252 results about "Helmholtz coil" patented technology

The invention discloses an oil abrasive particle multi-channel detection device based on Helmholtz coils, and belongs to the technical field of oil abrasive particle detection, the detection structure comprises an excitation assembly and an induction assembly, the excitation assembly comprises excitation coils and a tubular outer-layer skeleton, the excitation coils are wound around the two ends of the outer portion of the tubular outer-layer skeleton, and the induction assembly is wound around the tubular outer-layer skeleton. And a uniform magnetic field is generated. The induction assembly comprises a plurality of induction units arranged side by side. According to the invention, the Helmholtz excitation coil and the multiple groups of differential induction coils are designed, and the multiple induction units are arranged side by side to form a multi-channel detection system; the Helmholtz excitation coil generates a uniform magnetic field in a detection area, so that the detection system can keep consistent sensitivity to metal abrasive particles at different radial positions, and meanwhile, the throughput of mechanical oil is ensured by parallel connection of multiple channels; the problem of inaccurate detection caused by non-uniform radial magnetic field of an induction type oil abrasive particle detection system in a large-circulation pipeline is effectively solved.

The invention provides a device and method for testing the reliability of a power sensor, and the device comprises a magnetic field generation unit which is used for providing an alternating current for a Helmholtz coil through a power frequency current source, and generating a controllable magnetic field; the electric field generating unit is used for providing a high-voltage direct current or power frequency alternating current power supply for the parallel-plate capacitor through a high-voltage generator to generate a uniform electric field; the tested unit is used for providing a standard excitation signal through a standard source matched with the to-be-tested sensor, simulating an input condition of the to-be-tested sensor under an actual working condition and collecting output data of the to-be-tested sensor; and the control unit is used for setting test parameters, generating a control instruction according to the test parameters and generating a test result according to the output data. According to the device and the method, by simulating a strong magnetic field and a strong electric field environment and combining application of various measured parameters and an automatic control system, the reliability evaluation requirement of the sensor under the actual working condition is fully met.

The invention discloses an optical element measurement centering tool for a ship clutch shaft, and relates to the technical field of centering measurement tools, the optical element measurement centering tool comprises a fixing part, a shaft fixing assembly and a laser detection assembly, a mounting groove is formed in the surface of the fixing part, and under the cooperation of the laser detection assembly, a Helmholtz coil generates a uniform magnetic field to drive a magnetic needle to be oriented; the perpendicularity error of the reflective mirror and the axis of the magnetic needle is small, a dynamic vertical reference is provided for a laser beam, the problem of reference drift caused by ship vibration and shaft system inclination is solved, the laser beam is converted into parallel light through the collimating lens, the optical axis overlap ratio error is low, and then through cooperation of the pneumatic hinge and the vertical lead screw guide rail, the laser beam can be accurately measured. Initial alignment of the laser beams is completed in a very short time, fine trimming of light spots is achieved, efficiency is effectively improved compared with manual adjustment, the reflection angles of the reflectors are synchronously adjusted, it is ensured that the laser beams are perpendicular to the surface of the shaft all the time, physical contact errors of traditional contact type measurement are avoided, and measurement accuracy is improved.

The invention relates to the technical field of magnetron sputtering, and particularly discloses a magnetron sputtering silver-coated conductive material powder device based on an ultrasonic-electromagnetic suspension composite dispersion system and application of the magnetron sputtering silver-coated conductive material powder device. In order to solve the technical problems of powder agglomeration, low target material utilization rate and poor large-scale production uniformity, a porous ceramic tool plate is used as a core carrier, and a high-frequency ultrasonic vibrator array (adjustable in 20-100kHz), a planar rectangular cathode (with an inclination angle of 0-15 degrees) and a Helmholtz coil (0.1-0.5 T rotating magnetic field) are integrated; non-contact dispersion of powder and precise coating of a silver layer are achieved through the cavitation effect, electromagnetic suspension and multi-target cooperative sputtering. The tool disc adopts a gradient aperture design, and is combined with liquid nitrogen micro-channel cooling and a modular sub-cavity structure, so that the powder dispersion uniformity (CV value lt; 5%), the silver layer porosity (llt; 1%), the target material utilization rate (52%) and the single-furnace productivity (72 kg / 8 h) are obviously optimized, and an efficient and environment-friendly industrialization solution is provided for the field of electronic materials.

