# Photon-Electron Collision

1. Sep 30, 2004

### AKG

If I'm given an energy for an electron, and a wavelength for a photon, how can I determine the maximum energy loss for the electron?

2. Oct 31, 2004

### Andrew Mason

I am not sure of your question. Are you talking about an electron/photon collision where the electron is not strongly bound to an atom?

Free electron/photon collisions follow the Compton formula:

$$\triangle \lambda = \frac{h}{m_ec} (1 - cos\theta)$$

where $\theta$ is the angle of the electron's velocity after the collision compared to the direction of the original photon.

The electron gains energy in the collision.

AM

Last edited: Oct 31, 2004