ABSTRACT

This chapter is devoted to the interactions of neutrons with matter. This topic is of interest when we are looking for uses in science and technology or we are concerned with the radiation damage and hazards they pose. Neutron interactions with material media share some features with charged particles and some others with photons, but some aspects of these interactions are unique to them. We can talk about the slowing down of neutrons, i.e., neutrons losing energy by multiple elastic collisions along their path in the medium, in the same way as for charged particles. Their interactions resemble those of charged particles in that the neutron after scattering is the same one we started with except it is of lower energy and is deflected from its original path. Unlike the case of charged particles, which leave ionization trails along their paths, neutrons leave no track. Also, analogous to photon propagation, they may travel long distances without interactions and be absorbed in a single encounter.