The invention relates to an external field intelligent regulation and control photocatalytic hydrogen production integrated device and system. The device comprises a Fresnel lens; the double-layer vacuum glass tube comprises an outer-layer glass tube, an inner-layer glass tube and a vacuum layer located between the outer-layer glass tube and the inner-layer glass tube, and the inner-layer glass tube is connected with an external water source and the separation module; the Helmholtz coil comprises two conductor coils, and the two conductor coils are symmetrically arranged at the two ends of the outer-layer glass tube in a sleeving mode and are communicated with an external power source; the photocatalyst is arranged in the inner-layer glass tube and is positioned at a strip-shaped light band of the sunlight focused by the Fresnel lens; the separation module comprises a hydrogen separation membrane and a gas outlet and is used for efficiently separating gas generated by reaction; the Fresnel lens is connected with the double-layer vacuum glass tube through the fixing support and located on the upper side of the double-layer vacuum glass tube. The Helmholtz coil is used for generating a magnetic field to improve the photo-generated charge separation efficiency in the photocatalytic reaction process, so that the hydrogen production efficiency is improved. The efficiency of photocatalytic reaction hydrogen production can be improved through precise regulation and control of an external field.

The invention relates to the technical field of micro-nano robots, and provides a motion control method and system for a magnetic control micro-nano robot carrying medicine in a simulation environment, and the method comprises the steps: obtaining a motion image of a magnetic control silicon dioxide-based micro-nano robot cluster in the simulation environment in real time; according to a preset transportation task, the current state of the micro-nano robot cluster is judged; based on the current state of the micro-nano robot cluster, establishing a magnetic field generated by the micro-nano robot cluster and the three-dimensional Helmholtz coil, a fluid resistance field of a simulation environment and a dynamic model of a simulation environment channel boundary condition; and based on the motion image acquired in real time, using a deep learning model to identify real-time pose information of the micro-nano robot cluster and the simulated environment channel boundary information, and using a path planning algorithm to perform trajectory planning according to the real-time pose information and the simulated environment channel boundary information. And the magnetic field is adjusted to control the movement of the micro-nano robot cluster.

The invention discloses chemical mechanical polishing equipment, a polishing solution detection method, a polishing method and a medium. The chemical mechanical polishing apparatus includes: a polishing disk; the bearing head is used for polishing the wafer on the polishing disc; the liquid supply assembly is used for supplying polishing liquid to the bearing head, and the polishing liquid is distributed on the polishing surface of the polishing disc; the lifting check ring is arranged on the periphery of the polishing disc, a Helmholtz coil is arranged on the lifting check ring, the lifting check ring is provided with an avoiding position when polishing is stopped and a blocking position when polishing is conducted, and when the lifting check ring is located at the blocking position, the polishing surface of the polishing disc is located within the range of the Helmholtz coil so that a basic magnetic field can be formed on the polishing surface; the pulse generating arm is used for superposing a pulse magnetic field on the polishing liquid; and the magnetic field detection arm is arranged between the pulse generation arm and the bearing head and is used for detecting a nuclear magnetic resonance signal responding to the pulse magnetic field so as to determine the distribution condition of the polishing solution according to relaxation time data of hydrogen atoms reflected by the nuclear magnetic resonance signal.

The invention relates to the field of electromagnetic detection, and provides a wake flow electromagnetic field enhancement detection method based on a circulating water tank. The method comprises the following steps: constructing a wake flow electromagnetic field test device based on a circulating water tank, and fixing a to-be-tested model in a flow channel of the circulating water tank; a Helmholtz coil is arranged on the outer side of the circulating water tank to generate an enhanced background magnetic field; the rotating speed of the driving device is periodically changed, so that the water flow speed in the circulating water tank is periodically changed; measuring an electric field and a magnetic field of the target area; and the obtained signals are processed and analyzed.

