ABSTRACT
Ionizing radiation is invariably the consequence of physical reactions, involving subatomic particles, at the atomic or nuclear level. The possible radiation-producing reactions are many and, usually, although always, involve altering the configuration of neutrons and protons in an atomic nucleus or the rearrangement of atomic electrons about a nucleus. The energy distribution of the photons produced by the bremsstrahlung mechanism is continuous up to a maximum energy corresponding to the maximum kinetic energy of the incident charged particles. The angular distribution of radiation leaving a target is very difficult to compute since it depends on the target size and orientation. The electrons and positrons emitted by radionuclides undergoing beta decay produce bremsstrahlung as they slow down in the source material. The production of x-ray photons as bremsstrahlung and fluorescence occurs in any device that produces high energy electrons. The energy spectrum of x-ray photons emitted from an x-ray tube has a continuous bremsstrahlung component up to the maximum electron energy.
