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Particles and the LHC

  1. Nov 24, 2009 #1
    Hi all,
    Just a lay person here with a healthy interest and a quick question:-

    In a particle accelerator, as the particle 'beams' are accelerated, can it be said that the particle occupies more length along it's path as it's velocity increases. Is it possible that a particle could 'stretch' to the entire circumference of it's path within the accelerator as it's velocity approaches the speed of light.

    I'm sure this question reveals my limited understanding of particle accelerators and particle physics in general but would be grateful for and help or guidance.
    Thanks in advance,
  2. jcsd
  3. Nov 24, 2009 #2


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    Gold Member

    On the contrary, relativity is on our adventage, is not? Time dilates, length contracts.
  4. Nov 24, 2009 #3
    If you calculate the physical length of the electric (Coulomb) field of a particle in a beam (in a beam tube), it shrinks by a Lorentz factor gamma as it is accelerated, and is roughly 1/1000 of its at-rest length for a 1000 GeV proton. So instead of being ~10 cm (~1/3 nanosecond) long, it is 10 microns (~1/3 picosecond) long.
    Bob S
  5. Nov 25, 2009 #4
    Thanks guys. I was mistakenly thinking that under the principle of uncertainty, the position of a particle in an accelerator would be a probability wave that would lengthen the faster it's velocity.
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