Interaction of Radiation with Matter focuses on the physics of the interactions of ionizing radiation in living matter and the Monte Carlo simulation of radiation tracks. Clearly progressing from an elementary level to the state of the art, the text explores the classical physics of track description as well as modern aspects based on condensed matter physics. The first section of the book discusses the fundamentals of the radiation field. In the second section, the authors describe the cross sections for electrons and heavy ions—the most important information needed for simulating radiation track at the molecular level. The third section details the inelastic scattering and energy loss of charged particles in condensed media, particularly liquid water. The final section contains a large number of questions and problems to reinforce learning. Designed for radiation interaction courses, this textbook is the ideal platform for teaching students in medical/health physics and nuclear engineering. It gives students a solid grounding in the physical understanding of radiation track structure in living matter, enabling them to pursue further work in radiological physics and radiation dosimetry.