Axion thrust by enhanced scattering

  • Context: Graduate 
  • Thread starter Thread starter Ricvil
  • Start date Start date
  • Tags Tags
    Scattering Thrust
Click For Summary

Discussion Overview

The discussion revolves around the theoretical implications of axions, particularly in relation to enhanced scattering phenomena in waveguides and their potential for generating thrust. Participants explore the properties of axions, their interactions with photons, and the relevance of various scattering processes, including Rayleigh scattering and the Primakoff process.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants discuss the theoretical properties of axions, noting their uncharged, spin-0 nature and small scattering cross section with photons.
  • One participant references a paper on resonant backscattering in waveguides, suggesting that axions could be accelerated under specific conditions due to their electrodynamic properties.
  • Another participant questions the applicability of Rayleigh scattering to axions, pointing out that the parameters used in the paper may not be relevant to axions, which do not have a defined circumference.
  • Concerns are raised about the feasibility of accelerating axions, with some arguing that interactions would more likely result in photon production rather than acceleration.
  • Participants discuss the Primakoff process as a model for axion-photon interactions, emphasizing its specific conditions and limitations.
  • There is mention of the potential for resonant backscattering to be influenced by strong inhomogeneous magnetic fields in waveguides.
  • One participant introduces additional literature on axion electrodynamics and scattering processes, highlighting the role of topological insulators.
  • Another participant expresses frustration over the discussion becoming unfocused, suggesting that it lacks clear connections and references.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of certain scattering theories to axions, with no consensus reached on whether axions can be effectively treated as polarizable scatterers or if their interactions with photons can lead to acceleration. The discussion remains unresolved regarding the specific mechanisms and implications of axion interactions.

Contextual Notes

Limitations include the dependence on specific theoretical models and assumptions about axion properties, as well as the unresolved nature of the mathematical and physical implications of the discussed processes.

Ricvil
Messages
10
Reaction score
0
Axions in theory are uncharged, spin 0, very light particles, and have a very small scattering cross section when interacting with photons.
But there is a very interesting article about a strong enhanced scattering of neutral particles. "Resonant radiation pressure on neutral particles in a waveguide"- arxiv.org/pdf/physics/0103017
The article above talks about a ressonant backscattering of neutral particles, where under right conditions of frequency, a "arbitrarily small" polarizable scatter in a waveguide can have a huge effective scattering cross section.
Well, the axion has the electrodynamic property of produce electromagnectic polarization due to axion-photon mixing, so axion could be accelerated by resonant geometrical scattering inside waveguides under critical frequency of unimodal propagation, generating a axion thrust?
 
Physics news on Phys.org
I think this paper is talking about particles in the Rayleigh regime...
I looked for this, and eg here http://patarnott.com/pdf/Moosmuller2009JAWMA.pdf it gives some explanation on what Rayleigh particles are...I don't think this can be generalized to axions? I mean in the parameter [itex]x= \frac{2 \pi r}{\lambda} \ll 1[/itex], what would [itex]2 \pi r[/itex] stand for? the axion doesn't have a circumference.
Why would you accelerate axions? if you apply an external electromagnetic field, the axion will generally produce a photon (the reverse? Primakoff process), of course dependent on the polarization of your field (due to the coupling to F Ftilde). So I don't think you could accelerate it, rather than change it.
 
The "neutral particles" in the paper are things like dust particles. Not with an overall charge, but still made out of electrons and nuclei, which obviously show a significant interaction with photons.
Axions, if they exist at all, are so rare and couple so weakly to matter or light that there is nothing you could accelerate.
 
The Primakoff process ( in this context) models the resulting interaction between photon and axion fields under a strong and "static/stationary" background electromagnetic field, producing a approximate linear model of axion photon electrodynamic.
Basicaly, the Primakoff process models a very paticular situation of a "photon axion oscillation"
Rayleigh scattering is another example of a very particular situation of the most general electromagnectic scattering process.
The article about ressonante scattering is interesting because it shows a process where the transmission of electromagnectic waves (photons with momentum) inside a waveguide can be totally reflected (inversion of all photons momentuns) by a "arbitrarily small polarizable scatter".
Changes on momentum of photons must be compensated by the change of mometum of the scatter(force on the scatter).
If the scatter is free to move then it will accelerate.
The question:
Is the axion a effective "small polarizable scatter"?
 
Last edited:
What is the probability of a photon to scatter on the axion? or how could you explain this interaction: [itex]a \gamma \rightarrow a \gamma[/itex]??
 
The process are between two photons and one axion in quantum terminology.
I prefer look this process by axion electrodynamic field equations point of view, where the scattering process is more friendly.
For example, i have found this interesting article associating axion photon oscillation with a index of refraction point of view.
http://arxiv.org/abs/1003.0410
In this article, photon and axions fields are scattered by a strong inhomogeneous magnectic field.
The axion mass was not taked in consideration.
Perhaps the effect of ressonant backscattering in waveguide can be triggered by a strong inhomogeneous magnectic field applied on a section of the waveguide.
 
Another interesting article from condensate matter axion electrodynamic
http://arxiv.org/pdf/1503.00235
The axion field causes a "cross-polarization"
The article presents the expressions for the scattering caused by spheres of "topological isolators"
 
Sorry, is "Topological insulators".
 
This thread is becoming a collection of buzzwords with unclear relations and wild speculations. Not something we like to see here.
If you have some reference discussing the precise effect you are asking about, please send me a message and I'll open the thread again. Until then it remains closed.
 

Similar threads

  • · Replies 48 ·
2
Replies
48
Views
8K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 0 ·
Replies
0
Views
3K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 50 ·
2
Replies
50
Views
12K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 46 ·
2
Replies
46
Views
6K
  • · Replies 4 ·
Replies
4
Views
5K