Neutron detection mechanisms are generally based on indirect methods. Since neutrons are neutral in charge, they do not interact directly with the electrons in matter. As such, neutron detection relies on neutrons interacting with various nuclei, initiating the release of one or more charged particles. The electrical signals produced by the charged particles can then be processed by the detection system.

Two types of neutron interactions are generally used:

• Scattering  by a nucleus with transfer of some kinetic energy to the nucleus.

  If enough energy is transferred, then the recoiling nucleus ionizes the material surrounding the point of interaction. This is based on the interaction of neutrons with low-Z nuclides.

• Neutrons can cause a nuclear reaction

  The products from the reaction, which could include protons, alpha-particles, gamma-rays, and fission fragments, can initiate the detection process. Some reactions do require a minimum energy, but most are dominated by thermal neutron reactions