The invention provides a geomagnetic compensation and bias magnetic field generation system and method for cold atom interference. The system comprises a triaxial magnetometer, a triaxial Helmholtz coil, a voltage-controlled current source and an FPGA regulation and control module. The three-axis magnetometer is used for collecting space magnetic field data at a plurality of monitoring positions in the space where the three-axis Helmholtz coil is located in real time; the FPGA regulation and control module is used for calculating control voltage data required by the voltage-controlled current source according to a target magnetic field and any space magnetic field data collected by the three-axis magnetometer in each sampling period, controlling coil current transmitted to the three-axis Helmholtz coil, and outputting the coil current to the three-axis Helmholtz coil. And loop iteration is carried out until the three-axis Helmholtz coil generates a target magnetic field at a plurality of monitoring positions, wherein the target magnetic field is a near-zero magnetic field in the X / Y direction, and the magnetic field intensity in the Z direction is constant and is a non-zero value. The device can respond to the change of the environmental magnetic field in real time, and provides a stable and accurate magnetic field environment for the cold atom interference test on the basis of compensating the influence brought by the geomagnetic field.

The invention relates to the technical field of ground-air electromagnetic detection, in particular to a ground-air frequency domain electromagnetic detection background magnetic field real-time counteracting system and a control method, and the system comprises a self-counteracting transmitting coil, a self-counteracting control system and a self-counteracting current source; the self-counteracting transmitting coil is composed of three groups of Helmholtz coils, and the groups of coils are perpendicular to one another; the three groups of Helmholtz coils are fixed on the solid wood frame, and a self-counteracting control system and a self-counteracting current source are also stored on the solid wood frame; the three-component magnetic field sensor and the attitude sensor are fixed in the solid wood frame through binding ropes, and the three-component geomagnetic field orientation measured by the three-component magnetic field sensor corresponds to the three groups of Helmholtz coils. The influence of low-frequency noise caused by a geomagnetic field is eliminated, and high-sensitivity and low-noise electromagnetic signal measurement is realized.

The invention discloses a three-dimensional transient magnetic field monitoring system based on sensor array attitude-position combined correction, and the system comprises magnetic field measurement assemblies which are composed of M * N * K three-dimensional sensor arrays and are distributed at equal intervals according to a preset space interval so as to collect transient magnetic field data in real time; the lower computer synchronously collects original data in parallel through the IIC bus and uploads the original data; the upper computer integrates an attitude error correction unit and a cooperative position compensation unit, eliminates the attitude error of the sensor through rotation matrix calculation based on a uniform magnetic field and a gradient magnetic field generated by a Helmholtz coil, and constructs a global optimization model to compensate position deviation. The data processing module adopts cubic spline interpolation to reconstruct continuous magnetic field distribution, and the display module realizes sub-layer visualization and time sequence playback of vector and scalar space-time distribution through a dynamic rendering technology; according to the system, high-precision monitoring of the transient magnetic field is achieved through a hardware parallel architecture and a joint correction algorithm, and the system is suitable for transient magnetic field dynamic analysis in the fields of power equipment, medical imaging and the like.

The invention discloses a zero magnetic shielding device and a use method thereof, and the device comprises a magnetic shielding cylinder which is composed of a shielding cylinder body and a shielding cover detachably connected with the shielding cylinder body. And the non-magnetic multifunctional test frame is arranged in the magnetic shielding cylinder and consists of an arc-shaped seat, a lifting mechanism, a test bedplate, a track, a storage rack, a Helmholtz coil and a folding nylon magnetic sensing assembly. When the magnetic flux and residual magnetism switching test is carried out on the object to be tested in the magnetic shielding cylinder, the non-magnetic multifunctional test frame does not need to be replaced, the efficiency of the magnetic flux and residual magnetism switching test on the object to be tested in the magnetic shielding cylinder is improved, and the advantage of convenient switching test is achieved. And the method has the advantages of high measurement precision and wide application range.

