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Moderation of neutrons

  1. Feb 4, 2017 #1

    As we know, neutron does not have charge so it can not interact with any other particle with coulombic force. But in the reactor core fast neutrons can be slowed down. Does strong interaction govern this slowing down process?

    Thank you.
  2. jcsd
  3. Feb 4, 2017 #2


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    Staff: Mentor

    Have you found anything helpful via Google? :smile:
  4. Feb 4, 2017 #3


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    Staff: Mentor

    As berkeman indicated, one can use Google to search on "neutron moderation", or "neutron moderation process".

    However, the strong interaction does not play a significant role, until there it is absorbed by a nucleus. Basically, moderation is achieved by classical elastic collision process. In light water reactors (LWRs), neutrons are primarily moderated by collisions with protons. Since the neutron has about the same mass as a proton, it was lose nearly all of it's energy/momentum to the proton; however, that requires a center-on-center direct hit, which is highly unlikely. Most of the time, neutrons will strike a glancing blow, and lose some of the energy.

    One should be able to locate a textbook on introductory nuclear reactor physics in which one should find a discussion of neutron moderation.
  5. Oct 15, 2017 at 11:01 AM #4
    Imagine billiard balls. Neutron is the cue ball. Protons of hydrogen atoms in the moderator are the other balls. If the cue ball impacts a larger object, like the wall, It's likely to just bounce off. If it impacts smaller objects it'll just plow through. But if it impacts similar sized objects there will be a significant energy transfer causing the cue ball to slow down.
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