Editing Neutron source (section)

===Alpha decay===
Neutrons are produced when [[alpha particle]]s hit any of several light isotopes including isotopes of [[beryllium]], [[carbon]], or [[oxygen]]. Thus, a neutron source can be fabricated by mixing an alpha-emitter such as [[radium]], [[polonium]], or [[americium]] with a low-atomic-weight isotope, usually by blending powders of the two materials. Alpha neutron sources typically produce ~10<sup>6</sup>–10<sup>8</sup> neutrons per second. An alpha-beryllium neutron source may produce about 30 neutrons per 10<sup>6</sup> 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. Usual combinations of materials are [[plutonium]]-beryllium (PuBe), americium-beryllium (AmBe), or americium-[[lithium]] (AmLi).