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Equipment Design

  1. Jul 20, 2004 #1
    Can an electron beam gun be made to where the very end of the gun (the end that the electron is emitted from) can be made to be the exact size of an electron?

    The reason I ask is this: In attempts to discover how an electron travels through the two-slits experiement, it was determined that the electron has "wave-like" properties. This was one of the big steps toward quantum mechanics.

    But...How were these experiments truly performed? Did they have the electron gun, the two slits, the measuring plate behind in a completely vacuumed room with no other particles whatsoever in it. And was the gun point made to be the size of an electron?

    If not, then any of the aformentioned items could have changed the results. Since Electrons are sooooo small, then even the gun's barrel could have allowed the electron to have "bounced" around before being emitted. This could easily change the resulting position of the electron.

    And finally, has the two-slits experiment been done with measuring plates fully circling the entire experiement area to measure where electrons might have ended up?
  2. jcsd
  3. Jul 20, 2004 #2
    The electron can enter the apparatus as a plane wave and still exhibit the interference pattern, so it doesn't have to come from a point source. The two slit experiment has been done with several kinds of detectors, photograpic film, scintillation screens etc.. And yes, for the electron the experiment has to be carried out in a vacuum.
  4. Jul 20, 2004 #3


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    The interference pattern has also been observed from a josephson junction of a superconductor, so this phenomena is not restricted to free electrons moving in vacuum alone.

  5. Jul 20, 2004 #4
    Thank you ZapperZ, for adding that. I hadn't thought of that possibility.
  6. Jul 21, 2004 #5
    Thanks gang!
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