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Helmholtz coil with a ferrous core

  1. Apr 12, 2007 #1
    Dear all,
    I know that I can create a uniform field using the design of a Helmholtz coil with an air-core. However, if I use a ferrous core like iron, will I still be able to create a uniform field under the same conditions? Also, how is the equation for the magnetic field, B, changed when I add a ferrous core to the center of a Helmholtz coil?

    Thanks in advance,
    Mike
     
  2. jcsd
  3. Apr 12, 2007 #2

    marcusl

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    Are you trying to generate a uniform field inside the object?
     
  4. Apr 12, 2007 #3
    No. I am trying to create a uniform field between a pair of electromagnets just like the field inbetween any pair of helmholtz coils. Thanks.
     
  5. Apr 12, 2007 #4

    marcusl

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    This type of magnet used to be universally used for NMR, and can still be purchased, e.g.
    http://www.walkerldjscientific.com/Products/Product_Lines/Electromagnetics/electromagnetics.html

    The iron yoke concentrates all of the return flux lines, dramatically increasing the field strength in the useful region, and the two poles concentrate the flux even further. To design a high quality magnet takes more knowledge of electromagnetism and materials than can be provided in a post. Homogeneity depends critically on the size and shape of the pole pieces, and how close to saturation magnetization the iron is, for instance. Suggest you get a copy of a text like Reitz and Milford, Foundations of Electromagnetism, and do some background study. Then take a look online at sites like
    http://www.geocities.com/CapeCanaveral/2404/Elect67.htm

    Of course if you aren't too concerned about homogeneity, field strength, electrical efficiency, etc., you can just fool around and see what results.
     
    Last edited: Apr 12, 2007
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