Magnetic field scanning device and magnetic mass spectrometer

Abstract

The invention discloses a magnetic field scanning device and a magnetic mass spectrometer. The magnetic field scanning device comprises a magnetic assembly and a control assembly. The number of turns of the main coil in the magnetic assembly is smaller than that of the auxiliary coil. The first main coil and the second main coil in the magnetic core unit are connected in series to form a main magnetic unit, and the first auxiliary coil and the second auxiliary coil are connected in series to form an auxiliary magnetic unit. The control assembly is electrically connected with the main magnetic unit and the auxiliary magnetic unit and used for adjusting the current of the main magnetic unit and adjusting the current in the auxiliary magnetic unit so as to adjust the magnetic field intensity of the electromagnetic field between the first end and the second end, and then magnetic field scanning is achieved. According to the magnetic field scanning device, the magnetic field intensity can be rapidly stabilized at a set value required by adjustment through combined control of the main magnetic unit and the auxiliary magnetic unit during rapid magnetic field scanning.

Description

Technical Field

[0001] The present invention particularly relates to a magnetic field scanning device and a magnetic mass spectrometer comprising the device. Background Art

[0002] Magnetic mass spectrometer has the advantages of simple structure, good stability, high resolution, wide dynamic range, and high abundance sensitivity, and is therefore widely used in the quantitative analysis of isotope abundance and abundance ratio.

[0003] The mass analyzer is one of the most critical parts of a magnetic mass spectrometer. The mass analyzer usually includes a magnetic field scanning device, which is used to perform magnetic field scanning. Magnetic field scanning refers to the process of changing the magnetic field strength to facilitate the separation of charged ions passing through the magnetic field, thereby performing accurate mass spectrometry analysis.

[0004] However, existing magnetic field scanning devices have the problem of slow scanning speed, which seriously slows down the analysis speed of traditional magnetic mass spectrometers. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a magnetic field scanning device and a magnetic mass spectrometer comprising the device in view of the above-mentioned deficiencies in the prior art. The magnetic field scanning device has a high scanning speed.

[0006] According to an embodiment of a first aspect of the present invention, there is provided a magnetic field scanning device, comprising: a magnetic component and a control component; the magnetic component comprises a yoke, the yoke comprises a first end and a second end, the first end and the second end are arranged opposite to each other; the magnetic component further comprises a first coil unit and a second coil unit, the first coil unit and the second coil unit are arranged opposite to each other, the first coil unit is sleeved on the first end, and the second coil unit is sleeved on the second end; the first coil unit comprises a first main coil and a first auxiliary coil, the second coil unit comprises a second main coil and a second auxiliary coil, the first main coil and the second main coil are sleeved on the second main coil The number of turns of the first auxiliary coil is equal to that of the second auxiliary coil, and the number of turns of the main coil is less than that of the auxiliary coil; the first main coil is connected in series with the second main coil, and the series circuit of the first main coil and the second main coil is set as the main magnetic unit, and the first auxiliary coil is connected in series with the second auxiliary coil, and the series circuit of the first auxiliary coil and the second auxiliary coil is set as the auxiliary magnetic unit; the control component is electrically connected to the main magnetic unit and the auxiliary magnetic unit respectively, and the control component is used to adjust the current of the main magnetic unit, and adjust the current in the auxiliary magnetic unit to adjust the magnetic field strength of the electromagnetic field between the first end and the second end, thereby realizing magnetic field scanning.

[0007] Preferably, the control component includes a controller, which is electrically connected to the main magnetic unit and the auxiliary magnetic unit, respectively, and is used to obtain a set magnetic field strength value and obtain a corresponding magnetic field coarse adjustment threshold value according to the set magnetic field strength value; the controller is also used to adjust the current of the main magnetic unit so that the magnetic field strength of the electromagnetic field between the first end and the second end reaches the magnetic field coarse adjustment threshold value to complete rapid coarse adjustment of the magnetic field, and, by adjusting the current of the auxiliary magnetic unit, the magnetic field strength of the electromagnetic field between the first end and the second end reaches the set magnetic field strength value to complete fine adjustment of the magnetic field strength.

[0008] Preferably, the control component also includes a magnetic induction sensor, which is used to detect the magnetic field strength of the electromagnetic field between the first end and the second end and feed back a magnetic field induction signal; the controller is electrically connected to the magnetic induction sensor, and is used to receive the magnetic field induction signal fed back by the magnetic induction sensor, and obtain the current magnetic field strength of the electromagnetic field according to the magnetic field induction signal. The controller is also used to adjust the current in the main magnetic unit and the auxiliary unit according to the current magnetic field strength of the electromagnetic field until the magnetic field strength of the electromagnetic field reaches the set magnetic field strength value.

[0009] Preferably, the control component also includes a first regulating circuit and a second regulating circuit; the controller is used to obtain the corresponding first current value and second current value according to the set magnetic field strength value, the first current value is the current value in the main magnetic unit when the magnetic field strength reaches the magnetic field coarse adjustment threshold, the second current value is the current value in the auxiliary magnetic unit when the magnetic field strength reaches the set magnetic field strength value, and the first current value is greater than the second current value; the controller is electrically connected to the main magnetic unit through the first regulating circuit, and is used to adjust the current of the main magnetic unit through the first regulating circuit so that the current in the main magnetic unit reaches the first current value, and then the magnetic field strength of the main magnetic unit reaches the magnetic field coarse adjustment threshold; the controller is electrically connected to the auxiliary magnetic unit through the second regulating circuit, and is used to adjust the current of the auxiliary magnetic unit through the second regulating circuit so that the current in the auxiliary magnetic unit reaches the second current value, and then the overall magnetic field strength of the main magnetic unit and the auxiliary magnetic unit reaches the set magnetic field strength value.

[0010] Preferably, the first regulation circuit includes a first current detection unit and a first current regulation unit; the first current regulation unit is electrically connected to the main magnetic unit, and is used to adjust the current value in the main magnetic unit; the first current detection unit is electrically connected to the main magnetic unit, and is used to detect the current in the main magnetic unit and output a first feedback signal; the controller is electrically connected to the first current regulation unit and the first current detection unit, respectively, and is used to obtain the actual current value in the main magnetic unit according to the first feedback signal, and the controller is also used to control the first current regulation unit to adjust the current in the main magnetic unit according to the actual current value in the main magnetic unit and the first current value, so that the current in the main magnetic unit reaches the first current value.

