How does the polyurethane foam in a hbomb channel the xrays?

[Beamin]

Polyurethane is just a matrix of CHO atoms in a low density state. In the teller-ulam design the reaction is Fission fusion fission or more technically fission fusion fission fusion fission (see avatar with a two stage weapon with "spark plug" and 4th fission leads to last stage fission of almost 100%. That's why they can make them so small the fission is almost complete before the material flies apart. The PU foam is used as a director for the xrays so that they will thermally heat the casing or tamper and radiate more xrays on the inside crushing the next core using radiation pressure. Is that ratio of CHO is what needed or does one of those atoms (there are no molecules at this point just hot plasma) have the right electron state where the initial xrays are at a certain frequency to bump up the electrons and in optimal time reradiate them out as more xrays as they try to reach ground state. The time from excited to ground may be chosen specifically to give the bomb materials time to react in a controlled manor. Which atom does this? This isn't rocket science so we should be able to figure out why this low density material is best.

[Beamin]

Bonus points and a surprise visit from men in suits if you can guess the neutron source.

[helius]

While many details are in the public domain (see the seminal book "The Making of the Atomic Bomb"), intelligent people are hesitant to discuss such subjects in public fora. There have been harsh consequences for disclosing this type of information.

[raptor1956]

And then there's the idea that foam is a poison to prevent a fusion reaction from taking place and was promoted to thwart the development by non-nation state actors.

But, questions like this will without any doubt get you noticed by intelligence agencies and not just the obvious ones.

Probably safer to ask how to make a pressure cooker bomb.


Brian

[CopperCone]

I thought it just got so ridiculously hot that it did compression. You can't really focus x-rays. All you can do is try to make them in a favorable direction like the starwars directional xray 'lasers' using spaghetti structures. I don't think you can say the plasma acts as some kind of x-ray lens or something, you would probobly need a strong field to bend them, like gravity.

Being able to refract x-rays would mean that plasma would have a index of refraction for x-ray energy... that would mean unless the plasma phase is unique to the nuclear pressure you would have plasma x-ray lens being used in other applications.

There exist x-ray optics but they seem to be multistage complicated devices. They are made of light elements however. I wonder if you can dope a specific foam structure with the right elements to make some kind of temporary plasma based mirror or something... something 4th generation weapons might use if its possible. Would probably need to be 3d printed.

[CopperCone]

And then there's the idea that foam is a poison to prevent a fusion reaction from taking place and was promoted to thwart the development by non-nation state actors.

But, questions like this will without any doubt get you noticed by intelligence agencies and not just the obvious ones.

Probably safer to ask how to make a pressure cooker bomb.


Brian

bro you need to chill no one gives a shit. You need to buy like 100 tons of crap to even get these people to bat an eye. And try fixing a problem with them 

someone might actually care about a pressure cooker bomb because its easy to make without being a rogue dictator.. thats just bad advice.

[ez24]

Bonus points and a surprise visit from men in suits if you can guess the neutron source.

Li ?

[alpher]

Or jst google NWFAQ, pretty comprehensive.
One of the chapters deals specifily with e subject.

[alpher]

"The ablation process"
http://nuclearweaponarchive.org/Nwfaq/Nfaq4-4.html#Nfaq4.4.3.3

[Beamin]

I thought it just got so ridiculously hot that it did compression. You can't really focus x-rays. All you can do is try to make them in a favorable direction like the starwars directional xray 'lasers' using spaghetti structures. I don't think you can say the plasma acts as some kind of x-ray lens or something, you would probobly need a strong field to bend them, like gravity.

Being able to refract x-rays would mean that plasma would have a index of refraction for x-ray energy... that would mean unless the plasma phase is unique to the nuclear pressure you would have plasma x-ray lens being used in other applications.

There exist x-ray optics but they seem to be multistage complicated devices. They are made of light elements however. I wonder if you can dope a specific foam structure with the right elements to make some kind of temporary plasma based mirror or something... something 4th generation weapons might use if its possible. Would probably need to be 3d printed.

It's not focusing or reflecting xray like optics. The Xrays pass through/interact with the PU then heat the inside of the tamper/casing so much that xrays are reradiated (not reflected like a mirror, they are absorbed) back onto the contents of the inside of the package causing massive pressure then heating. I don't know if the heating is even needed as crushing solid metal that much generates tremendous amounts of heat on its own due to ALL the metallic bonds breaking at once. See how much energy it takes to bend metal now multiply that back with the metal resisting and becoming harder to compress as it gets smaller.

