Basic Question about Thomson and Compton Scattering

[atarr3]

Ok so I am doing a project on the derivation of the Compton Effect, and I would like to briefly discuss Thomson scattering, but I'm having a little trouble understanding what happens in Thomson scattering.

This is what I think I understand so far:
When a photon enters matter and interacts with electrons, the electron will be accelerated due to the magnetic and electric field of the photon. The electron will, in turn, emit radiation at the same frequency as the photon. So is this elastic scattering? And is this an interaction between the photon and ALL the electrons in the matter?

I'm also a little confused about Compton scattering. I've read that it is an example of inelastic scattering, but I know that in order to derive the Compton Effect I need to assume an elastic interaction between the photon and electron. Does inelastic scattering just mean that the frequency of the incident photon and the reradiated photon are different?

 

[NateD]

Yes, Thomson scattering is an example of elastic scattering. This is when a photon interacts with an electron and the energy of the photon is completely transferred to the electron and re-emitted in the same frequency as the incident photon. This means that the electron does not gain or lose energy during the interaction. The interaction occurs between the photon and all the electrons in the matter, not just a single electron. Compton scattering is an example of inelastic scattering. In this instance, the photon interacts with the electron but some of its energy is transferred to the electron and the rest is re-emitted at a lower frequency than the original photon. This means that the electron has gained energy during the interaction. To derive the Compton Effect, you need to assume an elastic interaction between the photon and electron, meaning that the photon's energy is completely transferred to the electron and re-emitted at the same frequency.