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Homework Help: Energy to Cross section conversion

  1. Jun 5, 2017 #1
    1. The problem statement, all variables and given/known data

    Using n-Pb collision experimental data, find sigma_0 in units of 1/keV^2 and convert to cm^2

    (I'm copy-pasta'ing from Mathematica, sorry for mess)

    \[Alpha]n = 7*10^-49m^3;
    mn = 939565; <--- Neutron mass in keV/c2
    \[HBar] = 1*10^-3; <--- Natural units and again keV*s
    b = -0.15*10^-3; <---- keV^-1/2
    Z = 82; <--- Lead atomic number
    v = 4 \[Pi]/137;
    \[Sigma] = ((-2.5*10^-4/b ) * mn^(3/2) * v * \[Alpha]n * Z^2/(\[HBar]^3))^2

    2. Relevant equations

    1ev = 8065.54 / cm

    3. The attempt at a solution

    So I got:
    Sigma = 4.29446*10^-55 / keV^2

    From the ev -> cm equation, I went to 1cm^2 = 8065.54^2/(0.001keV)^2

    So on my first attempt I got 2.7936*10^-41, which was wrong.

    After typing it out and doing it again I came to 6.60148*10^-69 cm^2 ... That seems a bit better but I"m pretty lost, not gonna lie.

    Thanks in advance
  2. jcsd
  3. Jun 11, 2017 #2
    Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.
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