What is the difference between photoelectric effect and Compton scattering? These two effects explains interaction of photon with electron. Why in photoelectric effect whole energy of photon is used up and in Compton photon gets reflected with some energy?

  • $\begingroup$ These are just two possible effects that play a role for low energy photons. With higher photon energy we would also be getting pair production. In case of the Compton effect the electron is quasi-free, while for the photoelectric effect it is bound to a nucleus or is part of a Fermi sea. Both effects have to satisfy energy, momentum and angular momentum conservation. Since the Compton effect deals with a two-particle system, it requires an outgoing photon to satisfy all conservation laws at the same time. In the three particle photoelectric effect an outgoing photon is not required. $\endgroup$
    – CuriousOne
    Oct 7 '14 at 9:23
  • $\begingroup$ Really helpful . $\endgroup$
    – user60180
    Oct 7 '14 at 9:51