3. Inelastic effects and energy filtering

3.1 Inelastic interactions

When a fast-moving electron penetrates a sample, several things can happen. It can pass through the sample:

• without interaction ;

• with one or more elastic interactions ;

• with one or more inelastic interactions ;

• with one elastic interaction, one inelastic interaction or a combination of several elastic and inelastic interactions.

Inelastic interactions are those that lead to one or more excitations of the electrons in the sample. Each interaction corresponds to a loss of energy in the incident electron.

The most likely is the collective excitation of...