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Homework Help: The Photoelectric Effect

  1. Nov 25, 2007 #1
    1. The problem statement, all variables and given/known data
    In an xray tube, a potential diff. of 70000v is applied across two electrodes. Electrons are emmited from cathode and acc. to anode, where x-rays are produced.
    my question is if the photoelectric effect problems apply and how they apply.
    (i.e use work function or E=hf)

    questions on paper
    a)find max frequency
    b)find max momentum

    2. Relevant equations
    Kmax = hf-Wo

    3. The attempt at a solution
  2. jcsd
  3. Nov 25, 2007 #2


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    In an X-ray device, electrons are accelerated via a potential difference (here 70 kV) and those electrons will ionize atoms in the target electrode. X-rays arise from atomic electrons 'refilling' the K-level and in some cases L-level shells.

    One needs to look at the binding energy of K electrons to determine the energy of X-rays for those particular elements.

    Those X-rays can certainly interact by the photo-electric effect, and knock out another electron. One may wish to look into "Auger electrons", or the "Auger effect".

    Another phenomenon is the brehmsstrahlung radiation.
  4. Nov 26, 2007 #3

    Thanks for your help, I get it now.
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