Optical (laser/maser) cooling of fusion products.

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Discussion Overview

The discussion revolves around the potential for optical cooling of fusion products, particularly focusing on the interaction of high-energy neutrons produced in fusion reactions with electromagnetic radiation. Participants explore the feasibility of collecting energy from these neutrons using methods such as microwave beams and gamma photons, while also considering the underlying physics of neutron interactions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants assert that neutrons do not respond to electromagnetic radiation at low energies, questioning the viability of using microwave beams to collect energy from them.
  • There is discussion about the conditions under which neutrons can interact with electromagnetic radiation, with references to the neutron's spin and magnetic moment as factors influencing this interaction.
  • Some participants express uncertainty regarding the energy levels required for photons to have an appreciable effect on neutrons, suggesting that high-energy photons (in the hundreds of MeV range) may be necessary.
  • One participant mentions the possibility of boosting photon energy using gamma beams, while others caution that this could lead to activation of reactor walls and may not be an efficient method for harnessing neutron energy.
  • There is a suggestion to consider alternative methods, such as substituting photons with protons or hydrogen atoms, to interact with neutrons.
  • Participants note that while there are methods for photon interaction in nonlinear materials, these methods are often inefficient and may not yield a net gain in energy.

Areas of Agreement / Disagreement

Participants express a range of views on the interaction of neutrons with electromagnetic radiation, with no clear consensus on the feasibility of using such interactions for energy collection. The discussion remains unresolved regarding the effectiveness of proposed methods and the underlying physics.

Contextual Notes

Some limitations include the dependence on specific energy levels for photon-neutron interactions, the efficiency of proposed energy conversion methods, and the lack of extensive literature on certain neutron-photon interactions.

obelenkiy
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Fusion raction produces high energy neutrons which cause activation of the walls of the reactor. Why can't their energy be collected by, for example, a microwave beam?
 
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obelenkiy said:
Fusion raction produces high energy neutrons which cause activation of the walls of the reactor. Why can't their energy be collected by, for example, a microwave beam?
Because neutrons do not respond to electromagnetic radiation at such low energies.
 
Astronuc said:
Because neutrons do not respond to electromagnetic radiation at such low energies.
Astronuc, just curious: neutrons can respond to EM radiation at high enough energy because of ... the neutron's spin? What else is there?
 
There is the neutron's magnetic moment, as well as the charges of the individual quarks. Not sure which Astronuc had in mind though.
 
Redbelly98 said:
There is the neutron's magnetic moment, .
Which results from its spin?
 
Redbelly98 said:
There is the neutron's magnetic moment, ...

mheslep said:
Which results from its spin?

As I understand it, it results from the spin and the fact that there is charge within the neutron's structure. If somebody else can confirm my thinking here, it would be appreciated.
 
mheslep said:
Astronuc, just curious: neutrons can respond to EM radiation at high enough energy because of ... the neutron's spin? What else is there?
It's the internal structure (quarks), magnetic moment and spin - pretty much as expressed by Redbelly.

I was prepared to say that neutrons don't interact with photons, but I've seen some articles on neutron-photon interactions. However, I don't believe there is much in the literature on photon interaction with free-neutrons, or neutrons as condensed matter. I caught one article on optically cooling neutrons, but I can't seem to locate the article.

I was also pondering electro-weak interactions.

I expect that photons have to be of very high energy - high (100's) MeV range - to have an appreciable effect on a neutron. The gamma photons we get from typical radio-nuclides or nuclear reactions have energies on the order of high keV up to <10 MeV.

There was a discussion elsewhere in the forums about photons scattering of protons, as opposed to electrons or positrons, and I expect the cross-section for photon-neutron scattering to less than that of protons.
 
Astronuc said:
I expect that photons have to be of very high energy - high (100's) MeV range - to have an appreciable effect on a neutron. The gamma photons we get from typical radio-nuclides or nuclear reactions have energies on the order of high keV up to <10 MeV.

Maybe, it's possible to boost the energy of photons by heating them with other gamma beams.
Are there frequency converters for such wavelengths?
 
obelenkiy said:
Maybe, it's possible to boost the energy of photons by heating them with other gamma beams.

And now your gammas are activating the walls.
 
  • #10
obelenkiy said:
Maybe, it's possible to boost the energy of photons by heating them with other gamma beams.
Are there frequency converters for such wavelengths?
Photon interaction can occur in nonlinear materials, but those methods and other frequency conversion methods are quite inefficient. You will use up much more energy in the conversion process than you would ever get from the neutrons that are to be captured, so it would be a pointless way of harnessing the neutron's energy.
 
  • #11
Astronuc said:
There was a discussion elsewhere in the forums about photons scattering of protons, as opposed to electrons or positrons, and I expect the cross-section for photon-neutron scattering to less than that of protons.


Substitute photons with protons or hydrogen atoms held in the shell around the reaction chamber?
 
  • #12
introduction first me for ask fusion raction

This is my first post and i am dedicating this to the Introduction Forum as per the forum rules. Before introducing myself, i would just like to thanks the Administrator of this forum for giving me opportunity to join this community.

Now, let me take the opportunity to introduce myself.

Hi, I am Andri Vista Medina from Indonesia & I'm new to this site. I am a new comer & have just put forward my first step in the vast & fast world of Internet & Web.
I'm positively looking forward to the forum and its members, hope all will guide, share and help me to increase my knowledge.

Fusion raction produces high energy neutrons which cause activation of the walls of the reactor.
 

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