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Orbiting Cloud Chamber

  1. Aug 14, 2008 #1
    I've read that cosmic rays are far higher energy than those generated in manmade particle accelerators. Would it be worthwhile to build an orbiting cloud chamber to collect cosmic rays before they impact the Earth's atmosphere? Or would the collision rate be too low to provide statistically sound scientific data?
     
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  3. Aug 15, 2008 #2

    ZapperZ

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    What kind if information are you expecting to get out of such a cloud chamber? You will note that the detectors that we have at all of these particle colliders (CDF, D0, ATLAS, CMS, etc) are huge, complicated beasts, all to be able to make very precise measurement of various properties of the collision. In other words, they are not simple cloud chamber.

    So it isn't just a matter of having a collision, but also a matter of having the right detector to detect as much as possible the result of that collision.

    Zz.
     
  4. Aug 15, 2008 #3

    Astronuc

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    The Alpha Magnetic Spectrometer Experiment was proposed for the International Space Station, but has been postponed or deferred indefinitely due to the limited budget and problems with Shuttle.

    http://ams.cern.ch/

    http://ams.cern.ch/AMS/ams01_homepage.html


    One objective is to better define the energy spectrum of high energy solar and cosmic particles. Such particles cause spallation reactions in structural materials which greatly increases exposure to astronauts.
     
  5. Aug 15, 2008 #4

    Vanadium 50

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    For many years, people flew particle detectors - mostly emulsions - on balloons to do exactly what the OP described. This ended up running out of steam for very high energies for two reasons: one is that the size of the detector grows ~linearly with the energy of the cosmic ray you want to look at, and it gets harder and harder for a balloon to lift it, and you don't know in advance where a high energy collision will occur, so you have to fly for a longer and longer time to get as many as you would like.

    As Astronuc pointed out, the last major experiment to be canceled from the ISS was a particle detector.
     
  6. Aug 15, 2008 #5

    D H

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    We have some already. The Compton Gamma Ray Observatory (launched 1991, deorbited 2000), International Gamma-Ray Astrophysics Laboratory (launched 2002), Swift Gamma-Ray Burst Mission (launched 2004), Gamma-ray Large Area Space Telescope (launched 2008) are orbiting gamma ray detectors. The Compton Gamma Ray Observatory (launched 1991, deorbited 2000) did exactly that. The CGRO observation of gamma ray burst 990123 helped determine that GRBs are highly collimated explosions.
     
  7. Aug 15, 2008 #6
    I guess the idea would be to detect the Higgs particle, or find proof for or against superstrings, etc. What energy level would be beyond the capability of any feasible ground-based atom smasher, but still possible with an orbiting cloud chamber?
     
  8. Aug 15, 2008 #7

    Astronuc

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  9. Aug 15, 2008 #8
    So they are rare, but they have been detected. Why is there still debate over Higg's particles then? How much better does the observation have to get to these ultra-high energy cosmic rays to resolve the standard model conclusively?
     
  10. Aug 15, 2008 #9

    Vanadium 50

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    Most collisions that are energetic enough to produce a Higgs don't. Maybe only one in a billion or a few billion do. So while there is a cosmic ray with the equivalent energy of an LHC collision hitting the earth every few minutes, the actual Higgs production rate is perhaps one per thousand years or so.

    Also, the LHC detectors weigh thousand of tons for a reason - you need that level of instrumentation right up to the collision point to tell if it's a Higgs or something else. Nothing nearly that heavy has ever been flown, much less orbited. It wouldn't help if you did - not only do you have the 1000 year problem, you don't know where the cosmic ray is going to hit in time to move your detector into position.
     
  11. Aug 15, 2008 #10

    D H

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    These ultra-high energy gamma rays are (drum roll please) ultra-high energy gamma rays; i.e. photons. They are not Higgs particles.
     
  12. Dec 17, 2009 #11
    1. I read in several places that ultra-high-energy cosmic rays are charged particles, not photons. So, which are they?

    2. If they are charged particles, how big would the diameter of a Bussard Collector have to be to guide one into a cloud chamber, or similar detector, once per year? Please show math!

    3. Also, if ultra-high energy, a la Higgs-energy, cosmic rays occur only once every thousand years, how can the LHC begin to approach the energy needed to look for the Higgs particle?

