317results about "Magnetic gradient measurements" patented technology

A wireless energy transfer system includes a foreign object debris detection system. The system includes at least one wireless energy transfer source configured to generate an oscillating magnetic field. The foreign object debris may be detected by at least one field gradiometer positioned in the oscillating magnetic field. The voltage of the at least one field gradiometer may be measured using readout circuitry and a feedback loop based on the readings from the gradiometers may be used to control the parameters of the wireless energy source.

A magnetic anomaly sensing system and method uses at least four triaxial magnetometer (TM) sensors with each of the TM sensors having X,Y,Z magnetic sensing axes. The TM sensors are arranged in a three-dimensional array with respective ones of the X,Y,Z magnetic sensing axes being mutually parallel to one another. The three-dimensional array defines a geometry that forms at least one single-axis gradiometer along each of the X,Y,Z magnetic sensing axes. Information sensed by the TM sensors is to generate scalar magnitudes of a magnetic anomaly field measured at each of the TM sensors, comparisons of the scalar magnitudes to at least one threshold value, distance to a source of the magnetic anomaly field using the scalar magnitudes when the threshold value(s) is exceeded, and a magnetic dipole moment of the source using the distance.

A sensing probe may be formed of a diamond material comprising one or more spin defects that are configured to emit fluorescent light and are located no more than 50 nm from a sensing surface of the sensing probe. The sensing probe may include an optical outcoupling structure formed by the diamond material and configured to optically guide the fluorescent light toward an output end of the optical outcoupling structure. An optical detector may detect the fluorescent light that is emitted from the spin defects and that exits through the output end of the optical outcoupling structure after being optically guided therethrough. A mounting system may hold the sensing probe and control a distance between the sensing surface of the sensing probe and a surface of a sample while permitting relative motion between the sensing surface and the sample surface.

A system for tracking a moving magnetic target uses a magnetic anomaly sensing system to continually determine magnetic gradient tensors associated with the target and converts the magnetic gradient tensors to gradient contraction scalars. A processor uses the magnetic gradient tensors and gradient contraction scalars to determine a minimum of bearing and range to the target. A velocity of the target is determined using the determined bearing and range at two points in time as the target is moving. To continually track with the moving target, the processor determines adjustments in elevation and azimuth using the magnetic gradient tensors and gradient contraction scalars along with bearing, range and determined velocities of the target. The processor can include a routine that determines range while accounting for asphericity errors introduced by the aspherical nature of constant magnetic gradient contours associated with the target.

A gradiometer for measuring properties of a magnetic field and in particular, for measuring magnetic field gradient components, comprising at least two magnetic sensors wherein at least two of the magnetic sensors are arranged to sense the magnetic field component in substantially the same direction. The magnetic sensors may be super conducting quantum interference device (SQUID) magnetometers, Hall probes, flux gates or magneto-resistive magnetometers. The gradiometer also includes a computer processor loaded with an adaptive signal-processing algorithm, for performing adaptive signal balancing of the magnetometer outputs. In a preferred embodiment the gradiometer may comprise at least eight magnetometers in a three-dimensional arrangement, and a set of three orthogonal global feedback coils, one for each direction x, y, z, such that the five independent magnetic field gradient components may be measured. The gradiometer may also be used to measure second or higher order magnetic field gradient components.

A magnetic field measurement system includes an array of magnetometers; at least one magnetic field generator with each of the at least one magnetic field generator configured to generate a first magnetic field at one or more of the magnetometers, wherein the generated first magnetic field combines with the ambient magnetic field to produce a directional magnetic field at the one or more of the magnetometers, where a magnitude and direction of the directional magnetic field is selectable using the at least one magnetic field generator; and a controller coupled to the magnetometers and the at least one magnetic field generator, the controller including a processor configured for receiving signals from the magnetometers, observing or measuring a magnetic field from the received signals, and controlling the at least one magnetic field generator to generate the first magnetic field and select the direction of the directional magnetic field.

The invention concerns an arrangement for magnetic field measurement of a measurement object (in particular a gradient coil in a magnetic resonance apparatus) with a magnetic field sensor that is designed to measure a magnetic field of the measurement object and with a measurement mechanism on which the magnetic field sensor is arranged at a first position. The measurement object has detectable reference points that can be used for calibration of a spatial position of a position sensor. The calibrated position sensor is arranged at a second position of the measurement mechanism, such that, with the first position and the second position, a spatial position relative to the measurement object can be associated with each magnetic field strength that is measured by the magnetic field sensor.

