Directional magnetic field

[Esquilo]

Hi, I have a question that I can't resolve and I have many doubts. Then considering the phenomenon of electromagnetic induction in which a magnetic field varying over time generates an electromotive force, the magnetic field propagates perpendicularly to the electric flow and therefore with closed lines. This is how I can direct and concentrate the magnetic field in a single direction, perhaps decreasing it from other directions?? Thanks

 

[berkeman]

There are various ways to guide and concentrate magnetic field. Could you post a reference with some diagrams for the method you are asking about? Thanks.

 

[Esquilo]

There are various ways to guide and concentrate magnetic field. Could you post a reference with some diagrams for the method you are asking about? Thanks.

hi berkemann, so the concept I'm following is to concentrate the magnetic field lines in a single "part" of a conductor (loop or solenoid) as happens in Halbach arrays, this is precisely the effect I want to obtain, but not with magnets but with coils with current flowing through them. the effect is also similar to the proximity effect (umbrella) that is created with antennas, in which the main lobe is longer than the secondary lobes, so it is a question of arranging and concentrating the magnetic field lines

 

[berkeman]

Thank you for posting more information and the diagrams.

Halbach arrays use DC permanent magnets: https://en.wikipedia.org/wiki/Halbach_array

The diagrams you posted are for RF EM radiation from antennas with directivity: https://en.wikipedia.org/wiki/Directivity

Antennas radiate EM, not just magnetic fields. In fact, the magnetic fields radiated by antennas are quite weak compared to DC permanent magnets. Is your intention to try to come up with an antenna array that somehow magnifies and directs magnetic field?

 

[Esquilo]

Thank you for posting more information and the diagrams.

Halbach arrays use DC permanent magnets: https://en.wikipedia.org/wiki/Halbach_array

The diagrams you posted are for RF EM radiation from antennas with directivity: https://en.wikipedia.org/wiki/Directivity

Antennas radiate EM, not just magnetic fields. In fact, the magnetic fields radiated by antennas are quite weak compared to DC permanent magnets. Is your intention to try to come up with an antenna array that somehow magnifies and directs magnetic field?

So berkerman, the antenna image refers to what I want the lobe of the variable magnetic field produced to be, so it was just an example. Then I want to exploit the phenomenon of electromagnetic induction, through a solenoid or coil conductor, in which the magnetic field lines coming out are very directive only from one direction of the coil, this is achieved with a lot of current, but the lines will always tend to be radial,

I would like to convey the magnetic field only from one direction. In the first image I have drawn the arrangement of the honeycomb structure of the Halbach coils which concentrate the magnetic field in a single direction, and do I think more overlapping structures will strengthen the final field?

In the second image there is the shape of the directivity of the magnetic field, very pronounced in one direction, in my opinion, with many adjustments it could be feasible, what do you think? It's just a matter of concentrating all the lines from a single direction like Halbach arrays do, but in this case I would like to overlap them to increase the magnetic field

 

[berkeman]

To be honest, I don't think there is a solution for what you are asking (based on my limited understanding of your request). But if you tell us what your application is and what you are trying to accomplish, maybe there is an alternative way of achieving it.

 

[DaveE]

What length/area scale are you interested in? Is this a tabletop experiment or more like an antenna question?

On small scales the likely answer is to use high permeability materials to direct the B-field into and out of the area of interest.

 

[marcusl]

Magnetic field lines are always loops, so you cannot emit a field in just one direction.