ABSTRACT
In the early days of the nuclear industry, scientists invented a way to measure the probability that an incoming particle would actually "hit" the nucleus and cause a nuclear reaction to occur. A nuclear cross section is a convenient way of measuring the probability that an incoming particle will hit the nucleus and, as the result of that collision, cause a particular nuclear reaction or set of reactions to occur. The number of particles that are scattered and the number of particles that are absorbed can vary tremendously depending upon the target and: the energy of the incoming particle, the type of particle, and the material from which the target is made. The chapter shows that the values of almost all nuclear cross sections are dependent on the kinetic energy of the incoming neutrons. It demonstrates how can find the macroscopic scattering, absorption, and fission cross sections based on only the knowledge of a material's physical properties.
