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Small but powerful magnet?

  1. Feb 19, 2007 #1
    Does anyone know if its commericially possible to get a 1-2T electromagnet (no superconductors) but one thats very small i.e. no wider than 2 cm and no taller than 1 cm (with the field in z)?

    It seems doubtful but I'm not sure where to look, google isn't helping much.
  2. jcsd
  3. Feb 19, 2007 #2


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    Hi beer. I'm pretty much a dummy when it comes to magnetic fields, but what I do know is that MRI magnets run between 1 and 3 Tesla. The coils are about 3 feet in diameter and about 4 feet long, consisting of superconducting windings such that the thickness of all these windings is on the order of 2 to 6 inches. They then run a few hundreds of amps through these windings which are immersed in liquid helium to make them superconducting. That's a lot of mass and energy to produce 1 to 3 T, so to suggest you might get 1 or 2 T out of something as small as you're suggesting seems totally unreasonable.
  4. Feb 19, 2007 #3


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    No chance. A rare-earth permanent magnet of that size, however, would have about 1T right at the pole face. The field would fall off rapidly with distance.
  5. Feb 20, 2007 #4
    Yeah I guessed it would be impossible, just needed to know for sure.

    I looked into Nd magnets, but the small ones I found were over 1T but only in circuit. In practise they were more like 0.2 T. Don't suppose anyone knows of ones stronger?

    I doubt piling them on top of each other would work? ^_-
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