Which two are the primary by-products of a photoelectric absorption interaction?

Which two are the primary by-products of a photoelectric absorption interaction?

• A. free electron
• B. scattered photon
• C. characteristic photon
• D. free electron and characteristic photon

Answer: (D)

In photoelectric absorption, the incoming photon is completely absorbed by an atom, and an inner-shell electron is ejected as a photoelectron. The atom then has a vacancy and tends to relax by an electron transition that releases energy as a characteristic X-ray photon. So the two main by-products are the free photoelectron and the characteristic photon produced during this relaxation. A scattered photon would come from a different process (Compton scattering), and while a characteristic photon can be emitted, it is the combination of the ejected electron plus that photon that represents the typical outcome of this interaction.

In photoelectric absorption, the incoming photon is completely absorbed by an atom, and an inner-shell electron is ejected as a photoelectron. The atom then has a vacancy and tends to relax by an electron transition that releases energy as a characteristic X-ray photon. So the two main by-products are the free photoelectron and the characteristic photon produced during this relaxation. A scattered photon would come from a different process (Compton scattering), and while a characteristic photon can be emitted, it is the combination of the ejected electron plus that photon that represents the typical outcome of this interaction.