The Compton effect is the increase in wavelength and change in direction of an X-ray or gamma ray photon when it collides with a charged particle, usually an electron.
It is also known as Compton scattering and named after
the American physicist Arthur Holly Compton.
The opposite effect, in which a photon gains energy (and therefore decreases
in wavelength) from a fast-moving electron, is known as the inverse
AND NUCLEAR PHYSICS