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Lightning Generates How Much Antimatter

  1. Aug 4, 2011 #1
    A relatively recent story about anti-matter being created by lightning caught my eye.

    http://www.space.com/10602-antimatter-beams-thunderstorms-nasa.html

    I was curious if anyone on this forum could quantify "how much" antimatter could be created by a terrestrial lightning strike.

    Thanks...
     
  2. jcsd
  3. Aug 4, 2011 #2

    Drakkith

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    Extremely little. I couldn't possibly give a guess in numbers though, as I do not know.
     
  4. Aug 5, 2011 #3
    Do you have any ideas on where to go for an answer?

    NASA website?
     
  5. Aug 5, 2011 #4

    Dotini

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    http://www.nasa.gov/mission_pages/GLAST/news/fermi-thunderstorms.html

    Scientists think the antimatter particles were formed in a terrestrial gamma-ray flash (TGF), a brief burst produced inside thunderstorms and shown to be associated with lightning. It is estimated that about 500 TGFs occur daily worldwide, but most go undetected.


    Somehow thunderclouds are able to combine water and sunlight in such a way as to discharge electrons upwards at near lightspeeds. This is a good puzzle, and demands an explanation. I'm working on it, but progress is slow.

    Respectfully submitted,
    Steve
     
    Last edited: Aug 5, 2011
  6. Aug 5, 2011 #5

    Drakkith

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    I don't think the explanation has anything to do with water and sunlight. See this image from the article for an explanation: http://i.space.com/images/i/7637/original/thunderstorms-make-antimatter.jpg?1294717754
    It is also explained at the bottom of the article.
     
  7. Aug 5, 2011 #6

    Dotini

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    Dear Drakkith, the graphic you supplied starts with the cloud already emitting electrons!
    What needs to be explained is how/why the cloud emits the electrons in the first instance. By all means, explain it if you can - anybody?

    Yours truly,
    Steve
     
  8. Aug 5, 2011 #7

    Drakkith

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    The voltage in the lightning formation process? I thought the article you linked made it pretty clear:

     
  9. Aug 6, 2011 #8

    Dotini

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    In a typical thundercloud, about 40 coulombs of positive charge will gather in the upper or P-region of the cloud. About 40 coulombs of negative charge will gather in the lower, or N-region. Each cloud to ground lightning flash involves voltage of between 100 million and a billion volts. Total duration is about 0.2 seconds, and the average current transferred may be about a thousand amperes. The typical cloud to ground discharge takes place between the N region and ground, a distance of about 2 miles, and is composed of a number of discrete strokes. The typical intracloud discharge takes place between the P-region and N-region over a distance of a mile or two. The discharge path is through ice and supercooled water (below 32 degrees but not frozen). Total time duration, charge transfer and length of an intracloud discharge are similar to the cloud to ground discharge, but the discharge processes differ. This is so because the cloud to ground discharge terminates on a conductor (the earth) while the intracloud discharge does not. The typical intracloud discharge is fundamentally composed of a single slowly moving spark or leader which bridges the gap between N-region and P-region in a few tenths of second. There is controversy as to whether the leader moves up from the N-region and carries a negative charge or moves down from the P-region and carries a positive charge. Each may in fact occur on different occasions. In the US there are about 5 intracloud discharges for every cloud to ground discharge.

    What we are apparently faced with is an intracloud discharge similar to what is described above which accelerates electrons upwards from the bottom up through the top of the cloud at speeds approaching that of light. The precise mechanism for this sequence of events is not described in the literature that I am aware of. The reader will be aware that sprites and jets are other forms of upward lightning that we have not yet addressed in this context.

    I'm continuing to research this question, albeit at a leisurely pace. My primary sources are "The Lightning Discharge" and "All About Lightning", both by Martin Uman, and "Ball and Bead Lightning: Extreme Forms of Atmospheric Electricity", by James D Barry.

    Readers familiar with the design and construction of particle accelerators are encouraged to chime in on what it would take in a terrestrial lab to accelerate electrons as described above.

    Note to moderators: Perhaps some consideration might be given to moving this thread to the Earth forum?

    Respectfully submitted,
    Steve
     
    Last edited: Aug 6, 2011
  10. Aug 6, 2011 #9
    Outstanding reply Diotini, I appreciate your response very much!!

    I would also encourage particle physics experts to use the data you've provided to give a ballpark idea of how much anti-matter might be generated by the lightning you've described above.
     
  11. Aug 7, 2011 #10
    I also doubt water or especially sunlight have anything to do with this phenomenon. High-energy "superthermal" electrons are frequently generated in plasmas through the coupling of energy from strong electric fields (e.g. from laser pulses) to plasma waves. This is a very complicated area of collective physics that I do not understand very well (and it gets brutally complicated in quasi-steady-state plasmas in MFE research, people write entire thick monographs on plasma wave phenomena...), but almost certainly that is basically what is going on - plasma waves, in the plasma generated by the lightning, drive electrons to very high speeds.
     
  12. Aug 7, 2011 #11
    Interesting article.

    Is this saying that positrons travelled over 2,800 miles without annihilating.... from cloud level to satellite orbit.........Is that plausible??

    I thought gamma rays in cosmic rays produced momentary positions at our outer atmosphere but that they immediately annihilate..,.don't reach earth....is that correct?

    If so why might they last so long going up but not down??
     
    Last edited: Aug 7, 2011
  13. Aug 7, 2011 #12
    If they are travelling at extreme speeds their probability of annihilating with anything will be low, and they will leave the dense parts of the atmosphere quickly so they could easily not slow down enough to annihilate before they escape the atmosphere.

    As for positrons produced in cosmic ray showers, hmm, I am not sure, but if they are secondary cosmic rays they will have a lot less energy than the primary and they are travelling into denser atmosphere, so I imagine they could slow and annihilate more easily. I don't think many primary cosmic rays are positrons.
     
  14. Aug 7, 2011 #13

    Dotini

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    Seemingly some antimatter is trapped in a magnetic belt around Earth.

    http://www.bbc.co.uk/news/science-environment-14405122
    A thin band of antimatter particles called antiprotons enveloping the Earth has been spotted for the first time.

    The find, described in Astrophysical Journal Letters, confirms theoretical work that predicted the Earth's magnetic field could trap antimatter.

    The team says a small number of antiprotons lie between the Van Allen belts of trapped "normal" matter.

    The antiprotons were spotted by the Pamela satellite (an acronym for Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) - launched in 2006 to study the nature of high-energy particles from the Sun and from beyond our Solar System - so-called cosmic rays.

    The new analysis, described in an online preprint, shows that when Pamela passes through a region called the South Atlantic Anomaly, it sees thousands of times more antiprotons than are expected to come from normal particle decays, or from elsewhere in the cosmos.


    Respectfully submitted,
    Steve
     
  15. Aug 27, 2011 #14

    Dotini

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  16. Oct 9, 2011 #15
    i should emagine it would be hard to tell, where lightning strikes is unpredictable, plus the anti matter would anaihalate with matter instantly, it would be hard to give some kind of amount.
     
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