    4. What is the energy needed to produce a Higgs particle?

    5. What is the heaviest component or material of detectors used in high energy particle physics?
     
  13. Dec 18, 2009 #12
    I found that Wikipedia has some pretty good info (if it's accurate).

    If I were to assume this Wiki article is correct, then nearly all cosmic rays are charged particles like hydrogen & helium nuclei rather than neutrons or photons. This makes them amenable to deflection by magnetic fields.

    The chart given below indicates the flux of cosmic rays vs. energy. Cosmic rays with energies of 100 TeV which exceeds the design potential of the Large Hadron Collider (7-14 TeV) have an isotropic flux of approximately 0.012 per square meter, per second, per spherical surface. That's about 396,293 cosmic rays per year for a spherical surface with 56.5-centimeter diameter.

    [​IMG]

    It would seem to me that a relatively simple orbiting detector, perhaps containing water or alchohol, could provide a dense transparent target filled with protons. Collisions between cosmic rays and protons would be of higher energy than anything achievable using ring accelerators on Earth.

    So, I've answered the first of my questions on my own.

    The second question might be answered by stating that the flux rate is high enough that no Bussard Collector would be required. And the diffuse rather than point source nature of cosmic rays makes focussing them impossible anyway.

    Also, the mass of the Higgs is unknown. Experiments at the LHC are designed to verify the standard model at TeV energies, or find new phenomena at those energies, not to look for the Higgs specifically.

    Most detectors use magnetic fields, so the heaviest component would probably be ferrous wires. The field strength and number of windings would lead to a mass estimate.

    So, I've answered all my own questions.

    One now wonders why we're building accelerators on the ground at all, since cosmic ray collisions would allow us to study a vast spectrum of energies beyond any artificial accelerator.
     
    Last edited: Dec 18, 2009
  14. Dec 18, 2009 #13

    ZapperZ

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    Er... hello? Ferrous wires? Have you ever seen one of those superconducting magnets at the LHC?

    At least, you think you have.

    When you can get the same luminosity up there as you can in a controlled accelerator (read what Vanadium posted), give me a call.

    BTW, if you think it is THAT easy to not only find one of these highest energy cosmic particle, but also to detect them (much less, to collide them), then why do you think detectors such as the Auger Observatory has acres and acres of land being used for their detection?

    Zz.
     
  15. Dec 18, 2009 #14
    Ok. If only one in a billion 100 TeV collisions produces a Higgs particle, then the surface area of the detector would have to be increased. If a spherical detector could be invented, its diameter would have to be 90 meters to intercept 10 billion cosmic rays per year. This might result in several Higgs particles produced per year.

    At some point a ring accelerator would have to be space-based because a ground based one could only be the radius of the Earth, and no larger. The most important point I'd like to suggest is that a passive cosmic ray collider, if it could be built, would seem to be much smaller than any ring accelerator of the same energy.
     
  16. Dec 18, 2009 #15
    And then I discover something called Plasma Acceleration, which if scaled up might achieve the same energies as the Large Hadron Collider in a linear accelerator less than 50 meters long. If built in the LHC tunnels, might achieve 5 Peta-electronvolts, about 1000-times higher energy than the LHC.

    http://en.wikipedia.org/wiki/Plasma_acceleration

    I think this might make an orbiting cloud chamber obsolete. At least in the short term anyway.
     
  17. Dec 18, 2009 #16

    ZapperZ

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    There's a difference between knowing something superficially, and knowing stuff in intimate details that you know all the issues surrounding something.

    I work with particle accelerators and know quite well about such plasma acceleration. Would you like to look up issues surrounding "plasma instabilities" and "higher order effects"? Or what about issue of "staging" in such a device?

    I no longer know what you are attempting to do with this thread. It is veering very closely to mindless speculation based on what you can read off Wikipedia.

    Zz.
     
  18. Dec 18, 2009 #17

    ZapperZ

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    Hey, if you can come up with the money, I'll build you one!

    Zz.
     
  19. Dec 18, 2009 #18

    Vanadium 50

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    You are missing one thing - well, many things - but one big one. To get the same center-of-mass energy as the LHC, you need a 1017 eV cosmic ray. The flux of those cosmic rays is 17 orders of magnitude smaller than the 100 TeV cosmics you are talking about.
     
  20. Dec 19, 2009 #19
    What makes you think the LHC has such a high center of mass energy?
     
  21. Dec 19, 2009 #20

    Vanadium 50

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    The LHC is a collider. That's what the C stands for. You have to get an extremely energetic cosmic ray to interact with a stationary proton to get the same center of mass energy as the LHC.
     
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