# Compton scattering

## Description

Compton scattering is an inelastic scattering of a photon by a free charged particle, usually an electron. It results in a decrease in energy (increase in wavelength) of the photon (which may be an X-ray or gamma ray photon), called the Compton effect. Part of the energy of the photon is transferred to the recoiling electron.

(The energy of light quanta depends only on the frequency of the light).

Compton scattering formula gives a mathematical relationship between the shift in wavelength and the scattering angle of the X-rays.

The quantity h/mc is known as the Compton wavelength of the electron; it is equal to 2.43×10−12 m. The wavelength shift λ′ − λ is at least zero (for θ = 0°) and at most twice the Compton wavelength of the electron (for θ = 180°).

## Variables

d | Initial wavelength (m) |

d_{0} | Wavelength after scattering (m) |

h | Planck constant |

m_{e} | electron mass |

c | Speed of light (m/s) |

θ | Scattering angle. (degree) |