[0011] Preferably, the second regulation circuit includes a second current detection unit and a second current regulation unit; the second current regulation unit is electrically connected to the auxiliary magnetic unit, and is used to adjust the current value in the auxiliary magnetic unit; the second current detection unit is electrically connected to the auxiliary magnetic unit, and is used to detect the current in the auxiliary magnetic unit and output a second feedback signal; the controller is electrically connected to the second current regulation unit and the second current detection unit, respectively, and is used to obtain the actual current value in the auxiliary magnetic unit according to the second feedback signal, and the controller is also used to control the second current regulation unit to adjust the current in the auxiliary magnetic unit according to the actual current value of the auxiliary magnetic unit and the second current value, so that the current in the first auxiliary coil and the second auxiliary coil reaches the second current value.

[0012] Preferably, the yoke also includes a connecting portion, one end of which is connected to the first end portion, and the other end of which is connected to the second end portion; the yoke is formed by stacking a plurality of first magnetic conductive sheets, the first magnetic conductive sheets are vertically arranged, and a plurality of the first magnetic conductive sheets are arranged along the width direction of the yoke, and two adjacent first magnetic conductive sheets are bonded by an adhesive layer, and each of the first magnetic conductive sheets is C-shaped.

[0013] Preferably, the first end portion is located directly above the second end portion, and the magnetic component further comprises a magnetic pole head, wherein the number of the magnetic pole heads is two, and the two magnetic pole heads are arranged opposite to each other, wherein one magnetic pole head is installed on the lower end surface of the first end portion and is located below the first coil unit, and the other magnetic pole head is installed on the upper end surface of the second end portion and is located above the second coil.

[0014] Preferably, the cross-section of the pole head is fan-shaped, and the pole head is formed by stacking a plurality of second magnetic conductive sheets, the plurality of second magnetic conductive sheets are arranged along the central arc direction of the pole head, and two adjacent second magnetic conductive sheets are bonded by an adhesive layer.

[0015] Preferably, the magnetic component also includes a support column, which is located between the two magnetic pole heads and extends in relative directions of the two magnetic pole heads. Both ends of the support column are respectively connected to the two magnetic pole heads to limit the two magnetic pole heads from moving toward each other.

[0016] Preferably, the first magnetic conductive sheet and the second magnetic conductive sheet are both made of silicon steel sheets.

[0017] Preferably, the first main coil and the first auxiliary coil are both mounted on the side wall of the first end, and the first main coil surrounds the outside of the first auxiliary coil, and the second main coil and the second auxiliary coil are both mounted on the side wall of the second end, and the second main coil surrounds the outside of the second auxiliary coil.

[0018] According to an embodiment of the second aspect of the present invention, a magnetic mass spectrometer is provided, comprising a mass analysis tube and the above-mentioned magnetic field scanning device, wherein the mass analysis tube is located between the first end and the second end of the magnetic field scanning device, and the magnetic field scanning device is used to perform a magnetic field scan on the mass analysis tube.

[0019] The magnetic field scanning device of the present invention is used to quickly and roughly adjust the magnetic field by setting a main magnetic unit (i.e., the first main coil and the second main coil) with a small number of turns; and an auxiliary magnetic unit (i.e., the first auxiliary coil and the second auxiliary coil) with a large number of turns is used to finely adjust the magnetic field. The current change amount adjusted each time in the main magnetic unit is large (for example, 1 ampere), which leads to a large change amplitude of the magnetic field strength adjusted each time. The adjustment accuracy of the auxiliary magnetic unit is high, and the minimum change amount of the current adjusted each time is small (for example, 0.1 ampere). Therefore, the change amplitude of the magnetic field strength adjusted each time by the auxiliary magnetic unit is small, and the magnetic field strength can be accurately adjusted. The control component measures the current magnetic field strength according to the magnetic induction sensor. If it is lower than the set value, the magnetic field strength is increased by gradually increasing the main coil current. When the magnetic field strength setting value is about to be reached but not yet reached, the coarse adjustment is stopped and the fine adjustment is started until the set magnetic field strength is reached. Therefore, the main magnetic unit and the auxiliary magnetic unit are combined to control the magnetic field strength to quickly stabilize the magnetic field strength at the setting value required for adjustment during the rapid scanning of the magnetic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a magnetic field scanning device in some embodiments of the present invention;

[0021] Figure 2 is a schematic diagram of the circuit structure of the control component in some embodiments of the present invention;

[0022] Figure 3is a comparison diagram of characteristic curves of silicon steel sheets and DT4 electrical pure iron in some embodiments of the present invention;

[0023] Figure 4 is a graph of magnet scanning speed under different materials in some embodiments of the present invention;

[0024] Figure 5 is a schematic diagram of the structure of a magnetic yoke in some embodiments of the present invention;

[0025] Figure 6 is a top view of a magnetic pole head in some embodiments of the present invention.

[0026] In the figure: a fixed top plate 1, a magnetic yoke 2, a first end 21, a second end 22, a first magnetic conductive sheet 23, a main magnetic unit 3, an auxiliary magnetic unit 4, an adjustment base 5, a coil terminal 6, a cooling water pipe 7, a magnetic pole head 8, a second magnetic conductive sheet 81, a magnetic induction sensor 9, a support column 10, and a fixed rod 11. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0028] In the description of the present invention, it should be noted that the terms "upper", "lower", "upstream", "downstream" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0029] The structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0030] In the description of the present invention, the terms “first”, “second” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0032] First of all, it should be noted that magnetic mass spectrometry has been widely used in the quantitative analysis of isotope abundance and abundance ratio due to its simple structure, good stability, high resolution, wide dynamic range, high abundance sensitivity and other advantages, forming dozens of mass spectrometry instruments such as thermal ionization mass spectrometry (TI MS), high resolution inductively coupled plasma mass spectrometry (HR-I CP-MS), glow discharge mass spectrometry (GD-MS), multi-collector plasma mass spectrometry (MC-I CP-MS), rare gas isotope mass spectrometry, stable isotope mass spectrometry, etc. One of the most important components of a magnetic mass spectrometer is its mass analyzer (electromagnet).

[0033] However, traditional magnetic mass spectrometers face great challenges in their application due to their large size, high energy consumption, slow analysis speed and other disadvantages. The fundamental reason for their significant disadvantage and slow analysis speed is that the scanning speed of the magnet cannot reach the expected design level due to the hysteresis effect.

