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Accelerate an Uncharged Particle?

  1. Jan 21, 2009 #1

    referframe

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    Particle accelerators use EM to guide and accelerate charged particles to close to the velocity of light. Is it conceptually possible to build a particle accelerator to accelerate uncharged particles that have a non-zero rest mass? Thanks in advance.
     
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  3. Jan 22, 2009 #2

    ZapperZ

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    What concept would you use? Neutron sources facilities all over the world would like to know.

    Zz.
     
  4. Jan 22, 2009 #3

    clem

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    High energy neutrons can be produced by accelerating deuterons, and "stripping" off the protons. Other high energy neutral particles can come from "charge exchange" interactions or the decay of much heavier particles.
     
  5. Jan 22, 2009 #4

    ZapperZ

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    But these, and the ones used at spallation neutron sources, still use conventional particle accelerators to accelerate charged entities first. The OP is asking for a direct acceleration of neutral particles.

    Zz.
     
  6. Jan 22, 2009 #5
    Oooo, a tame lump of neutron star?
     
  7. Jan 23, 2009 #6

    ZapperZ

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    Then why stop there? Why not just get one of those big bad black hole? I hear CERN might have quite a few to sell once they get the LHC back on track.

    Zz.
     
  8. Jan 23, 2009 #7

    referframe

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    Yes. I cannot think of an example (at least in the micro world) of F = ma where the "F" is not EM and the "m" is uncharged. Gravity, being basically a field of acceleration, is no longer considered an "F". Also, uncharged particles created from heavier particles or from collisions are not, in my opinion, an example of F = ma.
     
  9. Jan 24, 2009 #8
    I was actually thinking, to accelerate your neutrons, use a charged black hole !
     
  10. Jan 24, 2009 #9
    To accelerate something, you interact with it.

    We know about four interactions, weak, strong, EM, and gravity.

    EM is convenient, because it's a long-distance force (carrier of the interaction is massless).

    Gravity also works, for the same reason, but it's weaker. You could put a neutron at the top of a very tall tower and it will accelerate towards the ground.

    Weak and strong forces are short-distance. Weak is short-distance because it's carriers are very heavy, and strong is short-distance because there are no free gluons and you need heavy particles (e.g. virtual pions) to mediate the interaction. You need a long-distance force accelerate a particle in the vacuum far from any other objects.

    That does not mean that you can't use weak and strong interactions at all. You could create a cloud of neutrons and fire a beam of protons at it. Some protons will scatter on neutrons and pass momentum on to them.
     
  11. Jan 24, 2009 #10

    referframe

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    Forgive my ignorance: When the protons "scatter" on the neutrons does that involve one of the 4 forces ("interactions") of nature or is that just the wave function of the proton interacting with the wave function of the neutron in the QM equivalent of a classical 2-particle collision?
     
  12. Jan 24, 2009 #11

    malawi_glenn

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    no, the interaction probability amplitude is:

    i) Operate on initial state with Interaction Hamiltonian (e.g the "force" under consideration, weak, Em or Strong)

    ii) take result times final state

    iii) integrate over space, multiply with phase space

    So that is the basic procedure. You have wavefuntions and an interaction hamiltonian.
     
  13. Jan 24, 2009 #12
    It involves one of the 4 forces. In the absence of interactions, the wave function of the proton and the wave function of the neutron would just pass through each other.
     
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