Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

381 results about "Magnetic moment" patented technology

The magnetic moment is the magnetic strength and orientation of a magnet or other object that produces a magnetic field. Examples of objects that have magnetic moments include: loops of electric current (such as electromagnets), permanent magnets, elementary particles (such as electrons), various molecules, and many astronomical objects (such as many planets, some moons, stars, etc).

Orbitronics device having orbital hall effect or inverse orbital hall effect, and method for enhancing efficiency thereof

The present disclosure provides an orbitronic device having orbital Hall effect or inverse orbital Hall effect, and method for enhancing the efficiency thereof. The orbital torque device comprises: a ferromagnetic / non-magnetic heterojunction formed by compounding a ferromagnetic layer and a non-magnetic layer as an orbital current source, wherein the ferromagnetic layer contains a ferromagnetic material, the non-magnetic layer contains a non-magnetic material with weak spin-orbit coupling, the non-magnetic layer is used as an orbital Hall channel to generate orbital current, and the orbital current enters the ferromagnetic layer, so that an orbital torque is generated through an orbital-spin conversion effect of the ferromagnetic layer to realize switching of a magnetic moment. The present disclosure can provide orbitronic device with low cost and good performance.
Owner:TIANJIN POLYTECHNIC UNIV

Detection method of ocean magnetic field sensor based on diamond NV color center

The invention discloses a detection method of an ocean magnetic field sensor based on a diamond NV color center. The detection method comprises the following steps: S1, calibrating a base line; s2, alternately measuring fluorescence between two single quantum resonance frequencies, and obtaining a difference to realize DQ reading; s3, three-axis compensation current is adjusted based on closed-loop control, and the NV working point is maintained at zero magnetization bias; s4, obtaining background magnetic field change through digital demodulation and adaptive filtering; and S5, calculating a gradient based on the spatial difference of the multi-point light spots, judging the existence and trajectory of the underwater vehicle in combination with a threshold value and a spectrum matching method, calibrating the threshold value according to the magnetic field characteristics of the existing underwater vehicle, adopting short-time Fourier transform signal spectrum, comparing the threshold value with known submarine characteristic spectrum data, and prompting if the similarity exceeds a set threshold value. According to the detection method, the measurement precision and the anti-interference capability can be improved, and the method is suitable for real-time monitoring of weak magnetic anomalies (such as magnetic moment disturbance of an underwater vehicle).
Owner:OCEANOGRAPHIC INSTR RES INST SHANDONG ACAD OF SCI

Transient electromagnetic and magnetic method data joint inversion method

The invention discloses a transient electromagnetic and magnetic method data joint inversion method. The method comprises the following steps: acquiring transient electromagnetic observation data and magnetic method observation data; converting the transient electromagnetic observation data into transient electromagnetic moment data; based on the transient electromagnetic moment data and the magnetic method observation data, a joint inversion objective function is constructed, and the joint inversion objective function comprises a data fitting residual term and a model constraint term; performing parameter coupling on the model constraint term by using a multivariate Gaussian mixture model to obtain a coupled model constraint term; and combining the data fitting residual term and the coupled model constraint term into a final objective function, and minimizing the final objective function through an optimization algorithm to obtain an electrical parameter and a magnetic parameter of the underground medium. According to the method, transient electromagnetic and magnetic method data joint inversion is realized, the problem of low three-dimensional inversion calculation efficiency is solved by introducing transient electromagnetic moment, and electrical and magnetic parameters are coupled by utilizing rock physics constraint, so that the inversion result is more accurate, and the structure is more consistent.
Owner:INSTITUTE OF GEOLOGY AND GEOPHYSICS CHINESE ACADEMY OF SCIENCES

