Standard Compton Effect Explained Classically/Semiclassically

In summary: Quote:The standard Compton effect can be explained in a purely classical way without the need for any quantum mechanical concepts.
  • #1
lightarrow
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I know this topic has already been covered many times, but, is it possible to explain classically or semiclassicaly the standard Compton effect?
 
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  • #2
I remember reading once in some Quantum optics text that the standard Compton effect (together with the simplest form of the photoelectric effect) can indeed be explained semiclassically, i.e using quantum theory for matter and classical fields for EM. This was of course not recognised at the time though.

Don't remember the details or where I read it unfortunately :(
 
  • #3
lightarrow said:
I know this topic has already been covered many times, but, is it possible to explain classically or semiclassicaly the standard Compton effect?

What is the standard definition of the "standard Compton effect" ? I mean, what is the "effect" in the "Compton effect" ?

Daniel.
 
  • #4
dextercioby said:
What is the standard definition of the "standard Compton effect" ? I mean, what is the "effect" in the "Compton effect" ?

Daniel.

[tex]\lambda\prime-\lambda=\frac{h}{m_ec}(1-cos\theta)[/tex]

With "standard" I mean without considering the electron's spin.
 
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  • #5
Okay, then, so it's the shift in wavelength. IIRC, in high-school physics the treatment is semiclassical, or almost classical: the electron & the photon are assumed classical relativistic particles (i.e. always on their mass-sheet) and then E=h\nu for the photon is used and the shift is calculated imposing conservation of energy and momentum.

But to get back on topic, explaining the effect would require explaining what a photon is: and that can't be done without doing/knowing the quantization procedure for the em field. As for the quantized electron field, it's useless to think of the classical electron interacting with the quantized em field, so

The question's answer's "no".

Daniel.
 
  • #6
Sorry, I didn't explain well. I intended with light treated as a classical EM field.
 
  • #8
I have been thinking about this lately in the context of momentum loss of radiation upon passage through a diluted plasma. Momentum loss from stationary plasma should red-shift radiation. I found that there is no momentum transmitted from radiation field to electron if the em field is linearly polarised.

[OOOPS! I apologize. In replying to your post, I accidentally hit "edit" instead of "quote" and permanently edited your post. I can't seem to get the buffer to repost your entire original message. Oy! - Zz]
 
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  • #9
dextercioby said:
It can't be done.

Daniel.

So, what did they talk about?:

http://www.usenet.com/newsgroups/sci.astro/msg02581.html:
(Edit: this url doesn't work anylonger, at least from my server.)
Quote:
<<You should take a look at
"Atoms and light" by John N. Dodd (Plenum Press, New York, 1991).

In Chapter 6, the Compton scattering is treated in an entirely
classical way, without using energy and momentum conservation,
but just standard classical em + relativistic *kinematics*,
by the picture of a circularly polarized em wave impinging upon
a charged particle.
The calculation is based on deriving a steady-state solution
for the down-stream motion of the particle which is superimposed
to the constant rotation at the frequency of the passing wave.
I haven't read the analysis in detail, but my first impression
is that it is quite clever.

It is, especially in light of the comments at page 55, apparent
that the standard Compton effect, i.e. the one the Compton
explained using the notion of photon, does not actually *need*
this notion.
So, according to the author, the standard (spin-free) Compton
effect cannot be invoked to argue the existence of photons. >>

Unfortunately I don't have that book, so I can't make any comment.

Or: http://adsabs.harvard.edu/abs/1979PhDT...96B
Quote:
<<The Compton effect is given a classical explanation which yields the Klein-Nishina cross section and demonstrates the classical origin of photon-like behavior of the incident and scattered radiation>>.

Or: http://www.springerlink.com/content/r10am90am8v1a18p/
 
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Related to Standard Compton Effect Explained Classically/Semiclassically

1. What is the Standard Compton Effect?

The Standard Compton Effect is a phenomenon in which a photon (a particle of light) collides with a free electron. The photon transfers some of its energy to the electron, causing it to recoil and emit a new photon with a longer wavelength. This process is known as scattering, and it is an important concept in quantum mechanics.

2. How is the Standard Compton Effect explained classically?

Classically, the Standard Compton Effect can be explained by treating the electron as a particle with a fixed mass and the photon as a wave with a fixed energy. When the photon collides with the electron, the energy of the photon is transferred to the electron, causing it to recoil. The new photon emitted by the electron has a longer wavelength because some of the original energy of the photon has been transferred to the electron.

3. How is the Standard Compton Effect explained semiclassically?

Semiclassically, the Standard Compton Effect takes into account both the particle and wave nature of both the electron and the photon. The electron is still treated as a particle, but the photon is described as a wave packet (a group of waves). When the photon collides with the electron, the wave packet is scattered, resulting in a longer wavelength for the new photon.

4. What is the significance of the Standard Compton Effect?

The Standard Compton Effect is significant because it provides evidence for the wave-particle duality of matter and energy. It also helps us understand the behavior of photons and electrons in quantum systems, and it is used in many applications such as medical imaging and X-ray diffraction.

5. Is the Standard Compton Effect the same as the Compton Effect?

Yes, the Standard Compton Effect and the Compton Effect refer to the same phenomenon. The term "standard" is often used to distinguish it from other forms of Compton scattering, such as the Inverse Compton Effect, which involves a photon colliding with a high-energy electron.

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