Precise space magnetic field gradient testing method based on piezoelectric driving module
By using a piezoelectric driving module and a three-dimensional displacement stage to drive the Hall probe on the quadrupole magnet, the center and axis of the magnet are determined, and the magnetic field gradient test is carried out, the problem of low accuracy of the magnetic field gradient test in the prior art is solved, and a higher accuracy test effect is achieved.
Patent Information
- Application Number
- CN202411906321.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-05-02
AI Technical Summary
The prior art is difficult to accurately test the magnetic field gradient of quadrupole magnets, resulting in lower test accuracy.
The precision spatial magnetic field gradient test method based on the piezoelectric driving module is adopted. The Hall probe is driven to move on the test surface of the quadrupole magnet through a three-dimensional displacement stage, and the magnet center and axis are determined, and the magnetic field gradient test is selected appropriately on the axis.
It improves the accuracy of the magnetic field gradient test of quadrupole magnets, is suitable for industrial applications, and meets the requirements for quadrupole magnets with large magnetic field gradients.
Smart Images
Figure CN119916267A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of space safety, and in particular relates to a testing method for accurately testing the spatial magnetic field gradient within a quadrupole magnet. Background Art
[0002] There is a background magnetic field in the space environment, and there is a charge effect inside the beam. When the beam is transmitted in the space environment, in order to ensure the density of the far-end beam to the target, the beam should be regulated at the exit of the accelerator tube to obtain a nearly parallel beam with low spatial charge density. Multi-pole magnets such as quadrupole magnets, dipole magnets, and octupole magnets are typical electron beam modulation lenses. Researchers can control the beam through magnetic lenses.
[0003] In order to obtain a more precise control effect, it is necessary to conduct detailed tests on the physical parameters of various multi-pole magnets. Considering space applications, when the quadrupole magnet is small in size and light in weight, it is difficult to achieve uniform gradient fields. It is necessary to conduct gradient tests at different positions of the magnet, resulting in a large amount of test data and difficulty in ensuring spatial position accuracy. Existing test methods are difficult to meet the testing needs of some quadrupole magnets with large magnetic field gradients, resulting in low test accuracy. Summary of the invention
[0004] The purpose of the present invention is to provide a method for accurately testing the spatial magnetic field gradient of a quadrupole magnet, so as to solve the problem of low accuracy of quadrupole magnet gradient testing in the prior art.
[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:
[0006] A method for testing a precision spatial magnetic field gradient based on a piezoelectric drive module comprises the following steps:
[0007] Step 1, using a three-dimensional translation stage to drive the Hall probe to move on the test surface of the quadrupole magnet to be tested, and determining the magnet center of the quadrupole magnet to be tested;
[0008] Step 2, according to the magnet center of the quadrupole magnet to be tested, use a three-dimensional translation stage to drive the Hall probe to perform multiple rotation tests on the inner circle of the quadrupole magnet to be tested, thereby determining the axis of the quadrupole magnet to be tested;
[0009] Step 3, select three points on the axis of the quadrupole magnet to be tested whose difference does not exceed the gradient value of the random error of the Hall probe and take the average value to obtain the gradient value of the quadrupole magnet to be tested.
[0010] The present invention also has the following features:
[0011] Furthermore, in step 1, the test surface is a plane of the inner ring of the quadrupole magnet to be tested that is perpendicular to the central axis;
[0012] When determining the magnet center of the quadrupole magnet to be tested, the Hall probe is driven to move on the test surface of the quadrupole magnet to be tested by a three-dimensional translation stage, and then the magnetic field strength at each position of the test surface is tested, and four points with magnetic fields closest to zero are selected, and the center point of these four points is taken as the magnet center of the quadrupole magnet to be tested.
[0013] Further, in step 2, the center of the magnet of the quadrupole magnet to be tested is taken as the center of the circle, and an arbitrary length is taken as the radius;
[0014] When the Hall probe is driven by a three-dimensional translation stage to perform a rotation test on the test surface of the quadrupole magnet to be tested, a point with a magnetic field component only in the radial direction is selected;
[0015] Repeat the above operation to perform multiple rotation tests. Change the length of the radius in each rotation test to obtain multiple points with magnetic field components only in the radial direction. Connect all the points obtained, and the obtained axis is the axis of the quadrupole magnet to be tested.
[0016] Furthermore, in both step 1 and step 2, the Hall probe is driven to move in the form of a composite drive of a three-dimensional translation stage and a piezoelectric drive device.
[0017] Furthermore, the three-dimensional translation stage adopts a non-magnetic lead screw as a driving shaft, and the piezoelectric driving device adopts a two-dimensional piezoelectric stick-slip driving stage.
[0018] Furthermore, the linear positioning accuracy of the three-dimensional translation stage is less than or equal to 0.03 mm, and the motion range is greater than 300 mm × 300 mm × 1000 mm;
[0019] The driving mass of the two-dimensional piezoelectric stick-slip driving stage is greater than or equal to 10g, the positioning accuracy should be less than or equal to 1 micron, and the motion range is greater than 5mm×5mm.
