AGM device

Abstract

The utility model discloses an AGM (Absorbed Glass Mat) device, which comprises a bracket, a laser vibration meter positioned beside the bracket, a sample fixing structure arranged on the bracket, a magnet exciting coil arranged around the sample fixing structure and a pole head piece arranged on the magnet exciting coil, and an avoiding structure used for avoiding laser emitted by the laser vibration meter is arranged on the pole head piece; laser emitted by the laser vibration meter penetrates through the magnet exciting coil and the pole head piece to irradiate the sample structure, and vibration of the sample fixing structure is detected. According to the utility model, through the avoiding structure, the vibration of the sample fixing structure can be directly detected through the laser vibration meter, so that vibration detection errors are avoided, error accumulation during calculation is reduced, and the measurement precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of alternating gradient magnetometers, in particular to an AGM device. Background Art

[0002] Alternating Gradient Magnetometer (AGM) is a test method that characterizes the magnetic properties of magnetic materials by measuring the force exerted on them in a magnetic field. It features high measurement accuracy and fast response speed, and can achieve a good signal-to-noise ratio and complete testing in an alternating magnetic field. It is primarily used to measure how the magnetic moment of a material changes with the external magnetic field and temperature, and is particularly suitable for magnetic measurement and research of thin films and other weak signal materials.

[0003] Because the vibrations of the object being measured are extremely small, and the object must be placed in a gradient magnetic field, two excitation devices, electromagnets and gradient coils, are required to generate the corresponding magnetic field. The space near the object being measured is limited, making it impossible to place a vibration measurement device. Therefore, in the prior art, the object being measured is placed in the magnetic field using a sample rod. The vibration of the sample rod is then amplified using the rod's vibrations. A piezoelectric ceramic or bimorph sensor, such as a piezoelectric ceramic, located at one end of the rod, then converts the force signal sensed by the sensor into an electrical signal, from which the magnetization intensity of the sample is calculated. However, this method is computationally complex and prone to errors, which can accumulate and severely affect measurement accuracy.

[0004] Therefore, providing an AGM device with high measurement accuracy is a technical problem that urgently needs to be solved. Utility Model Content

[0005] The purpose of the utility model is to provide an AGM device to solve the problems of poor measurement accuracy, easy occurrence of measurement errors and error accumulation in the existing AGM devices in the background technology.

[0006] In order to achieve the above-mentioned objectives, the utility model proposes an AGM device, comprising a bracket, a laser vibrometer, a sample fixing structure, an excitation coil, and a pole piece; the laser vibrometer is located on the side of the bracket, and the laser emitted by the laser vibrometer penetrates the excitation coil and the pole piece and irradiates the sample fixing structure to detect the vibration of the sample fixing structure; the excitation coil is arranged around the sample fixing structure and is used to generate a magnetic field; the pole piece is connected to the excitation coil so that the magnetic field generated by the excitation coil extends toward the sample fixing structure; the pole piece is provided with an avoidance structure for avoiding the laser vibrometer so that the laser emitted by the laser vibrometer can irradiate the sample fixing structure.

[0007] Optionally, the sample fixing structure includes a first translation stage, a sample rod, a sample holder and a reflector.

[0008] Optionally, the first translation stage is mounted on the bracket, the sample holder is mounted on the first translation stage, the sample holder is mounted on the sample holder, and the reflector is mounted on the sample holder. The reflector can reflect the laser emitted by the laser vibrometer, and the reflected light is irradiated onto the laser vibrometer through the avoidance structure on the pole head.

[0009] Optionally, the avoidance structure consists of at least one through hole and is arranged through the pole piece.

[0010] Optionally, the laser vibrometer is provided with a receiver and a second translation stage. The receiver is used to receive reflected light formed by the laser vibrometer irradiating the sample fixing structure, and the second translation stage is used to drive the laser vibrometer to adjust its position.

[0011] Optionally, the laser vibrometer is provided with a receiver, and the line connecting the position point where the laser emitted by the laser vibrometer irradiates the sample fixing structure and the edge of the effective receiving surface of the receiver is a light zone, and the two ends of the pole head are used as dividing interfaces to divide the light zone into a near reflection zone, a penetration zone and a near receiving zone; the penetration zone is accommodated in the space formed by the avoidance structure.

