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Number of ionizations by heavy ion beam

  1. May 19, 2015 #1

    ORF

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    Hello

    If a heavy ion beam deposits a certain energy E in a volume V, how many ion-pairs will it produce in matter?

    I think that the number of ion-pairs will be the energy divided by the (average) energy of ionization. A friend told me that a part of the deposited energy will cause also atomic excitations without ionizations, but we don’t know the fraction of energy for each process. I suppose that the fraction of excitations will be negligible compared to ionizations, but I’m not sure of that.

    Thank for your time (with a reference to a book will be enough).

    Greetings!
     
  2. jcsd
  3. May 19, 2015 #2

    mfb

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    The fraction will depend on the target, the beam type and beam energy. You also get phonons and lattice displacements. There are programs that can simulate it.
     
  4. May 19, 2015 #3

    ORF

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    Hello

    Thank you for answering :)

    I'm interested in the case of matter=liquid water and E=Bragg's peak.

    On the other hand, you have aroused my curiosity: how can I find that programs?

    Greetings!
     
  5. May 19, 2015 #4

    mfb

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    Geant 4 is standard in high-energy physics, but I guess it works well for the Bragg peak, too.

    No lattice displacements for liquids of course.
     
  6. May 19, 2015 #5

    e.bar.goum

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    TRIM/SRIM will work well for this problem too, and is a little easier/quicker to run than Geant 4 for this kind of simple problem. http://www.srim.org/
    Don't let the terrible website fool you, it's good stuff, and is pretty standard in medium/lowish energy beam physics.
     
  7. May 20, 2015 #6

    ORF

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    Hello

    I've taken a look to Geant4 and SRIM, and SRIM seems easier :)

    Thank you for your help!

    Greetings!
     
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