1. Theoretical aspects: radiation interactions – matter

When an electron beam interacts with matter, we can distinguish between elastic interactions, mainly with the atom's nucleus and of which electron scattering is the main consequence, and inelastic interactions with the atom's electron cloud, mainly causing a transfer of energy from the primary beam to the atom.

These interactions give rise to a number of electronic and electromagnetic emissions that can tell us a great deal about the nature and composition of the target (figure 1 ).