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Superconducting magnet with HTS wire

  1. Jan 15, 2015 #1
    Hey guys, I am building a superconducting magnet. The wire I have is extremely thin, and is flat. To put it more into perceptive it has a width and height. When I wind it into a magnet, it is more like a disk coil, or racetrack coil. Because it has a different geometry than most other electromagnets, what equation would I use to calculate its magnetic field?

    Most equations I have seen are a little something like this.

    N=Number of turns
    L=length of turn

    The ones I have seen are PxNxI/L.

    That goes for a solenoid mainly. The length of the coil I will make, if it were to be a disk, would be the Thickness of the wire times the number of turns, its width would have nothing relevant enough do with the calculation I would assume. After I find the turn density, what do I do? It is going to be a really weird magnet.
  2. jcsd
  3. Jan 16, 2015 #2


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    In most cases you end up having to use numerical methods, e.g. FEM using something like COMSOL.
    Analytical methods rarely work unless you have a very simple geometry (e.g. a long solenoid(
  4. Jan 16, 2015 #3


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    The coil I think you are describing is called a “pancake” or a “flat spiral” coil.
    The question as to which model to use really depends on the inner to outer radius ratio.

    A simple magnetic model is a flat conductive disk with inner and outer radii that has a sheet current circulating, the sheet current is Nturns times the spiral current. That may give you a simple analytic solution.

    A first approximation of the field could be that of a single turn with the average radius, multiplied by spiral current and number of turns.
  5. Jan 16, 2015 #4
    F95toli: This is not a long solenoid though, this is a flat solenoid. To give you more of a perceptive of this wire, here is a link to the

    I just spent about 30 minutes googling what you suggested, and that you were stating seemed to be right, but all the equations I am finding are for inductance. I am not finding anything that gives me the tesla strength of the magnetic field.
  6. Jan 16, 2015 #5


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    Last edited: Jan 16, 2015
  7. Jan 20, 2015 #6

    Sorry for the late reply. I am only trying to fine the field that would come out of the Z axis if that is what you mean by axial field. my inner radii is .7535 CM, my outer is going to be 1.691, with 75 turns of HTS wire. I think Ill be able to do all the calculations myself, My math skills might not be that sharp for I am still in high school. I have heard the term vector before, but I forgot what it is for.
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