(3) Interaction of high energy photons with matter - LUTH

Compton Scattering – energy transfer (3)
Thus, in the case of a stationary electron, the wavelength of the photon becomes longer, i.e.
it looses energy.
If however the electron is more energetic than the photon ( m e c² >> ℏ) , we get the following:
' −
≈ v
c
● energy transfer possible in both directions
● frequency change ~ v / c
cos ' −cos
1− v
c cos'
● for random scattering angles, no net increase in the photon energy to first order, but there is a net
gain to second order (i.e. ~ v² / c² ) -> Inverse Compton Scattering
A. Zech, Instrumentation in High Energy Astrophysics
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