[0012] Optionally, there is at least one intersection between the avoidance structure and the edge of the penetration area, and a cross section perpendicular to the laser beam emitted by the laser vibrometer is made through the intersection, and the minimum distance between the cross section and the reflection plane of the sample fixing structure is , the distance between this cross section and the effective receiving surface on the receiver is , the minimum distance between the laser beam emitted by the laser vibrometer and the intersection point is , the minimum distance between the laser beam and the edge of the effective receiving surface is ,in, .

[0013] Optionally, an intersecting circle is formed between the edge of the penetrating light zone and the avoidance structure, and the laser beam emitted by the laser vibrometer passes through the center of the intersecting circle.

[0014] Optionally, the pole head piece is an integrated structure.

[0015] Optionally, the pole head component is formed by connecting a plurality of pole head sub-components.

[0016] Optionally, the avoidance structure includes at least one through hole.

[0017] Optionally, a through hole is provided on the pole head member of the integral structure.

[0018] Optionally, a plurality of the pole head components are provided with through holes, and the avoidance structure is composed of the through holes of the plurality of pole head components.

[0019] Optionally, the through hole can be a straight hole, a tapered hole, a stepped hole or a compound hole. It should be noted that the compound hole represents a combination of multiple holes; an end face circle with a diameter of 0.5mm~20mm is formed between the through hole and the end face of the pole head piece facing the sample fixing structure. By limiting the diameter of the end face circle, the area of the end face of the pole head piece facing the sample fixing structure is ensured, thereby ensuring the uniformity of the magnetic field.

[0020] Compared with the prior art, the present invention provides an AGM device with the following beneficial effects:

[0021] The AGM device utilizes an avoidance structure to detect the vibration of the sample fixing structure using a laser vibrometer. Compared to existing methods of detecting the vibration of the sample rod using piezoelectric ceramics or bimorphs, the laser vibrometer used in this application has higher accuracy than existing detection methods, thereby improving measurement accuracy and reducing error accumulation.

[0022] It should be noted that the laser vibrometer of the present application can directly detect the vibration of the object being measured, thereby further improving the detection accuracy and avoiding the accumulated error caused by inferring the vibration of the object being measured through the sample rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0024] Figure 2 This is a schematic diagram of the laser receiver receiving the reflected light from the sample structure in Example 1 of the present utility model.

[0025] Figure 3 This is a schematic diagram of the laser receiver receiving the reflected light from the sample structure in Example 2 of the present utility model.

[0026] Figure 4 This is a schematic diagram of the laser receiver in Example 3 of the present utility model receiving the reflected light from the sample structure.

[0027] Figure 5 This is a schematic diagram of the laser receiver in Example 4 of the present utility model receiving the reflected light from the sample structure.

[0028] Figure 6 This is a schematic diagram of the laser receiver in Example 5 of the present utility model receiving the reflected light from the sample structure.

[0029] Figure 7 This is a schematic diagram of a laser receiver receiving light reflected from a sample structure when multiple through holes are straight holes with the same diameter in Example 6 of the present invention.

[0030] Figure 8 This is a schematic diagram of a laser receiver receiving light reflected from a sample structure when the multiple through holes are straight holes with different diameters in Example 6 of the present invention.

[0031] Figure 9 This is a schematic diagram of a laser receiver receiving light reflected from a sample structure when multiple through holes in Example 6 of the present invention are a combination of straight holes and tapered holes with the same diameter.

[0032] Figure 10 This is a schematic diagram of a laser receiver receiving light reflected from a sample structure when all of the multiple through holes are tapered holes in Example 6 of the present invention.

[0033] Figure 11 This is a schematic diagram of a laser receiver receiving light reflected from a sample structure when the plurality of through holes in Example 6 of the present invention are a combination of straight holes and tapered holes of different diameters.

