One of the processes contributing to the attenuation of 's in matter, together with Compton scattering and
pair production. The photoelectric cross-section rises with Z5 (Z being the atomic number of the medium), but is proportional to 1/E3, hence plays a role only at low energies (say at keV).
's in matter, together with Compton scattering and
pair production. The photoelectric cross-section rises with Z5 (Z being the atomic number of the medium), but is proportional to 1/E3, hence plays a role only at low energies (say at 
keV).