Many physical techniques rely on the interaction between
high energy electrons and the atoms in a solid. There are
many possible interactions and some of the more useful (in
that they give rise to measurable effects) are simulated
on the next page. In the simulations that follow, high energy
electrons, typically 20keV or higher, are allowed to interact,
one by one, with a single atom of aluminium.
This atom is assumed to be part of a solid metallic specimen
and it contributes 3 electrons to a valence
band or conduction
band.
The nucleus is shown in blue here, with the ten inner shell
electrons shown individually while the three conduction
band electrons are indicated by the green area.