Magnetic memory, magnetic memory cell and magnetic memory system

PendingCN121078960AMagnetic memoryData store
The invention provides a magnetic memory, a magnetic memory unit and a magnetic memory system. The magnetic memory at least comprises a first antiferromagnetic layer, a free layer, a barrier layer, a reference layer and a second antiferromagnetic layer which are sequentially stacked from bottom to top, wherein the magnetic moment direction of the reference layer is a first direction, the magnetic moment direction of the free layer is a second direction, and the first direction is perpendicular to the second direction; when the magnetic memory is in a first mode, applying a current parallel to a second direction to the first antiferromagnetic layer, so that the magnetic moment direction of the free layer is changed from the second direction to a direction parallel to the first direction, and the magnetic memory is switched from the first mode to the second mode; the first mode is used for detecting a magnetic field around the magnetic memory; the second mode is used for data storage. Therefore, the magnetic memory can be switched from the sensing mode to the storage mode, and the occupied space and cost can be saved at the same time.
Owner:青岛海存微电子有限公司 +1

Magnetic random access memory and preparation method thereof

The invention provides a magnetic random access memory and a preparation method thereof. The magnetic random access memory is applied to a comparison circuit, and comprises a magnetic tunnel junction comprising a free layer, a barrier layer and a reference layer which are stacked in sequence; the spin-orbit torque layer is located on the side, away from the reference layer, of the free layer, the conductive material layer is located on the side, away from the spin-orbit torque layer, of the magnetic tunnel junction, and a conductive material of the conductive material layer has the following characteristics that spontaneous magnetization capacity is achieved, and the resistance temperature coefficient is smaller than 0; the conductive material layer comprises a first part and a second part which are arranged at an interval, the first part is in contact with the reference layer, a first input end of the comparison circuit is electrically connected with the first part, and a second input end of the comparison circuit is electrically connected with the second part. According to the invention, the technical problems that the reading window of the magnetic tunnel junction becomes small and even the reading is wrong and the magnetic random access memory needs to apply an auxiliary magnetic field along the current direction to realize the deterministic overturning of the magnetic moment are at least solved.
Owner:ZHEJIANG HIKSTOR TECHOGY CO LTD

Magnetic moment measurement system and method

Provided is a magnetic moment measurement system and method, which belong to the technical field of magnetic moment measurement, and solve the problems of insufficient accuracy, low efficiency, and vulnerability to disturbance from an external magnetic field in the existing magnetic moment measurement technique. The magnetic moment measurement method includes the following steps: acquiring a magnetic field vector and a magnetic gradient tensor at a center of a magnetic sensor array through the magnetic sensor array; calculating an angle of a magnetic moment vector; and according to the angle of the magnetic moment vector, selecting a corresponding magnetic moment inversion formula, and calculating the magnetic moment vector. By constructing the magnetic sensor array, and using the advanced inversion algorithm, this application not only significantly improves the magnetic moment measurement accuracy, but also greatly shortens the measurement cycle, simplifies the measurement system, and reduces the measurement error.
Owner:HARBIN INST OF TECH

Aviation transient electromagnetic pod coil attitude correction method and system

The invention discloses an aviation transient electromagnetic pod coil attitude correction method and system, and belongs to the field of aviation geophysical exploration, and the system comprises a surface scanning industrial camera module which is used for obtaining the image information of a suspension coil in real time; the industrial-grade integrated navigation module is used for outputting inertial navigation data; the time synchronization and data acquisition module is used for establishing a time unification mechanism; the visual processing module is used for extracting the image processed by the time unification mechanism to obtain visual features; the inertial navigation resolving module is used for obtaining an inertial navigation state of a coil attitude angle through angular velocity integration; the data fusion and attitude estimation module is used for performing fusion calculation by combining the visual features and the inertial navigation state to obtain a fusion result; and the projection area and magnetic moment calculation module is used for calculating the ground projection area and the effective emission magnetic moment component of the coil according to the fusion result. According to the method, the system complexity and the electromagnetic interference risk caused by multi-inertial navigation layout are reduced, and the detection precision and stability of the aviation transient electromagnetic data are improved.
Owner:INSTITUTE OF GEOLOGY AND GEOPHYSICS CHINESE ACADEMY OF SCIENCES

