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What is this notation? I haven't seen it before

  1. Aug 29, 2015 #1

    This is an equation/part of a question in my nuclear physics unit, where X5 represents the reactant nucleus and X6 is the product nucleus. The alpha symbol is most likely alpha decay, but I have no idea what it means in conjunction with 'p' like that. The rest of the question is:
    In the carbon cycle that occurs on the Sun, He-4 is built from four protons and
    C-12. First, C-12 absorbs a proton to form a nucleus, X1. Then X1 decays by
    positron emission to X2, which then absorbs a proton to become X3, which itself
    absorbs a proton to become X4. X4 then decays to X5 by positron decay and X5
    reacts via: X5(p,α)X6

    It's from the Walding Physics textbook if anyone has it.
  2. jcsd
  3. Aug 29, 2015 #2


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    It's a shorthand form for a nuclear reaction. There's an explanation here on page 2:

    http://oregonstate.edu/instruct/ch374/ch418518/Chapter 10 NUCLEAR REACTIONS.pdf

    It's basically T (P,x) R which is short for:

    Target nucleus + Projectile → x (emitted particle) + Residual nucleus
  4. Aug 29, 2015 #3
  5. Aug 30, 2015 #4


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    X5 + proton -> alpha particle + X6
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