I am little confused. Please correct me if I am wrong.

Gamma rays can produce electron and positron pair if they interact with atoms.

In the double slit experiment the final screen where interference pattern is observed is made up of atoms.

Suppose we do a thought experiment where a source of gamma ray is used in double slit experiment to observe gamma ray interference pattern then the gamma ray wave will show interference pattern on the screen ,but as the screen is made up of atoms, the gamma ray will produce electron positron pair instead of interference pattern.

My question is : Will the interference pattern still be observed with gamma rays in double slit experiment?


1 Answer 1


If you look at the table here of the wavelengths of electromagnetic waves you will see that gamma rays have very small wavelength,smaller than 10 pico meters. The smallest atom, the hydrogen atom has a size of ~53 pico meters. One cannot make a slit small enough for the double slit experiment , as it has to be smaller than the wavelength and a slit in material cannot be made smaller than the smallest atom.

  • $\begingroup$ But we would see diffraction of gamma rays around an edge of hydrogen atoms, right? $\endgroup$ Jan 13 at 19:15
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    $\begingroup$ The width of the slits can be smaller than the width of an atom, the spacing between the slits cannot. $\endgroup$
    – D Duck
    Jan 13 at 19:28
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    $\begingroup$ @DDuck I cannot envisage an experimental method that could separate a lattice to make a slit even for diffraction of one slit, smaller than he size of the smallest atom. $\endgroup$
    – anna v
    Jan 13 at 20:01
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    $\begingroup$ Slits don't have to be smaller than the wavelength, mm-wide slits work for visible light. Shorter wavelengths still make it harder, but more importantly almost everything is nearly-transparent (with no refraction) to gammas so there is nothing to make the slits out of. $\endgroup$ Jan 14 at 7:15
  • $\begingroup$ I think this answer is wrong and @Kevin Kostlan's reasoning is correct. $\endgroup$ Jan 14 at 7:56

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