Magnetic field suppression system
AssigneeTechnical Manufacturing Corporation
InventorIgor Kordunsky
Life of this patent
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Abstract
Apparatus and methods to reduce unwanted magnetic fields and unwanted motion in precision instruments are described. A coil assembly that is used to generate an opposing magnetic field can include a first coil configured to generate a static magnetic field and a second coil configured to generate a time-varying magnetic field. The first and second coils can be in close proximity and sized to suppress magnetic fields over a large localized region. The first coil can be connected to a choke to increase its impedance seen by the second coil.
Claims28
A magnetic field suppression system comprising:
- a first coil assembly having a first winding configured to generate a static magnetic field along a first direction through a center of the first coil assembly;
- and
- a second winding configured to generate a time-varying magnetic field along essentially the first direction;
- a second coil assembly oriented parallel to and spaced apart from the first coil assembly and having a third winding configured to generate a static magnetic field essentially along the first direction through a center of the second coil assembly;
- and
- a fourth winding configured to generate a time-varying magnetic field essentially along the first direction.
A method of suppressing magnetic field in a localized region, the method comprising:
- applying DC current to a first winding of a coil assembly to generate a first magnetic field that reduces a static component of a magnetic field present in the localized region;
- applying a first time-varying current to a second winding of the coil assembly to generate a second magnetic field that reduces a time-varying component of the magnetic field present in the localized region, wherein the first winding is located within 8 cm of the second winding;
- and
- supporting, with a vibration-isolation system, a payload in the localized region.
A system comprising:
- a first coil assembly having a first winding and a second winding, wherein:
- the first winding is configured to generate a static magnetic field along a first direction through a center of the first coil assembly, and
- the second winding is configured to generate a time-varying magnetic field along essentially the first direction;
- and
- a vibration-isolation platform, wherein the first coil assembly is configured to reduce a total amount of magnetic field in a localized region by suppressing ambient magnetic field in the localized region and the vibration-isolation platform is configured to support a payload within the localized region.
A magnetic field suppression system comprising:
- a first coil assembly having a first winding configured to generate a static magnetic field along a first direction through a center of the first coil assembly;
- and
- a second winding configured to generate a time-varying magnetic field along essentially the first direction;
- DC control circuitry connected to the first winding and configured to provide a DC or slowly varying current having cyclic variations of 1 Hz or less to the first winding;
- and
- AC control circuitry connected to the second winding and configured to provide at least a time-varying current having cyclic variations greater than 1 Hz to the second winding;
- and
- a magnetic field sensor arranged to sense magnetic field in a region in which the time-varying magnetic field is produced and to provide a signal indicative of the magnetic field to the AC control circuitry.
Dependencies are inferred from the claim text.