A torsion pendulum magnetic field measuring device and measuring method

Abstract

The present invention relates to the field of precision measurement technology, and proposes a torsion pendulum magnetic field measurement device and measurement method. The device includes: a vacuum chamber, a torsion pendulum mechanism, a magnetic field generating mechanism, and a measuring mechanism, wherein: one end of the torsion pendulum mechanism can be rotatably fixed to the upper top of the vacuum chamber, and the other end is connected to a sub-centimeter-scale magnetic induction component; a reflector is provided between the magnetic induction component and the torsion pendulum mechanism; the magnetic field generating mechanism is provided around the magnetic induction component, and is used to generate an artificial magnetic field along the x-axis and / or along the y-axis; a vacuum optical window is provided on one side wall of the vacuum chamber; the measuring mechanism is provided outside the vacuum chamber, and is used to collect the torsion pendulum motion signal of the reflector through the vacuum optical window, and calculate the quality factor of the torsion pendulum mechanism in the vacuum based on the torsion pendulum motion signal. Q ; When the quality factor Q When it is the maximum value, the artificial magnetic field intensity currently generated by the magnetic field generating mechanism is the magnetic field intensity to be measured.

Description

Technical Field

[0001] The present invention relates to the field of precision measurement technology, and more particularly to a torsion pendulum magnetic field measuring device and a measuring method. Background Art

[0002] Magnetic field measurement is a scientific technique used by humans to observe and study magnetic phenomena. With the continuous advancement of science and technology, magnetic field measurement technology has penetrated into various fields such as precision measurement, biology, medicine, geophysics, and interstellar research. Therefore, the accurate measurement of magnetic fields is particularly important.

[0003] A magnetometer has been proposed. This involves installing an artificial magnetic field coil within a magnetic shielding tube, which, driven by an external current source, generates multiple stable magnetic fields along the y-axis. The object under test is placed on a turntable and rotated, and the magnetic field is measured using a magnetometer probe placed within the magnetic shielding tube. However, in the field of precision measurement, measuring larger magnetic fields is often necessary. Some magnetic field measurement instruments are no longer suitable due to their limited range and are unable to measure centimeter-scale magnetic fields in the precision measurement field. Furthermore, existing magnetic probes have a scale of several centimeters, resulting in low spatial resolution, which does not meet the requirements of precision measurement and is limited to certain special environments, such as high vacuum conditions. Summary of the Invention

[0004] In order to overcome the defects of the magnetic field measuring instruments described in the above-mentioned prior art that cannot measure the magnetic field in the sub-centimeter area in the field of precision measurement and have low measurement spatial resolution, the present invention provides a torsion pendulum magnetic field measuring device and measurement method.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A torsion pendulum magnetic field measuring device comprises a vacuum chamber, a torsion pendulum mechanism, a magnetic field generating mechanism, and a measuring mechanism, wherein:

[0007] One end of the wiggling mechanism is rotatably fixed to the upper ceiling of the vacuum chamber, and the other end is connected to a sub-centimeter-scale magnetic induction component; a reflector is provided between the magnetic induction component and the wiggling mechanism;

[0008] The magnetic field generating mechanism is arranged around the magnetic induction component and is used to generate an artificial magnetic field along the x-axis direction and / or along the y-axis direction;

[0009] A vacuum optical window is provided on one side wall of the vacuum chamber; the measuring mechanism is provided outside the vacuum chamber and is used to collect the wiggling motion signal of the reflector through the vacuum optical window and calculate the quality factor of the wiggling mechanism in vacuum according to the wiggling motion signal. Q ;

[0010] When the quality factor QWhen it is the maximum value, the artificial magnetic field intensity currently generated by the magnetic field generating mechanism is the magnetic field intensity to be measured.

