Electrons And Photons

Hi, (1st time post)

When energy is given to an electron and then removed.

Is there a classical/quantum description that governs which direction the emitted photon will take?

Thanks in advance, If anyone can help answer this one.

Hi Chin:
You're probably thinking of the Compton Scattering formula which gives the final momentum of the photon and of the electron after collision. The scattering angle determines the resultant photon wavelength (energy).

Those formulas (which are based upon momentum and energy conservation) are given here:
http://hyperphysics.phy-astr.gsu.edu/Hbase...tum/compeq.html

Lunar

This post has been edited by Lunarlanding on Apr 26 2010, 03:55 AM

At the timing of releasing of electrons there takes the energy level difference. So there Quantum Mechanics is dealing which is a concept of electron. While in case of photon i would add that photon is a unit part of light so the energy releasing due changes of ground stage and excited stage is actually in the form of photon.

I believe you may be discussing photon/electron collision interaction dynamics as would be applied to an electron target at rest.

This may be a different condition in the context, if the OP's post is interpreted as an "Absorption/Emission of a Photon from a moving Electron transitioning in energy levels associated with Atoms?

The question would then seem, can a photon emission direction be determined by the source electron's orbit, spin, and energy level transition dynamics?--or, does that exact calculation remain an uncertainty?

Or, perhaps I misinterpreted the original statement?

This post has been edited by keith* on Apr 28 2010, 08:10 AM

As I understand it, For an electron to even emit a photon it has to be bounded (to an atom for example) as free electrons "cannot" absorb photons.
An electron simulated by an input photon should (with a high probability) emit a photon with the same wave vector (direction) as the input photon.

Could one control the direction of the emitted photon by controlling one or more of the electron's properties as it drops to its original energy state from the excited state?