neutronsensitive

Neutronsensitive is an adjective used to describe a material, device, or component that exhibits a measurable response to neutron radiation. In practice, this can mean detection of neutrons, absorption or scattering of neutrons, or activation that produces detectable byproducts. Neutronsensitive systems are often contrasted with those that respond primarily to gamma rays or charged particles. The degree and type of sensitivity can depend on neutron energy (thermal, epithermal, or fast) and on the presence of moderating or absorbing materials in the system.

Neutron interactions with matter occur mainly through elastic scattering with light nuclei, neutron absorption (capture) which produces charged particles or gamma radiation, and nuclear reactions such as (n,α), (n,p), or fission. Elastic scattering with hydrogen-rich media is especially effective for slowing fast neutrons, while capture by certain nuclei yields signals used for detection. Materials chosen for neutron sensitivity are selected for their likelihood of interaction with neutrons and the ease of converting the interaction into a measurable signal.

Common neutron-sensitive detectors and materials include helium-3 gas proportional counters, boron-10 and lithium-6 based detectors (such as BF3 counters and LiF/ZnS(Ag) scintillators), gadolinium-loaded scintillators, and various boron- or gadolinium-doped scintillating materials. Neutron sensitivity can be engineered for specific applications, often with moderators to tailor the energy range or shielding to reduce gamma background.

Applications span neutron radiography and diffraction, reactor monitoring and safety, radiation-dose measurement, and homeland security. In all cases, distinguishing neutron-induced signals from gamma or charged-particle backgrounds is a key design consideration, as is the choice of materials to achieve the desired neutron sensitivity and energy response.