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The first nuclear explosive devices provided the basic building blocks of future weapons. Pictured is the Gadget device being prepared for the Trinity nuclear test.. Nuclear weapons design are physical, chemical, and engineering arrangements that cause the physics package [1] of a nuclear weapon to detonate.
Furthermore, the neutrons emitted by a neutron bomb have a much higher average energy level (close to 14 MeV) than those released during a fission reaction (1–2 MeV). [10] Technically speaking, every low-yield nuclear weapon is a radiation weapon, including non-enhanced variants.
The nominal spherical critical mass for an untampered 235 U nuclear weapon is 56 kilograms (123 lb), [6] which would form a sphere 17.32 centimetres (6.82 in) in diameter. The material must be 85% or more of 235 U and is known as weapons grade uranium, though for a crude and inefficient weapon 20% enrichment is sufficient (called weapon(s)-usable).
The first detonation of a nuclear bomb that included U-233, on 15 April 1955. As a potential weapon material, pure uranium-233 is more similar to plutonium-239 than uranium-235 in terms of source (bred vs natural), half-life and critical mass (both 4–5 kg in beryllium-reflected sphere). [8]
A modulated neutron initiator is a neutron source capable of producing a burst of neutrons on activation. It is a crucial part of some nuclear weapons, as its role is to "kick-start" the chain reaction at the optimal moment when the configuration is prompt critical. It is also known as an internal neutron initiator.
In a fission nuclear reactor, uranium-238 can be used to generate plutonium-239, which itself can be used in a nuclear weapon or as a nuclear-reactor fuel supply. In a typical nuclear reactor, up to one-third of the generated power comes from the fission of 239 Pu, which is not supplied as a fuel to the reactor, but rather, produced from 238 U. [5] A certain amount of production of 239
These free neutrons will then interact with the surrounding medium, and if more fissile fuel is present, some may be absorbed and cause more fissions. Thus, the cycle repeats to produce a reaction that is self-sustaining. Nuclear power plants operate by precisely controlling the rate at which nuclear reactions occur. Nuclear weapons, on the ...
Some isotopes undergo spontaneous fission (SF) with emission of neutrons.The most common spontaneous fission source is the isotope californium-252. 252 Cf and all other SF neutron sources are made by irradiating uranium or a transuranic element in a nuclear reactor, where neutrons are absorbed in the starting material and its subsequent reaction products, transmuting the starting material into ...