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Global antineutrino map

  1. Sep 1, 2015 #1

    mfb

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    A group of scientists used geology models and data about nuclear reactors together with results from two neutrino detectors to produce a worldwide map of antineutrino emission. Man-made reactors are contributing 1% to the total emission, but the production is so localized it is clearly visible in many spots.

    Original publication
    phys.org news

    Next step: actually measure this...
    Could be interesting to monitor nuclear reactors from everywhere in the world, but that would need a very good angular resolution of the detectors.

    antinumap.jpg
     
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  3. Sep 1, 2015 #2

    e.bar.goum

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    That's really neat! Thanks for sharing it.

    Unfortunately, since this is what the sun looks like in neutrinos (in Super-K), I don't have too much hope of there being the resolution to measure this any time soon. :sorry: solpic_1500d_2_1.jpg
     
  4. Sep 1, 2015 #3

    Vanadium 50

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    Why the huge difference (factor of 5) between land and sea?
     
  5. Sep 1, 2015 #4

    e.bar.goum

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  6. Sep 2, 2015 #5
    Wikipedia says the continental crust is roughly 5 times as thick as the ocean crust. Could it be as simple as that?
     
  7. Sep 2, 2015 #6

    Orodruin

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    Last edited by a moderator: May 7, 2017
  8. Sep 2, 2015 #7
    Not really. It is a difference in elemental composition that matters. The continental crust is more enriched in the long-lived radioisotopes (U,Th,K).
     
  9. Sep 2, 2015 #8

    Avodyne

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    I suppose that bright dot on the US west coast isn't actually due to my watch with tritium tubes ...
     
  10. Sep 2, 2015 #9

    Redbelly98

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    France is pretty high, which is not too surprising. A large part of western China and Mongolia is too.
     
  11. Sep 2, 2015 #10
    Why?

    I can understand how dissolved uranium salts might tend to work their way out of the oceans, but the seeming abundance in stable precambrian rock seems odd. It would seem more likely to concentrate in volcanic/hotsprings areas. Over the long term it should wash out from wet stable geologies.
     
  12. Sep 2, 2015 #11

    e.bar.goum

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    The answer is in the link I posted upthread. http://www.world-nuclear.org/info/N...nium-Resources/The-Cosmic-Origins-of-Uranium/

     
  13. Sep 3, 2015 #12
    I read that post. It just doesn't make sense to me.

    If the salts are water soluble (at temperature) they would collect on land over time. If they aren't, they would collect in the ocean. But either way, stable wet areas like the Canadian Shield should be depleted (or at least neutral).

    I don't blame the web site's authors. They didn't have access to a neat "Global Antineutrino Map" [:bow:] when they made their theory. But I wonder how the theory stacks up against new data.

    Of course it's more likely I'm missing something, which is why I asked.
     
  14. Sep 3, 2015 #13

    DEvens

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    This is keen and disappointing at the same time.

    Keen because it is something I have not seen before. And at least somewhat interesting. Those hot-spots would seem to be interesting places to go look for interesting isotopes.

    Disappointing because I thought it was going to be something very much more. When I was in grad school, round about 1983 or so, there was a proposal by a certain now-well-known physicist to build a really sensitive neutrino detector.

    You have to recall that at the time there was a proposal in the USA for a thing called "The Strategic Defense Initiative" and immediately dubbed Star Wars. If you recall, that was a plan to build things that might hope to intercept incoming nuclear ballistic missiles. I don't have any idea if such a thing is possible, but that isn't the point. The point for this story is, during the construction of such a thing if it did indeed work, or was believed to work by the opposition, there would be a period during which opposition nuclear forces would be perceived to be losing their possible value. So there would be some pressure to "use it or lose it." Hence beginning to build such a thing might trigger a war.

    Anyway, the neutrino detector proposal was to detect scattering modes of neutrinos that supposedly had a much higher cross section. And to detect them, the proposal was for a multi-tonne ultra-pure single crystal of Boron. The idea was, with such a crystal you could detect phonon modes that would be excited by scattering neutrinos. Meaning you could get, so it was hoped, a directional neutrino detector. That is, a neutrino telescope, possibly with a very interesting angular resolution. You might hope to see individual stars with it, for example.

    During the Q&A period, an exchange somewhat like this occurred. (No I won't tell you who NI and LK were. At least one of them is dead anyway. 30 years is a long time in the life of a physics prof.)

    NI: Could it detect nuclear reactors?
    LK: Yes, quite likely.
    NI: Such as on nuclear submarines?
    LK: Yes, quite likely.
    NI: In real time? Distance and direction?
    LK: Yes, quite likely.
    NI: So it's more destabilizing than Star Wars?
    LK: If it gets me my funding, then I'm ok with that.

    Note that the reason it would be destabilizing is because a large fraction of the world's nuclear weapon arsenal is located on submarines. The idea is that they are hard to detect and hard to locate accurately. So they would be hard to kill in a surprise attack. So if you started something, your opponent's nuclear subs would surface some time later and punish you. But if a neutrino telescope could tell you exactly where the subs were, you could spare a warhead for each one, and hope that a surprise attack could get away with little reprisal.

    As far as I know the project was never done. I thought this might be it, but it is not.
     
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