[0034] In a magnetic mass spectrometer, in order to separate ions of different masses, the magnetic field strength needs to be changed. This process of changing the magnetic field is called magnetic field scanning. The scanning speed refers to the change in magnetic field strength per unit time.

[0035] Here, the working principle of the mass analyzer is explained. The mass analyzer includes: an electromagnet (magnetic field scanning device) and a mass analysis tube. The two ends of the mass analysis tube are connected to the ion source and the detector respectively. The charged particles from the ion source pass through the mass analysis tube, and the ions are separated according to their mass-to-charge ratio (m / z) by the action of the magnetic field. During the magnetic field scanning process, by changing the magnetic field strength, ions with different mass-to-charge ratios can be selectively passed through the analysis tube, thereby realizing the detection and analysis of the ions.

[0036] Magnetic field scanning is an essential process in mass spectrometry analysis, because the core function of a mass spectrometer is to separate different ions from a complex mixture for subsequent qualitative and quantitative analysis. Magnetic field scanning changes the magnetic field strength so that ions with different mass-to-charge ratios are subjected to different degrees of Lorentz force in the magnetic field, thus moving along different trajectories, achieving effective ion separation. Moreover, this helps to improve the resolution of the mass spectrometer, thereby improving the accuracy and reliability of the analysis.

[0037] It should also be noted that the hysteresis effect refers to the hysteresis effect of the magnetic induction intensity (or magnetization intensity) of a magnetic material changing with the intensity of the magnetic field under the action of a magnetic field. In other words, when a magnetic field acts on a magnetic material, the magnetic induction intensity of the material will change with the change in the intensity of the magnetic field. However, the change in the magnetic field of the material will not respond immediately to the change in the external magnetic field, but there will be a delayed response time, the so-called "hysteresis". In a magnetic mass spectrometer, the magnet used (i.e., the magnetic field scanning device) needs to adjust its magnetic field strength to achieve the separation and analysis of ions. Because the change and stabilization of the magnetic field both consume time, if the magnet has a significant hysteresis effect, it will seriously affect the analysis speed of the magnetic mass spectrometer.

[0038] The magnet (magnetic field scanning device) used in magnetic mass spectrometers usually consists of a yoke, a magnetic pole head, a coil and a fixed support mechanism. The coil is used to provide a stable current to form a stable magnet; the yoke is used to conduct magnetism and support the magnetic pole head and the coil; a uniform magnetic field is formed between the upper and lower magnetic pole heads, and the structure of the magnetic pole head directly affects the ion transmission optical path of the mass spectrometer. In order to ensure the stability of the magnetic field and the fastest possible response speed, the yoke and magnetic pole head are currently usually selected from DT4 or DT4C grade electrical pure iron with good magnetic conductivity, but due to the existence of coercive force, the scanning speed of this type of magnet is usually at the level of several seconds to tens of seconds. At the same time, when the magnetic field is required to change rapidly, the response speed of a single coil is also a key factor limiting the scanning speed.

[0039] Therefore, the present invention provides a fast scanning magnet structure and device that can be widely used in various types of magnetic mass spectrometers, which can shorten the magnetic field scanning time from tens of seconds to 100-200ms, greatly improving the analysis speed and use efficiency of the mass spectrometer.

[0040] Example 1

[0041] See also Figure 1 The present invention discloses a magnetic field scanning device, including a magnetic component and a control component.

[0042] The magnetic component includes a yoke 2, and the yoke 2 includes a first end 21 and a second end 22, and the first end 21 and the second end 22 are arranged opposite to each other. The magnetic component also includes a first coil unit and a second coil unit, and the first coil unit and the second coil unit are arranged opposite to each other, and the first coil unit is sleeved on the first end 21, and the second coil unit is sleeved on the second end 22. The first coil unit includes a first main coil and a first auxiliary coil, and the second coil unit includes a second main coil and a second auxiliary coil, and the number of turns of the first main coil and the second main coil is equal, and the number of turns of the first auxiliary coil and the second auxiliary coil is equal, and the number of turns of the main coil is less than the number of turns of the auxiliary coil. The first main coil and the second main coil are connected in series, and the series circuit of the first main coil and the second main coil is set as the main magnetic unit 3, and the first auxiliary coil and the second auxiliary coil are connected in series, and the series circuit of the first auxiliary coil and the second auxiliary coil is set as the auxiliary magnetic unit 4. The control component is electrically connected to the main magnetic unit 3 and the auxiliary magnetic unit 4 respectively, and is used to adjust the current of the main magnetic unit 3 and the current in the auxiliary magnetic unit 4 to adjust the magnetic field strength of the electromagnetic field between the first end 21 and the second end 22, thereby realizing magnetic field scanning.

[0043] It should be noted that the magnetic field scanning device is used to quickly and roughly adjust the magnetic field by setting a main magnetic unit with fewer turns (i.e., the first main coil and the second main coil); and an auxiliary magnetic unit with more turns (i.e., the first auxiliary coil and the second auxiliary coil) is used to finely adjust the magnetic field. The current change amount adjusted each time in the main magnetic unit is large (for example, 1 ampere), which leads to a large change in the magnetic field strength each time. The adjustment accuracy of the auxiliary magnetic unit is high, and the minimum change amount of the current adjusted each time is small (for example, 0.1 ampere). Therefore, the change in the magnetic field strength of the auxiliary magnetic unit each time is small, which can achieve accurate adjustment of the magnetic field strength. The control component measures the current magnetic field strength according to the magnetic induction sensor. If it is lower than the set value, the magnetic field strength is increased by gradually increasing the main coil current. When it is about to reach the set value of the magnetic field strength but has not yet reached it, the coarse adjustment is stopped and the fine adjustment is started until the set magnetic field strength is reached before the fine adjustment is completed. Therefore, the magnetic field scanning device is controlled by combining the main magnetic unit and the auxiliary magnetic unit, so that the magnetic field strength can be quickly stabilized at the set value required for adjustment.

[0044] However, the existing magnetic field scanning devices mostly use a single coil. If the adjustment accuracy requirement of the magnetic field strength is to be met, the current adjustment accuracy of the coil is very high. For example, the current in the coil is adjusted by 1 / 100 ampere each time. When the span of the magnetic field strength is large, many adjustments are required to reach the target magnetic field strength. This will result in a very low magnetic field scanning speed. If the current adjustment accuracy of the coil is low, for example, the current in the coil is adjusted by 1 ampere each time, the accuracy requirement of the magnetic field strength may not be met.