[0020] Furthermore, the Hall probe adopts a gallium arsenide Hall probe chip.
[0021] Furthermore, the Hall probe test accuracy is less than or equal to 10 μT, the active area is less than or equal to 0.1 mm, and the mass after packaging is less than 10 g.
[0022] Compared with the prior art, the present invention has the following technical effects:
[0023] The present invention provides a method for precisely testing the magnetic field gradient in the space of a quadrupole magnet. The method aims to solve the problems that the current test data volume of a quadrupole magnet is large and difficult to test, and the traditional three-dimensional mobile platform is not accurate enough, resulting in insufficient final test accuracy. A method for precisely testing the magnetic field gradient in a quadrupole magnet is proposed. The Hall probe is driven by a composite mode of a three-dimensional translation stage and a piezoelectric drive module to achieve precise movement in three-dimensional space. The magnetic axis position of the quadrupole magnet is quickly obtained through regional point-taking testing. The probe is then precisely moved on the magnetic field axis to test and obtain the magnetic field gradient of the quadrupole magnet. In addition, the Hall probe is driven by a composite of a three-dimensional translation stage and a piezoelectric drive device to enhance the movement accuracy of the Hall probe. While the test process is convenient, the accuracy of the gradient test is effectively improved, which is suitable for industrial use and promotion. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is a schematic diagram of the distribution of magnetic poles and magnetic field directions of a quadrupole magnet in one embodiment of the present invention;
[0025] Figure 2 It is a diagram showing the dimensions of the active area of the Hall chip and the internal structure of the three-dimensional Hall chip package in one embodiment of the present invention. DETAILED DESCRIPTION
[0026] It should be noted that all components in the present invention, unless otherwise specified, are components known in the prior art. For example, the three-dimensional translation stage and the piezoelectric drive device are both known and commonly used devices.
[0027] All methods in the present invention, unless otherwise specified, are methods known in the prior art, such as a method of composite driving of a three-dimensional translation stage and a piezoelectric drive device, which is a known method.
[0028] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.
[0029] A method for testing a precision spatial magnetic field gradient based on a piezoelectric drive module comprises the following steps:
[0030] Step 1: Use a three-dimensional translation stage to drive the Hall probe to move on the test surface of the quadrupole magnet to be tested, and determine the magnet center of the quadrupole magnet to be tested; the schematic diagram of the distribution of the magnetic poles and magnetic field direction of the quadrupole magnet is as shown in Figure 1 As shown;
[0031] The magnetic field distribution of the quadrupole magnet determines that when the Hall probe is rotating, only when the Hall probe moves to the magnetic axis can only the magnetic field component in the radial direction be measured.
[0032] Step 2, according to the magnet center of the quadrupole magnet to be tested, use a three-dimensional translation stage to drive the Hall probe to perform multiple rotation tests on the inner circle of the quadrupole magnet to be tested, thereby determining the axis of the quadrupole magnet to be tested;
[0033] Step 3, select three points on the axis of the quadrupole magnet to be tested whose difference does not exceed the gradient value of the random error of the Hall probe and take the average value to obtain the gradient value of the quadrupole magnet.
[0034] Move the Hall probe to a point on the straight line where the magnetic axis is located, close to the center of the magnetic field, and use the three-dimensional translation stage to drive the Hall probe to move a certain distance along the magnetic axis away from the center of the magnetic field, and test the difference in magnetic field strength values at the two points. This difference can be recorded as the magnetic field gradient value at that point; continue to move the Hall probe twice at equal distances, repeat the above process, and obtain the magnetic field gradient values at three points. Calculate the average of these three values to get the magnetic field gradient test value of the quadrupole magnet.
[0035] In actual testing, the distance of each movement can be selected to be 0.05mm.
[0036] As a preferred solution, in step 1, the test surface is a plane of the inner ring of the quadrupole magnet to be tested that is perpendicular to the central axis;
[0037] When determining the magnet center of the quadrupole magnet to be tested, the Hall probe is driven to move on the test surface of the quadrupole magnet to be tested by a three-dimensional translation stage, and then the magnetic field strength at each position of the test surface is tested, and four points with magnetic fields closest to zero are selected, and the center point of these four points is taken as the magnet center of the quadrupole magnet to be tested.
[0038] As a preferred solution, in step 2, the center of the quadrupole magnet to be tested is taken as the center of the circle, and any length is taken as the radius;
[0039] Use a three-dimensional translation stage to drive the Hall probe to perform a rotation test on the test surface of the quadrupole magnet to be tested, and select points with magnetic field components only in the radial direction;
[0040] Repeat the above operation to perform multiple rotation tests. Change the length of the radius in each rotation test to obtain multiple points with magnetic field components only in the radial direction. Connect all the points, and the obtained axis is the axis of the quadrupole magnet to be tested.
