Does Multiple Compton Scattering Occur in Laser-Electron Interactions?

danno
Messages
2
Reaction score
0
I'm testing my faith in the photon. I understand that energy levels are quantized, and I understand that the EM field carries momentum. I want to make sure the idea of a photon is necessary to intuitively understand the observations.

I am focused on compton scattering of a photon and an electron. The ideal experiment has a single electron suspended in a vacuum chamber. A laser pulse is shot across the chamber and the electron, if scattered, is detected when it impacts the wall of the chamber. Its momentum is recorded. For simplicity let's just say we measure the electrons scattered in the forward direction.

The experiment will measure electrons having momentum consistent with having collided with a particle of momentum h / lambda where lambda is the central frequency of the laser pulse. Ergo, photon.

I am wondering: if one turns up the laser intensity, does one sometimes observe an electron momentum consistent with having scattered off two or more photons? In other words, in the momentum distribution of the electrons, is there not only the first peak, but additional peaks higher order in the laser intensity (with decreasing spacing of course)? Or does something happen in QED wherein after the electron is entangled with the field after the first scattering, it does not undergo any additional scatterings? I do not know QED.

Thanks for your time!

Dan
 
Physics news on Phys.org
Actually, this paper says the electron only scatters once!

http://adsabs.harvard.edu/abs/1992Ap&SS.192..219I

However I suspect that the paper is saying that the multiple scattering probability is very close to zero due to the fact that the electron absorbs a lot of the photon energy, but not exactly zero. Bottom of page 226 to 227:

"Just in the first scattering event an electron transfers all its energy to a gamma-ray quantum and becomes inactive"

And first paragraph of section 3.2: "It has already been mentioned that an electron... in reality interacts with a field photon only once, transferring practically all its energy to the latter"

Not very particle-like.

Dan
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
Back
Top