[0045] Compared with the existing single-coil magnetic field scanning device, the present magnetic field scanning device does not require multiple adjustments. It only needs to adjust the current in the main magnetic unit 3 first to achieve rapid coarse adjustment of the magnetic field strength. When the magnetic field strength is about to reach but has not reached the set value, the coarse adjustment is stopped and fine adjustment is started until the set magnetic field strength is reached, thereby achieving a higher scanning speed.

[0046] The magnetic field scanning device in this embodiment can shorten the magnetic field scanning time from tens of seconds to 100-200ms, greatly improving the analysis speed and use efficiency of the mass spectrometer.

[0047] See also Figure 1 and Figure 5 The yoke 2 further includes a connecting portion, one end of which is connected to the first end portion 21, and the other end of which is connected to the second end portion 22. The yoke 2 is formed by stacking a plurality of first magnetic conductive sheets 23, which are vertically arranged and arranged along the width direction of the yoke. Two adjacent first magnetic conductive sheets 23 are bonded by an adhesive layer, and each first magnetic conductive sheet 23 is C-shaped.

[0048] Specifically, Figure 5 As shown, the silicon steel sheets are bonded by epoxy resin varnish with a viscosity coefficient of DI N4, and the punching sheets are stacked tangentially along the particle center track, and the stacking coefficient is not less than 98%. The thickness of each first silicon steel sheet is the same, wherein the thickness of any first silicon steel sheet is between 0.2-0.5mm, for example: the thickness of the first silicon steel sheet is 0.2mm, 0.3mm or 0.5mm. The stacking method of silicon steel sheets can effectively reduce the eddy current effect of the magnet. On the one hand, since the silicon steel sheet has a large resistivity, the eddy current size can be reduced. On the other hand, the insulating glue layer is used between the silicon steel sheets to block the eddy current, which reduces the induced electromotive force in the silicon steel sheet. In addition, when designing the magnet, when selecting the model of the silicon steel sheet, it is also necessary to consider that the magnetic field saturation characteristics of the silicon steel sheet are as close as possible to the performance of DT4 electrical pure iron to ensure that the magnetic field of the magnet has good stability.

[0049] The first end 21 is located directly above the second end 22, and the magnetic component also includes a pole head 8. There are two pole heads 8, and the two pole heads 8 are arranged opposite to each other. One of the pole heads 8 is installed on the lower end surface of the first end 21 and is located below the first coil unit, and the other pole head 8 is installed on the upper end surface of the second end 22 and is located above the second coil.

[0050] Specifically, if Figure 6As shown, the shape of the projection of the magnetic pole head 8 on the horizontal plane is adapted to the shape of the mass analysis tube. Exemplarily, the mass analysis tube is an arc-shaped tube, and the cross section of the magnetic pole head 8 is fan-shaped, and the arc-shaped mass analysis tube is located between two magnetic pole heads 8. The magnetic pole head 8 is formed by stacking a plurality of second magnetic conductive sheets 81, and the plurality of second magnetic conductive sheets 81 are arranged along the central arc direction of the magnetic pole head, and two adjacent second magnetic conductive sheets 81 are bonded by an adhesive layer.

[0051] Similar to the magnetic yoke, two adjacent second magnetic conductive sheets 81 are stamped and bonded by epoxy resin adhesive varnish with a viscosity coefficient of DI N4, and the punched sheets are stacked tangentially along the particle center track, and the stacking coefficient is not less than 98%. The thickness of each second silicon steel sheet is between 0.2-0.5mm, for example: the thickness of the first silicon steel sheet is 0.2mm, 0.3mm or 0.5mm.

[0052] The first magnetic conductive sheet 23 and the second magnetic conductive sheet 81 are both made of silicon steel sheets. Specifically, silicon steel sheets are a kind of soft magnetic material with small hysteresis loss. The use of silicon steel sheets in the magnetic field scanning device can effectively reduce the hysteresis effect and further improve the magnetic field scanning speed.

[0053] The first main coil and the first auxiliary coil are both sleeved on the side wall of the first end 21, and the first main coil surrounds the outside of the first auxiliary coil. The second main coil and the second auxiliary coil are both sleeved on the side wall of the second end 22, and the second main coil surrounds the outside of the second auxiliary coil.

[0054] In other words, the main coil and the auxiliary coil are respectively composed of a set of symmetrical coils connected in series, and the coils are wound with a flat enameled wire in a "racetrack-shaped" structure. During the winding process, sufficient tension is applied to the wire to minimize the distortion at the bends and ensure the tightness of the coils. After the main coil and the auxiliary coil are wound, they are integrally vacuum cast with resin. The main resin system is a radiation-resistant insulating material composed of epoxy resin, plastic resin, anhydride curing agent and accelerator.

[0055] The main coil is responsible for the coarse adjustment of the magnetic field strength. The coarse adjustment control loop (i.e., the first adjustment circuit) uses a DSP controller to control a 16-bit DA converter to set the current value. The change in the current is reflected in the voltage change of the current sampling resistor. If it is lower than the set value, the amplifier U1 B will increase the output voltage to increase the current to reach the set value. The auxiliary coil is responsible for the fine adjustment of the magnetic field strength. The principle of the fine adjustment control circuit (i.e., the second adjustment circuit) is the same as that of the main coil, but the current range of the auxiliary coil is 10 times that of the main coil, so the adjustment accuracy of the auxiliary coil is 10 times that of the main coil. When the magnetic field is scanned quickly, the combination of the main coil and the auxiliary coil can make the magnetic field strength quickly stabilize at the set value required for adjustment. See the control diagram of the magnet main coil and auxiliary coil circuit. Figure 2 .

[0056] In order to keep the coil temperature constant, after the coil is wound, the outer layer of the coil is wound around a cooling water pipe 7 with an outer square and an inner circle, which enters from the top and exits from the bottom to take away the heat from the outside.

[0057] Furthermore, the magnetic assembly also includes a support column 10, which is located between the two magnetic pole heads 8 and extends in relative directions of the two magnetic pole heads 8. Both ends of the support column 10 are respectively connected to the two magnetic pole heads 8 to limit the two magnetic pole heads 8 from moving toward each other.

[0058] Since a large magnetic attraction force is generated between the upper and lower magnetic pole heads 8 when the magnet is in use, causing the gap between the magnetic pole heads 8 to change, a plurality of support columns 10 of equal height are provided to ensure the stability of the working gap size between the two magnetic pole heads 8 during the operation of the magnet.

