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Does light interact with an atomic nucleus

  1. Aug 18, 2011 #1
    Greetings,


    I was wondering if a fully ionized atom would interact with a photon. Id expect so but cant seem to find any info about it.

    Thanks!
    Physics Novice
     
  2. jcsd
  3. Aug 18, 2011 #2

    mathman

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    Nuclear interactions involve photons of gamma ray energy only.
     
  4. Aug 18, 2011 #3

    ZapperZ

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    Er... protons, which are "fully ionized" hydrogen atoms, are accelerated in particle accelerators using RF, which is an electromagnetic wave, i.e. photons. This is what is done at the Tevatron, LHC, etc. So yes, photons do interact with atomic nucleus.

    Zz.
     
  5. Aug 18, 2011 #4
    Thanks for the quick reply mathman! Can you eleborate on that or point me in a direction to find out more? Does the energy simply go into a change in momentum? Discrete energys absorbed? Many many questions and not sure where to find the answers.

    Thanks again
     
  6. Aug 18, 2011 #5
    Zapper Z

    I always thought of that more as surfing the wave. My poorly composed question was more along the lines of whether thay actually absorb the energy. Of course that may be the case and the "surfing' analogy should go in the wastbasket.

    Thanks
     
  7. Aug 18, 2011 #6

    Drakkith

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    Zapper, what exactly do you mean? Are they shooting radio wave photons at these protons, or applying a high voltage to part of the accelerator, or what exactly?
     
  8. Aug 18, 2011 #7

    ZapperZ

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    I can't read minds. All you asked for is if photons INTERACTS with atomic nuclei. Being accelerated by such RF is a clear example that it does.

    "RF" is a broad spectrum. I accelerate electrons using 1.3 GHz RF.

    There aren't that many "DC" accelerator, i.e. where they apply static fields. Most accelerating structure, and certainly the ones at major accelerators, use RF sources, mainly out of Klystrons.

    Zz.
     
  9. Aug 18, 2011 #8

    Drakkith

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    I see. Alright, thanks Zapper.
     
  10. Aug 18, 2011 #9
    Zapper Z,
    Clearly it does.
    Can you address "My poorly composed question was more along the lines of whether thay actually absorb the energy. Of course that may be the case and the "surfing' analogy should go in the wastbasket." ?

    Thanks for your time. Ill bet you could read minds in a pinch.

    Kitk
     
  11. Aug 19, 2011 #10
    Thanks all. Got some clarity on the subject. It help that I refined my search a bit and relearned about arxiv.org. Thanks for the prompting on your blog Zapper
     
  12. Aug 19, 2011 #11

    sophiecentaur

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    On a historical note, the early accelerators used DC from a Van der Graaff generator. A blistering 1MeV or thereabouts!!
     
  13. Aug 19, 2011 #12

    ZapperZ

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    Yes, but that's why they are no longer used for most major accelerators. You just can't get the high gradients you need with such configuration.

    Zz.
     
  14. Aug 19, 2011 #13

    mathman

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    I assumed interact meant a reaction where an actual change takes place, not simply a change in energy.
     
  15. Aug 19, 2011 #14
    Mathman,

    Exactly what I was trying to ask, but note asking it very well :-)

    Thanks again
     
  16. Aug 20, 2011 #15

    mathman

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    There are at least two situations which may be the kind of thing you are asking about.
    1) Pair production - at high energies (above 1.022 Mev) photons, in the presence of a nucleus - needed for momentum balance, can transform into electron-positron pairs.

    2) See following reference:
    http://www.sbfisica.org.br/bjp/files/v37_679.pdf
     
  17. Aug 22, 2011 #16
    Mathman,

    Excellent! Just the kind of thing I was looking for. I appreciate you taking the time to find the reference.

    KitK
     
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