[0011] In this technical solution, the magnetic induction element performs a torsional pendulum motion under the artificial magnetic field and the magnetic field to be measured. In conjunction with the rotation of the torsional pendulum mechanism, the torsional motion of the reflector above the magnetic induction element can be detected by the measuring mechanism. The measuring mechanism collects the torsional pendulum motion signal and uses it to calculate the quality factor of the torsional pendulum mechanism in a vacuum. Q Among them, when Q When it is at its maximum value, it indicates that the magnetic field to be measured and the artificial magnetic field cancel each other out. At this time, the artificial magnetic field intensity generated by the magnetic field generating mechanism is the magnetic field intensity to be measured.

[0012] As a preferred embodiment, the torsion mechanism includes a connecting member and a torsion wire, wherein one end of the connecting member can be rotatably fixed to the upper top of the vacuum chamber, and the other end is connected to one end of the torsion wire, and the other end of the torsion wire is connected to the reflector.

[0013] As a preferred solution, the connecting member includes a magnetic damper.

[0014] As a preferred solution, the magnetic induction component includes a copper cylinder; the reflector is arranged at the center of the end surface of the copper cylinder.

[0015] As a preferred solution, the end face diameter of the magnetic induction component is less than 1 cm and the height is less than 1 cm.

[0016] As a preferred embodiment, the magnetic field generating mechanism includes a first coil group C1 and C2 arranged along the x-axis direction with the magnetic induction element as the center, and a second coil group C3 and C4 arranged along the y-axis direction with the magnetic induction element as the center; the first coil group C1 and C2, and the second coil group C3 and C4 are respectively connected to a regulated current power supply arranged outside the vacuum chamber through a coil circuit.

[0017] As a preferred solution, the first coil groups C1 and C2, and the second coil groups C3 and C4 are respectively fixed by brackets.

[0018] As a preferred solution, the device further includes a controller; a first output terminal of the controller is connected to the magnetic field generating mechanism, and is used to output a current control signal to the magnetic field generating mechanism, and modulate the magnetic field strength of the artificial magnetic field by controlling the output current; an input terminal of the controller is connected to the output terminal of the measuring mechanism, and is used to continuously receive the quality factor output by the measuring mechanism. Q , and judge the current quality factor QIs it the maximum value? If so, output a stop signal to the magnetic field generating mechanism, record the current output current value, and calculate the magnetic field strength of the artificial magnetic field as the magnetic field measurement result; otherwise, modulate the current control signal.

[0019] As a preferred solution, the device further includes a display module, the input end of the display module is connected to the second output end of the controller, and is used to display the current magnetic field measurement result.

[0020] Furthermore, the present invention also proposes a measurement method, which uses the torsion pendulum magnetic field measurement device proposed in the present invention to perform measurement, including the following steps:

[0021] S1. Powering the magnetic field generating mechanism to generate an artificial magnetic field along the x-axis or y-axis direction. Bx or By ;

[0022] S2, control the torsion pendulum mechanism to twist, collect the torsional motion signal of the torsional motion of the reflector through the measuring mechanism, and obtain the amplitude attenuation coefficient, that is, obtain the amplitude attenuation coefficient in the artificial magnetic field. Bx or By Quality factor under Q ;

[0023] S3. Modulate the power supply current configuration of the magnetic field generating mechanism to record different artificial magnetic fields Bx or By Quality factor under Q , take the quality factor Q The artificial magnetic field at its maximum value Bx or By As a result of magnetic field measurement.

[0024] Compared with the prior art, the beneficial effects of the technical solution of the present invention are: the present invention connects a sub-centimeter-scale magnetic induction component to the torsion pendulum mechanism, and utilizes the quality factor of the vacuum torsion pendulum system. Q Relationship with external magnetic field, by modulating artificial magnetic field and corresponding quality factor Q , when the quality factor Q When the magnetic field is at its maximum, the magnetic field to be measured and the artificial magnetic field cancel each other out. At this time, the magnetic field strength of the artificial magnetic field is the magnetic field strength of the magnetic field to be measured, realizing the measurement of the magnetic field in the sub-centimeter area in the field of precision measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the torsion pendulum magnetic field measurement device of Example 1.

