Slit system with adjustable slit width and magnetic mass spectrometer provided with slit system

Abstract

The utility model provides a slit system with adjustable slit width and a magnetic mass spectrometer provided with the same, the slit system comprises a thermal expansion module, a connecting rod module, a slit module and a fixing module, the thermal expansion module drives temperature change through electric power and generates linear deformation; the advantage of heat conduction in vacuum and the effect of thermal expansion and cold contraction of materials are utilized, and continuous linear deformation transmission of the thermal expansion module is achieved through the connecting rod module, so that stepless adjustment of the width of the slit is achieved. The transmission module performs transmission through the two connecting arms which are symmetrically arranged in a crossed mode and movably hinged to each other, so that the horizontal distance between the two ends of each connecting arm can be synchronously changed and adjusted, the thermal expansion module is arranged between the upper ends of the connecting arms, and the slit modules are symmetrically arranged between the lower ends of the connecting arms. The slit with a certain width is formed between the slit modules, and the width of the slit is accurately adjusted by utilizing the linear deformation of the thermal expansion module and the synchronous control of the transmission module on the deformation amount.

Description

Technical Field

[0001] The utility model relates to the technical field of mass spectrometers, and more specifically to a slit system with adjustable slit width for a magnetic mass spectrometer. Background Art

[0002] The magnetic mass spectrometer is the earliest type of mass spectrometer and is an indispensable analytical tool in the fields of nuclear science and geology. Usually, according to the different focusing methods, the mass analyzer of the magnetic mass spectrometer can be divided into a single focusing mass analyzer and a double focusing mass analyzer. The main component of the single focusing mass analyzer is a circular pipe with a certain radius, which is equipped with a fan-shaped magnet in the vertical direction to generate a uniform and stable magnetic field. During analysis, the ion beam injected from the ion source changes from a straight line motion to an arc motion under the action of the magnetic field, and because the motion curve radius of ions with different mass-to-charge ratios is different, they can be easily separated by the mass analyzer. Since the positions of the exit slit and the ion detector are fixed, that is, the curve radius of the ion arc motion is fixed, it is generally adopted to continuously change the acceleration voltage or magnetic field strength so that ions with different mass-to-charge ratios pass through the exit slit in turn, so that the ions are separated in space.

[0003] In a single-focusing mass analyzer, the ions generated by the ion source have different initial energies when they are accelerated, that is, different speeds. Even ions with the same mass-to-charge ratio cannot be focused on the detector in the end, resulting in low instrument resolution. In order to improve the resolution, a double-focusing mass analyzer is usually used, that is, a fan-shaped electric field is added before the magnetic analyzer. When the ions enter the fan-shaped electric field vertically, they will be affected by a force perpendicular to the direction of their incident speed, and they will move in a circular motion. When the electric field force on the ions is balanced with the centrifugal force of the ion motion, the radius of the ion motion deflection is determined by its mass-to-charge ratio, the speed of movement, and the electric field strength of the electrostatic field. When the electric field strength is constant, the radius of the ion motion deflection depends on the speed or mass-to-charge ratio of the ions. Therefore, the sector electric field separates and focuses ions with the same mass but different speeds, so that ions with inappropriate speeds cannot enter the slit entering the magnetic field, that is, it has the effect of speed separation and focusing; then, they enter the magnetic analyzer through the slit, and then focus in the direction of mass-to-charge ratio. By adjusting the magnetic field strength, different ion beams can enter the detector through the exit slit in the order of mass-to-charge ratio. This analyzer that achieves dual focusing of speed and direction at the same time is called a dual focusing analyzer. However, the focusing of both single focusing mass analyzer and dual focusing mass analyzer depends on the slit, and different resolution capabilities require the use of slits with different slit widths. Therefore, the slit width is closely related to the resolution capability of the magnetic mass spectrometer.

[0004] However, most of the slit systems currently set in magnetic mass spectrometers use slits with fixed slit widths. When replacing, the corresponding slits need to be switched pneumatically or manually through the vacuum. Since the slits are high-value consumables, the slit widths that can be switched are usually limited. At the same time, when replacing the slits, the magnetic mass spectrometer needs to be switched from high vacuum to atmospheric pressure, and the maintenance time is long, which causes many inconveniences to the use of the instrument; further, during long-term use, when the slit width is set in the magnetic mass spectrometer, the edge of the slit will be continuously hit by ions, so that the edge of the slit is no longer straight, affecting the resolution accuracy of the slit. Therefore, in order to achieve a better balance between the life and performance of the slit system, it is necessary to develop a slit system with adjustable slit width, so as to achieve different resolution capabilities of the mass spectrometer by adjusting the slit width, and at the same time, it is convenient to use a slit with a larger slit width to first find the corresponding ion signal and then switch to a slit with a smaller slit width to obtain a high-resolution signal, reducing the setting time of the slit with a smaller slit width, thereby protecting the slit as much as possible and ensuring the service life of the slit. At present, some magnetic mass spectrometers use piezoelectric quartz deformation to adjust the slit width, but this solution has a very small adjustment range, and the additional high voltage electric field required for the adjustment is difficult to shield, which can easily affect the working accuracy of the magnetic mass spectrometer. Utility Model Content

[0005] The utility model aims to overcome at least one defect of the above-mentioned prior art, and provides a slit system with adjustable slit width for a magnetic mass spectrometer and a magnetic mass spectrometer provided with the slit system, which simply and conveniently realizes stepless adjustment of the slit width in the magnetic mass spectrometer.

