Gamma-Ray Production and Absorption Processes

Abstract

How do $γ$-rays compare with other types of radiation? `Radiation' in common language describes 'energy packages' which travel on straight paths. `Electromagnetic radiation' is characterized by variations of electric and magnetic fields in space and time. Another type of 'radiation' are 'cosmic rays', very energetic particles discovered early in the 20th century in the upper atmosphere of the Earth and known to pervade interstellar space. These particles are called `cosmic radiation' because with their high energies they propagate at the speed of light and in certain aspects behave like photons of similar energies, $γ$-rays.