ABSTRACT
This chapter presents the fundamentals associated with the interaction of radiation with materials. It addresses available methods for setting an acceptable minimum dose to achieve the desired SAL and an acceptable maximum dose that ensures the safety and performance of the irradiated product over its lifetime. Radiation in the form of high-energy electrons produced by high-power accelerators or gamma rays produced by radioisotopes has been used to terminally sterilize a broad spectrum of medical devices and different types of pharmaceutical products. At intermediate photon energies that characterize the gamma ray and X-ray sources of radiation used in the radiation sterilization process, the dominant channel for interaction of the photons with the orbital electrons occurs via a process called Compton inelastic scattering. For most pharmaceutical products and low atomic number materials that make up the bulk of medical device products, high-energy electrons from an accelerator mainly lose energy in the material via many inelastic scattering events with the orbital electrons.
