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Effects of time on particles in an active synchrotron

  1. Dec 7, 2009 #1
    hello! 1st year college physics student here.

    has anyone thought of the effects of time on particles traveling 99.999999% C in a synchrotron? for as it has been explained to me, when something approaches the speed of light, time for the particle slows incredibly (but of course to the particle, time appears normal). in addition, i also understand that things traveling so fast, actually contract slightly relative to the observer.

    these are a few of the effects of traveling so fast, but is there any documentation on the effects of time on particles?
  2. jcsd
  3. Dec 7, 2009 #2
    Yes, I think a classical example of this is pion decay in the upper atmosphere, but I am struggling to find this on Wikipedia.

    The essence is that neutral pions exist for 26 nanoseconds, and that they are formed when high-energy protons hit the upper atmosphere. If they travel at close to the speed of light, you can work out they're meant to be able to travel about 26e-9 * 3e8 = 7.8 m before decaying, so we shouldn't see them in the lower atmosphere, but we do because they are so time-dilated, their lifetime becomes a lot longer so they can travel further. equivalently, to them their lifetime is the same but the distance to the surface of the Earth is greatly length-contracted, so they can reach it.

    I hope this is right.
  4. Dec 7, 2009 #3
    the decay of pions in the atmosphere creating muons. they have a life time of around 2.2 microsecs. so hardly any should reach sea level. However in earths reference frame their mean lifetime is nearer 35 microseconds which means they can travel around 10 000 m in earths reference frame
    This was confirmed and around 37 million muons reach sea level
  5. Dec 7, 2009 #4
    didnt realise mikeyW had replied =]

    You can do the maths by looking at length contraction
    and and the average lifetime of a muon and speed etc etc
  6. Dec 7, 2009 #5
    Fermilab (near Chicago) has a superconducting synchrotron named the Tevatron, with a circumference of 6.282 kilometers, that has two counter-rotating beams, one with protons, and the other with anti-protons, each beam with total particle energies of 980 GeV (beta = 0.999999). Time in the particle's reference frame is slowed by a factor 1044.
    Bob S
  7. Dec 7, 2009 #6
    Do you fellows think this subject can be expanded upon a bachelor thesis?
  8. Dec 7, 2009 #7
    Not on what was discussed here. You are a freshman now? When is the bachelor thesis due? Do you have any suggestions?
    Bob S
  9. Dec 7, 2009 #8


    User Avatar

    Staff: Mentor

    Depends on what the requirements for a bachelor thesis at your institution. Do you even have to start thinking about one this early?
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