[0059] The structure and control principle of the control component in this embodiment will be described below.

[0060] See also Figure 2 In this embodiment, the control component includes a controller, which is electrically connected to the main magnetic unit 3 and the auxiliary magnetic unit 4, respectively, and is used to obtain a set magnetic field strength value, and obtain a corresponding magnetic field coarse adjustment threshold value according to the set magnetic field strength value. The controller is also used to adjust the current of the main magnetic unit 3 so that the magnetic field strength of the electromagnetic field between the first end 21 and the second end 22 reaches the magnetic field coarse adjustment threshold value to complete the rapid coarse adjustment of the magnetic field, and by adjusting the current of the auxiliary magnetic unit 4, the magnetic field strength of the electromagnetic field between the first end 21 and the second end 22 reaches the set magnetic field strength value to complete the fine adjustment of the magnetic field strength.

[0061] Specifically, obtaining the corresponding magnetic field coarse adjustment threshold value according to the set magnetic field strength value means converting the set magnetic field strength value according to a preset ratio value. In the present embodiment, the preset ratio value is 95%-99%. For example: the magnetic field strength is set to 5000Gs; the preset ratio value is 95%, and the magnetic field coarse adjustment threshold value can be obtained as 4750Gs. The specific magnetic field adjustment process is as follows: First, after the magnetic field strength of the electromagnetic field is quickly adjusted to the magnetic field coarse adjustment threshold value of 4750Gs by the main magnetic unit 3, the magnetic field is precisely adjusted by adjusting the auxiliary magnetic unit 4, so that the magnetic field strength of the magnetic field is gradually increased to 5000Gs. In this way, both the rapid scanning of the magnetic field and the precision requirements of the magnetic field strength adjustment can be met.

[0062] In this embodiment, the controller can be implemented by an existing DSP controller. The DSP controller (Digital Signal Processor, DSP) is used to process digital signals. The DSP controller receives the set magnetic field strength value (digital signal) through the CAN bus and performs the above-mentioned processing on the digital signal.

[0063] It should be noted that the set magnetic field strength value can be directly manually input into the DSP controller by the staff through the CAN bus. It can also be pre-stored in the database, and when the magnetic field scan is required, the DSP controller can directly call it from the database. When performing the magnetic field scan, multiple different target values ​​of the magnetic field strength can be set, that is, the number of magnetic field strength values ​​is set to multiple. Multiple set magnetic field strength values ​​can be input into the DSP controller at one time, and the DSP controller arranges the multiple set magnetic field strength values ​​in order from low to high.

[0064] Furthermore, in order to achieve closed-loop control of the magnetic field strength, it is also necessary to detect the current magnetic field strength of the electromagnetic field in real time, and feed back the magnetic field strength to the controller, so that the controller can determine whether the real-time magnetic field strength reaches the first current value. The control component also includes a magnetic induction sensor, which is used to detect the magnetic field strength of the electromagnetic field between the first end 21 and the second end 22 and feed back a magnetic field induction signal. The controller is electrically connected to the magnetic induction sensor, and is used to receive the magnetic field induction signal fed back by the magnetic induction sensor, and obtain the current magnetic field strength of the electromagnetic field according to the magnetic field induction signal. The controller is also used to adjust the current in the main magnetic unit 3 and the auxiliary unit 4 at the current magnetic field strength of the electromagnetic field until the magnetic field strength of the electromagnetic field reaches the set magnetic field strength value.

[0065] Specifically, if the feedback link is not set, it will lead to error accumulation and fail to meet the accuracy requirements of magnetic field scanning. In the coarse adjustment stage, that is, the controller adjusts the current of the main magnetic unit 3 to quickly adjust the magnetic field strength of the electromagnetic field to the coarse adjustment threshold of the magnetic field. At this time, the controller receives the magnetic field induction signal fed back by the magnetic induction sensor 9 to determine whether the magnetic field strength in the electromagnetic field reaches the coarse adjustment threshold of the magnetic field. If so, the coarse adjustment stage ends and enters the fine adjustment stage, that is, the controller adjusts the current of the auxiliary magnetic unit 4 to accurately adjust the magnetic field strength of the electromagnetic field to the set magnetic field strength value. At this time, the controller receives the magnetic field induction signal fed back by the magnetic induction sensor 9 to determine whether the magnetic field strength in the electromagnetic field reaches the set magnetic field strength value. If so, the magnetic field scanning process ends.

[0066] In other words, the control method of the magnetic field strength adopts closed-loop control, and the magnetic field strength value is set by receiving instructions through the CAN bus. The controller measures the current magnetic field strength according to the magnetic induction sensor 9. If it is lower than the set value, the magnetic field strength is increased by gradually increasing the main coil current. When the magnetic field strength is about to reach the set value but has not yet reached the set value, the coarse adjustment is stopped and the fine adjustment is started until the set magnetic field strength is reached. The magnetic induction sensor 9 can select an existing Gauss meter, Hall sensor or magnetic sensitive sensor, as long as it has a fast response time.

[0067] like Figure 2 As shown, in this embodiment, the control component also includes a first regulating circuit and a second regulating circuit. The controller controls the main magnetic unit 3 (i.e. Figure 2 The main magnet in the magnet) and the auxiliary magnetic unit 4 (i.e. Figure 2 The controller is electrically connected to the main magnetic unit 3 through a first regulating circuit, and is used to regulate the current of the main magnetic unit 3 through the first regulating circuit, so that the current in the main magnetic unit 3 reaches the first current value, and then the magnetic field strength of the main magnetic unit 3 reaches the coarse adjustment threshold of the magnetic field. The controller is electrically connected to the auxiliary magnetic unit 4 through a second regulating circuit, and is used to regulate the current of the auxiliary magnetic unit 4 through the second regulating circuit, so that the current in the auxiliary magnetic unit 4 reaches the second current value, and then the magnetic field strength of the main magnetic unit 3 and the auxiliary magnetic unit 4 reaches the coarse adjustment threshold of the magnetic field.

[0068] Wherein, the first regulating circuit includes a first current detection unit and a first current regulating unit. The first current regulating unit is electrically connected to the main magnetic unit 3, and is used to adjust the current value in the main magnetic unit 3. The first current detection unit is electrically connected to the main magnetic unit 3, and is used to detect the current in the main magnetic unit 3 and output a first feedback signal. The controller is electrically connected to the first current regulating unit and the first current detection unit, respectively, and is used to obtain the actual current value in the main magnetic unit 3 according to the first feedback signal. The controller is also used to control the first current regulating unit to adjust the current in the main magnetic unit 3 according to the actual current value in the main magnetic unit 3 and the first current value, so that the current in the main magnetic unit 3 reaches the first current value.

