Mu metal box

[Hami Hashmi]

If the saturation of mu-metal was 0 and you had a box of it with wires wrapped around the box with a current passed through them (no external magnetic field) would the magnetic field be enhanced outside the box around the poles like this?

 

 

 

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[Externet]

I would say the magnetic field will be contained and follow the mu-metal path with minimal field outside it.

Your sketch should define/identify the colored sections to better understand you.

Edited October 16, 2018 by Externet

[Hami Hashmi]

20 hours ago, Externet said:

I would say the magnetic field will be contained and follow the mu-metal path with minimal field outside it.

Your sketch should define/identify the colored sections to better understand you.

Well in the sketch the red areas are the areas with highest field density. 

[swansont]

20 hours ago, Externet said:

I would say the magnetic field will be contained and follow the mu-metal path with minimal field outside it.

That's basically what it shows. The ambient field is uniform, and with the shielding, the flux lines concentrate at the end as they bunch up in the material.

[Hami Hashmi]

2 minutes ago, swansont said:

That's basically what it shows. The ambient field is uniform, and with the shielding, the flux lines concentrate at the end as they bunch up in the material.

Even if the saturation was 0 the outside field would be similar?

And if not, is there any possible way for a material (theoretical or otherwise) to dampen the magnetic field uniformly in this instance?

[swansont]

1 hour ago, Hami Hashmi said:

Even if the saturation was 0 the outside field would be similar?

And if not, is there any possible way for a material (theoretical or otherwise) to dampen the magnetic field uniformly in this instance?

What do you mean by saturation is 0?

Magnetic field lines have to make closed loops. That limits what you can do.

[Hami Hashmi]

22 hours ago, swansont said:

What do you mean by saturation is 0?

Magnetic field lines have to make closed loops. That limits what you can do.

Oh ok. I meant that if the actual mu-metal box had a saturation of 0 would it be able to dampen the field then.

 

Would a box made out of magnetic monopoles be able to dampen the field? (I know they are theoretical).

Edited October 17, 2018 by Hami Hashmi

[swansont]

1 hour ago, Hami Hashmi said:

Oh ok. I meant that if the actual mu-metal box had a saturation of 0 would it be able to dampen the field then.

 

Would a box made out of magnetic monopoles be able to dampen the field? (I know they are theoretical).

What do you mean that that the saturation is 0?

[Hami Hashmi]

Ok nevermind about that but what if the box was made from a material that had very high permiability, very high saturation rate, a extremely low coercivity, near zero magnetostriction, and extremely large anisotropic magnetoresistance? Would it dampen the magnetic field uniformly then?

[swansont]

Basically the field is going to look like a dipole. The field has to end up obeying Maxwell's equations. An approximately uniform field from a single component is only going to arise if you are far away from the source, and looking at small areas.

[Hami Hashmi]

Ok. So the magnetic field will be enhanced around the poles?

[Hami Hashmi]

Sorry, will still be enhanced around the poles? 

[Hami Hashmi]

Hi

[Hami Hashmi]

Ok, what if you wrapped the mu-metal in a layer of nonconducting material with the wires on top? What would happen then?

[swansont]

Really, what you need to do is find a simulator that will answer these questions, or, for the simplest geometries, solve the equations yourself.

[Hami Hashmi]

8 hours ago, swansont said:

Really, what you need to do is find a simulator that will answer these questions, or, for the simplest geometries, solve the equations yourself.

How would i find those simulators?

And how would i use them to solve this question?

[swansont]

15 hours ago, Hami Hashmi said:

How would i find those simulators?

And how would i use them to solve this question?

There is software that does this. I don't know if there are web-based calculators. One might use a search engine.

You enter the geometry, parameters and boundary conditions. It does finite-element calculations. The picture I uploaded was the result of such software.

[Hami Hashmi]

Ok. So I type down magnetic field simulator?

[Hami Hashmi]

Is this one good? https://www.falstad.com/vector3dm/ And how do i simulate what i mentioned above?

[Hami Hashmi]

Like a magnetic shield surrounded by an electric insulator covering.

[Hami Hashmi]

How do i simulate it? I looked around but I couldnt find a way to do it.

Edited November 2, 2018 by Hami Hashmi

[Hami Hashmi]

bump

[Strange]

I googled finite element simulation magnetic field and found a few examples:

• http://www.femm.info/wiki/HomePage
• https://quickfield.com/glossary/magnetic-simulation.htm
• https://uk.comsol.com
• http://getdp.info
• https://caelinux.com/CMS3/

I don't know if anyone of them will do what you want.

[Hami Hashmi]

ok thanks.