The discussion centers on the relationship between photon energy and the absorption cross section in the context of the photoelectric effect and photoionization. It is established that as photon energy increases, the absorption cross section decreases, which contradicts the expectation that higher energy photons would enhance ionization. The conversation highlights the importance of distinguishing between core-level photoemission and standard photoemission, which typically involves visible to UV light. Participants emphasize the need for credible references and caution against relying on Wikipedia for complex scientific topics.
PREREQUISITESPhysicists, researchers in atomic and molecular physics, students studying photoelectric effects, and anyone interested in the nuances of photon interactions with matter.
mathman said:Resonance?
wdlang said:the higher the energy of the photon, the more powerful it can ionize an atom
but why then the absorption cross section decreases with the photon energy?
ZapperZ said:You need to learn to provide references.
Zz.
wdlang said:
ZapperZ said:<Sigh>
Please cite specifically where it says "... absorption cross section decreases with the photon energy..."
Zz.
wdlang said:see Cross section
ZapperZ said:That is core-level photoemission. It is no longer the same "photoelectric" effect that is characterized by the Einstein equation. Notice the energy of the photon being used. The standard photoemission is done using predominantly visible to UV light that probes the conduction band, not core levels.
BTW, as someone who has done photoemission spectroscopy extensively, I would use this particular entry in Wikipedia as the poster child why someone should NOT use Wikipedia to learn from.
Zz.
wdlang said:i know this
i have in mind the photoelectric effect of atoms not metals
wdlang said:not a resonance