An atomic magnetometer includes a light source for a probe beam and a medium in which the probe beam is to be propagated. The medium is a substance which changes a polarization rotation angle of the probe beam depending on a magnetic field intensity at a first measurement position and a magnetic field intensity at a second measurement position different from the first measurement position. The atomic magnetometer directly measures a difference between the magnetic field intensity at the first measurement position and the magnetic field intensity at the second measurement position as a difference in polarization rotation angle, along a propagation path of the probe beam.

A magnetic sensor arrangement (1), having magnetically sensitive sensor elements (7, 8) whose electrical properties are changeable as a function of a magnetic field that a moving, passive transmitter element (11) is able to influence. The magnetic sensor arrangement (1) has two sensor elements (7, 8) in a gradiometer arrangement that are each respectively associated with one of two magnetic regions (4, 5) of a permanent magnet embodied in the form of a gap magnet (2; 20; 23), which regions are spaced apart from each other by a predetermined distance (sa). The regions (4, 5) and the gap magnet (2; 20; 23)—in terms of the for example wedge-shaped embodiment, the dimensions (h, b, t), the gap width (sa), the gap depth (st), and their positions in relation to the sensor elements (7, 8)—are situated so as to minimize the offset of the output signal of the sensor elements (7, 8) in the gradiometer arrangement.

An atomic magnetometer includes a light source for a probe beam and a medium in which the probe beam is to be propagated. The medium is a substance which changes a polarization rotation angle of the probe beam depending on a magnetic field intensity at a first measurement position and a magnetic field intensity at a second measurement position different from the first measurement position. The atomic magnetometer directly measures a difference between the magnetic field intensity at the first measurement position and the magnetic field intensity at the second measurement position as a difference in polarization rotation angle, along a propagation path of the probe beam.

A gradiometer in which a probe beam for reading sequentially passes through two magnetic field measurement regions to obtain signals according to magnetic flux densities of the respective regions is formed using an optically pumped magnetometer. In particular, in a gradiometer using a high sensitivity optically pumped magnetometer, a geometric arrangement enabling obtainment of a large signal from a dipole moment as a signal source is defined.

A magnetic field sensor including a body including a magnetic mechanism capable of forming a torque applied on the body by action of an external magnetic field to be detected; a connector, separated from the body, mechanically connecting the body to an inlay portion of the sensor by at least one pivot link having an axis perpendicular to the direction of the magnetic field to be detected; a detector detecting stress applied by the body by action of the torque, separated from the connector and including at least one suspended stress gauge including a first part mechanically connected to the inlay portion, a second part mechanically connected to the body, and a third part provided between the first and second parts and suspended between the inlay portion and the body.

A gradient sensor of a component of a magnetic field comprising at least one elementary sensor comprising a deformable mass (31) equipped with a permanent magnet (32) having a magnetization direction substantially colinear to the direction of the gradient of the component of the magnetic field to be acquired by the sensor. The deformable mass (31) is able to deform under the effect of a force exerted on the magnet by the gradient, the effect of this force being to shift it, by dragging the deformable mass (31), in a direction substantially colinear to the component of the magnetic field for which the sensor has to acquire the gradient. The deformable mass (31) is anchored to a fixed support device (33) in at least two anchoring points (36) substantially opposite relative to the mass (31). The elementary sensor also comprises measuring means (35, 35.1, 35.2, 35.3) of at least one electric variable translating deformation or stress of the deformable mass (31) engendered by the gradient.

Magnetic position sensors, systems and methods are disclosed. In an embodiment, a position sensing system includes a magnetic field source with a dipole moment in a direction along a z-axis; and a sensor module spaced apart from a center of the dipole moment a distance y0 along a y-axis and spaced apart a distance z0 from a center of the dipole moment along a z-axis, at least one of the magnetic field source or the sensor module configured to move relative to the other along a path in the y=y0 plane, the sensor module configured to determine a relative position of the magnetic field source to the sensor module with respect to the path from a ratio of a gradient dBz / dx to a gradient dBz / dy, where Bz is a magnetic field component associated with the permanent magnet, and where an x-axis, the y-axis and the z-axis are at right angles.

