# Homework Help: Compton scattering and collision within blackbody

1. Feb 9, 2013

### Bailey

1. The problem statement, all variables and given/known data
Consider a blackbody contain atoms that typically produce photons with energy of about 7eV. Estimate the number of photon-electron collision each photon undergoes before it escape the object. Assume the blackbody has a temperature of 1000K.

2. Relevant equations

λ2 - λ1 = λcompton(1 - cosθ)

3. The attempt at a solution

Not sure if I have all relevent equation but this is what i did:

calculated total kinetic energy by converting the temperature to kinetic energy using Boltzmann constant: kinetic energy=(3/2)KT. Then dived the total kinetic energy by 7eV

2. Feb 10, 2013

### clamtrox

I don't understand how this helps.

How much energy does a single photon lose in a single Compton scattering? What is the average energy lost over multiple scatterings (with different angles θ)?

3. Feb 10, 2013

### Bailey

Both were not given, but I assume 180 degree for max scattering?

4. Feb 11, 2013

### clamtrox

Assuming 180 degree angle is not entirely correct, but you can certainly do it like that, and it will give you at least a good order of magnitude estimate. Ideally you would like to take an average over all possible angles.