1. Can Compton Scattering like scattering happens for K shell electron like it happens for valence shell electron for X and Gamma Ray?
2. If yes, probability is more for K or Valence Shell electron? And more importantly why its high (either K or valence shell)?
Thank you.
Dear Debasish,
the attached link may help you :
Article Compton scattering of photons from bound electrons: Full rel...
However, I havn't got the full text yet.
There is another paper supporting the assumption that Compton scatter at core level electrons may deviate slitely at least from the Compton scatter behavior of the average electron entity.
Article Compton scattering by bound electrons
All electrons of different shells (1s, 2s,..., valence) have the same cross sections to the photon. Thus, the probability of interaction of the photon with the electron is the same for any orbital electron.
1. Yes, its possible
2. Only when incoming photon has very high energy compared to K shell binding energy. In that case K shell electron will look almost free to the incoming photon.
I feel lower energy photons will prefer to interact with valence electrons whereas high energy photons will prefer to interact with K shell electron
Answer lies in the "ease with which momentum conservation takes place".
See Hubble data or plot. How probability of Compton scattering varies with energy for various elements. Its non-zero although small.
@Munish Kumar Sir: Can you please add reference of "Hubble data or plot".
The energy of the gamma-quantum needed for Compton scattering is equal to the electron mass, which is approximately 0.5 MeV. The deepest K levels for very heavy atoms like Uranium is of order of 0.1 MeV, for lighter atoms it is smaller. Therefore, while considering the scattering the atomic potential is just a small correction. All electrons may be treated as free.
If there is a small correction, it is for the decrease of the cross section as the discrete electronic structure of the atom imposes only limitations.
Compton scattering or incoherent scattering can be understood as an inelastic scattering of X or gamma rays on electrons in a material medium. Only a part of the incident photon energy is transferred to the electron, which is ejected from its orbit due to the large momentum transfer, and the new photon is scattered off at a lower energy. The Klein-Nishina formula for Compton scattering from atomic electrons, assume that the electrons have a binding energy less to incoming photon, and the dispersion probability is independent of the orbital.
The coherent scattering occurs when the binding energy of the electron is greater than the incident photon (refers to the binding energy plus the kinetic energy). In this case, the photon is scattered changing only the direction without loss energy.
In reference to the Hubbell's table, you can be found online in the NIST. Unfortunately, this table only is valid to free atom systems. For molecules or solids, this table is not valid.
Thank you all for your answers.
So we understood that Compton scattering takes place for both Valence and K shell electrons.
For 662 keV gamma ray whose probability of Compton scattering shall be more (Valence and K shell electrons) for Ge? and why?
I think that you are directing the conversation towards: Compton effect plus photoelectric effect (PE), the interaction of the photon in a germanium crystal by means of PE (photopeak), etc. Could you better explain your question?
No Sir. I want to know the probability of Compton scattering only for Ge for Valence shell e vs K Shell e.
The scattering probability of K vs valence shell is the same. This is because the cross section is the same.
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