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Post by vegemeister on Mar 26, 2017 3:48:13 GMT
Critical mass is considered with bombs. But the critical masses in CoaDE are actually much greater than IRL. You run into it when trying to scale up bombs, at the high-yield end where explosive compression is insignificant and you're just squashing a hollow sphere of U-233 into a critical configuration. The maximum yield/mass ratio occurs around 1.35 Mt, which is the smallest amount of U-233 that can achieve 50% fission from a non-compressing design. Pushing yield higher increases the ratio of explosive mass to core mass, because you have to increase the hollow sphere diameter to avoid criticality problems, and you can't change the shape of the high-velocity explosive part of the explosive lenses. The reason we can make atomic hand grenades is that CoaDE allows impossibly small explosive compression ratios. I think I recall reading somewhere on nuclearweaponarchive.org that it was very difficult to get below 0.3 or so.
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Post by samchiu2000 on Mar 26, 2017 7:07:31 GMT
Critical mass is considered with bombs. But the critical masses in CoaDE are actually much greater than IRL. You run into it when trying to scale up bombs, at the high-yield end where explosive compression is insignificant and you're just squashing a hollow sphere of U-233 into a critical configuration. The maximum yield/mass ratio occurs around 1.35 Mt, which is the smallest amount of U-233 that can achieve 50% fission from a non-compressing design. Pushing yield higher increases the ratio of explosive mass to core mass, because you have to increase the hollow sphere diameter to avoid criticality problems, and you can't change the shape of the high-velocity explosive part of the explosive lenses. The reason we can make atomic hand grenades is that CoaDE allows impossibly small explosive compression ratios. I think I recall reading somewhere on nuclearweaponarchive.org that it was very difficult to get below 0.3 or so. Oh i see~ And what about the reactor?
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Post by newageofpower on Mar 26, 2017 8:19:43 GMT
Reactors also follow critical mass laws; to obtain a sub-kg reactor core (as seen with minireactors in CoADE) would require a ludicrous amount of neutron reflector and almost certainly mass more than a less extreme design.
Unlike with nuclear warheads, we can't squash the fissile material to a critical density using explosives.
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Post by samchiu2000 on Mar 26, 2017 9:07:15 GMT
Reactors also follow critical mass laws; to obtain a sub-kg reactor core (as seen with minireactors in CoADE) would require a ludicrous amount of neutron reflector and almost certainly mass more than a less extreme design. Unlike with nuclear warheads, we can't squash the fissile material to a critical density using explosives. As I know the reactor in COADE don't necessarily need a neutron deflector to work. The deflector actually only reduce the radiation hazard of the reactor. And i also find that decrease in mass of control rod will make the reactor stop generating power due to criticality , so i doubt if the control rod will affect the critical mass of the fissile material in the reactor...
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Post by deltav on Mar 27, 2017 22:12:30 GMT
Nuclear reaction is started by sufficient density of neutrons flying everywhere. Get enough critical mass, and you get enough neutrons. Neutron reflector instead reflect the neutron back to the fissile material, so even with less critical mass, you can still have a nuclear bomb, or a working nuclear reactor. Sound a good explain but why the smallest nuke IRL is order of magnitudes heavier than the one in COADE? en.wikipedia.org/wiki/W54This 6 kT nuke is 23 kg in Mass. There are even smaller nukes out there that are top secret, one known to measure 13 x 62 cm, about the diameter of a grapefruit. en.wikipedia.org/wiki/Suitcase_nuclear_deviceThey are unacknowledged due to politics I think, but it can be done. What it looks like when a mini nuke explodes.
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ndeo
Junior Member
It's not a flashlight... It's a High-frequency relativistic boson cannon
Posts: 67
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Post by ndeo on Mar 28, 2017 3:00:06 GMT
The USSR had made impractical californium-252 nuclear bullets but overheating was an issue The half-life is ~2.645 years
Edit: seems sketchy, bare sphere criticality is only 2.73kg
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Post by concretedonkey on Mar 28, 2017 4:11:56 GMT
Sound a good explain but why the smallest nuke IRL is order of magnitudes heavier than the one in COADE? en.wikipedia.org/wiki/W54This 6 kT nuke is 23 kg in Mass. There are even smaller nukes out there that are top secret, one known to measure 13 x 62 cm, about the diameter of a grapefruit. en.wikipedia.org/wiki/Suitcase_nuclear_deviceThey are unacknowledged due to politics I think, but it can be done. ... What it looks like when a mini nuke explodes. ... just a fast correction , SADM is variable 10t to 1kt from the info I have. link
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Post by deltav on Mar 28, 2017 6:01:34 GMT
en.wikipedia.org/wiki/W54This 6 kT nuke is 23 kg in Mass. There are even smaller nukes out there that are top secret, one known to measure 13 x 62 cm, about the diameter of a grapefruit. en.wikipedia.org/wiki/Suitcase_nuclear_deviceThey are unacknowledged due to politics I think, but it can be done. ... What it looks like when a mini nuke explodes. ... just a fast correction , SADM is variable 10t to 1kt from the info I have. linkThank you much but no need.... the common use was as the link stated, but with the W54 SADM up to 6 kT yield was tested. "A 1958 test of the XW-54 warhead yielded 6 kilotons...." "While the explosive power of the W54, up to an equivalent of 6 kiloton of TNT (though the more common yield was much lower..." en.wikipedia.org/wiki/Special_Atomic_Demolition_MunitionEdit: I only know what they tell me...
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Post by concretedonkey on Mar 28, 2017 6:47:35 GMT
Wasn't aware of XW-54. Interesting, I might ramp up the yield of the small nukes in my restock thread. Thanks
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Post by deltav on Mar 28, 2017 8:31:47 GMT
Wasn't aware of XW-54. Interesting, I might ramp up the yield of the small nukes in my restock thread. Thanks I think the "X" means it was the prototype... They must have figured that 6 kT is too large for tactical field use.
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Post by Enderminion on Mar 28, 2017 11:09:18 GMT
In Army/Airforce terms, Xwhatever is not general issue
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Post by ash19256 on Mar 28, 2017 17:24:25 GMT
In Army/Airforce terms, Xwhatever is not general issue Yeah, IIRC an X designation means that it's an experimental prototype (think X-1, X-15, etc.), while a Y designation means that it's a pre-production prototype (ie. Northrop Grumman YF-23, which was a direct competitor to the F-22, which was the YF-22 before it was accepted).
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