[0069] In this embodiment, the first current detection unit can use an existing current sampling resistor, such as Figure 2 The first current regulating unit can use an existing field effect transistor, such as Figure 2By increasing the voltage input to the field effect transistor Q1 to extend the conduction time of the field effect transistor Q1, the current value in the main magnetic unit 3 is increased.

[0070] Similarly, the second regulating circuit includes a second current detection unit and a second current regulating unit. The second current regulating unit is electrically connected to the auxiliary magnetic unit 4, and is used to adjust the current value in the auxiliary magnetic unit 4. The second current detection unit is electrically connected to the auxiliary magnetic unit 4, and is used to detect the current in the auxiliary magnetic unit 4 and output a second feedback signal. The controller is electrically connected to the second current regulating unit and the second current detection unit, respectively, and is used to obtain the actual current value in the auxiliary magnetic unit 4 according to the second feedback signal. The controller is also used to control the second current regulating unit to adjust the current in the auxiliary magnetic unit 4 according to the actual current value and the second current value of the auxiliary magnetic unit 4, so that the current in the first auxiliary coil and the second auxiliary coil reaches the second current value.

[0071] In this embodiment, the second current detection unit adopts an existing current sampling resistor, such as Figure 2 The second current regulating unit adopts the existing field effect transistor, such as Figure 2 By increasing the voltage input to the field effect transistor Q2 to extend the conduction time of the field effect transistor Q2, the current value in the main magnetic unit 3 is increased.

[0072] like Figure 2 As shown, the controller is also integrated with a DA converter and an ADC converter. Among them, the DA converter (Digital-to-Analog Converter, DAC, i.e., digital-to-analog converter) is used to convert analog signals into digital signals. Specifically, the DSP controller receives the set magnetic field strength value (digital signal) through the CAN bus and processes the digital signal. The DSP controller is responsible for converting the set value into the corresponding current value and outputting the control signal through the 16-bit DA converter. The controller sets the current value required for the main coil by controlling the 16-bit DA converter. The DA converter outputs an analog signal, which passes through the amplifier U1 B and controls the switch of MOSFET-N after amplification, thereby adjusting the current passing through the main coil. The current in the main coil generates a voltage drop through the current sampling resistor R1, and this voltage drop reflects the magnitude of the current. The 16-bit ADC converter converts this voltage signal into a digital signal and feeds it back to the DSP controller. If the detected current is lower than the set current value, the DSP controller adjusts the output of the DA converter and increases the output voltage through the amplifier U1 B, thereby increasing the on-time of MOSFET-N and increasing the current of the main coil until the current reaches the set value. The current control principle of the auxiliary magnetic unit 4 is the same as that of the main magnetic unit 3, and will not be repeated here.

[0073] The overall working process of the magnetic field scanning device is described below:

[0074] The magnetic field scanning device in this embodiment provides a stable and uniform magnetic field for the magnetic mass spectrometer while greatly improving the scanning speed when the magnetic field changes rapidly, thereby improving the performance of the magnetic mass spectrometer. The magnetic field scanning device belongs to a Faraday cup moving device for a surface thermal ionization mass spectrometer, which includes: a fixed top plate 1, a magnetic yoke 2, a main coil, an auxiliary coil, an adjustment base 5, a coil terminal 6, a cooling water pipe 7, a magnetic pole head 8, a magnetic induction sensor 9, a support column 10 of equal height, a fixing rod 11 and a control component.

[0075] The fixed top plate 1 is used to fix and connect the yoke 2, the coil, the adjustment base 5 and the equal height support column 10 and other components. A lifting ring can also be installed on the fixed top plate 1 for moving and installing the magnet.

[0076] like Figure 3 As shown, the yoke 2 and the magnetic pole head 8 are made of 0.5mmB50A600 grade silicon steel sheets (or other grades with similar magnetic field saturation characteristics) whose magnetic field saturation characteristics are closest to electrical pure iron DT4. The silicon steel sheets are stamped and bonded with epoxy resin adhesive varnish with a viscosity coefficient of DI N4. The punched sheets are stacked tangentially along the particle center track, and the stacking coefficient is not less than 98%. The stacked silicon steel sheets have good insulation effect, and the yoke 2 and the magnetic pole head 8 have the same good processing characteristics as DT4 pure iron. The yoke 2 and the magnetic pole head 8 can be processed by CNC machine tools to the shape and structure required by the magnet design.

[0077] The main coil and auxiliary coil are composed of a group of symmetrical coils connected in series. The coils are wound with a flat enameled wire in a "racetrack-shaped" structure. Sufficient tension is applied to the wire during the winding process to minimize the distortion at the bends and ensure the tightness of the coils. After the main coil and auxiliary coil are wound, they are integrally vacuum cast with resin. The main resin system is a radiation-resistant insulating material composed of epoxy resin, plastic resin, anhydride curing agent and accelerator.

[0078] In order to keep the coil temperature constant, after the coil is wound, the outer layer of the coil is wound around a cooling water pipe 7 with an outer square and an inner circle, which enters from the top and exits from the bottom to take away the heat from the outside.

[0079] The adjustment base 5 is composed of an adjustment bottom plate and adjustment bolts, which can realize the posture adjustment of the magnet as a whole in all directions, front and back, left and right, up and down. Since a large magnetic attraction will be generated between the upper and lower magnetic pole heads 8 when the magnet is in use, causing the gap between the magnetic pole heads 8 to change, equal-height support columns 10 are provided to ensure the stability of the working gap size between the two magnetic pole heads 8 during the operation of the magnet. The fixing rod 11 is used to fix, position and support each single component of the magnet, such as the top plate 1, the yoke 2, the main coil, the auxiliary coil, the adjustment base 5, the magnetic pole heads 8, etc.

[0080] like Figure 2 As shown, the control component includes a DSP controller, a magnet power supply, a first regulating circuit, and a second regulating circuit. The first regulating circuit is electrically connected to the main coil (i.e., the main magnetic unit 3 mentioned above), and the second regulating circuit is electrically connected to the auxiliary coil (i.e., the auxiliary magnetic unit 4 mentioned above). The magnet power supply is electrically connected to the first regulating circuit and the second regulating circuit, respectively, for supplying power to the first regulating circuit and the second regulating circuit. The magnet power supply provides a voltage of +60V as a power supply for the main coil and the auxiliary coil.

