Why no Compton with Potoelectric effect?

[trizz10]

In the photoelectric effect all the energy of the photon is considered to be absorbed in both freeing the electron and giving it Kinetic energy. But why can’t there be a lower frequency photon left over or residual energy absorbed by the material from which the electron came?

 

[jtbell]

In general, both processes (photoelectric and Compton) are possible. The relative probabilities vary with photon energy and the target material. For example, see the graphs on page 22 of:

http://pdg.lbl.gov/2010/reviews/rpp2010-rev-passage-particles-matter.pdf

 

[Bob S]

In the photoelectric [deep core photoejection] effect all the energy of the photon is considered to be absorbed in both freeing the electron and giving it Kinetic energy. But why can’t there be a lower frequency photon left over or residual energy absorbed by the material from which the electron came?

There are always atomic x-ray photons emitted from the target atom after a deep core photoejection. They represent atomic transitions filling the vacancy in the K, L, or M shell. Unlike Compton scattering, there is no direct instantaneous secondary photon.

Bob S