From Citizendium - Reading time: 1 min
Compton Scattering is a phenomenon in physics, first explained by Arthur Holly Compton, that confirms the quantum nature of x-rays. If a stream of x-rays is fired at a target the rays will be scattered and the scattered radiation will have smaller frequency (and longer wavelength) than the incident radiation. The change in wavelength is dependant on the angle through which the radiation is scattered. Arthur Compton earned the 1927 Nobel Prize for Physics for his discovery.
For radiation of wavelength λ that is incident on a target consisting of charged particles of mass m and scattered at an angle θ from its incident direction, the wavelength λ' of the scattered radiation can be determined from:
In the Compton scattering formula, the quantity is known as the Compton wavelength. It is the wavelength of a photon whose energy is equal to the energy of one of the particles that the photons scatter from. The change in photon wavelength of the scattered photon can range between zero and twice the Compton wavelength. These limits correspond to (no scattering) and degrees (when the photon scatters directly backward from its incident direction), respectively.
For an electron, the Compton wavelength is meters.