1.07.1 Introduction

Radiation effects research has been conducted using a variety of energetic particles: neutrons, electrons, protons, He ions, and heavy ions. Energetic ions can be used to understand the effects of neutron irradiation on reactor components, and interest in this application of ion irradiation has grown in recent years for several reasons including the avoidance of high residual radioactivity and the decline of neutron sources for materials irradiation. The damage state and microstructure resulting from ion irradiation, and thus the degree to which ion irradiation emulates neutron irradiation, depend upon the particle type and the damage rate. This chapter will begin with a summary of the motivation for using ion irradiation for radiation damage studies, followed by a brief review of radia­tion damage relevant to charged particles. The contri­bution of ion irradiation to our understanding of radiation damage will be presented next, followed by an account of the advantages and disadvantages of the various ion types for conducting radiation damage studies, and wrapping up with a consideration of prac­tical issues in ion irradiation experiments.