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Author: Subject: Nuclear device core detonation speed, etc?
Fyndium
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[*] posted on 17-12-2020 at 04:02
Nuclear device core detonation speed, etc?


What is the detonation speed in a core of thermonuclear device? The pressures generated cited by Wiki are 64 billion bar. The one of the first nuclear tests was presumed to have been ejected the steel plate covering the mine shaft beyond escape velocity.

What would be an upper limit to any nuclear reaction mass speed, except for theoretical speed of light? What kind of effects these could exert compared to conventional explosives? Would the (theoretical) antimatter-matter reaction have even higher reaction speeds than nuclear (fusion)?

If there was a configuration that allowed high explosives to be used as a rocket propellant, couldn't that induce huge acceleration speeds? I have read somewhere that interceptor missiles used some sort of high energy propellant for faster acceleration?

[Edited on 17-12-2020 by Fyndium]
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Fulmen
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[*] posted on 17-12-2020 at 09:06


A thermonuclear device utilizes both fission and fusion, but neither process have much in common with a detonation. Both processes happen all throughout the fuel assembly at once. Fission is a chain reaction driven by neutrons, and one step (i.e. the time it takes for one neutron to cause a fission event) is in the order of 10 nanoseconds. The entire reaction will be over in something like 1 microsecond.





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Dornier 335A
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[*] posted on 17-12-2020 at 09:12


The velocity of the fast neutrons driving the chain reaction is close to the speed of light, so that would be the detonation velocity. I doubt the velocity is related to the pressure like in conventional explosives though. The antimatter-matter annihilation on the other hand is not a chain reaction so it's hard to define a detonation velocity. The reaction can only proceed in the boundary layer.

Regarding the rocket:
No rocket engine is strong enough to withstand a high explosive. So the propellant has to burn and not detonate. Now, a good rocket contains lots of stored energy per dry weight which requires high energy density. Conventional bipropellants like liquid hydrogen/liquid oxygen easily store twice as much energy per weight as high explosives. The propellant also needs to have good efficiency, which requires light exhaust gases. Water and hydrogen are good, nitrogen and carbon dioxide from HEs are bad. Acceleration is just a matter of thrust-to-weight ratio and has little to do with the fuel used. The interceptor missiles probably used some kind of APCP but had a huge internal surface area to burn it as quickly as possible.




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Fulmen
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[*] posted on 17-12-2020 at 09:45


Nah, even with fusion the speed will be less than 20% of c, for fission the average is closer to 5%. And detonation velocity simply doesn't apply, there is no detonation as understood in the context of conventional explosives.



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MadHatter
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[*] posted on 17-12-2020 at 10:42
HMX based rocket propellants


https://scitoys.com/he_rocket_fuels.html

In some cases high explosives can be part
of a propellant mix.




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[*] posted on 17-12-2020 at 19:09


Quote: Originally posted by Dornier 335A  
The velocity of the fast neutrons driving the chain reaction is close to the speed of light, so that would be the detonation velocity. I doubt the velocity is related to the pressure like in conventional explosives though. The antimatter-matter annihilation on the other hand is not a chain reaction so it's hard to define a detonation velocity. The reaction can only proceed in the boundary layer.

Regarding the rocket:
No rocket engine is strong enough to withstand a high explosive. So the propellant has to burn and not detonate. Now, a good rocket contains lots of stored energy per dry weight which requires high energy density. Conventional bipropellants like liquid hydrogen/liquid oxygen easily store twice as much energy per weight as high explosives. The propellant also needs to have good efficiency, which requires light exhaust gases. Water and hydrogen are good, nitrogen and carbon dioxide from HEs are bad. Acceleration is just a matter of thrust-to-weight ratio and has little to do with the fuel used. The interceptor missiles probably used some kind of APCP but had a huge internal surface area to burn it as quickly as possible.


What Is A Rotating Detonation Engine - And Why Are They Better Than Regular Engines https://www.youtube.com/watch?v=rG_Eh0J_4_s

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Pyro_cat
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[*] posted on 17-12-2020 at 19:11


Since this is a nuke thread I have to add Going Nuclear a multi part series https://www.youtube.com/playlist?list=PLYu7z3I8tdEnTQMXpP6gY...

This was my favorite nuke series.
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Fulmen
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[*] posted on 19-12-2020 at 08:28


Agreed, it's well worth a watch.



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[*] posted on 24-12-2020 at 01:25


Matter-Antimatter? How fast? Dunno.

Maybe I'll explore that.

Plenty hot though. In Fission and Fusion, a tiny perectage of Mass is converted to Energy.

With Matter-Antimatter, I would assume complete Annihilation. No residual mass, all energy!
And, that would be quite a bang.

You ah... have some Anti-matter, you are looking to sell?

Used to be a guy floating around, that claimed UFOs were powered by Antimatter. It was a fun story!

I think his name is Lazar, and regardless of his stories, I believe he is a supplier that some of our members make purchases from. https://en.wikipedia.org/wiki/Bob_Lazar

His original interviews were very entertaining. But, you can't just dial them up anymore. A few decades of me-toos, have buried things.

[Edited on 24-12-2020 by zed]

[Edited on 24-12-2020 by zed]

[Edited on 24-12-2020 by zed]
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Fulmen
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[*] posted on 24-12-2020 at 11:47


Nuclear reactions occur in the femtosecond-range or faster, so it's getting pretty close to "instantly". The limitations will be the physical matter/antimatter interaction.
The energy content in matter is in the order of some 20MT per kilo, meaning the Tsar Bomba converted 2.5kg (5lbs) of mass into energy.




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[*] posted on 4-1-2021 at 11:49


Attachment: NFAQ.pdf (2.9MB)
This file has been downloaded 875 times

atomcentral.com
nuclearweaponarchive.org

yt:thecentralnuclear


Videos:

Castle Bravo
Grable
Hardtack
Ivy Mike
Plumbbob
Redwing
Teapot
Tsar

Speed: 90km/s (Page 99)

[Edited on 5-1-2021 by Nitrosio]
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