APSO-LM fusion-based multi-magnetic accurate positioning method

The invention provides a multi-magnetic accurate positioning method based on APSO-LM fusion, and solves the technical contradictions that global search and local convergence are unbalanced and the resolving efficiency is low in the existing multi-magnetic accurate positioning technology. The method comprises the following steps: constructing a magnetic moment calibration module, selecting a sensor array calibration point, collecting magnetic field data, and calculating a precise magnetic moment amplitude based on a magnetic dipole model; an NSS-VMGT initial positioning result is input through a parameter initialization module, APSO and LM algorithm parameters are configured, and particle vectors are normalized; generating a particle swarm by using an APSO global search module, and iteratively screening a global optimal parameter as an LM initial value; calculating a residual error and a Jacobian matrix by means of an LM local refining module, and iteratively optimizing and outputting a magnetic source position and a magnetic moment; and the dynamic compensation module is used for calibrating clock skew and inhibiting environment interference. The device is realized based on STM32H743, and comprises a 7 * 7 lis2mdltr sensor array, a dual-chip data acquisition link, an APSO-LM algorithm hardware acceleration module and an upper computer interaction unit.
Owner:GUILIN UNIV OF ELECTRONIC TECH

Magnetic code disc film material and preparation method and application thereof

The invention provides a magnetic code disc film material and a preparation method and application thereof. By introducing the TiN layer, a proper amount of nitrogen atoms can enter lattice gaps of iron, electron cloud distribution of iron atoms is changed, and the magnetic moment of the iron atoms is changed; the magnetic moment of Fe atoms can be influenced by N atoms and crystal structures, an alpha-Fe8N phase is formed in FeCoCr through introduction of N ions, the average magnetic moment of each Fe atom in the alpha-Fe8N phase is 2.4 mu B, alpha-Fe8N is a metastable phase, a sample can finally form stable gamma '-Fe4N through annealing, and the magnetic moment of the stable gamma'-Fe4N is generally about 2.5 mu B-2. 7 mu B and is higher than the magnetic moment 2.2 mu B of the Fe atoms in metal Fe; besides, Ti forms a Ti-Fe weak magnetic phase pinning magnetic domain wall in the FeCoCr thin film, and the coercive force and residual magnetism of the FeCoCr layer can be effectively improved at the same time through the method.
Owner:JIHUA LAB

Calculation method and device of iron-based biphase magnetic material capable of enhancing magnetic moment

The invention provides a calculation method and device of an iron-based biphase magnetic material capable of enhancing magnetic moment. The calculation method comprises the following steps: providing crystal structure samples of a soft magnetic material and a hard magnetic material; optimizing the crystal structure samples of the soft magnetic material and the hard magnetic material to obtain a crystal structure with lowest energy; compounding the multi-layer soft magnetic material structure layer and the multi-layer hard magnetic material structure layer to obtain an initial crystal structure of the biphase magnetic material; wherein interface pinning exchange coupling is formed between the soft magnetic material structure layer and the hard magnetic material structure layer; calculating to obtain the magnetic moment of the crystal structure of the new biphase magnetic material; and regulating the number of soft magnetic material structure layers and hard magnetic material structure layers in the initial crystal structure of the double-phase magnetic material, calculating the magnetic moment of the double-phase magnetic material again, and taking the crystal structure of the double-phase magnetic material with the maximum magnetic moment as the target crystal structure of the double-phase magnetic material.
Owner:WUHAN UNIV +2

Magnetic multi-target positioning and magnetic moment inversion method based on measuring line vertical gradient

The invention belongs to the field of magnetic target body positioning, and relates to a measuring line vertical gradient-based magnetic multi-target positioning and magnetic moment inversion method, which comprises the following steps of: obtaining a unit orthogonal primary function and a primary function coefficient corresponding to each component of magnetic anomaly gradient data vertical to a measuring line, and calculating an energy curved surface of the magnetic anomaly gradient data vertical to the measuring line; detecting a local energy peak value of the energy curved surface, obtaining an energy peak value ratio sequence, obtaining a target number and horizontal position estimation corresponding to the target according to an energy sudden change value in the energy ratio sequence, and calculating a target depth corresponding to a measuring line vertical magnetic anomaly gradient energy extreme value by using a dichotomy method, and constructing a linear equation set about the target magnetic moment by using the measuring line vertical magnetic anomaly gradient data and the unit orthogonal basis function, and obtaining target magnetic moment parameter estimation through a least square method. According to the invention, the anisotropy difference of the estimation precision of the horizontal position of the target is effectively reduced, and the problem of target detection omission caused by large difference between the target burial depth and the magnetic moment module value in multi-target positioning is improved.
Owner:JILIN UNIVERSITY

