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L-edge of absorption

  1. May 17, 2009 #1
    What is the L-edge of absorption? For example, Si has its L2,3 edge at 99.8 eV? The second atomic shell is L, but what does 2,3 mean?

  2. jcsd
  3. May 17, 2009 #2
    The k-edge and L edge of an atom refers to the minimum energy (or maximum wavelength) photon (UV or x-ray) that can remove an (photo) electron from the K or L shells (usually meaning ionize), such that other bound electrons cascade down to fill the vacancies. The photon energies correspond to "edges" in a plot of photon attenuation vs. photon energy where there is a sudden large increase in the attenuation coecfficient. Figure 1 in this reference shows a k-shell photoelectron ejection, with the possible atomic electron cascades.
    L(2,3) may refer to the electron transition that fills the L shell vacancy (M-shell to L-shell)
    Last edited: May 17, 2009
  4. May 17, 2009 #3
    Thanks for the reply, Bob. That's a very nice reference, and now I understand.
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