Physics:Neutron fluence

Particle fluence is defined as the number of particles traversing a unit area in a certain point in space in a unit period of time. Most frequently, it is measured in cm^-2.

In particular, neutron fluence in high-energy physics applications is of interest in the context of the radiation environment around the interaction regions of colliders; it serves as a measure for potential radiation damage for the detector systems to be used there. It is common practice to express charged and neutral particle contributions to radiation in terms of dose ( Radiation Measures and Units) and 1 MeV neutron equivalent fluence ( also NIEL Scaling), respectively.

The 1 MeV equivalent MeV equivalent neutron fluence is the fluence of 1 MeV neutrons producing the same damage in a detector material as induced by an arbitrary particle fluence with a specific energy distribution. The choice of this particular normalization is partly due to historical reasons, as the standard energy to scale to was considered first in damage studies in the MeV range, in neutron physics; however, there is also a physical background: the neutron spectra expected in detectors at future hadron colliders typically have a probability density peaking in this energy region.