Compton scattering and collision within blackbody

Bailey
Messages
45
Reaction score
0

Homework Statement


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.


Homework Equations



λ2 - λ1 = λcompton(1 - cosθ)


The Attempt at a Solution



Not sure if I have all relevant 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
 
Physics news on Phys.org
Bailey said:
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

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)?
 
Both were not given, but I assume 180 degree for max scattering?
 
Bailey said:
Both were not given, but I assume 180 degree for max scattering?

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.
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.

Similar threads

Back
Top