[0041] Specifically, the linear positioning accuracy of the three-dimensional translation stage is less than or equal to 0.03 mm, and the motion range is greater than 300 mm × 300 mm × 1000 mm;
[0042] The driving mass of the two-dimensional piezoelectric stick-slip drive stage is greater than or equal to 10g, the positioning accuracy should be less than or equal to 1 micron, and the motion range is greater than 5mm×5mm.
[0043] As a preferred solution, the Hall probe uses a gallium arsenide Hall probe chip with a test accuracy of less than or equal to 10μT, an active area of less than or equal to 0.1mm, and a mass of less than 10g after packaging.
[0044] Further preferably, in both step 1 and step 2, the Hall probe is driven to move by a composite drive of a three-dimensional translation stage and a piezoelectric drive device.
[0045] The three-dimensional translation stage adopts a non-magnetic lead screw as a driving axis, and the piezoelectric drive device adopts a two-dimensional piezoelectric stick-slip drive stage.
[0046] A three-dimensional translation stage is used to move the Hall probe within a large range, and a piezoelectric drive device is used to achieve precise movement of the Hall probe. The combination of the two enhances the movement accuracy of the Hall probe, which not only facilitates the test process but also effectively improves the accuracy of the gradient test.
[0047] The Hall probe is a common device for testing the strength of a spatial magnetic field. This embodiment provides a specific selection of a gallium arsenide semiconductor chip, such as Figure 2 As shown in the figure, the size of the active area can be as low as 0.08mm, which effectively improves the spatial test accuracy. The positioning accuracy of the Hall probe can reach 0.03mm using a three-dimensional translation stage, and the movement accuracy achieved by the piezoelectric drive module can reach 1μm. Combining the two, the Hall probe can be moved in a linear direction with micron-level accuracy.
Claims
1. A precision spatial magnetic field gradient testing method based on a piezoelectric drive module, characterized in that: The following steps are involved: Step 1, using a three-dimensional translation stage to drive the Hall probe to move on the test surface of the quadrupole magnet to be tested, and determining the magnet center of the quadrupole magnet to be tested; Step 2, according to the magnet center of the quadrupole magnet to be tested, use a three-dimensional translation stage to drive the Hall probe to perform multiple rotation tests on the inner circle of the quadrupole magnet to be tested, thereby determining the axis of the quadrupole magnet to be tested; Step 3, select three points on the axis of the quadrupole magnet to be tested whose difference does not exceed the gradient value of the random error of the Hall probe and take the average value to obtain the gradient value of the quadrupole magnet to be tested.
2. The precise spatial magnetic field gradient testing method based on a piezoelectric drive module according to claim 1, characterized in that: In step 1, the test surface is a plane of the inner ring of the quadrupole magnet to be tested that is perpendicular to the central axis; When determining the magnet center of the quadrupole magnet to be tested, the Hall probe is driven to move on the test surface of the quadrupole magnet to be tested by a three-dimensional translation stage, and then the magnetic field strength at each position of the test surface is tested, and four points with magnetic fields closest to zero are selected, and the center point of these four points is taken as the magnet center of the quadrupole magnet to be tested.
3. The precise spatial magnetic field gradient testing method based on a piezoelectric drive module according to claim 2, characterized in that: In step 2, the center of the quadrupole magnet to be tested is taken as the center of the circle, and any length is taken as the radius; When the Hall probe is driven by a three-dimensional translation stage to perform a rotation test on the test surface of the quadrupole magnet to be tested, a point with a magnetic field component only in the radial direction is selected; Repeat the above operation to perform multiple rotation tests. Change the length of the radius in each rotation test to obtain multiple points with magnetic field components only in the radial direction. Connect all the points obtained, and the obtained axis is the axis of the quadrupole magnet to be tested.
4. The precise spatial magnetic field gradient testing method based on a piezoelectric drive module according to claim 1, characterized in that: In both step 1 and step 2, the Hall probe is driven to move by a composite drive of a three-dimensional translation stage and a piezoelectric drive device.
5. The precise spatial magnetic field gradient testing method based on a piezoelectric drive module according to claim 4, characterized in that: The three-dimensional displacement stage adopts a non-magnetic lead screw as a driving shaft, and the piezoelectric driving device adopts a two-dimensional piezoelectric stick-slip driving stage.
6. The precise spatial magnetic field gradient testing method based on a piezoelectric drive module according to claim 5, characterized in that: The linear positioning accuracy of the three-dimensional translation stage is less than or equal to 0.03 mm, and the motion range is greater than 300 mm × 300 mm × 1000 mm; The driving mass of the two-dimensional piezoelectric stick-slip driving stage is greater than or equal to 10g, the positioning accuracy should be less than or equal to 1 micron, and the motion range is greater than 5mm×5mm.
7. The precise spatial magnetic field gradient testing method based on a piezoelectric drive module according to claim 6, characterized in that: The Hall probe adopts a gallium arsenide Hall probe chip.
8. The method for testing the precise spatial magnetic field gradient based on a piezoelectric drive module according to claim 7, characterized in that: The Hall probe test accuracy is less than or equal to 10 μT, the active area is less than or equal to 0.1 mm, and the mass after packaging is less than 10 g.