Neutron flux refers to the amount or number of neutrons passing through an area in a given time. It measures the intensity or density of neutrons and is often used in the context of nuclear reactions or nuclear reactors. Full definition
What also comes with it are very high neutron flux levels, which open up a variety of applications for stockpile stewardship, high energy density physics and nuclear physics. (llnl.gov)
The upper internals structure (UIS) houses instrumentation which measures critical properties such as flow velocity, temperature, neutron flux levels, etc.. (nuclearstreet.com)
Examples include fast neutron flux materials test facilities, fuel - cycle separations test facilities, and facilities for novel nuclear applications,» and using the higher heat generated in fast reactors for industrial purposes as well as power generation, it says. (scientificamerican.com)