Photon's change of direction of propagation

In summary, when a photon encounters an atom with an energy that does not match the energy difference between its levels, it will get scattered by the atomic electrons in a probabilistic manner, changing its direction and wave vector. This is known as Compton scattering and can be described by the Klein-Nishina formula.
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Goodver
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Photons propagate in a certain direction. When it encounters an atom on its way, and an energy of photon is equal to the energy difference between some levels in the atom photon can be absorbed.

But, what happens if an energy of the photon does not match energy difference between levels in the atom. Since atom is "on the way" of photon propagation. How photon will behave in this way? Will the vector of propagation be changed? If yes, on which angle will it deviate? And what makes it to deviate? Or the direction of the photon will stay unchanged?
 
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Goodver said:
How photon will behave in this way? Will the vector of propagation be changed? If yes, on which angle will it deviate? And what makes it to deviate? Or the direction of the photon will stay unchanged?

It will get scattered by the atomic electrons into some solid angle in some direction at an angle relative to the original propagation direction with some wave vector given by the differential scattering cross section for the interaction. The out-state will be given probabilistically based upon the in-state. In this particular case one can look at Compton scattering: http://en.wikipedia.org/wiki/Klein–Nishina_formula
 
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1. How does a photon change its direction of propagation?

A photon changes its direction of propagation through the process of scattering, which occurs when it interacts with matter or other particles in its path.

2. What determines the direction of a photon's propagation?

The direction of a photon's propagation is determined by its energy and momentum. These properties dictate how it will interact with matter and which direction it will travel.

3. Can a photon change its direction without interacting with matter?

Yes, a photon can change its direction of propagation without interacting with matter through the phenomenon of refraction. This occurs when a photon passes through a medium with a different density, causing it to bend.

4. How does the change in direction of a photon affect its wavelength and frequency?

The change in direction of a photon does not affect its wavelength or frequency. These properties remain constant for a photon, regardless of its direction of propagation.

5. What happens to a photon after it changes its direction of propagation?

After changing its direction of propagation, a photon will continue to travel in its new direction until it interacts with matter again. It may also undergo further changes in direction through scattering or refraction.

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