# Compton effect and kinetic energy

1. Aug 31, 2013

### cassimoe

1. The problem statement, all variables and given/known data
What is the maximum possible kinetic energy (keV) of a Compton electron and the corresponding minimum energy of a scattered photon resulting from scattering of

a) 100 keV photon
b) 1 MeV photon

2. Relevant equations
Δλ = 0.24(1-cosθ)

3. The attempt at a solution
Δλ = 0.24(1-(-1))
= 0.48A

I do not know how to figure the energy of the scattered photon

2. Aug 31, 2013

### cassimoe

Compton Scatter

1. The problem statement, all variables and given/known data

what fraction of the energy of a 1 MeV photon is lost if it Compton scatters through an angle of 90 degrees

2. Relevant equations

Δλv= 0.24(1-cosθ)

3. The attempt at a solution
Δλv= 0.24(1-cosθ)
= 0.24(1-cos90)
= 0.24(1-0)
Δλ = 0.24A

I am confused from here

3. Aug 31, 2013

### Staff: Mentor

OK, you've got the change in wavelength of the photon. What's the initial wavelength? (How do you find the wavelength of a photon given the energy?)

Then, what's the final wavelength?

Last edited: Aug 31, 2013
4. Aug 31, 2013

### Staff: Mentor

Threads merged. These two problems are actually rather similar, and you should be able to use basically the same technique to solve both of them. My hint applies to both of them.