Biomagnetic Technologies, Inc.

James R Marsden

Douglas N Paulson

John P Wikswo

Mark S DiIorio

Frank W Vanesky

D Scott Buchanan

Eugene C Hirschkoff

William C Black, Jr

David S Buchanan

Stephen E Robinson

Duane B Crum

A magnetometer includes a support. The support has two support surfaces that intersect each other along an intersection line. The intersection line is perpendicular to a reference axis of the support. The support surfaces are preferably perpendicular to each other and are each inclined at an angle of 45 degrees to the reference axis. A planar sensor/detector array is mounted on each support surface. Each array includes at least two pairs of magnetic field sensors and associated SQUID detectors arranged such that the magnetic field sensors lie on a line that is parallel to the intersection line of the two support surfaces. The magnetometer can be used adjacent to a surface to measure components and spatial variation of the magnetic field near the surface, with the measured components resolved into the magnetic field vectors parallel to and perpendicular to the surface.

Magnetometer and method of measuring a magnetic field

A magnetometer is prepared by depositing three thin-film SQUID magnetic field detectors upon a substrate. Two of the detectors incorporate stripline SQUID detectors deposited at right angles to each other, to measure the orthogonal components of a magnetic field that lie in the plane of the substrate. The third detector uses a planar loop SQUID detector that measures the component of the magnetic field that is perpendicular to the substrate. The stripline SQUID detectors have thin-film base and counter electrodes separated by an insulating layer which is at least about 1 micrometer thick, and a pair of Josephson junctions extending between the electrodes through the insulating layer.

Thin film SQUID detector including a loop responsive to a magnetic flux

A SQUID package includes a layered SQUID base and a SQUID mounted upon the base. The SQUID base is formed as a first substrate layer of an electrically insulating material, a shielding layer of a material that is superconducting at the SQUID operating temperature overlying the first substrate layer, and a second substrate layer of an electrically insulating material overlying the shielding layer. The shielding layer protects the SQUID from dc and ac interference such as magnetic and electrical fields, which would otherwise interfere with its operation. Related components such as input and output circuitry can be mounted on the base. An input coil used to detect magnetic fields can also be placed on the base, but in that case the shielding layer is made to cover only a portion of the SQUID base, and the input coil is positioned over the portion of the base that has no shielding layer.

Packaged SQUID system with integral superconducting shielding layer

Thin-film three-axis magnetometer and squid detectors for use therein

A shielded room is constructed with walls having one shell made of electrically conductive facing sheets that prevent penetration of electromagnetic energy into the room, and two shells made of high magnetic permeability facing sheets that prevent penetration of magnetic fields into the room, one within the electrically conductive sheet and one outside the electrically conductive sheet. The edges of the conductive facing sheets are sealed to each other against leakage of electromagnetic energy with a joint compound made of a mixture of electrically conductive metallic particles in a flowable viscous base that enhances the electrical conductivity across the joint and excludes air from the sealed region. To prevent deterioration, the edges of the high magnetic permeability facing sheets are sealed to each other against leakage of magnetic fields with a joint compound made of a mixture of a high magnetic permability material in a flowable viscous base that enhances the 'magnetic conductivity' of the joint and excludes air from the sealed region.

Construction of shielded rooms using sealants that prevent

An information storage device includes a magnetic recording medium, preferably supported upon a rotating disk, an electromagnetic writing device that writes magnetic patterns into the recording medium, and a superconducting quantum interference device (SQUID) that reads the magnetic patterns in the recording medium, the writing device and the SQUID preferably being mounted upon a read/write head. The SQUID as operated in its superconducting state is a highly sensitive and directional detector of the magnetic state of the recording medium, permitting it to be spaced relatively distantly from the recording medium yet read the state of small areas of the medium. Use of high temperature superconductors in the SQUID permits practical construction of the information storage device. The read/write head may support a plurality of write devices, and an array of SQUIDs can be utilized so that little or no relative movement of the read/write head is required to read and write from all tracks of the disk.

Growing community of inventors

San Diego, CA, United States of America

James R Marsden