In nuclear engineering, a prompt neutron is a neutron immediately emitted by a nuclear fission event, as opposed to a delayed neutron decay which can occur within the same context, emitted after beta decay of one of the fission products anytime from a few milliseconds to a few minutes later.
Prompt neutrons are emitted with life times on the order of 10−22 seconds after exitation of the nuclide that emits the neutron. This emission is controlled by the nuclear force and is extremely fast. By contrast, so-called delayed neutrons are delayed by the time delay associated with beta decay (mediated by the weak force) to the precursor excited nuclide, after which neutron emission happens on a prompt time scale (i.e., almost immediately).
Read more about Prompt Neutron: Principle, Importance in Nuclear Fission Basic Research, Importance in Nuclear Reactors, Fraction Definitions
Famous quotes containing the word prompt:
“Can anything be so elegant as to have few wants and to serve them one’s self, so as to have somewhat left to give, instead of being always prompt to grab?”
—Ralph Waldo Emerson (1803–1882)