Spontaneous fission (SF) is a form of radioactive decay in which a heavy atomic nucleus splits into two or more lighter nuclei. In contrast to induced fission, there is no inciting particle to trigger the decay; it is a purely probabilistic process.
Spontaneous fission is a dominant decay mode for superheavy elements, with nuclear stability generally falling as nuclear mass increases. It thus forms a practical limit to heavy element nucleon number. Heavier nuclides may be created instantaneously by physical processes, both natural (via the r-process) and artificial, though rapidly decay to more stable nuclides. As such, apart from minor decay branches in primordial radionuclides, spontaneous fission is not observed in nature.
Observed fission half-lives range from 4.1 microseconds (250 102No ) to greater than the current age of the universe (232 90Th ).[1]: 16
^Schunck, Nicolas; Regnier, David (1 July 2022). "Theory of nuclear fission". Progress in Particle and Nuclear Physics. 125. arXiv:2201.02719. doi:10.1016/j.ppnp.2022.103963.
and 29 Related for: Spontaneous fission information
Spontaneousfission (SF) is a form of radioactive decay in which a heavy atomic nucleus splits into two or more lighter nuclei. In contrast to induced...
30 Nuclear fission can occur without neutron bombardment as a type of radioactive decay. This type of fission is called spontaneousfission, and was first...
weapons and nuclear reactors. Plutonium-240 exhibits a high rate of spontaneousfission, raising the neutron flux of any sample containing it. The presence...
for spontaneousfission or even induced fission with fast neutrons; uranium-235, and to a lesser degree uranium-233, have a much higher fission cross-section...
isotope of the same element. Neutrons are also produced in the spontaneous and induced fission of certain heavy nuclides. As a consequence of the Pauli exclusion...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
identical nuclei fissioning. As the atomic number increases, spontaneousfission rapidly becomes more important: spontaneousfission partial half-lives...
in microseconds, it then seemed that instability with respect to spontaneousfission would limit the existence of heavier elements. In 1939, an upper...
produced as a synthetic element. Naturally occurring technetium is a spontaneousfission product in uranium ore and thorium ore (the most common source),...
neutrons for deformed nuclei, which gives it greater stability against spontaneousfission. Hassium is a superheavy element; it has been produced in a laboratory...
identical nuclei fissioning. As the atomic number increases, spontaneousfission rapidly becomes more important: spontaneousfission partial half-lives...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
Some isotopes undergo SF with emission of neutrons. The most common spontaneousfission source is the isotope californium-252. 252Cf and all other SF neutron...
gun-type fission weapon using plutonium called Thin Man. In April 1944, the Los Alamos Laboratory determined that the rate of spontaneousfission in plutonium...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
one to two million times that of spontaneousfission, so weapon engineers are careful to use fuel of high purity. Fission weapons used in the vicinity of...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
identical nuclei fissioning. As the atomic number increases, spontaneousfission rapidly becomes more important: spontaneousfission partial half-lives...
identical nuclei fissioning. As the atomic number increases, spontaneousfission rapidly becomes more important: spontaneousfission partial half-lives...
identical nuclei fissioning. As the atomic number increases, spontaneousfission rapidly becomes more important: spontaneousfission partial half-lives...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
identical nuclei fissioning. As the atomic number increases, spontaneousfission rapidly becomes more important: spontaneousfission partial half-lives...
identical nuclei fissioning. As the atomic number increases, spontaneousfission rapidly becomes more important: spontaneousfission partial half-lives...
occur when atoms react with natural neutrons (from cosmic rays, spontaneousfission, or other sources), or are bombarded directly with cosmic rays. The...
decay and spontaneousfission. Almost all alpha emitters have over 210 nucleons, and the lightest nuclide primarily undergoing spontaneousfission has 238...
material that self-sustains a fission chain reaction. In this case, called criticality, k = 1. A steady rate of spontaneousfission causes a proportionally...
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