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Homework Help: Radioactive Source Emitting Only Alpha and Gamma Radiation

  1. Jun 30, 2013 #1
    The problem statement, all variables and given/known data

    "How could you show that a radioactive source was only emitting alpha and gamma radiation?"

    The attempt at a solution

    This really stumped me...obviously they have different penetration distances, and different strengths of ionisation, but I don't know how to show that only these are being emitted. All I could come up with is using a beta radiation detector to show that beta is not being emitted?
  2. jcsd
  3. Jun 30, 2013 #2


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    Your beta detector can show that there is no beta radiation. But what if your source was just a gamma emitter? Or just an alpha emitter?

    The key word in the problem above is, '... emitting alpha AND gamma radiation.', emphasis on the AND.
  4. Jun 30, 2013 #3
    So would I first demonstrate that there's no beta present, and then say how you can prove alpha is present, and then how to prove gamma is present? Would it be that the radiation count will decrease between being in front of and behind a sheet of paper, showing that alpha radiation has been absorbed, and then that this number wouldn't change behind a sheet of aluminium because gamma would penetrate it?
  5. Jun 30, 2013 #4
    It would be true that you have to show beta radiation is not present, and also that both alpha and gamma radiation must be present. I think on approach is to first consider what exactly alpha and beta radiation is composed of, and then ask what this form of radiation does when a magnetic field is applied to it. Detecting gamma rays is not an easy matter, but there are detectors out there capable of detecting gamma rays.
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