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Compton Scattering is an inelasatic scattering

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In the main text, there is a mistake in the introduction part. It states:

"Compton scattering is an example of elastic scattering of light by a free charged particle, where the wavelength of the scattered light is different from that of the incident radiation."


Of course, even that description describes that it is inelastic scattering


References:

Pratt, R. H., et al. "Compton scattering revisited." Radiation Physics and Chemistry 79.2 (2010): 124-131. Lupiloui (talk) 11:00, 4 January 2023 (UTC)[reply]

No sir. There is no energy transfer except for kinetic energy - just like, e.g., elastic electron-proton scattering. Kinetic energy ist transferred from the e to the p (in lab frame) but as long as the p does not go into an excited state (delta resonance = incease of mass), it is elastic. In Compton scattering neither the mass of the e changes (there is no such thing as an excited e) neither the mass of the photon (zero). — Wassermaus (talk) 07:31, 1 June 2023 (UTC)[reply]

Equation (4)

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No derivation of equation (4) for the scattering angle of the electron is given. I have reason to doubt that this equation is correct. Specifically, see section 4.2 of tutorial on Compton Scattering written by Paul D'Alessandris to be found at https://phys.libretexts.org/Bookshelves/Modern_Physics/Book:_Spiral_Modern_Physics_(D'Alessandris)/4:_The_Photon/4.2:_Compton_Scattering TychoTor (talk) 23:45, 22 March 2023 (UTC)[reply]

I'm also not quite sure where this comes from as there is no indication at all in the text. A chapter by Daniel Boulard visible here: https://www.sciencedirect.com/topics/nursing-and-health-professions/compton-effect shows a similar equation, but using cosine of phi, not cotan. Is there any clarification possible? 204.83.156.100 (talk) 19:25, 30 October 2024 (UTC)[reply]
I'll answer myself I imagine, there seems to be a decent overview of the derivation at the end of the following document: https://pleclair.ua.edu/PH253/Notes/compton.pdf 204.83.156.100 (talk) 20:29, 30 October 2024 (UTC)[reply]

Debye is under-represented here

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Debye independently discovered this effect and actually published his theory in "Zerstreuung von Röntgenstrahlen und Quantentheorie" in Physikalische Zeitschrift in April 1923, before Compton's December 1923 paper. Debye apparently later said that Compton deserved the name of the effect because he had done more work but at the moment Debye also has a measly entry in the See also section. Any objections to giving Debye a bigger role in the article? Jason Quinn (talk) 11:24, 27 December 2023 (UTC)[reply]

elastic collisions

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"Compton scattering is commonly described as inelastic scattering, because the energy in the scattered photon is less than the energy of the incident photon. Energy of the incident photon is transferred to the recoil particle, but only as kinetic energy. The electron gains no internal energy, respective masses remain the same, the mark of an elastic collision. From this perspective, Compton scattering could be considered elastic because the internal state of the electron does not change during the scattering process. Whether Compton scattering is considered elastic or inelastic depends on the specific definition of these terms being used."

This section does not add anything substantial and is confused. Strictly, the reaction gamma H -> gamma p e is inelastic, although there is no harm in considering the reaction as gamma e -> gamma e, which is elastic. Total energy is always conserved, so the use of energy non-conservation, which is used to distinguish classical collisions is not useful. 108.17.124.171 (talk) 18:06, 10 May 2024 (UTC)[reply]

I am giving it a go with trying to clarify that paragraph. It does have something important to say, but I do agree it sounded confused. IndigoManedWolf (talk) 17:06, 3 August 2024 (UTC)[reply]

Energy Levels where different interactions dominate

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The article states: "Compton scattering is one of four competing processes when photons interact with matter. At energies of a few eV to a few keV, corresponding to visible light through soft X-rays, a photon can be completely absorbed and its energy can eject an electron from its host atom, a process known as the photoelectric effect. High-energy photons of 1.022 MeV and above may bombard the nucleus and cause an electron and a positron to be formed, a process called pair production; even-higher-energy photons (beyond a threshold energy of at least 1.670 MeV, depending on the nuclei involved), can eject a nucleon or alpha particle from the nucleus in a process called photodisintegration."

However in chapter 2 of reference 9 (principles of radiotherapy) it states that "The energy range in which the photoelectric effect predominates in tissue is about 10–25 keV.", "the energy range in which the Compton effect dominates (~25 keV–25 MeV)" and "The energy range in which pair production dominates is ≥ 25 MeV".

Is this only due to these ranges being in tissue rather than in air? Does this make a difference? Apologies if this is an error on my part, otherwise some of the numbers in this article are off by alot.

Reference 9:

  1. Camphausen KA, Lawrence RC. "Principles of Radiation Therapy" Archived 2009-05-15 at the Wayback Machine in Pazdur R, Wagman LD, Camphausen KA, Hoskins WJ (Eds) Cancer Management: A Multidisciplinary Approach Archived 2013-10-04 at the Wayback Machine. 11 ed. 2008.

2A00:23C6:A185:8E01:ED56:3025:C984:7B6 (talk) 12:49, 9 December 2024 (UTC)[reply]