[0034] Markings in the figure: 100, bracket; 200, laser vibrometer; 210, receiver; 220, second translation stage; 300, sample fixing structure; 310, first translation stage; 320, sample rod; 330, sample holder; 340, reflector; 400, excitation coil; 500, pole piece; 510, pole sub-component; 600, avoidance structure; 610, through hole; 700, light area; 710, near reflection area; 720, penetration area; 730, near receiving area. DETAILED DESCRIPTION

[0035] The following is a detailed description of the present invention in conjunction with the accompanying drawings and specific implementations. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] An AGM device of the present application can be applied to occasions such as magnetic measurement and research, and of course can also be used in other similar application scenarios. An AGM device is described in detail below.

[0037] Example 1

[0038] See attached Figure 1 and Figure 2FIG2 is a schematic diagram illustrating the structure of an embodiment of an AGM device according to the present application. The AGM device comprises a bracket 100, a laser vibrometer 200 positioned adjacent to the bracket 100, an excitation coil 400 disposed around a sample securing structure 300, a pole piece 500 connected to the excitation coil 400, and a relief structure 600 disposed on the pole piece 500. The relief structure 600 is used to avoid the laser vibrometer 200, allowing the laser beam emitted by the laser vibrometer to strike the sample securing structure 300. It should be noted that the excitation coil 400 has holes that do not block the laser beam emitted by the laser vibrometer 200. However, the laser vibrometer 200 is conventional and is not improved in this application, so it will not be described in detail.

[0039] The present invention places the object to be measured on the sample fixing structure 300 so that the object to be measured is located between multiple pole pieces 500. The excitation coil 400 and the pole piece 500 cooperate to generate a gradient magnetic field for the object to be measured, causing the object to vibrate. While the object to be measured is vibrating, the laser vibrometer 200 irradiates the laser beam on the sample fixing structure 300. Then, due to the vibration of the sample fixing structure 300, the reflected light carries the vibration information of the sample fixing structure, thereby obtaining the vibration information of the sample fixing structure 300. Compared with the existing method of detecting the vibration information of the sample fixing structure 300 by using piezoelectric ceramics, the present invention is more convenient than the conventional method of detecting the vibration information of the sample fixing structure 300 by using piezoelectric ceramics. The laser vibrometer 200 utilizes a non-contact measurement method, a highly sensitive photoelectric detector, and advanced signal processing technology to achieve higher-precision vibration measurement. However, due to the limited space near the object being measured, the laser vibrometer cannot be placed there. Therefore, this application utilizes a relief structure 600 to allow the laser beam emitted by the laser vibrometer 200 to pass through the excitation coil 400 and the pole piece 500 and illuminate the sample fixing structure 300, allowing the laser vibrometer 200 to detect the vibration of the sample fixing structure 300, thereby improving the accuracy of vibration detection of the object being measured and the accuracy of magnetic detection of the object being measured. It should be noted that in this application, the relief structure 600 only needs to be provided on the pole piece 500 located between the sample fixing structure 300 and the laser vibrometer 200.

[0040] See attached Figure 1 and Figure 2As shown, in the present invention, the sample fixing structure 300 includes a first translation stage 310 mounted on the top of the bracket 100, a sample holder 320 mounted on the first translation stage 310, a sample holder 330 mounted on the sample holder 320, and a reflector 340 mounted on the sample holder 330. The reflector 340 reflects the laser beam emitted by the laser vibrometer 200 to form a reflected beam. This reflected beam is then reflected to the laser vibrometer 200 by the avoidance structure 600 on the pole piece 500. It should be noted that the reflector 340 can be a light-reflecting object such as a mirror or reflective film.

[0041] The present invention utilizes the first translation stage 310 to drive the sample holder 320 to move vertically and horizontally, thereby adjusting the positions of the sample holder 320 and the sample holder 330. This allows the laser beam emitted by the laser vibrometer 200 to illuminate the sample holder 320 or the reflector 340, thereby detecting the vibration of the object being measured. The present invention utilizes the reflector 340 to enhance the reflectivity of the laser beam at the object being measured, thereby improving the detection accuracy of the laser vibrometer 200. Furthermore, the present invention can detect the vibration of the reflector 340, thereby directly determining the vibration condition of the sample carried on the sample holder 330, thereby reducing errors in sample vibration calculations.

