Neutron flux is the process of passing neutrons through a region in space.
Both within natural processes and in the experimental laboratory, neutron flux may be applied to atomic nuclei, in which nuclei are bombarded with neutrons at a steady rate. This can be used to produce different isotopes, including unstable, radioactive ones, of a given chemical element.
Neutron flux may refer to the number of neutrons passing through a unit area in unit time It is most commonly measured in neutrons/cm2-sec. This is drawn from the mathematical definition of flux.