Permanent magnet magnetizing control method based on magnetic domain dynamics and magnetizer

ActiveCN120183845AMagnetic bodiesMagnetization saturationMaterials science
The invention provides a permanent magnet magnetizing control method based on magnetic domain dynamics and a magnetizer, and particularly relates to the technical field of permanent magnet magnetizing. Obtaining a three-dimensional model of the permanent magnet to be magnetized, and dividing the three-dimensional model into a plurality of magnetic domain units; obtaining a magnetic moment kinetic equation of each magnetic domain unit; magnetic moment directions of the magnetic domain units are randomly distributed when magnetizing is not carried out, the magnetic moments of the magnetic domains do spin precession under the action of an effective magnetic field, and the magnetic moment directions approach to the direction of the effective magnetic field; the magnetic moment direction of each magnetic domain unit at different moments is subjected to numerical solution, and the change track of the magnetic moment direction of the magnetic domain unit from the initial magnetic moment direction is determined according to the instantaneous magnetic moment direction of the magnetic domain unit at different moments; and determining the consistency degree of the magnetic moment direction of each magnetic domain unit according to the change track, and generating a relation graph of the magnetizing saturation, the pulse magnetic field intensity and the pulse duration. According to the method, the magnetizing precision and efficiency can be improved.
Owner:ZHEJIANG UNIV +1

Magnetic field control self-checking system and method for nuclear magnetic resonance gyroscope

The invention provides a magnetic field control self-checking system and method for a nuclear magnetic resonance gyroscope, and belongs to the technical field of nuclear magnetic resonance gyroscopes, test parameters are input from an upper computer, an AD signal acquisition circuit converts triaxial magnetic field driving current into digital signals, and the digital signals are simultaneously transmitted to an FPGA operation core; according to the magnetic moment precession amplitude-frequency equation, magnetic moment precession signals are calculated through the test parameters and the digital signals; the amplitude, the frequency and the phase information of the signal are input into the gyro output signal generation module; generating a high-frequency carrier sinusoidal signal carrying low-frequency change characteristics from the amplitude, frequency and phase information of the magnetic moment precession signal through a CORDIC algorithm, and simulating a gyro output signal; and the DA conversion circuit outputs a simulated gyro output signal to test the magnetic field control system, so that rapid self-inspection and performance optimization of the magnetic field control system without real operation of gyro equipment are realized, and the system is used for independent test and evaluation of the magnetic field control system and is suitable for popularization.
Owner:BEIHANG UNIV +1

Spinning electronic device with adjustable spin current spatial distribution and polarization direction

PendingCN120614979AHeterojunctionSpin current
The invention discloses a spin current spatial distribution and polarization direction adjustable spin electronic device, which comprises a substrate, and is characterized in that the substrate is provided with a non-magnetic spin source layer, a ferromagnetic layer arranged on the non-magnetic spin source layer and a current reforming layer arranged on the ferromagnetic layer; specifically, the non-magnetic spin source layer and the ferromagnetic layer form a heterojunction, and a current reforming layer with a specific plane geometric structure grows on the heterojunction. According to the invention, anisotropic magnetic moment flipping of the spin torque and full electromagnetic moment flipping of the spin torque are realized.
Owner:TONGJI UNIV

Indoor local magnetic field modeling method and device based on magnetic source equivalence principle

