Abstract: A magnetometer comprises a magnetic field pickup coil and a magnetic field detector that receives electrical signals from the pickup coil and produces an electrical detector output responsive thereto. The pickup coil and detector, which are preferably made of high temperature superconductors, are enclosed in an insulated enclosure having no vacuum insulation structure. Preferably, the enclosure is made of a foamed polymer material such as styrofoam. A coolant is provided to the interior of the enclosure, to cool the pickup coil and detector to a temperature below their superconducting transition temperature. A number of such modular magnetometers may be connected together to form an array.

Abstract: 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.

Abstract: A biomagnetometer includes a magnetic field sensor unit having a magnetic field pickup coil. A vessel contains the sensor unit. The vessel includes a flexible contact face with the magnetic field sensor unit mounted in the interior of the vessel adjacent to the flexible contact face. Insulation at the flexible contact face of the vessel prevents excessive heat flow through the flexible contact face. Pickup units using this structure can be connected together into flexible or rigid arrays. In operation, the pickup coil is cooled to a temperature of less than its superconducting transition temperature. A detector measures the magnitude of magnetic fields sensed by the sensor unit.

Abstract: A biomagnetometer has a magnetic pickup coil positioned remotely from a detector and inductively coupled to the detector. The detector is preferably made from a low-temperature superconductor, while the pickup coil can be made of a high-temperature superconductor. The detector and pickup coil can therefore be placed into separate containers, with an inductive coupler between the containers. In one approach, the detector is maintained at liquid helium temperature, and the pickup coil and electrical connector are cooled by liquid nitrogen. The resulting biomagnetometer permits the container with the pickup coil to be moved and positioned easily, and to be changed readily between various configurations particularly suited for performing various functions.

Abstract: A magnetically shielded enclosure provides a shielded environment having very low, constant levels of magnetic and electrical signals resulting from external sources, so that the magnetic signals produced by the body of a person in the enclosure can be measured in the absence of outside interference. The walls of the enclosure include concentric layers of a superconducting material and a material that is electrically and thermally conductive, and the person and magnetic measurement apparatus are enclosed therein. The superconducting layer is preferably supported on, and in thermal contact with, the conductive layer, and is cooled to a temperature below its superconducting transition temperature by cooling the conductive layer. Optionally, a magnetic cancellation field is applied prior to transforming the superconducting material to the superconducting state or otherwise sealing the enclosure, to zero the internal magnetic field.

Abstract: A biomagnetometer has a magnetic pickup coil positioned remotely from the detector. The detector is made from a low-temperature superconductor, while the pickup coil and an electrical connector between the detector and the pickup coil are made of a high-temperature superconductor. Although the detector is maintained in a dewar at a sufficiently low temperature to reduce electronic noise, the pickup coil and the electrical connector need only be maintained at a temperature at which they are superconducting. In one approach, the detector is maintained at liquid helium temperature, and the pickup coil and electrical connector are cooled by liquid nitrogen. The resulting biomagnetometer permits the pickup coil to be moved and positioned easily, and to be changed readily.

Abstract: Apparatus for making biomagnetic measurements includes a biomagnetometer for measuring magnetic fields produced by the body and an electromagnetic location measurement and recording system for automatically determining the location of the portion of the body from which the magnetic signals are being gathered. The electromagnetic location recording system permits establishing a real time body frame of reference with respect to the biomagnetometer, so that biomagnetic signals can be correlated directly with body location and structure. The electromagnetic location recording system may be operated continuously at radiation wavelengths which do not interfere with the taking of data, or intermittently with the taking of biomagnetic data, to avoid interference with the measured values of the biomagnetic data.