Neutron Transport Theory and Simulation

Devoted to describing neutron movement in media and the corresponding laws, neutron transport theory is the research basis for transmutation and activation, radiation damage to materials, radiation dose, and biological safety, among other topics. There are two methods for neutron transport calculation: the Monte Carlo method (also called the probabilistic method or the stochastic method) and the deterministic method. The Monte Carlo method is a numerical method based on probability and statistical theories. It can explicitly describe the characteristics of randomly moving particles and the process of physical experiments. In contrast, in the deterministic method, a group of mathematical-physical equations is first built up to explain the physical characteristics of the target system. Then, by discretizing the variables including direction, energy, space and time in these equations, an approximate solution can be obtained with numerical calculation. This chapter introduces the basic principles of neutron interactions with matter, neutron transport theory, simulation methods and codes for fusion neutron transport calculations.