The invention discloses liquid dressing production equipment, and relates to the technical field of medical instrument production equipment.The liquid dressing production equipment is characterized in that firstly, neodymium iron boron magnets of a driving rotary disc and a driven rotary disc are in coupling transmission, and a middle isolation sleeve is matched, so that complete physical isolation inside and outside a kettle is achieved; a uniform magnetic field generated by Helmholtz coils is used for weakening attraction force among particles, a dynamic magnetic field gradient formed by rotation of a permanent magnet arranged in a stirring paddle can cooperate with mechanical shearing, so that the internal structure of an aggregate is deeply destroyed, meanwhile, the Helmholtz coils in three orthogonal directions provide a global uniform static magnetic field, and the aggregate is fully dispersed. The stability of the magnetic background in the kettle can be ensured, the global effect of the dynamic magnetic field gradient is matched, the local defect caused by purely depending on mechanical shearing is avoided, the dispersion uniformity is remarkably improved, the influence of the concentration gradient on the physical and chemical properties is reduced, and the influence of initial agglomeration on the subsequent process can be reduced by utilizing the efficient dispersion capacity of the magnetic mixing assembly.

The invention discloses a device and method for verifying the performance of an electromagnetic field composite energy-taking passive sensor, and the device comprises a verification box which is internally provided with a dual-channel excitation source which is used for outputting magnetic field excitation and electric field excitation. The double-channel excitation source comprises high-voltage electrode plates installed on the left inner wall and the right inner wall of the verification box, two symmetrical brackets fixed to the bottom of the verification box, a convex bottom table fixed to the top ends of the two brackets, and a Helmholtz coil installed at the top end of the convex bottom table. According to the invention, the magnetic field and the electric field are arranged to be a vertically-crossed dual-channel excitation structure, so that excitation of fundamental waves and harmonic waves can be simultaneously or independently carried out to generate electromagnetic composite fields with different waveforms and different phase angles, and an excitation environment is provided for the composite energy-taking sensor through electromagnetic field excitation for a period of time; therefore, the performance of the sensor can be tested in various scenes.

A calibration system leverages a 3-axis Helmholtz coil device for generating a referential magnetic field for calibrating the magnetometer on-board a vehicle. The calibration system may include the magnetic field generator, a vehicle platform, and a computing device to determine the calibration parameters. The vehicle platform supports the vehicle with the magnetometer being calibrated. The magnetic field generator generates a referential magnetic field in three-dimensional space for calibration of the magnetometer. The computing device is configured to: receive magnetometer measurements from the magnetometer on-board the vehicle during generation of the referential magnetic field, and determine calibration parameters for calibrating the magnetometer based on the magnetometer measurements and the referential magnetic field generated by the magnetic field generator.

An inductive heater assembly for heating a power tool battery pack, the inductive heater assembly comprising a housing, a battery pack interface configured to receive the power tool battery pack, a charging base, a coil portion located within the housing. The coil portion including a first coil winding and a second coil winding configured to generate an electromagnetic field, wherein the first coil winding and the second coil winding to form a Helmholtz coil.

The invention provides a single-target permanent magnet positioning method and device based on a magnetic dipole model, and relates to the technical field of magnetic sensing, and the single-target permanent magnet positioning method based on the magnetic dipole model comprises the steps: generating a uniform magnetic field through a Helmholtz coil, and measuring the magnetic moment data of a to-be-measured magnetic dipole; the magnetic dipole to be tested is a cylindrical permanent magnet; the MSSA algorithm used for short-distance positioning and the ICNN-GRU-Attention neural network algorithm used for long-distance positioning are fused, and a fusion positioning algorithm is obtained; and inputting the magnetic moment data and magnetic field intensity data received by using a sensor array into the fusion positioning algorithm, and determining a target position of the magnetic dipole to be measured. According to the method, the positioning area is divided into the close-distance area, the mixed area and the long-distance area, and the positioning algorithms in different application ranges are fused to generate the adaptive fusion algorithm, so that the positioning precision of the single-target permanent magnet is improved.

The invention discloses a design method of a multistage nested Helmholtz coil system, and relates to the technical field of general instrument and meter manufacturing. According to the reciprocal analysis design method for the coil structure parameters and the magnetic field characteristics of the multistage nested Helmholtz coil system under the global sensitivity, the optimal design expression of each design parameter of the multistage nested Helmholtz coil system can be determined based on the reciprocal analysis design method, and the multi-parameter expression of the magnetic field characteristics can be obtained; the coil parameter design priority is defined, and an optimization design strategy for the magnetic field design indexes is provided. When a macroscopic design requirement of a target uniform magnetic field is provided, an optimal solution of each design parameter of the multistage nested Helmholtz coil system can be directly obtained. According to the method, the Helmholtz coil can be efficiently and accurately improved and designed according to needs.

