Compton scattering theory question

[salmayoussef]

The question is this: When a photon bounces off an electron, it gives some of its energy to the electron. The photon has no mass, however, and it must continue to travel at speed c. How is its reduced energy manifested?

Now, I do somewhat understand what the Compton effect is and I read in my course notes that in an elastic collision (which is what this is, right?) of a photon with an electron, momentum is conserved. Would it make sense to say that the photon transfers energy to the electron and the frequency decreases because of this loss of energy? Could someone please help clarify? Thanks!

 

[vela]

Yes, that's exactly what happens.

 

[jtbell]

I read in my course notes that in an elastic collision (which is what this is, right?) of a photon with an electron, momentum is conserved.

In any collision, whether elastic or inelastic, momentum is conserved.

A collision is elastic if the total kinetic energy is conserved. This is true for Compton scattering because we have a photon and electron coming in, and a photon and electron going out. The sum of the rest-energies is the same before and after, therefore the total KE is the same before and after.