In Thomson scattering a charged particle emits radiation under incident light. The particle may be an ordinary atomic electron, so emission coefficients have practical applications.
If  is the energy scattered by a volume element  into solid angle  between wavelengths  and  per unit time then the Emission coefficient is .
The values of  in Thomson scattering can be predicted from incident flux, the density of the charged particles and their Thomson differential cross section (area/solid angle).