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Homework Help: Compton effect and visible light

  1. Feb 7, 2006 #1
    why is it extremely dificult to observe the compton effect using visible light?

    is it because visible light does not have a short enough wavelenght to excite the electrons?
     
  2. jcsd
  3. Feb 7, 2006 #2

    SpaceTiger

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    Compton scattering becomes noticable when the energy of the light is comparable to the rest energy of the electron (~511 keV, hard X-rays). Visible light is much less energetic than this (~few eV), so the scattering process can conserve energy and momentum without a significant change in the wavelength of the photon.
     
  4. Feb 7, 2006 #3
    does wavelength tell you the energy?
     
  5. Feb 7, 2006 #4

    SpaceTiger

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    Yes. For a photon,

    [tex]E=h\nu=\frac{hc}{\lambda}[/tex]
     
  6. Feb 7, 2006 #5
    so my assumption that visible light does not have a short enough wavelenght to excite the electrons is correct? since thei wavelenght is long, making energy low, hence, not enough eV to excite the electron?
     
  7. Feb 7, 2006 #6

    SpaceTiger

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    The electron can receive both energy and momentum from a visible photon, but both would be just a tiny fraction of its rest energy. But yes, that's basically right.
     
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