Can Photons Transfer Only Part of Their Energy to Electrons?

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Discussion Overview

The discussion revolves around whether photons can transfer only part of their energy to electrons during interactions, particularly in the context of bound versus free electrons and the Compton effect.

Discussion Character

  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions if photons can transfer only part of their energy to electrons.
  • Another participant asserts that photons either transfer their entire energy or none at all, referencing quantum electrodynamics (QED) principles.
  • A different viewpoint suggests that for bound electrons, the entire energy is transferred, while for free electrons, photons can transfer only part of their energy, citing the Compton effect as an example.
  • One participant emphasizes that in Compton scattering, the process involves a photon being absorbed and a new photon being emitted, regardless of whether they are the same photon or not.
  • Another participant insists that it cannot be the same photon that is involved in the scattering process.

Areas of Agreement / Disagreement

Participants express differing views on the energy transfer of photons to electrons, with no consensus reached on whether partial energy transfer is possible or if photons must fully disappear upon interaction.

Contextual Notes

Some claims depend on specific conditions, such as whether electrons are bound or free, and the discussion references complex quantum processes without resolving the underlying assumptions or definitions.

scilover89
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Photon"s energy

When photons trasfer energy to electron, can it transfer only part of its energy and not whole?
 
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The whole energy.The photon is either absorbed,or emitted.If that didn't happen,then the vertex of QED would have at least 2 photonic lines...This is not possible,even if assuming one of the 2 photons were virtual.

Daniel.
 
Hello scilover89,

If you have a bound electron (like in an atom), then the whole energy is transfered.
But for free electrons it is different. The photon can transfer only part of it to the electron.
"In the Compton effect, individual photons collide with single electrons that are free or quite loosely bound in the atoms of matter. Colliding photons transfer some of their energy and momentum to the electrons, which in turn recoil. In the instant of the collision, new photons of less energy and momentum are produced that scatter at angles the size of which depends on the amount of energy lost to the recoiling electrons."
from http://www.britannica.com/nobel/micro/138_88.html
 
Last edited by a moderator:
Nope.The photon dissapears completely.Take the 2 Feynman diagrams...
Daniel.
 
Compton scattering is a photon in photon out process. Whether it is the same photon or a different one doesn't matter. The process is important for gamma rays.
 
It's not the same photon.It can't be.

Daniel.
 

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