What Happens When a Photon Collides with a Proton in Glass?

AI Thread Summary
When a photon collides with a proton in glass, it typically does not interact directly, as photons primarily interact with electrons rather than protons, especially at energies below 1 or 2 MeV. The probability of interaction with protons is significantly lower, with a cross section about 3.3 million times smaller than that for electrons. At energies above approximately 2 MeV, photons can produce electron-positron pairs through interactions with protons. For a deeper understanding of these interactions, Richard Feynman's "QED" is recommended, along with specific articles detailing photon behavior in matter. Overall, the interaction dynamics depend heavily on the energy of the incoming photon.
cragar
Messages
2,546
Reaction score
3
say we have a slab of glass and an incoming photon , and it hits a proton in the slab of glass , will it get absorbed and re-emitted or will it oscillate the proton , what will happen ,
Any input will be much appreciated
 
Science news on Phys.org
I suggest looking at "QED" by Richard Feynman for a comprehensive view of photon matter interactions. Except for extremely high energy gamma rays, photons do not interact with individual protons.
 
Below 1 or 2 MeV, The photons interact only with the electrons in the glass. The cross section for interaction with the protons is about 3.3 million times smaller than the interactions with the electrons. Please review this article from the Review of Particle Properties from the Lawrence Berkeley Lab on the passage of particles (including photons) through matter.

http://pdg.lbl.gov/2009/reviews/rpp2009-rev-passage-particles-matter.pdf

See in particular pages 22 to 28 and Figure 27.14, which shows the interaction of photons with the electrons in the glass. Above ~ 2 MeV, the photons begin to produce electron positron pairs by scattering off the protons.

Bob S
 
thanks for the responses
 
Thread 'A quartet of epi-illumination methods'
Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So...
I am currently undertaking a research internship where I am modelling the heating of silicon wafers with a 515 nm femtosecond laser. In order to increase the absorption of the laser into the oxide layer on top of the wafer it was suggested we use gold nanoparticles. I was tasked with modelling the optical properties of a 5nm gold nanoparticle, in particular the absorption cross section, using COMSOL Multiphysics. My model seems to be getting correct values for the absorption coefficient and...
Back
Top