[0081] Specifically, the DSP controller is also integrated with a DA converter and an ADC converter. The first regulation circuit includes an amplifier U1 B, a field effect transistor Q1 and a current sampling resistor R1. The second regulation circuit includes an amplifier U2B, a field effect transistor Q2 and a current sampling resistor R2. The DSP controller is the core of the circuit and is responsible for receiving and processing instructions from the CAN bus, which set the required magnetic field strength value. The DSP controller sets the current value required for the main coil by controlling the 16-bit DA converter. The DA converter outputs an analog signal, which is amplified by the amplifier U1 B and controls the switch of the MOSFET-N, thereby adjusting the current passing through the main coil.

[0082] The current in the main coil generates a voltage drop through the current sampling resistor R1, and this voltage drop reflects the magnitude of the current. The 16-bit ADC converter converts this voltage signal into a digital signal and feeds it back to the DSP controller. If the detected current is lower than the set current value, the DSP controller will adjust the output of the DA converter and increase the output voltage through the amplifier U1 B, thereby increasing the conduction time of the MOSFET-N and increasing the current of the main coil until the current reaches the set value.

[0083] Fine-tuning of auxiliary coil: The current control principle of auxiliary coil is the same as that of main coil, but the current range of auxiliary coil is 10 times that of main coil, so it can achieve more precise magnetic field strength adjustment. When the current of main coil approaches but does not reach the set magnetic field strength, DSP controller will start the fine-tuning circuit of auxiliary coil, and make the magnetic field strength reach the set value accurately through similar current feedback and adjustment mechanism.

[0084] When the magnetic field is scanned quickly, the DSP controller controls the main coil and the auxiliary coil at the same time. The main coil is responsible for the coarse adjustment of the magnetic field strength to quickly approach the set value; the auxiliary coil is responsible for fine adjustment to ensure that the magnetic field strength accurately reaches the set value.

[0085] like Figure 4 As shown, the scanning speeds of magnets of different materials and structures were compared. The magnetic field of the magnet made of pure DT4 material was only 76.26% of the rated value within 100ms, and the response time constant of the magnet was approximately 33.74ms. When the whole piece of DT4 pure iron was cut into 9 pieces, the magnetic field rose to 94.7% of the rated value within 100ms, and the time constant of the two-pole magnet was about 5.3ms. When silicon steel sheets were used, the magnetic field rose to 98.06% of the rated value within 100ms, and the time constant of the two-pole magnet was about 1.94ms.

[0086] In summary, this device can improve the scanning speed of existing magnets while ensuring the stability of the magnetic field, shorten the instrument acquisition time, improve the working efficiency of the mass spectrometer, and expand the application fields and scenarios of the magnetic mass spectrometer.

[0087] Example 2

[0088] The present invention also discloses a magnetic mass spectrometer, comprising a mass analysis tube and the magnetic field scanning device in Example 1, wherein the mass analysis tube is located between the first end 21 and the second end 22 of the magnetic field scanning device, and the magnetic field scanning device is used to perform magnetic field scanning on the mass analysis tube.

[0089] Specifically, the fast scanning magnet in the magnetic mass spectrometer (i.e., the magnetic field scanning device in Example 1) supplies power to the main coil and the auxiliary coil through the coil terminal 6. The current in the main coil and the auxiliary coil generates a stable uniform magnetic field between the yoke 2 and the pole head 8. The magnetic induction sensor 9 detects the real-time magnetic field strength and feeds back to the magnetic field control system (i.e., the control component in Example 1).

[0090] Among them, in order to reduce the hysteresis effect and improve the scanning speed of the magnet, the material of the yoke 2 and the pole head 8 is stacked with amorphous silicon steel sheets. The main coil and the auxiliary coil are made of multi-layer spiral wires. After winding, the whole is vacuum cast with resin. The outside of the coil is a single-layer spiral air-conducting copper cooling water pipe 7 to control the temperature stability of the coil. The fixed top plate 1 is used to fix and connect the yoke 2, coil, adjustment base 5 and equal height support column 10 and other components. The adjustment base 5 is used to adjust the overall posture of the magnet in the X, Y, and Z directions. The equal height support column 10 is used to ensure the stability of the working gap size between the two pole heads 8 during the operation of the magnet. The fixing rod 11 is used to fix the individual components of the magnet.

[0091] By adopting the magnetic field scanning device in Example 1, the magnetic mass spectrometer can shorten the magnetic field scanning time from tens of seconds to 100-200ms, thereby greatly improving the analysis speed and use efficiency of the mass spectrometer.

[0092] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A magnetic field scanning device, characterized in that: include: Magnetic components and control components; The magnetic component comprises a yoke (2), the yoke (2) comprises a first end (21) and a second end (22), the first end (21) and the second end (22) being arranged opposite to each other; The magnetic assembly further includes a first coil unit and a second coil unit, wherein the first coil unit is arranged opposite to the second coil unit, the first coil unit is sleeved on the first end, and the second coil unit is sleeved on the second end; The first coil unit includes a first main coil and a first auxiliary coil, the second coil unit includes a second main coil and a second auxiliary coil, the first main coil and the second main coil have the same number of turns, the first auxiliary coil and the second auxiliary coil have the same number of turns, and the number of turns of the main coil is less than that of the auxiliary coil; The first main coil is connected in series with the second main coil, and the series circuit of the first main coil and the second main coil is set as a main magnetic unit (3); the first auxiliary coil is connected in series with the second auxiliary coil, and the series circuit of the first auxiliary coil and the second auxiliary coil is set as an auxiliary magnetic unit (4); The control component is electrically connected to the main magnetic unit (3) and the auxiliary magnetic unit (4) respectively, and is used to adjust the current of the main magnetic unit (3) and the current in the auxiliary magnetic unit (4) to adjust the magnetic field strength of the electromagnetic field between the first end and the second end, thereby realizing magnetic field scanning.

2. The magnetic field scanning device according to claim 1, characterized in that: The control component comprises a controller, the controller being electrically connected to the main magnetic unit (3) and the auxiliary magnetic unit (4) respectively, and the controller being used to obtain a set magnetic field strength value and obtain a corresponding magnetic field coarse adjustment threshold value according to the set magnetic field strength value; The controller is also used to adjust the current of the main magnetic unit (3) so that the magnetic field strength of the electromagnetic field between the first end and the second end reaches a magnetic field coarse adjustment threshold value to complete rapid coarse adjustment of the magnetic field, and to adjust the current of the auxiliary magnetic unit (4) so ​​that the magnetic field strength of the electromagnetic field between the first end and the second end reaches a set magnetic field strength value to complete fine adjustment of the magnetic field strength.

