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Alpha neutron sources typically produce ~10 6 –10 8 neutrons per second. An alpha-beryllium neutron source may produce about 30 neutrons per 10 6 alpha particles. The useful lifetime for such sources depends on the half-life of the radioisotope. The size and cost of these neutron sources are comparable to spontaneous fission sources.
Any alpha-emitting radioisotope will suffice, but usually a high specific activity alpha-emitter is chosen. Historically a variety of isotopes such as radium were used, but in modern times the transuranic isotopes Am-241 and Pu-239 are almost exclusively used in AmBe and PuBe neutron sources, respectively. [1]
The following are among the principal radioactive materials known to emit alpha particles. 209 Bi , 211 Bi , 212 Bi , 213 Bi 210 Po , 211 Po , 212 Po , 214 Po , 215 Po , 216 Po , 218 Po
Large neutron sources are rare, and usually limited to large-sized devices such as nuclear reactors or particle accelerators, including the Spallation Neutron Source. Neutron radiation was discovered from observing an alpha particle colliding with a beryllium nucleus, which was transformed into a carbon nucleus while emitting a neutron, Be(α ...
Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. [5] They are generally produced in the process of alpha decay but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α.
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.
Bomb-making materials linked to the New Year's Day attack in New Orleans were recovered by FBI agents and local law enforcement Thursday at the suspect's residence in Houston, Texas, sources ...
A common type of startup neutron source is a mixture of an alpha particle emitter such as 241 Am (americium-241) with a lightweight isotope such as 9 Be (beryllium-9). The primary sources described above have to be used with fresh reactor cores. For operational reactors, secondary sources are used; most often a combination of antimony with ...