The whole technique of gamma-ray spectroscopy rests upon:

• the uniqueness of gamma energies emitted by different radioactive species; and
• the high precision with which these energies can be measured.

This module on high resolution gamma-ray spectroscopy contains the following sections on properties of gamma-rays:

Sources of gamma radiation
Interactions in matter
Interactions with surroundings
Attenuation coefficients
Detectors

and also a practical gamma-ray section:

Practical analysis