Question about light ?

  • Thread starter cragar
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  • #1
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This may be a dumb question but if light is an oscillating E and B field, If i shot an electron into to a laser beam will it get deflected by the lights E and B fields. Or is this like Compton scattering.
 

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  • #2
The electron would have to be deflected because light has momentum.
 
  • #3
Drakkith
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The oscilatting fields are what make up a photon. Any transfer of energy would have to occur because the photon gets absorbed or scattered by the electron, not a simple interaction because of one of the fields.
 
  • #4
The oscilatting fields are what make up a photon. Any transfer of energy would have to occur because the photon gets absorbed or scattered by the electron, not a simple interaction because of one of the fields.

That is energy measured in an orthogonal direction to that of the momentum gained though right?
 
  • #5
Drakkith
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That is energy measured in an orthogonal direction to that of the momentum gained though right?

If that means what I think it means, then yes. The photon would only effect the electron by being absorbed or scattered, which transfers it's momentum to the electron. A photon passing near an electron would not deflect either one.
 
  • #6
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so basically it is Compton scattering
 
  • #7
Claude Bile
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Compton scattering is the limiting case where the photon has high energy and can essentially be approximated as a classical particle.

Outside this limit, the EM field will still impart momentum to an electron, but it may be a stretch to say that it obeys the laws of Compton scattering.

Claude.
 
  • #8
Drakkith
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so basically it is Compton scattering

It depends on the frequency of the laser beam. If it is high enough the electron MIGHT get scattered. Otherwise it will not unless it is travelling at relativistic speeds. In which case it could undergo inverse compton scattering.

If the electron and the photons are not of sufficient energy, then I don't think the electron will be scattered. I don't know too much on the subject so someone else may need to clarify that.
 

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