A triaxial magnetic sensor performance detection system is characterized in that an industrial personal computer is connected with a group of A / D conversion modules and two groups of D / A conversion modules, and the group of A / D conversion modules is connected with a tested sensor installed on a test tool or a non-magnetic lifting platform; one group of D / A conversion modules is connected with three groups of high-precision current-stabilized power supplies; the D / A conversion module is connected with the three high-precision compensation power supplies, and the three high-precision current stabilization power supplies and the three high-precision compensation power supplies are connected with the three-axis Helmholtz coil. The three-axis Helmholtz coil matched with the device adopts the design of a main coil and an auxiliary coil, the electromagnetic coefficient of the main coil is relatively large, and a wide-range magnetic field simulation test is met. The electromagnetic coefficient of the secondary coil is small, the precision of magnetic field simulation is improved, and a space interference magnetic field is compensated in a real-time closed-loop mode. By designing a reasonable high-precision steady-current power supply conversion coefficient and coil parameters, the magnetic field simulation precision and the sensor performance calibration precision of the system device in an office are effectively improved. And the high-precision power supply is matched with the high-resolution and high-synchronism data acquisition module, so that higher-precision three-axis magnetic field simulation and measurement are realized. Meanwhile, the linearity index of the designed high-precision steady-current power supply can reach 0.002%.

The present invention relates to the field of magnetron sputtering technology, and specifically discloses a magnetron sputtering silver-coated conductive material powder device based on an ultrasonic-electromagnetic suspension composite dispersion system and its application. In response to the technical difficulties of powder agglomeration, low target utilization rate and poor uniformity in large-scale production, the present invention uses a porous ceramic tooling disk as the core carrier, integrates a high-frequency ultrasonic vibrator array (adjustable at 20-100kHz), a planar rectangular cathode (tilt angle 0-15°) and a Helmholtz coil (0.1-0.5T rotating magnetic field), and realizes non-contact dispersion of powder and precise coating of silver layer through cavitation effect, electromagnetic suspension and multi-target collaborative sputtering. The tooling disk adopts a gradient aperture design, combined with liquid nitrogen microchannel cooling and modular cavity structure, so that the powder dispersion uniformity (CV value <5%), silver layer porosity (<1%), target utilization rate (52%) and single furnace production capacity (72kg / 8h) are significantly optimized, providing an efficient and environmentally friendly industrial solution for the field of electronic materials.

The invention relates to the field of laser additive manufacturing, and particularly discloses a laser coaxial fuse additive manufacturing device and method based on double-magnetic-field collaboration.The laser coaxial fuse additive manufacturing device comprises a movement system, a coaxial fuse additive manufacturing system, a double-magnetic-field auxiliary system and a control monitoring system, and a wire feeding mechanism is arranged outside the device. The double-magnetic-field auxiliary system is composed of a magnetic pressure induction system and a symmetrical sliding type magnetic field generation system. The magnetic pressure sensing system is arranged around the welding head and generates a vertical magnetic field; the symmetrical sliding type magnetic field generation system generates a horizontal magnetic field through Helmholtz coils on the two sides. The two magnetic field systems are mutually independent and adjustable and form orthogonal configuration in space. The device is provided with a high-speed camera to monitor the state of the molten pool in real time, the magnetic field intensity and proportion are dynamically adjusted through a controller and double electromagnetic generators, and accurate control over molten drop transition and molten pool flowing is achieved. According to the invention, the quality and stability of coaxial fuse additive manufacturing are improved.