[0026] Figure 2 Schematic diagram of amplitude attenuation of the torsional pendulum motion in Example 1.

[0027] Figure 3 is the wiggling quality factor of Example 1 Q Relationship diagram with the modulated magnetic field.

[0028] Figure 4 This is a schematic structural diagram of the magnetic induction component of Example 1.

[0029] Figure 5 FIG. 4 is a structural diagram of the torsion pendulum magnetic field measurement device of Example 1.

[0030] Figure 6 This is a flow chart of the measurement method of Example 2.

[0031] Among them, 1-vacuum chamber, 11-vacuum optical window, 2-torsion pendulum mechanism, 21-magnetic induction component, 22-reflecting mirror, 23-connecting component, 24-torsion wire, 3-magnetic field generating mechanism, 4-measuring mechanism, 5-current-stabilized power supply, 6-coil circuit, 7-controller, 8-display module. DETAILED DESCRIPTION

[0032] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting the present invention;

[0033] In order to better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size;

[0034] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0035] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0036] Example 1

[0037] This embodiment proposes a torsion pendulum magnetic field measuring device, such as Figure 1 FIG. 1 is a schematic structural diagram of the torsion pendulum type magnetic field measuring device of this embodiment.

[0038] The torsion pendulum type magnetic field measuring device proposed in this embodiment includes a vacuum chamber 1 , a torsion pendulum mechanism 2 , a magnetic field generating mechanism 3 , and a measuring mechanism 4 .

[0039] One end of the oscillating mechanism 2 is rotatably fixed to the upper ceiling of the vacuum chamber 1 , and the other end is connected to a sub-centimeter-scale magnetic induction component 21 . A reflector 22 is provided between the magnetic induction component 21 and the oscillating mechanism 2 .

[0040] The magnetic field generating mechanism 3 is disposed around the magnetic induction component 21 and is used to generate an artificial magnetic field along the x-axis direction and / or along the y-axis direction.

[0041] A vacuum optical window 11 is provided on one side wall of the vacuum chamber 1; the measuring mechanism 4 is provided outside the vacuum chamber 1 and is used to collect the wiggling motion signal of the reflector 22 through the vacuum optical window 11 and calculate the quality factor of the wiggling mechanism 2 in vacuum based on the wiggling motion signal. Q .

[0042] When the quality factor Q When it is the maximum value, the artificial magnetic field intensity currently generated by the magnetic field generating mechanism 3 is the magnetic field intensity to be measured.

[0043] In this embodiment, the magnetic induction element 21 performs a torsional oscillation in the artificial magnetic field and the magnetic field to be measured, and further cooperates with the rotation of the oscillating mechanism 2, so that the torsional motion of the reflector 22 above the magnetic induction element 21 can be detected by the measuring mechanism 4. The measuring mechanism 4 collects the torsional oscillation motion signal and uses it to calculate the quality factor of the oscillating mechanism 2 in a vacuum. Q Among them, when Q When it is the maximum value, it means that the magnetic field to be measured and the artificial magnetic field cancel each other out. At this time, the artificial magnetic field intensity generated by the magnetic field generating mechanism 3 is the magnetic field intensity to be measured.

[0044] It should be noted that in a magnetic field, the torsional motion of the torsion pendulum structure around the suspension wire will continuously cut the magnetic field lines, resulting in energy dissipation of the torsion pendulum structure, thereby causing the quality factor of the torsion pendulum to decrease. Q By utilizing this characteristic of the torsion pendulum, this embodiment generates an artificial magnetic field at the torsion pendulum position by cooperating with the magnetic field generating mechanism 3 to offset the magnetic field to be measured, so that the energy of the torsion pendulum structure will not be dissipated, and the quality factor Q Will not decrease.

[0045] In this embodiment, the amplitude attenuation coefficient of the oscillating mechanism 2 can be collected by the measuring mechanism 4. β ,like Figure 2 The figure shows the amplitude attenuation of the torsional pendulum motion. β Calculate the quality factor Q , whose expression is: Q =1 / β ; After artificial processing, we get Figure 3 The wiggle quality factor shown Q Relationship diagram with the modulated magnetic field.

