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Compton Scattering Calculator

Compton Wavelength Shift

Calculate the wavelength shift from the scattering angle

From Photon Energy

Calculate Compton scattering from incident photon energy in keV

Formula

Δλ = (h/m_e·c)(1 - cos θ) | λ_C = h/(m_e·c) ≈ 2.426 pm | E' = E / (1 + (E/m_e·c²)(1 - cos θ))

Frequently Asked Questions

What is Compton scattering?
Compton scattering is the inelastic scattering of a photon by a charged particle (usually an electron). The photon loses energy (increases wavelength) and the electron recoils. The wavelength shift depends only on the scattering angle: Δλ = (h/mc)(1 - cos θ).
What is the Compton wavelength?
The Compton wavelength of the electron is λ_C = h/(m_e·c) ≈ 2.426 pm. It represents the wavelength shift when a photon scatters at 90°. At 180° (backscatter), the shift is exactly 2λ_C ≈ 4.85 pm.
When is Compton scattering important?
Compton scattering dominates at photon energies from about 100 keV to several MeV, typical of gamma rays and hard X-rays. At lower energies, photoelectric absorption dominates; at higher energies, pair production becomes important.

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