[0042] See attached Figure 1 and Figure 2 As shown, in the present invention, a receiver 210 and a second translation stage 220 are provided on the laser vibrometer 200. The receiver 210 is used to receive the light reflected by the sample fixing structure 300 irradiated by the laser vibrometer 200, and the second translation stage 220 is used to drive the laser vibrometer 200 to adjust its position.

[0043] The present invention is configured to receive the reflected laser beam through the receiver 210 ; the second displacement stage 220 can drive the laser vibrometer 200 to move, so that the laser beam emitted by the laser vibrometer 200 can be irradiated on the sample fixing structure 300 .

[0044] See attached Figure 1 and Figure 2 As shown, in the present invention, the line connecting the point where the laser emitted by the laser vibrometer 200 irradiates the sample fixing structure 300 and the edge of the effective receiving surface of the receiver 210 is a light zone 700. The two ends of the pole piece 500 are used as the dividing interface, and the light zone 700 is divided into a near-reflection zone 710, a penetration zone 720 and a near-receiving zone 730; the penetration zone 720 is accommodated in the space formed by the avoidance structure 600.

[0045] The present invention forms a light zone 700 from all the motion trajectories of the laser beam emitted from the laser vibrometer 200 to the laser beam reflected onto the effective receiving surface. The light zone 700 is then divided into a near-reflection zone 710, a through zone 720, and a near-receiving zone 730 using the two end surfaces of the pole piece 500 as dividing interfaces. The space formed by the through zone 720 and the avoidance structure 600 is compared to ensure that the avoidance structure 600 does not block the trajectory of the laser beam in the through zone 720, and ensure that all reflected lasers within the through zone 720 can be reflected onto the effective receiving surface of the receiver 210, thereby ensuring that the vibration of the sample fixing structure 300 can be detected.

[0046] See attached Figure 1 and Figure 2 As shown, in the present invention, there is at least one intersection between the avoidance structure 600 and the edge of the through-zone 720. A cross section perpendicular to the laser beam emitted by the laser vibrometer 200 is made through the intersection, and the minimum distance between the cross section and the reflection plane of the sample fixing structure 300 is , the distance between the cross section and the effective receiving surface on the receiver 210 is , the minimum distance between the laser beam emitted by the laser vibrometer 200 and the intersection point is , the minimum distance between the laser beam and the edge of the effective receiving surface is ,in, It should be noted that an end face circle with a diameter of 0.5 mm to 20 mm is formed between the through hole 610 and the end face of the pole piece 500 facing the sample fixing structure 300.

[0047] The utility model is through 、 、 and The relationship between the two is defined, thereby limiting the size of the through hole 610. Specifically, the minimum distance from the edge of the effective receiving surface on the receiver 210 to the laser beam is fixed by the receiver 210. Therefore, The value is fixed, and the minimum distance between the reflecting plane and the receiver 210 is fixed, so and The sum is fixed, at this time, only need to 、 、 It is sufficient to confirm two values among the three, and all three are related to the dividing circle, so it is only necessary to confirm the intersection position. At this time, the minimum size of the through hole 610 can be determined, so that the pole head piece 500 can be processed and the laser beam emitted by the laser vibrometer 200 can be avoided; by limiting the end face circle diameter, the area of the end face of the pole head piece 500 facing the sample fixing structure 300 is avoided, thereby ensuring the uniformity of the magnetic field and the accuracy of the magnetic moment measurement of the object being measured.

[0048] See attached Figure 1 and Figure 2 As shown, in the present invention, when the pole piece 500 is an integral structure, the avoidance structure 600 is a through hole 610 provided on the pole piece 500. When the through hole 610 is a straight hole, the diameter of the through hole 610 is the same everywhere. is a fixed value, and since the through hole 610 is a straight hole, after the sample fixing structure 300 and the laser vibrometer 200 are fixed in their installation positions, and The sum of is a fixed value, and since the through hole 610 is a straight hole, the through area 720 is accommodated in the through hole 610, The value of is the distance from the end face of the pole piece 500 away from the sample fixing structure 300 to the reflection plane. The value of can also be confirmed in 、 and When the value is determined, it can be calculated The value of .