The invention discloses a metal-assisted chemical etching method and equipment based on three-dimensional magnetic field guidance. The etching method comprises the steps of pre-cleaning, adding a metal catalytic material, soaking in an erosion liquid, placing in a magnetic field guidance erosion device, performing three-dimensional magnetic field guidance erosion, performing post-treatment and the like. According to the metal-assisted chemical etching method, the controllable magnetic field is generated through the three-dimensional Helmholtz coil, so that the motion trail of the metal catalytic material in the metal-assisted chemical etching process is accurately restrained and controlled, the controllability and accuracy of the etching process can be remarkably improved, and manufacturing of a complex micro-nano structure becomes more efficient. In addition, by adjusting the direction and strength of the magnetic field, the processing rate of the metal catalytic material is effectively increased. Through the magnetic guiding effect, the metal catalytic material can be etched in the preset direction, the consistency and directivity of an etching track are ensured, and a microscopic three-dimensional structure with a specific shape and size is manufactured.

The invention relates to the technical field of miniature medical robots, and discloses a magnetic liquid metal-based soft drug-loaded capsule robot, which comprises a soft capsule robot main body, a soft capsule robot cover and a degradable sealing sleeve, the soft capsule soft robot main body comprises a bottom fan-shaped magnetic liquid metal storage cabin, a left fan-shaped medicine storage cabin, a left rectangular medicine release port, a right fan-shaped medicine storage cabin and a right rectangular medicine release port. According to the soft drug-loaded capsule robot based on the magnetic liquid metal and the preparation and driving method of the soft drug-loaded capsule robot, a Helmholtz coil is used for generating a clockwise rotating composite magnetic field on a YZ plane, and anticlockwise rolling of a capsule is achieved through magnetic response of the magnetic liquid metal; the problem of limited energy supply of the micro-robot is solved through driving of an external magnetic field, and movement in any direction and accurate positioning are supported; the gelatin sealing sleeve is melted through external laser irradiation, and instant release of the medicine is achieved (suitable for emergency treatment).

The invention discloses a Helmholtz coil material lightning magnetic field shielding performance measuring device, which comprises a magnetic field generation device, a shielding test box is arranged in a magnetic field coverage range of the magnetic field generation device, an open hole is formed in the shielding test box, and the open hole enables a magnetic line of force of the magnetic field generation device to transversely penetrate through the shielding test box. The shielding test box is internally provided with the signal measurement unit, the signal measurement unit measures the magnetic field in the shielding test box, the lightning stroke magnetic field environment is accurately simulated, and the repeatability and accuracy of the shielding performance test are improved. The invention further discloses a method for measuring the lightning magnetic field shielding performance of the Helmholtz coil material, the lightning magnetic field shielding performance of the measured shielding material is measured by applying the device for measuring the lightning magnetic field shielding performance of the Helmholtz coil material, and the problem that traditional measurement is poor in accuracy is effectively solved.

The invention belongs to the technical field of scale inhibition and descaling, and particularly relates to an electromagnetic decontamination device based on a three-dimensional Helmholtz coil, which comprises a sine wave driving circuit, a pipeline and the three-dimensional Helmholtz coil sleeved at the center of the outer side of the pipeline, the sine wave driving circuit is connected with the three-dimensional Helmholtz coil, and the three-dimensional Helmholtz coil is connected with the pipeline. The three-dimensional Helmholtz coil is used for changing the magnitude of driving currents passing through the X direction, the Y direction and the Z direction of the three-dimensional Helmholtz coil, so that the three-dimensional Helmholtz coil generates a three-dimensional space magnetic field which is globally uniform and controllable in size and direction. The three-dimensional space magnetic field completely covers fluid in the range of the coil, deformation and vibration effects are generated on large water molecules, hydrogen bonds are bent and broken, the large water molecules are promoted to be dissociated into high-activity small molecules, and the dissolving capacity of water to scale component substances such as calcium carbonate is enhanced. Meanwhile, scale forming component ions can form new crystal nucleuses wrapped by active water molecules, the possibility of forming large particles is reduced, and direct scaling on the wall surface is reduced.

