Abstract
The processes that give rise to changes in the microstructure and the physical and mechanical properties of materials exposed to energetic particles are initiated by essentially elastic collisions between atoms in what has been called an atomic displacement cascade. The formation and evolution of this primary radiation damage mechanism are described to provide an overview of how stable defects are formed by displacement cascades, as well as the nature and morphology of the defects themselves. The impact of the primary variables cascade energy and irradiation temperature are discussed, along with a range of secondary factors that can influence damage formation.Radiation-induced changes in microstructure and mechanical properties in
structural materials are the result of a complex set of physical processes initiated by
the collision between an energetic particle (neutron or ion) and an atom in the
lattice. This primary damage event is called an atomic displacement cascade. The
simplest description of a displacement cascade is to view it as a series of many
billiard-ball-like elastic collisions among the atoms in the material. This chapter
describes the formation and evolution of this primary radiation damage
mechanism to provide an overview of how stable defects are formed by
displacement cascades, as well as the nature and morphology of the defects
themselves. The impact of the relevant variables such as cascade energy and
irradiation temperature is discussed, and defect formation in different materials is
compared.