The invention provides an indoor local magnetic field modeling method and device based on a magnetic source equivalence principle, and belongs to the technical field of indoor localization, and the method comprises the steps: collecting the data of a three-axis magnetometer in a space range through an array type magnetic sensor, and obtaining the original measurement information of an indoor magnetic field; based on a magnetic source equivalence principle, an indoor magnetic field is modeled into an equivalent magnetic dipole model consisting of a plurality of equivalent magnetic dipoles, and a magnetic field generated by the model is consistent with a real magnetic field in an observation area by setting magnetic moment and position parameters of the magnetic dipoles; according to the measured value of the array type magnetic sensor, an observation model is established in combination with an equivalent magnetic dipole model and used for describing the relation between the measured value and model parameters; through a nonlinear least square optimization method, parameters of the equivalent magnetic dipole model are solved according to the observation model, the equivalent magnetic dipole model of the indoor magnetic field is obtained, and the parameters comprise the magnetic moment and the position of the magnetic dipole. The precision and the reliability of the model are remarkably improved.
Owner:AEROSPACE INFORMATION RES INST CAS

Intelligent non-contact pipeline detection system based on metal magnetic memory effect

The invention relates to the technical field of pipeline detection, in particular to an intelligent non-contact pipeline detection system based on a metal magnetic memory effect, and provides the following scheme: dividing a to-be-detected pipeline into a plurality of grid units, obtaining self-leakage magnetic field data of each grid, constructing a magnetic moment matrix, and forming a magnetic field matrix; according to the method, abnormal grids are positioned based on a magnetic field matrix, a grid with the highest abnormal score is selected from a spatially continuous abnormal set through screening logic to serve as a seed grid, authenticity of adjacent abnormal grids is verified step by step in combination with a local inversion window and magnetic flux continuity constraint, false anomalies caused by magnetic flux diffusion or noise are eliminated, and the accuracy of the abnormal grids is improved. Performing magnetic moment matrix updating on the confirmed real defect grid; and finally, calculating a magnetic gradient modulus by utilizing the updated magnetic moment matrix and determining a damage grade. Adjacent lattice infection can be effectively inhibited, the defect positioning precision and the damage evaluation reliability are improved, and the method is suitable for a non-contact inspection scene of an in-service pipeline.
Owner:CHN ENERGY SUQIAN POWER GENERATION CO LTD +1

Physical unclonable function generator and true random number generator

The embodiment of the invention provides a physical unclonable function generator and a true random number generator. The physical unclonable function generator comprises a storage array and a control unit, a storage unit in the storage array comprises a magnetic storage device, and the magnetic storage device comprises a magnetic tunnel junction; the control unit is used for controlling the application of a magnetic field along a target direction to the storage array, and reading the resistance state of the storage unit to generate a physical unclonable function after the application of the magnetic field is stopped; wherein the target direction is perpendicular to or approximately perpendicular to the magnetic moment direction of the free layer in the magnetic tunnel junction in the in-plane direction, and the randomness and uniformity of the physical unclonable function are improved.
Owner:TRUTH MEMORY CORP

Self-excited cesium optical pump atom magnetometer and magnetic field measurement method

The invention provides a self-excited cesium optical pump atomic magnetometer and a magnetic field measurement method. The magnetometer comprises a physical probe part and a circuit part. The physical probe part comprises a cesium spectrum lamp, an optical element, a cesium atom absorption gas chamber, a radio frequency coil and a photoelectric detector; the circuit part comprises a photoelectric conversion circuit, a phase-locked amplification circuit and a radio frequency excitation circuit modulated by square waves. A macroscopic magnetic moment is generated by pumping cesium atoms through left-handed circularly polarized light, a radio frequency magnetic field induces Larmor precession, light intensity changes are detected and fed back to a radio frequency coil to form self-oscillation, and the external magnetic field intensity is calculated according to the linear relation between oscillation frequency and the magnetic field. Square wave modulation is adopted to broaden the measurement bandwidth, a magnetic field direction adjusting system is additionally arranged to automatically keep an angle of 45 degrees between an optical axis and a magnetic field so as to eliminate a blind area, the hemisphere automatic switching function is achieved, and the advantages of being high in sensitivity, fast in response, high in adaptability, small in size and low in power consumption are achieved.
Owner:ZHEJIANG GUOSHUI SUB TECHNOLOGY RESEARCH CO LTD

