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Calculating Activity of proton beam

  1. Mar 19, 2013 #1
    1. The problem statement, all variables and given/known data
    A natural lithium target 3.8 mg cm-2
    thick is bombarded with a
    125 µA beam of 3.5 MeV protons initiating a 7Li(p,n) reaction.
    Assuming a reaction cross section of 300 mb, calculate the
    activity produced by a 15 minute bombardment.

    2. Relevant equations

    3. The attempt at a solution
    125μA=125μC/s(1 proton/1.602*10-19C)(15*60s)=7.022*1017 protons. I'm not really sure where I would go from here. I got μ/[itex]\rho[/itex]=0.0258 cm2/g. Yet, I can't find the actual linear attenuation coefficent. I figured we would use the activation equation, but I'm not sure on the flux, and the other units.
  2. jcsd
  3. Mar 21, 2013 #2


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    Staff: Mentor

    You can convert the given area density to an atomic density - ideally in the units atoms/barn. Together with the given cross-section, ...
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