Abstract: A method and a measuring device for determining the spatial distribution of a magnetic field vector. At least a pair of sensor elements is provided. Each sensor element measures a component of the magnetic field vector. The sensor elements are aligned in a parallel, spaced-apart relationship along an axis parallel to the measured components.

Abstract: An improved AC susceptometer and methodology for its use which is particularly suitable for the characterization of the properties of superconducting materials. Added to the circuitry of a conventional AC susceptometer is frequency domain analytical equipment for measuring the induced magnetic response. The addition of frequency domain measuring equipment permits the determination of the harmonic components of the induced magnetic response. The measurement of the harmonic components of the response also provides novel methodology for studying the phenomena of flux penetration, flux pinning and movement and permits the measurement of parameters such as lower critical field, critical temperatures, and the irreversibility line.

Abstract: An improved AC susceptometer and methodology for its use which is particularly suitable for the characterization of the properties of superconducting materials. Added to the circuitry of a conventional AC susceptometer is frequency domain analytical equipment for measuring the induced magnetic response. The addition of frequency domain measuring equipment permits the determination of the harmonic components of the induced magnetic response. The measurement of the harmonic components of the response also provides novel methodology for studying the phenomena of flux penetration, flux pinning and movement and permits the measurement of parameters such as lower critical field, critical temperatures, and the irreversibility line.

Abstract: Apparatus and methodology for mapping the superconductive properties of a sample of superconducting material. The material is cooled so that it is a mixed state and an alternating magnetic field is induced in a portion of the sample to be tested. The harmonic component of the induced alternating magnetic response is measured at a location proximate to the point of induction. As the inducing and measuring devices are displaced relative to the sample the measured amplitude of the harmonic component is stored in suitable storage means as a function of location in the sample. Thus, a map of the superconducting properties of the sample may be generated.

Abstract: Apparatus and methodology for the rapid and inexpensive characterization of superconducting materials. The method and apparatus induces an alternating magnetic field in the sample to be tested. If the material is a superconductor odd harmonics are generated in the alternating magnetic response of the material near the transition temperature. The superconducting transitions are manifested by a peak or peaks in the odd harmonic components of the alternating magnetic response as a function of temperature. The peaks of the harmonic components are detected to indicate the presence and number of superconducting transitions.

Abstract: An improved piezoelectric transducer permitting linear scanning along two intersecting planes. The transducer is fabricated from a cross shaped piezoelectric plate covered on both faces with metallic electrodes. First and second linear arrays are formed by the partial dicing of the opposite faces of the electrodes and plate. The two segments of the orthogonal arrays are integrated in the crossed area. An aperture may be disposed in the central area so as to permit a surgical implement, such as a biopsy needle, to be inserted into the tissue under ultrasonic visualization. Scanning electronics are alternately connectable to each of the arrays by means of a multiple pole switch under the control of a clock.

Abstract: An improved biplane phased array transducer for real time medical imaging in at least two sector planes having a composite piezoelectric plate with an array of transducer elements disposed on each major surface of said plate, the array on one side being at an angle to the array on the other side, said transducer elements being defined by dicing each major surface of said composite plate through the conductive electrode surface and into a portion of the composite piezoelectric material, and electrical connections provided whereby each array may be grounded alternately so that real time sector imaging in two planes is obtained.

Abstract: A thin film capacitor is formed of a thin crystalline electrically insulative or semiconductive substrate. With the insulative substrate a thin conductive metal layer is deposited on the substrate and a thin film of a crystalline strontium barium niobate deposited on the thin conductive metal layer so that its 2.77.ANG. spaced atomic planes are oriented in a non-perpendicular manner to the substrate and an additional thin conductive layer is deposited on the surface of the strontium barium niobate film. When a semiconductive substrate is employed the strontium barium niobate film is deposited directly on the substrate. These capacitors exhibit a low temperature coefficient of capacitance and a high capacitance density.

Abstract: An infrared thermal detector includes an infrared thermal sensing element, a load resistor, and a voltage supply means. The infrared thermal sensing element is a pyroelectric material whose electrical conductivity changes with temperature. The circuit and device parameters are chosen such that the detector will have frequency response over a broad band from dc (0 Hertz) to a high frequency determined by the electronic time constant of the circuit. The detector thus has all the advantages of either a pyroelectric detector without a chopper, or a thermistor bolometer having a fast response time.

Abstract: A pyroelectric target made of a pyroelectric material which is anisotropic dielectrically. Electrodes are provided on two plane parallel faces. To raise the pyroelectric figure of merit, the angle between the pyroelectric axis and the normal to the planar faces is greater than substantially 0.degree. but less than 90.degree.. A method of manufacturing such a target includes the step of selecting such an angle and cutting the faces into the material at the selected angle. A pyroelectric vidicon tube incorporating such a pyroelectric target has improved performance. Preferably, the projection of the normal to the planar faces onto a plane perpendicular to the pyroelectric axis is parallel to the axis along which the dielectric constant is lowest.