[Beamin]

And then there's the idea that foam is a poison to prevent a fusion reaction from taking place and was promoted to thwart the development by non-nation state actors.

But, questions like this will without any doubt get you noticed by intelligence agencies and not just the obvious ones.

Probably safer to ask how to make a pressure cooker bomb.


Brian

bro you need to chill no one gives a shit. You need to buy like 100 tons of crap to even get these people to bat an eye. And try fixing a problem with them 

someone might actually care about a pressure cooker bomb because its easy to make without being a rogue dictator.. thats just bad advice.

No way in hell I would google that last device. You know that sets off red flags everywhere. And if your stupid enough not to figure that out on your own you kind of deserve a stern talk.


I don't see how the UE would poison the bomb. Poisons are usually things like Xe and other absorbers and if it was true how hard would it be to replace the PU with something else? It's literally the one part you can get at home depot.

[CopperCone]

why would you restrict the pressure being generated from X-ray only? All the electromagnetic energy associated with the plasma formation results in the mechanical pressure required to compress the thing inside of it. The material is probobly designed to absorb as much energy as possible but the result in uniform compression.

I think the book 'on nuclear war' had the EM spectrum of a nuclear blast listed, I need to look at that again.

I am saying you probobly can do some tricky shit to actually reflect/direct x-rays rather then just reheating something to insane temperatures to form a device that behaves differently.

[gildasd]

Just a wild guess...
X rays cannot be focused, they emit in the shape of the explosion.
But, a explosion could be shaped for an extremely short instant using various foams that resist pressure differently.
The formed explosion then emits for that instant how its designers intend.

Rings a distant bell about something about mining explosives, might have read something years ago, probably a science magazine.

[capt bullshot]

No idea. I've got all my atomic bomb knowledge from reading Tom Clancy's "The Sum of All Fears", there's no foam mentioned in that book. But there's a really catching description of how they built an H-Bomb and why it failed to detonate with its desigend capacity.

[gildasd]

No idea. I've got all my atomic bomb knowledge from reading Tom Clancy's "The Sum of All Fears", there's no foam mentioned in that book. But there's a really catching description of how they built an H-Bomb and why it failed to detonate with its desigend capacity.

A real good book, you made me want to read it again.

[hamster_nz]

What I found interesting was that when work was carried out to refubish warheads in the 2000s nobody could make the FOGBANK aerogel that was in spec.

This threatened the whole program, as it was  impossible to refurbish the wareheads.

The issue was eventually traced to a missing 'contaminant' in the feedstock.

(This is all there on Wikipedia, no state secrets have been harmed by this post)

 https://en.m.wikipedia.org/wiki/FOGBANK

Puts a new twist on the adage 'use it or loose it' I guess. Lets hope it gets lost.

[hamster_nz]

The problem is that you want the secondary (the H-bomb bit) to get a very even 'all over tan' in the most extreme tanning booth ever made. Anything that can cast a shadow will cause uneven heating, and therefore uneven compression in the secondary, and either lower the yield or stop it working at all.  Given this, it is easy to see why it would be helpful to have a robust low-density foam made out of mostly light-weight atoms to keep everything in place.

Oh, and for the morbidly curious, Greenpeace once published an exploded-but-not-THAT-exploded view of a British thermonuclear warhead. It isn't as common on the web as it once was, but here is a link:

http://alt.war.nuclear.narkive.com/QEDLSYs5/w80-internal-drawings-from-greenpeace:i.1.1.full

(just google Greenpeace British H-Bomb diagram if/when the link breaks).

[Beamin]

Just a wild guess...
X rays cannot be focused, they emit in the shape of the explosion.
But, a explosion could be shaped for an extremely short instant using various foams that resist pressure differently.
The formed explosion then emits for that instant how its designers intend.

Rings a distant bell about something about mining explosives, might have read something years ago, probably a science magazine.

Look at my avatar all this happens in nano seconds before the case of the device is ruptured. Rather then contain it they use speed so fast matter doesn't have time to start moving very far. The bomb is done exploding before you would even see the case start to deform. Then you have a lot of angry pixies inside that want to get out in a hurry.