A discrete magnetic angle sensor device according to an embodiment includes a first magnetic field gradiometer and a second magnetic field gradiometer. The first magnetic field gradiometer and the second magnetic field gradiometer are of different types of a group of gradiometer types. An embodiment may improve an accuracy of a determination of a rotation angle.

The invention provides various systems, machine readable programs and methods for performing imaging using a MR scanner. The MR scanner includes at least one local radio-frequency transmit coil and at least one local gradient coil. The local radio-frequency transmit coil(s) and local gradient coil(s) cooperate to define an imaging volume. The MR scanner further includes a control system for performing an imaging operation on a patient's anatomy disposed within the imaging volume. The control system permits a selective simultaneous increase of the gradient magnetic field strength and peak B1 field strength by substantially the same factor, f.

Noise compensation in controlled source electromagnetics (CSEM) comprises measuring time-varying magnetic gradients of the marine environment subjected to CSEM. From the measured magnetic gradients, oceanographic electric and magnetic field noise is determined and used for noise compensation of CSEM measurements of electric and magnetic fields. Selection of magnetic gradient measurement provides improved measurement of oceanographic magnetic noise as other electromagnetic noise sources produce negligible magnetic gradients in the marine environment. Electric field noise is then predicted from the magnetic measurements.

The invention discloses a magnetic resistance Z-axis gradient sensor chip which is used for detecting the gradients of components of a Z-axis magnetic field generated by magnetic media in the X-Y plane so as to conduct magnetic imaging on the magnetic media. The magnetic resistance Z-axis gradient sensor chip comprises a Si substrate, two or two groups of sets containing a plurality of flux leaders and magnetic resistance sensing units which are electrically connected, wherein the distance between the sets is Lg. The magnetic resistance sensing units are located on the Si substrate and located above or below the edges of the flux leaders, the components of the Z-axis magnetic field are converted into the mode that the components of the Z-axis magnetic field are parallel to the surface of the Si substrate and in the direction of the sensitive axes of the magnetic resistance sensing units, and the magnetic resistance sensing units are electrically connected into a half-bridge or whole-bridge gradient meter, wherein the distance between opposite bridge arms is Lg. The sensor chip can be used together with a PCB, a PCB and back magnetor a PBC and back magnet and packaging shell. According to the magnetic resistance Z-axis gradient sensor chip, measurement of the Z-axis magnetic field gradient is achieved by using plane sensitive magnetic resistance sensors, and the magnetic resistance Z-axis gradient sensor chip has the advantages of being small in size and low in power consumption, having higher magnetic field sensitivity than a Hall sensor and the like.

An atomic magnetometer / magnetic gradiometer comprises at least one detection gas chamber, wherein the detection gas chamber is filled with alkali metal vapor; a laser light source, which is used for emitting an excitation light beam and a detection light beam to irradiate the detection gas chamber, wherein the excitation light beam is used for enabling alkali metal vapor in the detection gas chamber to be polarized, and the detection light beam is used as polarized light to pass through the alkali metal vapor and then reach the polarization detection device; a modulation coil which is used forgenerating a modulation magnetic field with the known intensity for the alkali metal vapor; a polarization detection device which is used for receiving the detection light beam, and according to thepolarization angle change information of the to-be-measured magnetic field overlapped by the modulated magnetic field, the polarization angle change information of the light beam is detected, and of the detection light beam in a to-be-measured magnetic field subjected to superposition by the modulation magnetic field, acquiring detection signals of magnetic field intensity or magnetic field gradient of the to-be-measured magnetic field. The invention further provides a MEG device and method based on the atomic magnetometer / the magnetic gradiometer. The invention is based on a discrete atomicmagnetometer / the magnetic gradiometer, and realizes the detecting of the brain magnetic signals of the wearable multi-channel detection of MEG signals.

The invention relates to a method of selecting a set of coil elements from a multitude of physical coil elements comprised in a coil array for performing a magnetic resonance imaging scan of a region of interest.

