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Outside the Magnet: Fringe Field
Note: ‘Magnetic Shielding’ is also sometimes
used to describe RF shielding (Faraday cage)
•
Magnet is shielded to reduce extent
of fringe field
5 G line for an unshielded 7 T is 23m
away!
•
Active & passive shielding is use
•
Active shielding causes a sharp field
gradient
Magnitude and variation of field need to be
understood