[0046] In this embodiment, the magnetic field generating mechanism 3 is input with steady currents of different magnitudes to modulate the artificial magnetic field with different magnetic field strengths, and the measuring mechanism 4 is used to measure the different artificial magnetic fields and quality factors. Q The corresponding relationship, when the quality factor QAt maximum, the artificial magnetic field cancels out the magnetic field to be measured. When they are equal in magnitude and opposite in direction, the magnetic field strength of the artificial magnetic field equals the magnetic field strength of the magnetic field to be measured. Furthermore, by connecting a sub-centimeter-scale magnetic induction element 21 to the wiggling mechanism 2, this embodiment can measure magnetic fields in the sub-centimeter region, effectively improving the spatial resolution of the measurement.

[0047] In an optional embodiment, the torsion mechanism 2 includes a connecting member 23 and a torsion wire 24, wherein one end of the connecting member 23 can be rotatably fixed to the upper top of the vacuum chamber 1, and the other end is connected to one end of the torsion wire 24, and the other end of the torsion wire 24 is connected to the reflector 22.

[0048] Furthermore, in an optional embodiment, the connecting member 23 includes a magnetic damper.

[0049] The magnetic damper is a device that uses the force exerted by a magnetic field on a conductor moving therein to achieve vibration damping. By rotating the magnetic damper, the torsional motion of the reflector 22 can be detected by the measuring mechanism 4, so that the torsional motion data can be collected and recorded.

[0050] In an optional embodiment, the magnetic induction component 21 includes a copper cylinder; the reflector 22 is arranged at the center of the end surface of the copper cylinder.

[0051] Furthermore, in an optional embodiment, the end surface diameter of the magnetic induction component 21 is less than 1 cm, and the height is less than 1 cm.

[0052] Further optionally, the end surface diameter of the magnetic induction component 21 is 0.8 cm and the height is 0.8 cm. Figure 4 FIG. 1 is a schematic structural diagram of the magnetic induction component 21 of this embodiment.

[0053] In this embodiment, by reducing the size of the magnetic induction element 21 , the spatial resolution of the magnetic field measurement can be further improved.

[0054] In an optional embodiment, the magnetic field generating mechanism 3 includes a first coil group C1 and C2, arranged along the x-axis with the magnetic induction element 21 as the center, for generating an artificial magnetic field along the x-axis; and a second coil group C3 and C4, arranged along the y-axis with the magnetic induction element 21 as the center, for generating an artificial magnetic field along the y-axis. The first coil group C1 and C2, and the second coil group C3 and C4, are each connected to a regulated current power supply 5 located outside the vacuum chamber 1 via a coil circuit 6. By modulating the output of the regulated current power supply 5, the magnetic field intensity of the artificial magnetic field is modulated.

[0055] As an example, the first coil groups C1 and C2 of this embodiment are used to generate an artificial magnetic field along the x-axis direction, and the second coil groups C3 and C4 are used to generate an artificial magnetic field along the y-axis direction. When measuring the x-axis magnetic field component, the artificial magnetic field is modulated by modulating the output of the first coil groups C1 and C2 by the regulated current power supply 5. Bx , and then through the quality factor Q Similarly, when measuring the y-axis magnetic field component, the output of the second coil group C3 and C4 is modulated by modulating the current-stabilized power supply 5 to modulate the artificial magnetic field. By , and then through the quality factor Q The maximum value of determines the y-axis component of the magnetic field to be measured.

[0056] Furthermore, in an optional embodiment, the first coil groups C1 and C2, and the second coil groups C3 and C4 are respectively fixed by brackets.

[0057] As an exemplary description, in this embodiment, the first coil groups C1 and C2, and the second coil groups C3 and C4 are Helmholtz coils, and each coil is fixed by an aluminum bracket.

