Lecture
This lecture covers the concepts of Fick's law, diffusion equation, boundary conditions, neutron balance, scattering, isotropic assumption, and the diffusion length. It explains the relationship between neutron flux and current, the steady-state diffusion equation, Laplacian in different geometries, and the behavior near the outer surface. The lecture also discusses the diffusion area, diffusion length, and the summary of neutron density, flux, current, and the Boltzmann equation.