Magnetic shielding.

[shiznannigan]

Sorry if this seems like a complete newbie question.. I don't have much knowledge about magnets.

What I am trying to do is magneticly shield half of a magnet, so that only one side is magnetic.

Here is an illustration of what I would like to do:

http://img.photobucket.com/albums/v214/shiznannigan/shielding.jpg

My first question, obviously, is will it work? I know things like computer speakers are magneticly shielded, but I'm not sure exactly how, or if it would work for only one side of a magnet.

My second question is, would the strength of the magnet, or it's lifespan, be comprimised?

My third, and hopefully final, question, is what material would be ideal for shielding? I've heard brass and copper will work best, as I obviously don't want the shielding material to be magnetic.

Any help with any of these questions would be great. Thanks!

 

[IRstuff]

A simple websearch usually does wonders:

http://www.amuneal.com/pages/magnetic-shielding-materials.htm

http://www.amuneal.com/pages/magshield-intro.php

TTFN

 

[sreid]

Non magnetic materials will provide zero shielding from static magnetic fields. A low carbon steel cup with the magnet inside will work. The wall of the cup must be larger than the magnet so the north and south pole are not "shorted." The steel must be thick enough so it isn't saturated by the magnetic flux.

 

[prex]

There is just nothing in nature that will stop a magnetic field like an electrical insulator stops an electrical current.
Also there is no such thing in nature as a monopole, a magnet with only a north (or south) pole: the magnetic field works necessarily in closed circuit and any operation with magnets assumes that a circuit is created. Or, in other words, if you kill one pole with a suitable shielding material, then in fact you short circuit your magnet, making it useless.
So you should first of all specify what you want to do with that magnet and build a working application; then you should specify what and how much you need to shield from the field.
And, confirming what sreid said, brass and copper will do just nothing to your field, only a ferromagnetic material (suitably dimensioned) will provide some shielding.

prex

http://www.xcalcs.com

Online tools for structural design

 

[alansimpson]

Shielding materials are magnetic. They redirect field rather than really shield and as such shielding on one pole of magnet will affect lines of flux on the other pole. Trial and error may get a field suitable to your requirements.
Try

http://www.magnetic-shield.com

for materials.