Which effect is responsible for increased energy of emitted photons compared to absorbed ones?

The Compton Effect is responsible for the increased energy of emitted photons compared to those that are absorbed. In the context of this effect, when a photon interacts with a loosely bound or free electron, it transfers a portion of its energy to the electron and is scattered at a different angle with reduced energy. The electron receives energy and is ejected from its atom.

The key aspect that makes this effect significant is that the energy of the emitted photon is less than the energy of the incident photon due to this interaction, but the process does highlight the energy transfer involved. In many cases, depending on the scattering angle, the emitted photon can carry away a significant amount of energy compared to the energy initially absorbed by the electron.

This understanding of the Compton Effect helps explain phenomena such as the decreased energy of scattered photons and the conservation of energy and momentum during the interaction. By analyzing the results of this effect, one can understand the dynamics of photon interactions in various materials, particularly in radiation therapy and imaging.