Difference in Raman, Rayleigh, and Compton scattering

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Raman scattering is inelastic scattering from molecules. The photon interacts with the molecule and changes the molecules vibrational, rotational or electron energy.

Rayleigh scattering is in the main elastic scattering from small particles whose size is less than that of the wavelength of the photon. The scattering can occur of atoms or molecules and for molecules the scattering can be inelastic with a change of rotational energy of the molecule.

Compton scattering is inelastic scattering of a photon from a free charged particle. If the charged particle is a bound electron then the energy of the photon must be much greater than the binding energy of the electron.

Side note: Rayleigh scattering is a particular case of Mie scattering. This theory explains in particular the white colour of objects which are made of particles of size greater than the typical wavelength : milk, clouds, chemical powders...

To add to the answer there is Thomson (no "p") scattering which is the elastic scattering of electromagnetic radiation by a free charged particle, as explained by classical electromagnetism.
It is just the low-energy limit of Compton scattering when the particle kinetic energy and photon frequency do not change as a result of the scattering.
This limit is valid as long as the photon energy is much smaller than the mass energy of the particle.

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cindy50633
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cindy50633

Updated on February 07, 2020

Comments

  • cindy50633
    cindy50633 over 3 years

    I'm studying modern physics and have some questions about these three different scattering.

    In the book and wiki all tells me Raman and Rayleigh scattering are inelastic and elastic collision separately, but what about Compton scattering?

    Does Compton scattering include this two type of scattering since the picture in the book give me two angle of scattering with one differ from the original angle while one remains unchanged? Or it can't be categorized in any of above since it interact with an "electron"?

    Hope to know the details, by the way I'm studying modern physics by Serway

  • garyp
    garyp almost 8 years
    For Rayleigh, do you intend to say "wavelength is less" or did you mean "size is less"? Also, it's important that the particle must be polarizable, so you can't get Rayleigh scattering from an elementary particle.
  • Farcher
    Farcher almost 8 years
    @garyp Thank you for point out the nonsense I was writing which I have now corrected.
  • Dimitri
    Dimitri almost 8 years
    You could also point out that Rayleigh scattering is a particular case of Mie scattering. This theory explains in particular the white colour of objects which are made of particles of size greater than the typical wavelenght : milk, clouds, chemical powders...
  • Farcher
    Farcher almost 8 years
    @Dimitri One of the nice things about this forum is that one can edit other people answers. Please feel free to add and/or amend whatever you want in my answer. I did also think of making a comment about Thomson scattering. So please go ahead.
  • Dimitri
    Dimitri almost 8 years
    @Farcher I had never tried that. Thanks, I just edited your post for the Mie part and will let you add info about Thomson scattering.
  • Farcher
    Farcher almost 8 years
    @Dimitri Once you edited it I was asked if it was acceptable to me which of course it was. So it seems to be such a good system one wonders why it is not implemented on other forums. Anyway, many thanks.
  • cindy50633
    cindy50633 almost 8 years
    @Farcher Does the bound electron collision you mean in the explanation will become another effect as "photoelectric effect"? Or we still can refer a bound electron as a Compton effect?
  • Farcher
    Farcher almost 8 years
    @cindy Does this link answer your question? physics.stackexchange.com/questions/31581/…
  • cindy50633
    cindy50633 almost 8 years
    Yes,thank you,it helps a lot especially the pdf=w=. So if there is a free electron now,the possibility of photoelectric effect should be approximately zero,right~
  • jiggunjer
    jiggunjer over 6 years
    The Compton definition is an oxymoron: how can a free charged particle be a bound electron, which by definition isn't free?
  • Farcher
    Farcher over 6 years
    @jiggunjer I agree but an electron whose binding energy is very small compared with the energy of the incoming photon is considered to all intents and purposes considered to be free.
  • user1993
    user1993 over 5 years
    just a dumb question, but do either of these 3 types of scattering explain why a blue chair looks blue? Because I am under the impression that non-fluorescent objects are visible to us because of scattering, just not sure which type of scattering
  • Dawood ibn Kareem
    Dawood ibn Kareem over 5 years
    @user1993 I would recommend asking that as a new question.
  • Mathews24
    Mathews24 over 4 years
    Perhaps worth adding that Thomson scattering is the low-energy limit of Compton scattering.
  • Farcher
    Farcher over 4 years
    @Mathews24 Thank you. As per your suggestion I have added to my answer.