at LLNL and the like.

Some of the folks at the Relativistic Heavy Ion Collider and at the LHC at CERN, which is soon to be operational again, will no doubt want to look for additional nuclear forces aside from the strong nuclear force and the weak nuclear force. The existence of additional nuclear forces has been hinted at by experimental anomalies as we probe the nature of fundamental particle physics at ever greater energy levels. One can only speculate what nuclear devices might be capable for devices that would somehow involve the principles of the application of any yet to be discovered nuclear forces.

I personally think that this is a fine thread with lots of good comments being posted.

Regards;

Jim

 

[sanman]

Here's an idea that I posted in its own thread:

https://www.physicsforums.com/showthread.php?p=1763651#post1763651

What do you think of this? Could buckyballs be the answer?

 

[James Essig]

Hi Sanman;

The idea of using buckballs or other fullerines to contain compressed hydrogen, perhaps in a metallic state does seem to have good potential within the field of nuclear weapons design.

Any way in which hydrogen in its various isotopic forms can be produced in an ever more dense and stable manner potentially allows for more of the hydrogen isotopic fusion fuel to be fused instead of being blasted away by the fission primary stage. Note that the most exothermic fusion reactions convert about 0.7 percent of the reactants mass to energy. This allows 1 kilogram of this ideal fusion fuel to yield about 180 kilotons + when fully fused. Thus any process that allows more densely concentrated precursor fuel can potentially lead to higher mass specific yields for thermonuclear devices.

Thanks for asking.

Jim

 

[sanman]

Hi James,

Thanks for your response. My understand is however that nobody has found a way to synthesize these idealized these densely-hydrogen-filled buckyballs. I was wondering if quantum tunneling might be able to get hydrogen inside buckyballs. Since hydrogen is smaller and lighter than the buckyball, perhaps it could tunnel its way across the graphene shell, to get inside the buckyball.

Another idea I had was perhaps using an ultra-short (femtosecond/attosecond) pulse laser, to deform a local region on the buckyball's graphene mesh long enough for hydrogens to get inside.

Does anyone else have any speculations or conjectures on how metallic or ultra-dense hydrogen within the confinement of buckyballs could be achieved?

 

[sanman]

Another idea I had was to use the photon resonance with the buckyball to manipulate the surface plasmons and/or volume plasmons to help us get the hydrogen inside.

http://www-als.lbl.gov/als/science/sci_archive/103plasmon.html

Perhaps with the volume plasmon effect we could make the buckyball expand and contract enough, so that when its mesh is expanded we could get the hydrogen inside, and then when its mesh contracts it will compress the hydrogen.

Hmm, sort of like the pumping action of a heart, except without any primary inlet and outlet. All the gaps in the expanded mesh could act as inlets.

Later on, by introducing muons into the picture, then all bond orbital lengths could be made to contract even further -- not just the D-T bonds, but also the C-C bonds -- so that everything gets even more compressed.

 

[James Essig]

Hi sanman;

Those are some very interesting ideas. Another possible way to get the hydrogen, deuterium, and/or tritium inside is to beam it at the sample of carbon buckyballs or other fullerenes in a manner similar to ion beam deposition. For those of the Physics Forums readership who might not be familiar with ion beam deposition, it is a technique by which a relatively low energy ion beam is directed to a metal surface or alloy surface wherein it is desired to produce special surface characteristics within the surface layer of certain pieces of metal such as for very hard surfaced temperature and scratch resistant components of mechanical systems and the like.

Regarding the application of muons, in consideration of ultra dense forms of metallic hydrogen, one thing comes to mind, and that is muon catalyzed fusion. The ultra dense state of the hydrogen would allow a significantly reduced mean free path for the muons within the sample hydrogen thus potentially allowing more hydrogen nuclei to be fused via the muons acting as an intermediary between the hydrogen nuclei. Once a sample of such densely packed hydrogen would undergo muon catalyzed fusion, perhaps the fusion process could boot-strap itself with the energy released by the muon catalyzed fusion reactions thus resulting in a thermonuclear explosion.

I am not sure, however, how small muon production apparatus have become. One would not want to build a substantially large particle accelerator just to initiate a modest size thermonuclear device's explosion. However, your idea of using muons to facilitate the filling of the buckyballs is intriguing.

Note, I am not sure if this posting went through so it may appear in duplicate form at least temporarilly. I have been having some software troubles as of late.

Thanks;

Jim

 

[sanman]

Hi Jim,

I totally agree with you - that's why I posted about the muons, because of their ability to catalyze the hydrogen fusions. I had posted about this a couple of months ago, on a separate thread:

https://www.physicsforums.com/showthread.php?t=226759

Here's a good refresher on muon-catalyzed fusion for everyone:

http://en.wikipedia.org/wiki/Muon-catalyzed_fusion

So to make a net energy profit, 600 fusions have to be catalyzed per muon before it expires. Right now, the best that's been demonstrated is 150, so that has to be quadrupled at least.

The density of frozen hydrogen is cited at 0.088g/cm^3:
http://hyperphysics.phy-astr.gsu.edu/Hbase/pertab/h.html

The density of metallic hydrogen is cited at 0.4g/cm^3:
http://www.springerlink.com/content/h226824477441582/

Metallic hydrogen seems to offer a density ~5 times greater than frozen hydrogen, which I'd hope might be enough for net energy output above breakeven.

