Neutron diffusion refers to the process by which neutrons spread out from a source in a material, such as a nuclear reactor. This movement occurs due to random collisions with atoms in the material, which can be influenced by factors like temperature and material composition. Understanding neutron diffusion is crucial for controlling nuclear reactions and ensuring safety in nuclear facilities. In nuclear physics, neutron diffusion plays a significant role in determining how effectively a reactor can sustain a chain reaction. The behavior of neutrons is modeled using mathematical equations, which help predict their distribution and interactions within the reactor core, impacting the performance of nuclear reactors and the design of nuclear fuel.