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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?
Because neutrons do not respond to electromagnetic radiation at such low energies.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?
Astronuc, just curious: neutrons can respond to EM radiation at high enough energy because of ... the neutron's spin? What else is there?Astronuc said:Because neutrons do not respond to electromagnetic radiation at such low energies.
Which results from its spin?Redbelly98 said:There is the neutron's magnetic moment, .
Redbelly98 said:There is the neutron's magnetic moment, ...
mheslep said:Which results from its spin?
It's the internal structure (quarks), magnetic moment and spin - pretty much as expressed by Redbelly.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?
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.
obelenkiy said:Maybe, it's possible to boost the energy of photons by heating them with other gamma beams.
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.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?
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.
Optical cooling is a technique used to reduce the thermal energy of particles such as atoms, ions, or molecules using laser or maser radiation. In the case of fusion products, this technique is used to cool down the high-energy particles produced during a fusion reaction.
Optical cooling works by using the momentum of photons from a laser or maser to slow down the movement of particles. When photons interact with a particle, they transfer some of their momentum to the particle, causing it to slow down. This process is repeated multiple times until the particle reaches a lower energy state.
Optical cooling allows for the precise control of particle velocity and energy, which is crucial for studying fusion reactions. It also reduces the spread of particle energies, making it easier to confine and manipulate the particles for further experiments.
One of the main challenges is finding the right frequency of light to effectively cool down the particles. This requires a thorough understanding of the energy levels of the particles and the properties of the laser or maser used. Another challenge is the potential for heating due to the absorption of photons by the particles, which can counteract the cooling process.
Optical cooling is being used in several fusion research facilities around the world, including the National Ignition Facility in the United States and the Wendelstein 7-X stellarator in Germany. It is being used to study the behavior of fusion products and their interactions with the surrounding plasma, with the ultimate goal of achieving sustainable fusion energy production.