[0058] In an optional embodiment, the device further includes a controller 7. The first output terminal of the controller 7 is connected to the magnetic field generating mechanism 3, and is used to output a current control signal to the magnetic field generating mechanism 3, thereby modulating the magnetic field strength of the artificial magnetic field by controlling the output current; the input terminal of the controller 7 is connected to the output terminal of the measuring mechanism 4, and is used to continuously receive the quality factor output by the measuring mechanism 4. Q , and judge the current quality factor Q Is it the maximum value? If so, a stop working signal is output to the magnetic field generating mechanism 3, and the current output current value is recorded, and the magnetic field strength of the artificial magnetic field is calculated as the magnetic field measurement result; otherwise, the current control signal is modulated.

[0059] In this embodiment, a controller 7 is added to output a current control signal to the magnetic field generating mechanism 3 according to the data fed back by the measuring mechanism 4, thereby achieving magnetic field intensity modulation of the artificial magnetic field.

[0060] Furthermore, in an optional embodiment, the device further includes a display module 8 , the input end of the display module 8 being connected to the second output end of the controller 7 , for displaying the current magnetic field measurement result.

[0061] like Figure 5 , which is a structural diagram of the torsion pendulum type magnetic field measurement device of this embodiment.

[0062] As an example, magnetic field measurement experiments were conducted using a Mag612 magnetic field meter from Bartington, UK, and the torsion pendulum magnetic field measurement device proposed in this embodiment. The magnetic sensing element 21 in this embodiment was a copper cylinder with an end diameter of 0.8 cm and a height of 0.8 cm. The results of the experiments are shown in Table 1 below, comparing the spatial resolution and measurement range.

[0063] Table 1 Comparison of magnetic field measurement spatial resolution and measurement range

[0064]

[0065] It can be seen that the spatial resolution in this embodiment is 8×8×8 mm, which obviously can measure the magnetic field in the sub-centimeter scale space, and the measurement range is ±300 μT.

[0066] Example 2

[0067] This embodiment uses the torsion pendulum magnetic field measuring device proposed in Example 1 to propose a measurement method. Figure 6 FIG. 1 is a flow chart of the measurement method of this embodiment.

[0068] The measurement method using the torsion pendulum magnetic field measurement device proposed in this embodiment includes the following steps:

[0069] S1. Power the magnetic field generating mechanism 3 to generate an artificial magnetic field along the x-axis or y-axis direction. Bx or By ;

[0070] S2, control the torsion mechanism 2 to twist, and collect the torsional motion signal of the torsional motion of the reflector 22 through the measuring mechanism 4 to obtain the amplitude attenuation coefficient, that is, to obtain the amplitude attenuation coefficient in the artificial magnetic field. Bx or By Quality factor under Q ;

[0071] S3, modulating the power supply current configuration of the magnetic field generating mechanism 3, and recording different artificial magnetic fields Bx or By Quality factor under Q , take the quality factor Q The artificial magnetic field at its maximum value Bx or By As a result of magnetic field measurement.

[0072] It can be understood that the measurement method of this embodiment is applied to the torsion pendulum magnetic field measurement device of the above-mentioned embodiment 1, and the options in the above-mentioned embodiment 1 are also applicable to this embodiment, so they will not be described again here.

[0073] The same or similar reference numerals correspond to the same or similar components;

[0074] The terms used in the drawings to describe positional relationships are for illustrative purposes only and are not to be construed as limiting the present invention.

