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Cathode ray create interference pattern?

  1. May 5, 2012 #1
    If I were to construct a cathode ray tube in which the beam of electrons was focused on a double slit, behind which was a screen of phosphorous, could I create an interference pattern?
    Could this setup be made at home? I imagine making the slits would be the most difficult part. Or is this experiment fundamentally flawed in some way?
  2. jcsd
  3. May 6, 2012 #2
    You could get an interference pattern, but the wavelength of electrons is so small the slits would have to be very very finely spaced (think: too finely spaced to see with the naked eye) for the pattern to be readily visible. Consider that the wavelength of light is around 0.5 micrometers and the slits have to be about the thickness of a human hair apart to get a nice clean interference pattern. Now consider that the wavelength of an electron at 10 kV (i.e. typical output of cathode ray tube) is about 12.3 picometers!

    This page has a lot more information: http://en.wikipedia.org/wiki/Electron_diffraction

    Electron diffraction is used to study crystals, as the spacing between atoms is on the order of the required length needed to produce diffraction.
  4. May 10, 2012 #3
    Thanks for your response, that makes perfect sense
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