Interactions of Radiation with Matter

Radiation interaction with matter is generally analyzed by considering charged particles and electromagnetic radiation separately. As discussed in Chapter 5 the two types of charged particles emitted are α and β particles (electrons or positrons). The mass of these particles differs by many orders of magnitude and the types of nuclear interactions they undergo are thus dramatically different. Other important heavy charged particles that need to be considered are protons, deuterons and helium. The characteristics of electromagnetic radiation (γ rays and X-rays) interactions are quite different (photons are massless and travel at the speed of light) to that of charged particles and are considered separately. This chapter discusses the mechanisms of interaction for both charged particles (α, protons and electrons) and electromagnetic radiation (γ rays and X-rays). The characteristics and interactions of neutrons with matter are described in Chapter 7.