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Decay chain of 240 Pu. Plutonium-240 (240 Pu or Pu-240) is an isotope of plutonium formed when plutonium-239 captures a neutron.The detection of its spontaneous fission led to its discovery in 1944 at Los Alamos and had important consequences for the Manhattan Project.
240 Pu undergoes spontaneous fission at a small but significant rate (5.8 × 10 −6 %). [1] The presence of 240 Pu limits the plutonium's use in a nuclear bomb, because a neutron from spontaneous fission starts the chain reaction prematurely, causing an early release of energy that disperses the core before full implosion is reached. This ...
Of these decay processes, only alpha decay (fission of a helium-4 nucleus) changes the atomic mass number ... 240 Pu: 240 Pu α 6561 a 5.1683 236 U:
The "reactor-grade" plutonium produced by a regular LWR burnup cycle typically contains less than 60% Pu-239, with up to 30% parasitic Pu-240/Pu-242, and 10–15% fissile Pu-241. [126] It is unknown if a device using plutonium obtained from reprocessed civil nuclear waste can be detonated, however such a device could hypothetically fizzle and ...
Cluster decay, like alpha decay, is a quantum tunneling process: in order to be emitted, the cluster must penetrate a potential barrier. ... 240 Pu: 34 Si < 6 ...
Moreover, 239 Pu and 240 Pu cannot be chemically distinguished, so expensive and difficult isotope separation would be necessary to separate them. Weapons-grade plutonium is defined as containing no more than 7% 240 Pu; this is achieved by only exposing 238 U to neutron sources for short periods of time to minimize the 240 Pu produced.
Watchdogs are raising new concerns about legacy contamination in Los Alamos, the birthplace of the atomic bomb and home to a renewed effort to manufacture key components for nuclear weapons. A ...
Alpha decay is by far the most common form of cluster decay, where the parent atom ejects a defined daughter collection of nucleons, leaving another defined product behind. It is the most common form because of the combined extremely high nuclear binding energy and relatively small mass of the alpha particle.