Compton Scattering, also known
as incoherent scattering, occurs when the incident x-ray photon
ejects a electron from an atom and an x-ray photon of lower energy
is scattered from the atom. Relativistic energy and
momentum are conserved in this
process below)
and the scattered x-ray photon has less energy and therefore a
longer wavelength than the incident photon. Compton scattering is
important for low atomic number specimens.
The change in wavelength of the scattered photon is given by:

Theta is the scattering angle of the scattered
photon. Note the fundamental constants for the speed of light,
Planck constant, and electron mass.
Ref::http://www.ndt-ed.org |