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Question:
From a HS physics teacher: A conducting enclosure provides shielding from external electric fields. Is there any way to shield something from external MAGNETIC fields?


Replies:
Yes - a superconducting enclosure! There is also something called mu-metal but I am not sure how it works. You might want to look up the literature on magnetic monopole searches to see what kind of equipment they used.

Arthur Smith

In particle physics we often use mu-metal (mentioned in the first reply) to shield our detectors from magnetic fields. This is a big problem because the beams of particles used in particle physics are always directed and focussed by magnets, but the detectors used to detect particles are sensitive to the magnetic fields, and kidisrupt things. We wrap or surround the detectors with this special metal.

I think the helpful property of the material is that the magnetic permeability of the metal, mu (as it is called in most textbooks), is greater than that of the detector you want to shield. So, in a sense, it "absorbs" the em field This is a sketchy anwswer, and if you want to really find out how mu metal works I can detail it for you. You can also find it for yourself in any books on detectors or detection techniques.

robin d erbacher


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