Magnetic shielding

Patent · Thu Jan 01 04:00:00 EST 1987

OSTI ID:866383

Kerns, John A ^[1]; Stone, Roger R ^[2]; Fabyan, Joseph ^[1]

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1. Livermore, CA
2. Walnut Creek, CA

A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• DOE Contract Number: W-7405-ENG-48
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4698197
• OSTI ID: 866383
• Country of Publication: United States
• Language: English

Related Subjects

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additive
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ambient
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bridges
carbon
carbon steel
carrier
carrier material
concentration
conductive
conductive filler
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cross-sectional
dimension
dispersed
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egress
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epoxy
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facilitate
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field
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gap
greases
hardening
heavy
ingress
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liquid
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magnetic material
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magnetic shielding
magnetically
magnetically-conductive
material
maximum
minimize
multi-part
nominal
non-magnetic
non-magnetic material
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plastic
predetermined
predetermined volume
preferably
respect
shield
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single-magnetic-domain-sized
sized particles
soft
sometimes
steel
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substantially
substantially encloses
throughout
vacuum
volatility
volume