Compton scattering - energy of the scattered photon

In summary, the conversation revolves around solving a problem related to a Compton collision between a photon and an electron. The original photon energy is given, and the angle of the electron after scattering is known. The goal is to find the energy of the scattered photon. Several equations and information are given, but the specific method to solve for x, the angle of the scattered photon, is still unclear.
  • #1
Makla
2
0
[Mentor's note: This thread does not use the template because it started in one of the non-homework forums. I moved it here instead of deleting it and asking the poster to repost here, because it had accumulated several useful replies.]

Hi.
I have the exact same problem that ZachWeiner had in here:
A photon whose energy equals the rest energy of the electron undergoes a Compton collision with an electron. If the electron moves off at an angle of 40 degrees with the original photon direction, what is the energy of the scattered photon?

Unfortunately the answers don't help me much. I would need more information how to get the energy of the scattered photon.

Thanks.
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
Write down your conservation of momentum and energy equations.

If an object is scattered with some y momentum. To conserve overall y momentum the object that was at rest must have equal and opposite momentum in y.

This should be done using 4 momentum.
 
  • #3
Makla said:
Hi.
I have the exact same problem that ZachWeiner had in here:
A photon whose energy equals the rest energy of the electron undergoes a Compton collision with an electron. If the electron moves off at an angle of 40 degrees with the original photon direction, what is the energy of the scattered photon?

Unfortunately the answers don't help me much. I would need more information how to get the energy of the scattered photon.

Thanks.
Step 1. get the angle (x) of the photon after scatter.
Step 2. increase in Compton wavelength is given by 1-cos(x).
Step 3. get energy from Compton wavelength.

Note: Your original photon energy has a Compton wavelength of 1 (corresponding to 511 kev). So the final energy of the photon will be 511/(2-cos(x)) kev.
 
  • #4
how

How do I get x?
I know this:
y = 40°
hc/lam = 0,511 MeV

In x direction: h/lam = h/lam' cos(x) + p_e cos(y)
In y direction: h/lam' sin(x) = p_e sin(y)

We also know: lam' - lam = lam_c (1 - cos(x))
Where:
lam = wavelength before scattering
lam' = wavelength after scattering
x = angle of the scattered photon
y = angle of the electron

I don't know how to get x.
 
  • #5


Hello,

Compton scattering is a type of scattering in which a photon collides with an electron and transfers some of its energy to the electron, causing it to recoil. The scattered photon will have a different energy than the original photon, and this change in energy can be calculated using the Compton scattering formula:

Δλ = h/mc (1-cosθ)

Where Δλ is the change in wavelength, h is Planck's constant, m is the mass of the electron, c is the speed of light, and θ is the angle of scattering.

The energy of a photon can be calculated using the equation E = hc/λ, where E is the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength.

Using these equations, you can calculate the energy of the scattered photon by taking the energy of the original photon and subtracting the change in energy caused by Compton scattering. I hope this helps. Let me know if you have any further questions.
 

What is Compton scattering?

Compton scattering is a physical phenomenon in which a photon (electromagnetic radiation) interacts with a charged particle, transferring some of its energy to the particle and changing its direction of motion.

How is the energy of the scattered photon affected in Compton scattering?

The energy of the scattered photon is affected by the angle at which it is scattered and the energy of the incoming photon. The scattered photon will have less energy than the incoming photon, and the amount of energy loss is directly proportional to the scattering angle.

What is the formula for calculating the energy of the scattered photon in Compton scattering?

The formula for calculating the energy of the scattered photon is Es = Ei/(1 + (Ei/mec2)(1-cosθ)), where Es is the energy of the scattered photon, Ei is the energy of the incoming photon, me is the mass of the electron, c is the speed of light, and θ is the scattering angle.

What is the significance of Compton scattering in the field of physics?

Compton scattering is significant because it provides evidence for the wave-particle duality of light. It also allows scientists to measure the properties of subatomic particles, such as the mass and charge of the electron, and to study the structure of matter.

What are some real-world applications of Compton scattering?

Compton scattering has many practical applications, such as in medical imaging techniques like X-rays and CT scans, and in materials analysis techniques like X-ray diffraction. It is also used in particle accelerators to determine the energy and momentum of particles, and in the detection of gamma rays in astronomy.

Similar threads

  • Advanced Physics Homework Help
Replies
1
Views
3K
Replies
8
Views
854
  • Introductory Physics Homework Help
Replies
10
Views
371
  • High Energy, Nuclear, Particle Physics
Replies
21
Views
2K
Replies
3
Views
2K
  • High Energy, Nuclear, Particle Physics
Replies
2
Views
982
  • Advanced Physics Homework Help
Replies
2
Views
2K
  • Quantum Physics
Replies
1
Views
2K
Replies
1
Views
824
  • Quantum Physics
Replies
4
Views
688
Back
Top