[0075] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A torsion pendulum magnetic field measuring device, characterized in that: The invention comprises a vacuum chamber (1), a torsion pendulum mechanism (2), a magnetic field generating mechanism (3), and a measuring mechanism (4), wherein: One end of the oscillating mechanism (2) is rotatably fixed to the upper roof of the vacuum chamber (1), and the other end is connected to a sub-centimeter-scale magnetic induction component (21); a reflector (22) is provided between the magnetic induction component (21) and the oscillating mechanism (2); The magnetic field generating mechanism (3) is arranged around the magnetic induction component (21) and is used to generate an artificial magnetic field along the x-axis direction and / or along the y-axis direction; A vacuum optical window (11) is provided on one side wall of the vacuum chamber (1); the measuring mechanism (4) is arranged outside the vacuum chamber (1) and is used to collect the wiggling motion signal of the reflector (22) through the vacuum optical window (11), and calculate the quality factor of the wiggling mechanism (2) in vacuum based on the wiggling motion signal. Q ; When the quality factor Q When it is at its maximum value, the artificial magnetic field intensity currently generated by the magnetic field generating mechanism (3) is the magnetic field intensity to be measured.

2. The torsion pendulum magnetic field measuring device according to claim 1, characterized in that: The torsion swing mechanism (2) comprises a connecting member (23) and a torsion wire (24), wherein one end of the connecting member (23) is rotatably fixed to the upper top of the vacuum chamber (1), and the other end is connected to one end of the torsion wire (24), and the other end of the torsion wire (24) is connected to the reflector (22).

3. The torsion pendulum magnetic field measuring device according to claim 2, characterized in that: The connecting member (23) includes a magnetic damper.

4. The torsion pendulum magnetic field measuring device according to claim 1, characterized in that: The magnetic induction component (21) comprises a copper cylinder; the reflector (22) is arranged at the center of the end surface of the copper cylinder.

5. The torsion pendulum magnetic field measuring device according to claim 4, characterized in that: The end face diameter of the magnetic induction component (21) is less than 1 cm, and the height is less than 1 cm.

6. The torsion pendulum magnetic field measuring device according to claim 1, characterized in that: The magnetic field generating mechanism (3) comprises a first coil group C1 and C2 arranged along the x-axis direction with the magnetic induction component (21) as the center, and a second coil group C3 and C4 arranged along the y-axis direction with the magnetic induction component (21) as the center; the first coil group C1 and C2, and the second coil group C3 and C4 are respectively connected to a constant current power supply (5) arranged outside the vacuum chamber (1) through a coil circuit (6).

7. The torsion pendulum magnetic field measuring device according to claim 6, characterized in that: The first coil groups C1 and C2, and the second coil groups C3 and C4 are fixed by brackets respectively.

8. The torsion pendulum magnetic field measuring device according to any one of claims 1 to 7, characterized in that: The device further comprises a controller (7); The first output end of the controller (7) is connected to the magnetic field generating mechanism (3) and is used to output a current control signal to the magnetic field generating mechanism (3), and modulate the magnetic field intensity of the artificial magnetic field by controlling the output current; The input end of the controller (7) is connected to the output end of the measuring mechanism (4) and is used to continuously receive the quality factor output by the measuring mechanism (4). Q , and judge the current quality factor Q Is it the maximum value? If so, a stop signal is output to the magnetic field generating mechanism (3), and the current output current value is recorded, and the magnetic field strength of the artificial magnetic field is calculated as the magnetic field measurement result; otherwise, the current control signal is modulated.

9. The torsion pendulum magnetic field measuring device according to claim 8, characterized in that: The device further comprises a display module (8), the input end of the display module (8) being connected to the second output end of the controller (7) and being used for displaying the current magnetic field measurement result.

10. A measurement method using the torsion pendulum magnetic field measurement device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Powering the magnetic field generating mechanism (3) to generate an artificial magnetic field along the x-axis or y-axis direction Bx or By ; S2, controlling the torsion pendulum mechanism (2) to twist, collecting the torsion motion signal of the torsion motion of the reflector (22) through the measuring mechanism (4), and obtaining the amplitude attenuation coefficient, that is, obtaining the amplitude attenuation coefficient in the artificial magnetic field. Bx or By Quality factor under Q ; S3, modulating the power supply current configuration of the magnetic field generating mechanism (3) to record different artificial magnetic fields Bx or By Quality factor under Q , take the quality factor Q The artificial magnetic field at its maximum value Bx or By As a result of magnetic field measurement.

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