Write head, write head device, write head manufacturing method and magnetizing method

The present application relates to a write head, a write head device, a write head manufacturing method and a magnetizing method. The write head comprises: a second wafer, comprising a silicon body, and a first oxide layer and a second oxide layer which are located on the upper surface and the lower surface of the silicon body, respectively; and a magnetic pole array penetrating through the silicon body, and having a magnetic pole writing end located above the second oxide layer and directly facing one Z-bridge arm, and a magnetic pole supporting end surrounded by the first oxide layer, the magnetic pole array being a hard magnetic pole array, and having a magnetic moment in a +Z-direction or a -Z-direction; or the magnetic pole array being a soft magnetic pole array surrounded by a primary coil, and direct current passing through the primary coil and generating a magnetic moment in the +Z-direction or -Z-direction in the soft magnetic pole, wherein during writing, the magnetic pole writing end generates in a pinning layer of the Z-bridge arm a direct-current writing magnetic field comprising a Z-direction component, so that the magnetic moment of the pinning layer turns to the direction of the direct-current writing magnetic field comprising the Z-direction component. The present invention has the advantages of simple structure, high writing efficiency, low price and the like.
Owner:MULTIDIMENSION TECH CO LTD

Magnetic storage unit and device based on signal time delay

PendingCN120895067ADigital storageSpin-transfer torqueMagnetic memory
The invention provides a magnetic storage unit and device based on signal time delay. The unit comprises a first spin orbit moment layer and a first magnetic tunnel junction arranged on the first spin orbit moment layer. The distances between the first magnetic tunnel junction and the two ends of the first spin orbit moment layer are respectively a first distance and a second distance, and the first distance and the second distance are not equal; respectively inputting a first pulse signal and a second pulse signal from two ends of the first spin orbit moment layer along the first distance and the second distance; and the first pulse signal and the second pulse signal form a first write-in spin transfer torque current at the first magnetic tunnel junction due to signal time delay, so that the magnetic moment of a free layer of the first magnetic tunnel junction is subjected to deterministic overturning under the action of the first write-in spin transfer torque current. Deterministic writing of the magnetic tunnel junction can be realized without an additional auxiliary magnetic field, the device structure is simplified, and the area and power consumption overhead are reduced.
Owner:BEIHANG UNIV

Spacecraft multi-layer near-field method magnetic moment calculation method and device

The embodiment of the invention provides a spacecraft multi-layer near field method magnetic moment calculation method and device, and the method comprises the steps: determining the characteristics of a spacecraft, and determining the experiment arrangement of a magnetometer based on the characteristics of the spacecraft; wherein the magnetometer experiment arrangement comprises at least two layers; determining a magnetic moment conversion matrix based on magnetometer experimental arrangement; determining a magnetic moment result through a multi-layer near field method based on magnetometer experimental arrangement; a magnetic moment measurement is determined based on the magnetic moment conversion matrix and the magnetic moment result. Based on the multilayer near-field method and the magnetic dipole magnetic field model, optimization of the spacecraft multilayer near-field method magnetic moment calculation method can be realized, so that the magnetic characteristics of the spacecraft can be evaluated.
Owner:BEIJING INST OF SPACECRAFT ENVIRONMENT ENG

Flywheel unloading method and device based on PID control and storage medium

The invention discloses a flywheel unloading method and device based on PID control and a storage medium. The flywheel unloading method comprises the steps that the angular momentum deviation between the angular momentum of a flywheel deployed on a satellite and a reference angular momentum is determined; determining a PID control item for performing angular momentum unloading on the flywheel according to the angular momentum deviation; determining a control moment corresponding to the angular momentum deviation through a PID control mode based on a PID control item; according to the control torque, the unloading magnetic torque used for conducting angular momentum unloading on the flywheel is determined; according to the included angle between the magnetic moment and the unloading magnetic moment of the multiple magnetic torquers, weight information among the multiple magnetic torquers is determined, and the weight information is used for indicating the magnetic moment distribution proportion among the multiple magnetic torquers; according to the unloading magnetic moment and the magnetic moment distribution proportion, the magnetic moments of the multiple magnetic torquer are determined; and according to the determined magnetic moment, angular momentum unloading is carried out on the flywheel through a plurality of magnetic torquers.
Owner:GALAXY AEROSPACE (BEIJING) NETWORK TECH CO LTD

