And if so, what factors determine it?
I know that the scale of the explosion is an insane amount larger than the teeny molecules causing it, but I’m wondering if there could ever be nuclear explosions small enough to take out a single house or block, rather than a whole city from high above.
In: Physics
As far as I understand, yes. (I am not an expert, I have my physics BA, but that’s it; I never took nuclear physics or the like).
The main requirement for Sustained Fission reactions is having criticality, which means that any initial Fission reactions will cause additional Fission reactions in a constant rate(this is usually the goal in nuclear reactors). Nuclear Bombs want to take this a step further, and achieve Supercriticality, where additional Fission reactions happen at an increasing rate, thus allowing it to react fast and make a detonation.
This is all dependent on the size and shape of the nuclear material, as this is just a measure of how likely the neutron byproducts are to hit another atom and cause another Fission reactions – the less atoms there are, the less likely to have additional reactions.
If you look up Critical Mass on Wikipedia, you’ll see Plutonium-239 has a Critical Mass of 10kg, so any samples less than that would “fizzle out” without a detonation, and we would probably just get a big dose of radiation. The minimum size of a bomb would likely need to be somewhat bigger than 10kg, which would still have considerable destructive power.
Latest Answers