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Smith-Percell Radiation

  1. Dec 21, 2003 #1
    I did a board search here and didn't find anything on "Smith-Percell Radiation". It is an interesting phenomina to me, because it was thought up about 50 years ago, and scientists are still arguing over the exact mechanism of its source.

    It is described in a book I read a couple of years back and continue to read, "Waves and Grain", by Mark Silverman. The original paper was less than a full page, and appeared in Physical Review in 1953. The abstract was:

    It occurred to one of the authors (EMP) that if an electron passes close to the surface of a metal diffraction grating, moving at right angles to the rulings, the periodic motion of the charge induced on the surface of the grating should give rise to radiation. S.J. Smith and E.M. Purcell, 1953

    I found the original paper on Physical Review's web site, but couldn't see it because you have to subscribe to their services to view it:


    It is weird an electron of constant velocity giving rise to EMR, but is it really? Might the radiation arise from electrons bound in atoms in the diffraction grating? Mark didn't approach that part, he just used this as a chapter-opening-attention-grabber. I thought that part up as possible, and then did some web searches on Smith-Percell radiation. There is quite a bit of information out there, and the continuing argument is exactly that, about from where the radiation is actually eminating: the electrons in motion or the electrons in the diffraction grating, a wake similar to Cherenkov Radiation, other? I understand very little of these articles, but they are still interesting to read:

  2. jcsd
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