λ' = wavelength after collision, λ = wavelength before collision, = Compton wavelength of particle, θ = angle of trajectory after collision.
Comments
When a photon of wavelength λ collides with a stationary particle, it will recoil at an angle θ with a new wavelength λ'.
The Compton effect equation states that in this case the shift in the wavelength will be λ' − λ= λc(1 − conθ) where λc is called the Compton wavelength of the particle.
References
The CRC Handbook of Chemistry and Physics , 81st edition, 2000-2001 Introductory
