Re: Why is Mu Metal used?

Marian B

(Like many physics explanations, the one below is concise, simple and
somewhat wrong)

We want to shield an M field.

A changing M field *can* be shielded with non-amagnetic conductors
(think like the conductor appears as a short to the induced currents,
thus draining power from the field, weakening it)

A static M field can only be shielded by re-directing it with something
that has high magnetic permeability ("magnetic conductor"). Mu metal is
named after magnetic permeability, because it has such a high mu.

So the mu-metal shield lets the magnetic field flow around the shielded
cavity (for the most part).

Cheers, Marian

On 20.02.2016 19:48, 'cheater00 .' @cheater [TekScopes] wrote:
Hi guys,
Why is Mu Metal used to shield CRTs in scopes, rather than just
grounded copper foil? I never understood the precise reason for that.


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