[0049] Example 2

[0050] See attached Figure 3 As shown, the difference between this embodiment and embodiment 1 is that in this embodiment, the through hole 610 is set as a stepped hole, and the plane where the pole head piece 500 contacts the excitation coil 400 is used as the processing plane, the top hole with the largest aperture is processed, and then the aperture is gradually reduced for processing until the pole head piece 500 is penetrated.

[0051] In this embodiment, the connecting hole 610 is set as a stepped hole. Compared with a straight hole, the stepped hole can effectively reduce the aperture on the end face of the pole head 500 facing the sample fixing structure 300, increase the area on the end face of the pole head 500 facing the sample fixing structure 300, and improve the accuracy of the magnetic moment detection of the object under test.

[0052] Example 3

[0053] See attached Figure 4 As shown, the difference between this embodiment and the above embodiment is that the through hole 610 in this embodiment is a stepped hole and a tapered hole arranged in combination, that is, the end of the pole head piece 500 close to the excitation coil 400 is a processing plane, the stepped hole is processed first, and the tapered hole is processed at the bottom of the stepped hole, and the pole head piece 500 is passed through the tapered hole.

[0054] This embodiment combines a stepped hole with a tapered hole, passing the end of the stepped hole through the tapered hole. Compared to passing through the entire stepped hole, this effectively reduces the aperture on the end face of the pole head 500 facing the sample fixing structure 300, increases the area on the end face of the pole head 500 facing the sample fixing structure 300, and improves the accuracy of the magnetic moment detection of the object being measured. It should be noted that the through hole 610 in this embodiment can also be provided by combining a stepped hole, a straight hole, and a tapered hole.

[0055] Example 4

[0056] See attached Figure 5 As shown, the difference between this embodiment and the above embodiment is that the through hole 610 in this embodiment is a conical hole, and the processing direction of the conical hole is the same as the direction of the pole head 500 pointing to the sample fixing structure 300, that is, the cone head of the conical hole faces the sample fixing structure 300, and the cone bottom faces the laser vibrometer 200.

[0057] In this embodiment, the through hole 610 is set as a tapered hole. Compared with the straight hole in the above embodiment, the setting of the tapered hole can effectively reduce the aperture of the end face of the pole head 500 facing the sample fixing structure 300 and increase the area of the end face of the pole head 500 facing the sample fixing structure 300. Compared with the stepped hole, the volume of the pole head 500 processed and milled can be effectively reduced, thereby further improving the accuracy of the magnetic moment detection of the object under test.

[0058] Example 5

[0059] See attached Figure 6 As shown, the difference between this embodiment and the above embodiments is that, in this embodiment, the through hole 610 is formed by a straight hole and a tapered hole. Specifically, the plane where the pole head 500 contacts the excitation coil 400 is used as the processing plane, and the straight hole is processed first and then the tapered hole. This reduces the processing difficulty of the tapered hole, improves the processing efficiency, ensures the processing accuracy of the through hole 610, and can effectively reduce the aperture on the end face of the pole head 500 facing the sample fixing structure 300, increase the area on the end face of the pole head 500 facing the sample fixing structure 300, and improve the accuracy of the magnetic moment detection of the object being measured.

[0060] Example 6

[0061] See attached Figure 7 — Figure 11 As shown, the difference between this embodiment and the above embodiments is that in this embodiment, the pole head component 500 is formed by connecting multiple pole head sub-components 510, and the avoidance structure 600 is composed of multiple through holes 610. Specifically, the number of through holes 610 is the same as the number of pole head sub-components 510, that is, each pole head sub-component 510 is provided with a through hole 610, and each through hole 610 can be any one of a straight hole, a tapered hole, and a stepped hole.

[0062] This embodiment reduces the difficulty of processing the through hole 610 by configuring the pole head component 500 to be composed of multiple pole head sub-components 510, and facilitates the processing of the through hole 610. Simply put, multiple pole head sub-components 510 are connected to form the pole head component 500 in any embodiment of Example 1 to Example 5.