Another significant problem mentioned may be the "alpha-sticking", whereby the alpha-particle produced by the fusion reaction might snatch away the muon due to its double-positive charge. I'm hoping that within the confines of the metallic hydrogen and surrounding buckyball, the alpha particle might have more difficulty leaving, so its muon might be kept available.
The other problem, mentioned in that older thread, is that the main holdup in the fusion process is the time it takes to form the muonic bond between D-T (5 nanosecs). Again, I'm hoping that the metallic state with its shorter interatomic separation distances, would accelerate the bond formation process.

Another way to favor net energy output is to reduce the energy requirements of a muon production:

http://www.springerlink.com/content/r5370246874n605u/ The next question is, how many hydrogens can fit into a C60 buckyball, at near-metallic pressures?

If required, there are larger sizes of buckyball, including C540:

http://www.3dchem.com/moremolecules.asp?ID=218&othername=c540

Perhaps with a nested buckyball (buckyonion), you could afford even higher pressures and densities of hydrogen inside.

Comments?

 

[sanman]

Here's something recent on dtµ formation, which is the main bottleneck in the muon-catalyzed fusion process:

http://www.springerlink.com/content/923x12g703511t21/

 

[James Essig]

Hi sanman;

The idea of using buckyonions I think is really neat for potentially storing high density hydrogen or deuterium. Another possible nanoscale storage material for dense hydrogen is carbon nitride which may have a bulk modulus in some forms higher than that of even pure diamond. If the pressure and temperature of the fusing hydrogen was high enough for devices based on dense hydrogen fusion fuel stored within carbon fullerenes, perhaps the carbon buckyballs could undergo nuclear fusion also, i.e., carbon nuclear fusion.

Regarding reliable warheads which use benign, cheap, and safe fusionable materials, I wonder if anyone has seriously investigated a so called water bomb, Such a device might make an excellent latter generation nuclear weapon if not a good fourth generation nuclear weapons technology.

The idea here is that a very high mass specific yield fission or fission fusion device would be used to set of a fusion reaction within a much larger volume of pure ordinary water, or perhaps pure heavy water. The yield of such devices could be staggering but kept at a safe predeployed level, wherein, when it was time to deploy the device, the liquid water could be quickly and safely added to the device in a manner in which the detonation of the primary would fuse the oxygen and hydrogen in the water thus resulting in a device with extreme yield.

If a spherically symmetrically exploding primary device could not produce the requisite pressures and temperatures to ignite the water stage, then perhaps a focused or shaped charged style nuclear device could.

It occurred to me to mention that other cheap, safe, and non-volatile exothermically nuclear fusionable fuels could be used in the construction of adjustable yield or yield augmentable thermonuclear devices including but not limited to carbon, perhaps even carbon containing plastic materials such as solid polymers, Nylon, Kevlar, and the like. Such high strength materials might somehow be utilized for their high elastic modulus to momentarily, at least on the scale of nanoseconds, provide mechanical resistance to the intense energy blast from the devices primary for purposes of allowing a super high pressure and temperature wave to develop within the carbonaceous fusion fuel in order to initiate a self propagating fusion wave front to travel thru the fussile material. Note that carbon is a good absorber of certain forms of ionizing radiation on the energy scale of nuclear reactions and has utility in modern nuclear fission reactors as a neutron flux moderator.

Although white dwarf stars as the dead remnant of stars with a mass of below about 1.4 times that of the sun are much more dense than ordinary matter at STP, in fact about a million times as dense, they can and do occasionally under go supernova which result in the complete fusioning of the entire star in a fraction of a second. So in a sense, carbon detonation fusion devices already exist in the form of naturally occurring solar mass range bodies.

Now the temperatures and pressures required to initiate a carbon fusion reaction are likely to need to be much higher, in fact they are higher, than that required for the initiation of traditional fussile materials in nuclear devices such as Lithium Dueteride. As a result, a highly optimized mass specific energy dense primary may be required, perhaps even a shaped charge type primary might be required to set off the carbonaceous or other higher atomic number fusion fuel. The use of these exotic fuels would probably only make sense for devices that have extremely high yield and thus which have a relatively large mass wherein cheap fusion fuel is desired.

Thanks;

Jim

 

[vanesch]

I have the impression there's a lot of talking here without any sound ground. Now, of course, apart from some rudimentary knowledge, I'm of course no nuclear weapon expert - and has been said here, anyone who is will not put his knowledge to display on a public forum.

However, it seems to me that always the same elementary errors are made. It is not because certain mechanisms seem 'violent' that they also correspond to high particle energies. I think that most of the mechanisms proposed here, where one wants to take into account any solid material strength, miss the point that solid materials obtain their strength from eV level binding energies, not something that can contain KeV and MeV energy particles. What nuclear explosions is concerned, any material can be seen in good approximation as a fluid.

As to metallic hydrogen, the gas giants are full of it, under much higher pressure, and with much higher inertial confinement than can be achieved in a small box, and of course there's sometimes the occasional muon which comes by (be it by the rare capture of a muon neutrino), and they don't explode like monster thermonuclear bombs.

As to the 'water bomb', as there have been nuclear tests under water, clearly (happily!) there is no self-ignition of water. H-H fusion is much more difficult than D-T and D-D fusion, and H-H is still much easier than O-O fusion. You need a supernova to achieve that!

So please, a bit more realism in the discussion, and when things become hypothetical, please provide at least some numerical estimates for the claims.