Interactions of Electrons with Matter

Two different types of interactions appear:

Elastic Interactions
No energy is transferred from the electron to the sample. The electron either passes without any interaction (direct beam) or is scattered by the electrostatic attraction of the positive potential inside the electron cloud. The arising signals are mainly exploited in TEM and electron diffraction.

Inelastic Interactions
Energy is transferred from the incident electrons to the sample producing secondary electrons, phonons, UV quanta or cathodo-luminescence. Ionization of atoms by removing inner shell electrons leads to the emission of X-rays or Auger electrons. These signals are used in analytical electron microscopy.

A script giving an introduction can be downloaded here: interactions.