A real-time positioning method and system for a vector sensor network based on magnetic moment invariants

The application discloses a kind of vector sensor network real-time positioning method and system based on magnetic moment invariant, belongs to magnetic anomaly detection field, solve the problem that actual positioning performance is low in traditional network positioning method, real-time and positioning accuracy is poor.The technical points of the present application are as follows: in the positioning of distributed magnetic sensor network, the real-time magnetic field information observed by the magnetic sensor node is inverted, and a method for constructing a cost function with fewer parameters is proposed based on the magnetic moment invariant, reducing the number of parameters to be solved.The present application is suitable for actual outdoor positioning scene.
Owner:HARBIN ENG UNIV

Magnetic impurity simulation method, device and system based on current dipole

The invention discloses a current dipole-based magnetic impurity simulation method, device and system, belongs to the technical field of nondestructive testing, and solves the problem of how to improve the magnetic impurity simulation precision. Comprising the steps of inputting simulation parameters of target magnetic impurity particles, calculating target driving current, introducing a medium correction coefficient to perform reverse correction on the target driving current, and solving actual driving current; actual driving current is applied to the current dipole array of the selected level, and a simulated magnetic field is generated; an analog magnetic field signal is extracted based on a phase-locked amplification technology and is used for magnetic field signal inversion verification or sensitivity calibration. According to the method, the magnetic moment generated by the current dipole is equivalent to the excitation moment of the magnetic impurities, the medium correction coefficient k is introduced to carry out reverse correction on the target driving current, the actual driving current is solved, and the magnitude mapping relation from the magnetic impurity particle parameters to the actual driving current is established; and the accuracy and reliability of sensitivity calibration of the quantum detection equipment are improved.
Owner:STATE GRID ANHUI ELECTRIC POWER CO LTD ELECTRIC POWER SCI RES INST

Underground rock stratum water-bearing while-drilling nuclear magnetic resonance 3D imaging method

PendingCN120762126AAnalysis using nuclear magnetic resonanceProspecting/detection of underground waterMacroscopic scaleReceiver coil
The invention relates to the technical field of geological disaster prevention and control, and discloses an underground rock stratum water-bearing while-drilling nuclear magnetic resonance 3D imaging method which comprises the following steps: arranging a plurality of long lead grounding sources with the length of 500-1000 meters and the interval of 10-20 meters on the ground, and supplying alternating current pulses with the frequency of Ramole frequency to enable hydrogen nuclei in underground water to form macroscopic magnetic moment, after the excitation current pulse is cut off, the same coil is used for picking up nuclear magnetic resonance (NMR) signals generated by excitation of different excitation pulse moments; a receiving coil is installed behind the drill bit and dynamically receives FID signals along with advancing of the drill bit. A long wire grounding source is arranged on the ground to form an excitation magnetic field, and a receiving coil is mounted behind a drill bit to dynamically receive nuclear magnetic resonance signals while drilling, so that high-precision detection of the water-bearing property of an underground rock stratum from two dimensions of the earth surface and the underground is realized. The change of the aquifer and the potential water inrush hidden danger can be monitored in real time, and the detection precision and the resolution ratio are effectively improved.
Owner:CHINA UNIV OF MINING & TECH

Method and system for quickly locating anomalies in transient electromagnetic prospecting in a well