The application discloses a geomagnetic vector measurement system compensation method based on a three-dimensional helmholtz coil, and steps include: S01. Constructing a geomagnetic vector measurement system interference magnetic field compensation model; S02. Placing the geomagnetic vector measurement system in the center region of the three-dimensional helmholtz coil, and generating magnetic field data of different directions and different sizes through the three-dimensional helmholtz coil, so as to obtain multiple groups of measurement data, wherein the measurement data include output values of three-axis magnetic field sensors, true values generated by the three-dimensional helmholtz coil and a change rate of the true values generated by the three-dimensional helmholtz coil with time; S03. Obtaining an error model equation group according to the data obtained in the step S02 and the geomagnetic vector measurement system interference magnetic field compensation model; and S04. Solving parameters in the error model equation group, and compensating the magnetic interference field of the geomagnetic vector measurement system by using the solved parameters. The application has the advantages of simple operation, low cost, high compensation precision, strong flexibility and the like.

The invention provides an electromagnetic field constraint system and constraint method for a CO2 laser amplifier, and the system comprises a spiral electrode which is wound on a discharge tube of the CO2 laser amplifier, the spiral electrode comprises a first DC positive electrode, a radio frequency positive electrode, a second DC positive electrode and a ground electrode which are sequentially and adjacently arranged, and the current flows through the first DC positive electrode in the electric field direction from the first DC positive electrode to the ground electrode. The electric field direction of the current from the second direct current positive electrode to the ground electrode is partially perpendicular to the electric field direction of the current from the radio frequency positive electrode to the ground electrode; the CO2 laser amplifier discharge tube and the Helmholtz coil are coaxially arranged, and the magnetic field direction of the Helmholtz coil is perpendicular to the electric field direction from the radio frequency positive electrode to the ground electrode. In the discharge area of the CO2 laser amplifier, the strong electromagnetic field restraint system is adopted, the vertical alternating high-voltage electric field and the vertical alternating high-voltage magnetic field are used for restraining plasma movement, the electro-optical conversion efficiency can reach about 20%, the CO2 laser power can be effectively improved, and the arc discharge problem under the high radio frequency power injection condition is avoided.

The Helmholtz coil structure comprises a plurality of coils and a plurality of plate bodies, the plurality of coils are correspondingly arranged on the plurality of plate bodies, the plurality of plate bodies are in a split plug-in type, the plurality of coils are connected with one another in pairs and are coaxially arranged in parallel through the plate bodies, and the plurality of plate bodies are connected with the plurality of coils in a split plug-in type. And the plurality of groups of parallel plate bodies are inserted and connected to form a polyhedral structure, so that the plurality of groups of coils act together to establish a magnetic field which is perpendicular to each other in three directions in the space of the inner cavity of the polyhedron. According to the Helmholtz coil structure provided by the embodiment of the utility model, the plurality of plate body split bodies form a three-dimensional structure, so that the stability of the coil after connection can be improved, the stability of magnetic field distribution is further improved, and the Helmholtz coil structure is convenient to assemble.

The invention provides a calibration device and a calibration method, and the calibration device comprises a low-temperature device which is used for containing low-temperature liquid to provide a low-temperature environment; the sensor is arranged in the low-temperature device, comprises at least one three-dimensional gradiometer and is used for measuring a magnetic field and obtaining a voltage amplitude; the coil array is arranged below the low-temperature device and comprises a first coil and a plurality of second coils, and the second coils are arranged in the first coil and used for sequentially generating magnetic fields under the action of the excitation signals; the excitation module is electrically connected with the coil array and used for sequentially applying excitation signals to the coils in the coil array and detecting the magnitude of the excitation signals applied to the coils to obtain detection values; and the processing module is electrically connected with the sensor and the excitation module and is used for realizing coefficient calibration of the three-dimensional gradiometer according to the voltage amplitude and the detection value. The problems that an existing calibration mode using a large Helmholtz coil is inconvenient to operate and cannot be carried out in a shielded room are solved.

Method for testing a measurement object (1) with three-dimensional inductive receiving elements (2, 3, 4), characterized in that a Helmholtz coil having a coil pair (6, 7) is used to generate a magnetic field (8), that the measurement object (1) to be tested is arranged in the substantially constant homogeneous magnetic field (8) between the coil pair (6, 7), and that the measurement object (1) is arranged with respect to the three substantially perpendicular axis directions (x, y, z) of the Helmholtz coil (6, 7) such that the three-dimensional receiving elements (2, 3, 4) are each substantially tilted by 45° to the axis directions (x, y, z).