ABSTRACT
Radiation interaction with matter is a subject of radiation science (i.e., radiation physics, radiation chemistry, and radiation biology). This subject is roughly divided into two parts. The Ÿrst is the fate of incident radiation, or, more speciŸcally, the amount of energy deposited in matter (the linear energy transfer (LET) or stopping power). The second is the change of matter due to the absorption of radiation energy. Both aspects of radiation-matter interaction are understood microscopically in terms of collisions among the radiation particle, the medium molecules, and the products of the interaction itself. Thus, knowledge of the relevant atomic collision processes is an essential ingredient of radiation science. As a part of this knowledge, this chapter provides a general picture of the collisions between electrons and molecules. The roles that these electron-molecule collisions play in radiation-matter interaction are described in other chapters.
