Is the Compton scattering angle related to the incident energy?

In summary, the Compton equation is used to determine the shift in wavelength of a scattered photon based on its scattering angle, independent of the incident photon's energy. Using conservation equations, another formula can be derived to describe the relationship between scattering angle and energies of the incident photon and scattered electron. The higher the energy of the incident photon, the smaller the scattering angle, but this is not always true as the probability distribution for scattering angle must also be considered. The differential cross section formula, or Klein-Nishina formula, is necessary for calculating the probability distribution. There is also a way to represent Compton scattering using a Feynman diagram.
  • #1
Adel Makram
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The Compton equation determines the shift of the wave-length of the scattered photon as a function of the ##cos\theta## of the scattered photon. It does not depend on the energy of the incident photon. With some manipulation using the equations of conservation of the momentum and energy, one gets another equation describing the relation between the scattering angles, energy of the incident photon and that of the scattered electron.
Still, how does the scattering angle vary with the energy of the incident photon? Intuitively, the higher the energy the smaller the angle, but is it really true? I mean what makes the nature prefer a small angle when we increase the incident photon energy.
I thought of the following as a possible solution: At any angle, the higher the angle value, the lower the energy of the scattered photon by Compton equation. The difference between the incident and the scattered energy is equal to the kinetic energy of the scattered electrone by law of energy conservation. But, because the kinetric energy of the electron can not increase infinitely, this means a higher left-over energy of the scattered photon when the incident energy is high. But from Compton equation, the higher energy the lower wavelength and this can be only achieved at lower scattered angle.
 
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  • #2
For a given incoming photon energy, the outgoing photon can emerge at different angles, with correspondingly different energies. The familiar formula for the scattering angle doesn't give any information about which angle is most likely.

To get the probability distribution for the scattering angle, you need to use the differential cross section for Compton scattering, a.k.a. the Klein-Nishina formula. The scattering-angle formula is purely kinematic, and comes from energy and momentum conservation. The Klein-Nishina formula comes from quantum electrodynamics.
 
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So, is there a way to represent Compton scattering using Feynman diagram?
 
Last edited:

1. What is Compton scattering?

Compton scattering is a phenomenon in which an incident photon interacts with a charged particle, usually an electron, and loses some of its energy. This results in a change in the photon's direction and wavelength.

2. How is the Compton scattering angle defined?

The Compton scattering angle is the angle between the incident photon's direction and the direction of the scattered photon.

3. What determines the Compton scattering angle?

The Compton scattering angle is determined by the incident energy of the photon and the mass of the charged particle it interacts with, usually an electron.

4. Is there a relationship between the Compton scattering angle and the incident energy?

Yes, there is a direct relationship between the Compton scattering angle and the incident energy. As the incident energy increases, the Compton scattering angle also increases.

5. How is the Compton scattering angle related to the incident energy?

The Compton scattering angle is directly proportional to the incident energy and can be calculated using the formula θ = arccos(1 - (me*c^2)/(E + me*c^2)), where θ is the Compton scattering angle, me is the mass of the electron, c is the speed of light, and E is the incident energy.

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