Superconducting magnet with HTS wire

  • #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.

p=permeability
I=current
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.
 

Answers and Replies

  • #2
f95toli
Science Advisor
Gold Member
3,112
601
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(
 
  • #3
Baluncore
Science Advisor
8,696
3,352
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.
 
  • #4
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(
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

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.
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
There are many users of pancake coils for SC magnets.
Google 'magnetic field of pancake coil' or 'magnetic field of spiral coil' and you will get examples of flat spiral design.

What are your inner and outer radii ?
Do you need axial field only ?
http://spectronet.de/portals/visqua..._measurement/090520_tag1/090520_03_andris.pdf

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.
 

Related Threads on Superconducting magnet with HTS wire

  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
3
Views
2K
Replies
1
Views
776
  • Last Post
Replies
5
Views
5K
Replies
8
Views
2K
  • Last Post
Replies
1
Views
1K
Replies
6
Views
1K
Replies
10
Views
2K
Replies
4
Views
7K
Replies
2
Views
2K
Top