3. The magnetic field scanning device according to claim 2, characterized in that: The control component further includes a magnetic induction sensor, which is used to detect the magnetic field strength of the electromagnetic field between the first end and the second end and feed back a magnetic field induction signal; The controller is electrically connected to the magnetic induction sensor, and is used to receive a magnetic field induction signal fed back by the magnetic induction sensor, and obtain the current magnetic field strength of the electromagnetic field according to the magnetic field induction signal. The controller is also used to adjust the current in the main magnetic unit (3) and the auxiliary unit (4) at the current magnetic field strength of the electromagnetic field until the magnetic field strength of the electromagnetic field reaches a set magnetic field strength value.

4. The magnetic field scanning device according to claim 3, characterized in that: The control component also includes a first regulating circuit and a second regulating circuit; The controller is used to obtain a corresponding first current value and a second current value according to a set magnetic field strength value, the first current value being a current value in the main magnetic unit (3) when the magnetic field strength reaches a magnetic field coarse adjustment threshold, the second current value being a current value in the auxiliary magnetic unit (4) when the magnetic field strength reaches a set magnetic field strength value, and the first current value being greater than the second current value; The controller is electrically connected to the main magnetic unit (3) via a first regulating circuit, and is used to regulate the current of the main magnetic unit (3) via the first regulating circuit, so that the current in the main magnetic unit (3) reaches a first current value, thereby causing the magnetic field strength of the main magnetic unit (3) to reach the magnetic field coarse adjustment threshold; The controller is electrically connected to the auxiliary magnetic unit (4) via a second regulating circuit, and is used to regulate the current of the auxiliary magnetic unit (4) via the second regulating circuit, so that the current in the auxiliary magnetic unit (4) reaches a second current value, thereby causing the overall magnetic field strength of the main magnetic unit (3) and the auxiliary magnetic unit (4) to reach a set magnetic field strength value.

5. The magnetic field scanning device according to claim 4, characterized in that: The first regulating circuit includes a first current detection unit and a first current regulating unit; The first current regulating unit is electrically connected to the main magnetic unit (3) and is used to regulate the current value in the main magnetic unit (3); The first current detection unit is electrically connected to the main magnetic unit (3) and is used to detect the current in the main magnetic unit (3) and output a first feedback signal; The controller is electrically connected to the first current regulating unit and the first current detecting unit respectively, and is used to obtain an actual current value in the main magnetic unit (3) according to the first feedback signal. The controller is also used to control the first current regulating unit to regulate the current in the main magnetic unit (3) according to the actual current value in the main magnetic unit (3) and the first current value, so that the current in the main magnetic unit (3) reaches the first current value.

6. The magnetic field scanning device according to claim 5, characterized in that: The second regulating circuit includes a second current detection unit and a second current regulating unit; The second current regulating unit is electrically connected to the auxiliary magnetic unit (4) and is used to regulate the current value in the auxiliary magnetic unit (4); The second current detection unit is electrically connected to the auxiliary magnetic unit (4), and is used to detect the current in the auxiliary magnetic unit (4) and output a second feedback signal; The controller is electrically connected to the second current regulating unit and the second current detecting unit respectively, and is used to obtain an actual current value in the auxiliary magnetic unit (4) according to the second feedback signal. The controller is also used to control the second current regulating unit to regulate the current in the auxiliary magnetic unit (4) according to the actual current value of the auxiliary magnetic unit (4) and the second current value, so that the current in the first auxiliary coil and the second auxiliary coil reaches the second current value.

7. The magnetic field scanning device according to any one of claims 1 to 6, characterized in that: The magnetic yoke (2) further comprises a connecting portion, one end of which is connected to the first end portion (21), and the other end of which is connected to the second end portion (22); The magnetic yoke (2) is formed by stacking a plurality of first magnetic conductive sheets (23), wherein the first magnetic conductive sheets (23) are arranged vertically, and the plurality of first magnetic conductive sheets are arranged along the width direction of the magnetic yoke, and two adjacent first magnetic conductive sheets (23) are bonded together by an adhesive layer, and each of the first magnetic conductive sheets (23) is in a C shape.

8. The magnetic field scanning device according to claim 7, characterized in that: The first end portion is located directly above the second end portion, and the magnetic component further comprises a magnetic pole head (8). The number of the magnetic pole heads (8) is two, and the two magnetic pole heads (8) are arranged opposite to each other, wherein one magnetic pole head (8) is installed on the lower end surface of the first end portion and is located below the first coil unit, and the other magnetic pole head (8) is installed on the upper end surface of the second end portion and is located above the second coil.

9. The magnetic field scanning device according to claim 8, characterized in that: The cross section of the magnetic pole head (8) is fan-shaped. The magnetic pole head (8) is formed by stacking a plurality of second magnetic conductive sheets (81). The plurality of second magnetic conductive sheets (81) are arranged along the central arc direction of the magnetic pole head, and two adjacent second magnetic conductive sheets (81) are bonded together by an adhesive layer.

10. The magnetic field scanning device according to claim 8, characterized in that: The magnetic component also includes a support column (10), which is located between the two magnetic pole heads (8) and extends in relative directions of the two magnetic pole heads (8). Both ends of the support column (10) are respectively connected to the two magnetic pole heads (8) to limit the two magnetic pole heads (8) from moving toward each other.

11. The magnetic field scanning device according to claim 9, characterized in that: The first magnetic conductive sheet and the second magnetic conductive sheet are both made of silicon steel sheets.

12. The magnetic field scanning device according to claim 1, characterized in that: The first main coil and the first auxiliary coil are both sleeved on the side wall of the first end, and the first main coil surrounds the outside of the first auxiliary coil. The second main coil and the second auxiliary coil are both sleeved on the side wall of the second end, and the second main coil surrounds the outside of the second auxiliary coil.

13. A magnetic mass spectrometer, characterized in that: It comprises a mass analysis tube and a magnetic field scanning device according to any one of claims 1 to 12, wherein the mass analysis tube is located between a first end and a second end of the magnetic field scanning device, and the magnetic field scanning device is used to perform a magnetic field scanning on the mass analysis tube.

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