[0063] The above embodiments are intended to illustrate the present application, not to limit the present application. Any solution that is a simple transformation of the present application falls within the scope of protection of the present application.

Claims

1. An AGM device, characterized in that: It includes a bracket (100), a laser vibrometer (200), a sample fixing structure (300), an excitation coil (400), and a pole piece (500); The laser vibrometer (200) is located beside the bracket (100), and the laser emitted by the laser vibrometer (200) penetrates the excitation coil (400) and the pole piece (500) and irradiates the sample fixing structure (300), thereby detecting the vibration of the sample fixing structure (300); The excitation coil (400) is arranged around the sample fixing structure (300), and the excitation coil is used to generate a magnetic field; The pole piece (500) is connected to the excitation coil (400), so that the magnetic field generated by the excitation coil (400) extends toward the sample fixing structure (300); The pole piece (500) is provided with an avoidance structure (600) for avoiding the laser vibrometer (200) so that the laser emitted by the laser vibrometer can be irradiated on the sample fixing structure (300).

2. The AGM device according to claim 1, characterized in that The sample fixing structure (300) comprises a first displacement stage (310), a sample rod (320), a sample holder (330), and a reflector (340); The first displacement stage (310) is mounted on the bracket (100), the sample rod (320) is mounted on the first displacement stage (310), the sample holder (330) is mounted on the sample rod (320), and the reflector (340) is mounted on the sample holder (330). The reflector (340) can reflect the laser emitted by the laser vibrometer (200), and the reflected light formed by the reflection is irradiated onto the laser vibrometer (200) through the avoidance structure (600) on the pole head (500).

3. The AGM device according to claim 1, characterized in that The laser vibrometer (200) is provided with a receiver (210) and a second displacement stage (220). The receiver (210) is used to receive reflected light formed by the laser vibrometer (200) irradiating the sample fixing structure (300). The second displacement stage (220) is used to drive the laser vibrometer (200) to adjust its position.

4. The AGM device according to claim 1, characterized in that The laser vibrometer (200) is provided with a receiver (210), and the line connecting the position where the laser emitted by the laser vibrometer (200) irradiates the sample fixing structure (300) and the edge of the effective receiving surface of the receiver (210) is a light zone (700), and the two ends of the pole head (500) are used as the dividing interface, and the light zone (700) is divided into a near reflection zone (710), a penetration zone (720) and a near receiving zone (730); The penetration area (720) is accommodated in the space formed by the avoidance structure (600).

5. The AGM device according to claim 4, characterized in that There is at least one intersection between the avoidance structure (600) and the edge of the penetration area (720), and a cross section perpendicular to the laser beam emitted by the laser vibrometer (200) is made through the intersection, and the minimum distance between the cross section and the reflection plane of the sample fixing structure (300) is , the distance between the cross section and the effective receiving surface on the receiver (210) is , the minimum distance between the laser beam emitted by the laser vibrometer (200) and the intersection point is , the minimum distance between the laser beam and the edge of the effective receiving surface is ,in, .

6. The AGM device according to claim 5, characterized in that An intersecting circle is formed between the edge of the penetration zone (720) and the avoidance structure (600), and the laser beam emitted by the laser vibrometer (200) passes through the center of the intersecting circle.

7. The AGM device according to any one of claims 1 to 6, characterized in that: The avoidance structure (600) comprises at least one through hole (610); Furthermore, the pole piece (500) is an integral structure, or is formed by connecting a plurality of pole sub-pieces (510).

8. The AGM device according to claim 7, characterized in that The pole head piece (500) having an integral structure is provided with a through hole (610).

9. The AGM device according to claim 7, characterized in that A through hole (610) is provided on each of the plurality of pole head sub-components (510), and the avoidance structure (600) is composed of the through holes (610) of the plurality of pole head sub-components (510).

10. The AGM device according to claim 7, characterized in that The through hole (610) may be a straight hole, a tapered hole, a stepped hole or a composite hole.

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