Energy Transfer and Energy Absorption in Photon Interaction

Question 1

photoelectric effect

Answer 1

photon interacts with a tightly bound orbital electron
of the absorber atom. If the photon energy ν exceeds the binding energy EB of the orbital electron, the electron is ejected from the atom as a photoelectron with kinetic energy EK = hν −EB.

Question 2

Rayleigh scattering

Answer 2

interaction between incident photon and the whole complement of atomic orbital electrons. It is therefore characterized as photon scattering on tightly bound atomic electrons. In the interaction the atom is neither excited nor ionized; after the interaction the bound electrons revert to their original state, the atom as a whole absorbs the transferred momentum but its recoil energy, because of its large mass, is very small and the incident photon scattered with scattering angle θ has essentially the same energy as the original photon. Since in Rayleigh scattering no electrons are released or produced, there is no energy transfer to CPs

Question 3

Compton effect

Answer 3

term used to describe a photon interaction with a loosely bound atomic orbital electron and, in theoretical studies, an assumption is usually made that the interacting electron is “free and stationary

Question 4

Photoelectric effect

Answer 4

an interaction between the incident photon and a tightly bound orbital electron of the absorber atom, is considered an interaction between the photon and whole atom. The photon disappears and the orbital electron, called photoelectron, is ejected from the absorber atom leaving behind a shell vacancy in the absorber atom.

Question 5

Rayleigh scattering

Answer 5

refers to an interaction of the incident photon with a full complement of orbital electrons tightly bound to the nucleus of the absorber atom. This means that the photon interacts with the
whole atom. The scattered photon is emitted with scattering angle θ and with energy identical to that of the incident photon. No vacancy is produced in the absorber atom and the incident photon loses no energy except for the negligible amount of energy
used up as recoil energy of the absorber atom.

Question 6

Compton effect

Answer 6

an interaction of the incident photon with a loosely bound, essentially “free electron”. The incident photon is scattered with scattering angle θ and some of its incident energy is transferred to the emitted electron, referred to as the Compton or recoil electron. The scattered photon leaves the interaction site with a lower energy than that of the incident photon and in a direction different from that of the incident photon. The Compton electron leaves behind an electronic vacancy in the absorber atom and the fate of the vacancy as well as the fate of the Compton electron are discussed in (g) and (h), respectively