The invention discloses a full-tensor magnetic field gradiometer based on the giant magnetic impedance effect. The full-tensor magnetic field gradiometer comprises an X-Y-direction gradiometer body, a Z-direction gradiometer body and signal leads. The X-Y-direction gradiometer body comprises a cross-shaped substrate and a giant magnetic impedance thin film, the Z-direction gradiometer body comprises a rectangular substrate and a giant magnetic impedance thin film, a junction point at the input end and a junction point at the output end of an electric bridge are connected with the signal leads, and the signal leads are arrayed symmetric with the geometric center of the whole gradiometer as the three-dimensional center. The full-tensor magnetic field gradiometer has the advantages of being high in accuracy, minimized, low in cost, wide in frequency response, rich in information and the like. Due to the design of preparing a three-dimensional structure through planar thin films, the problem of space consistency of the full-tensor magnetic field gradiometer based on the giant magnetic impedance thin films is solved, and the magnetic field gradient measuring sensor with the size at the chip level is designed for the first time.

A gradiometer in which a probe beam for reading sequentially passes through two magnetic field measurement regions to obtain signals according to magnetic flux densities of the respective regions is formed using an optically pumped magnetometer. In particular, in a gradiometer using a high sensitivity optically pumped magnetometer, a geometric arrangement enabling obtainment of a large signal from a dipole moment as a signal source is defined.

An apparatus for measuring and detecting a magnetic signature of a magnetically detectable object from a distance includes a portable sensor group for detecting the magnetic signature. The portable sensor group includes three gradient sensors, each of the three gradient sensors adapted to independently measure both a magnitude and a direction of the magnetic signature, a first of said gradient sensors measuring an axial gradient in the vertical direction, a second of said gradient sensors measuring a first horizontal gradient in the vertical direction, and a third of said gradient sensors measuring a second horizontal gradient in the vertical direction.

The invention discloses a parallelism error compensation method and system in magnetic sensor array measurement. A detected magnetic sensor array is fixed to a rotary platform in multiple modes, the magnetic sensor array is rotated, meanwhile, data output by magnetic sensors under different rotating angles are collected, therefore, the fixed azimuth error angles and fixed pitching error angles of magnetic shafts of the magnetic sensors are acquired, a correction matrix is obtained to correct the magnetic sensors, parallelism errors between three-component magnetometer sensitive shafts can be compensated to be within 0.02 degree, and the locating precision of a gradient tensor instrument on a magnetic target is effectively improved.

A magnetic shielding device includes: a passive shield having an inner space; a first coil that cancels a magnetic field entering in the inner space; a first magnetic sensor that measures the magnetic field entering in the inner space; a second magnetic sensor located in a position farther from the first coil than the first magnetic sensor; and a controller that controls the first coil so that a gradient between a first magnetic field measured by the first magnetic sensor and a second magnetic field measured by the second magnetic sensor be less than a predetermined threshold.

The invention discloses a measuring and controlling device for aviation superconducting full tensor magnetic gradient based on GPS (Global Positioning System) synchronization. The measuring and controlling device is characterized by being positioned in a pod of a suspension and pod subsystem; the measuring and controlling device for the aviation superconducting full tensor magnetic gradient consists of an SQUID (Superconducting Quantum Interference Device) reading circuit, a data acquisition and communication module, a flying position and pose information recording module, a working environment monitoring module and a human-machine interface module; other four modules are connected by taking a star topology structure with the data acquisition and communication module as the core. According to the device, after a specific signal at the designated time is resampled by a PPS (Pulses Per Second) frequency doubling sampling clock generated through a digital phase-locked loop based on a GPS time service function, the synchronization of the device and the position and pose information which are given out by a GPS integration navigation is realized by using a time stamp, so that the foundation is laid for inversion by altitude projection; besides, the measuring and controlling device has the characteristics of simplicity for realization, and high extendibility and reliability, and is particularly suitable for being applied under an aviation platform.

A magnetic sensor device (1) is proposed in which magnetic field-sensitive sensor elements (7, 8) are arranged, the electrical properties of which sensor elements (7, 8) can be changed as a function of a magnetic field which can be source transmitter element (11) to affect. The magnetic sensor device (1) has two sensor elements (7, 8) in the gradiometer device, which are assigned to permanent magnets (2; 20; 23) in each case One of two magnetic regions ( 4 , 5 ) of the magnet that are arranged at a predetermined distance (sa). Areas (4, 5) and opening magnets (2; 20; 23) in terms of eg wedge shape, dimensions (h, b, t), opening width (sa) and opening depth (st) and their relative to the sensor element ( 7 , 8 ) are positioned in such a way that deviations of the output signals of the sensor elements ( 7 , 8 ) are minimized in the gradiometer arrangement.