The application belongs to the technical field of tunnel electromagnetic exploration, and particularly relates to a method and system for rapidly positioning anomalies by using transient electromagnetic exploration in a well, which comprises the following steps: constructing a coaxial orthogonal detection array composed of four transmitting coils and one receiving coil and lowering the array into a borehole; adjusting the position of the transmitting coils so that the receiving coil is in a primary field zero magnetic flux state; preliminarily judging the anomaly body azimuth quadrant and depth range through grouped transmission and rotating observation, and combining 90-degree phase difference excitation to improve the positioning accuracy to a 45-degree cone angle range; obtaining a pure secondary field response through equivalent anti-phase transmission of side coils to realize high-resolution imaging of the shallow part; and enhancing the magnetic moment through in-phase transmission of all coils to realize deep tracking detection. The application realizes rapid and accurate positioning of the full-space anomaly body in the borehole, and is suitable for the fields of tunnel advanced prediction, mine goaf detection and the like.
Owner:JILIN WATER RESOURCE & HYDROPOWER CONSULTATIVE CO OF P R CHINA +1

Method and apparatus for designing a low leakage excitation coil for generating a high uniform magnetic field

The application provides a low magnetic leakage excitation coil design method and device capable of generating a high uniform magnetic field, and belongs to the technical field of magnetic field control. The method comprises the following steps: determining a target magnetic induction intensity and a target uniform region length; based on a pre-constructed two-dimensional distribution function of the uniform region length and the central magnetic field intensity, the size parameters of the low magnetic leakage excitation coil corresponding to the target magnetic induction intensity and the target uniform region length are determined by using an interpolation method or a table lookup method; based on the size parameters and the condition that the magnetic moment of the low magnetic leakage excitation coil is zero, the ratio of the inner and outer turns of the low magnetic leakage excitation coil is determined; and based on the required target magnetic induction intensity and the target uniform region length, the designed low magnetic leakage excitation coil is in a low magnetic leakage state to the outside of the system, the magnetic interference on the surrounding equipment is reduced, and the measurement accuracy is effectively improved.
Owner:BEIJING INST OF SPACECRAFT ENVIRONMENT ENG

Magnetic Heads Having Low Magnetic Coercivity (HC) And High Saturated Magnetic Flux Density (BS) In Ferromagnetic (FM) Layer(s) Or Shield(s) With Minimized Saturation

Magnetic moments can be increased in hard disk drive (HDD) shields and ferromagnetic layers to minimize magnetic saturation while still maintaining low magnetic coercivity (Hc) and high saturated magnetic flux (Bs). A textured layer can be used to induce nucleation and growth of an interfacial nature such that body centered cubic (BCC) ferromagnetic materials with high Bs and low Hc are obtained while also increasing the magnetic moment. The textured layer will cause the ferromagnetic material to grow with low Hc regardless of the crystallographic orientation.
Owner:WESTERN DIGITAL TECHNOLOGIES INC

Multilayer PCB-based coil array for sensor localization in magnetoencephalography

The present application is drawn to a system and method, as well as method for manufacture of a device and system for determining the position and orientation of at least one magnetic field sensor comprising: a rigid structure comprising an array of at least five electromagnetic coils; at least one wire that connects to and powers the electromagnetic coils; wherein the placement and orientation of the electromagnetic coils on the rigid structure are predetermined; wherein the electromagnetic coils, each having a predefined magnetic moment per unit current, are constructed with a printed circuit board (PCB) comprising at least one conductive layer; and wherein the system is configured such that a stray magnetic field emanating from the at least one, as measured at the location of the at least one magnetic field sensor, generates substantially lower magnetic field intensity than that produced by each of the at least five electromagnetic coils.
Owner:QUSPIN INC

Magnetic platform for sample orientation

A method is provided for positioning and orienting a platform such as a sample or workpiece relative to a frame of reference where the platform is a complex magnetic object that contains at least two magnetic domains with non-collinear magnetic moments and the method includes generating a spatially and temporally varying magnetic field so that each magnetic moment of the complex magnetic object interacts with the applied magnetic field. This can be used to performs an operation on a workpiece such as addition or removal of material. This can be used where the object includes a sample and, in each measurement configuration of the sample, radiation transmitted, reflected or scattered is measured from said sample material and analyzed to obtain information about the sample material.
Owner:11886827 CANADA LTD