[0006] The utility model provides a slit system with adjustable slit width, the slit system comprises a thermal expansion module, a connecting rod module, a slit module and a fixing module, the thermal expansion module is driven by electricity to change temperature and produce linear deformation; the connecting rod module comprises two connecting arms which are cross-symmetrically arranged and movably hinged, the thermal expansion module is arranged between one ends of the connecting arms, the slit modules are symmetrically arranged between the other ends of the connecting arms, and a slit with a certain width is formed between the slit modules, the thermal expansion module adjusts the horizontal spacing of the connecting arms and correspondingly adjusts the width of the slit; the thermal expansion module, the connecting rod module and the slit module are fixed as a whole by the fixing module.

[0007] In this technical solution, the thermal expansion module is linearly deformed by electric drive, and then the linear deformation of the thermal expansion module is transmitted to the slit module by the connecting rod module, thereby realizing the precise adjustment of the slit width. Among them, all components in the magnetic mass spectrometer are in a high vacuum state. The thermal expansion module uses the advantages of heat conduction in vacuum and the effect of thermal expansion and contraction of materials to cause the thermal expansion module to change temperature and produce linear deformation through electric drive. For specific materials, its linear expansion coefficient is rated within a certain temperature range; and due to the locality of electric drive temperature adjustment, except for the obvious thermal expansion and contraction effect of the thermal expansion module, the thermal expansion and contraction effect of other parts is not obvious because the temperature of the parts is close to room temperature due to contact with the vacuum cavity. Therefore, the linear deformation of the thermal expansion module can be realized through temperature control, thereby realizing stepless adjustment of the slit width through continuous deformation of the thermal expansion module. Secondly, the thermal expansion module generates linear deformation through electric drive, and can be connected and driven by the power system of the magnetic mass spectrometer, without adding additional electric field, magnetic field and gas path, etc., and does not affect the working accuracy of the magnetic mass spectrometer; at the same time, the control circuit of the thermal expansion module can be fully integrated with the electrical system of the magnetic mass spectrometer, and can be easily automatically controlled through the electrical system of the magnetic mass spectrometer, so that the slit width required to be used can be freely adjusted, and the slit with a larger slit width can be conveniently used to find the corresponding ion signal first and then switch to a slit with a smaller slit width to obtain a high-resolution signal, reducing the setting time of the slit with a smaller slit width, thereby protecting the slit as much as possible and ensuring the service life of the slit. Specifically, in the slit system, the thermal expansion module, the connecting rod module and the slit module are installed as a whole by the fixed module, thereby relatively fixing the transmission relationship between the thermal expansion module, the connecting rod module and the slit module, facilitating the stable transmission of the connecting rod module, ensuring the stability of the horizontal spacing of the slit module adjusted by the linear deformation of the thermal expansion module, and also making the slit system easier to assemble and disassemble with other components in the magnetic mass spectrometer. The connecting rod module includes two connecting arms that are cross-symmetrically arranged and movably hinged, so that the horizontal spacing between the upper and lower ends of the connecting arms can be changed and adjusted synchronously. Therefore, the thermal expansion module is arranged between the upper ends of the connecting arms, and the horizontal spacing of the upper ends of the connecting arms is adjusted by the linear deformation of the thermal expansion module. The slit modules are symmetrically arranged between the lower ends of the connecting arms, and a slit with a certain width is formed between the slit modules. When the thermal expansion module undergoes linear deformation to adjust the horizontal spacing between the upper ends of the connecting arms, the horizontal spacing between the lower ends of the connecting arms also changes synchronously, thereby symmetrically adjusting the horizontal spacing between the slit modules and realizing precise adjustment of the slit width. At the same time, the range and accuracy of the slit width adjustment can be conveniently adjusted by changing the thermal expansion module and temperature control mode with different material properties, thereby improving the applicability of the slit system.

[0008] Furthermore, the fixing module includes a first fixing component and a second fixing component, the connecting rod module and the slit module are supported by the first fixing component, and the thermal expansion module is fixed integrally with the first fixing component through the second fixing component. In the present technical solution, in order to fix the transmission relationship between the thermal expansion module, the connecting rod module and the slit module, and to facilitate the stable transmission of the connecting rod module between the thermal expansion module and the slit module, it is configured so that the fixing module includes a first fixing component and a second fixing component, wherein the connecting rod module and the slit module are supported by the first fixing component, thereby ensuring the stability of the horizontal spacing of the slit module adjusted by the connecting rod module transmission; further, it is configured so that the thermal expansion module is fixed integrally with the first fixing component through the second fixing component through fasteners, thereby ensuring the stability of the thermal expansion module adjusting the spacing between the two connecting arms in the connecting rod module.

[0009] Preferably, in the connecting rod module, the connecting arm is hinged by a rotating shaft, the rotating shaft passes through the connecting arm and the first fixing component, and the first fixing component fixes the edge of the slit module; the connecting arm is divided into an upper connecting arm and a lower connecting arm with the position of the rotating shaft as a dividing line, the upper connecting arm is connected to the thermal expansion module, and the lower connecting arm extends into the first fixing component and is connected to the slit module. Preferably, an elastic retaining ring is sleeved on the rotating shaft protruding from the surface of the first fixing component to ensure that the hinged connecting arm rotates freely and protect the movement of the rotating shaft from affecting the overall stability of the slit system. By such a setting, not only the relative stability between the thermal expansion module, the connecting rod module and the slit module is improved, but also the accuracy of the slit width adjustment is improved; further, the ratio of the force arm between the upper connecting arm and the lower connecting arm is the ratio of the linear deformation of the thermal expansion module to the slit width adjustment amount of the slit. By reasonably setting the ratio of the force arm between the upper connecting arm and the lower connecting arm, the fine design of the slit width adjustment range and adjustment accuracy can be achieved, and at the same time, adjusting this ratio can take into account the balance between the occupied space and adjustment sensitivity of the slit system.

[0010] Further, the second fixing assembly is arranged in the middle of the horizontally arranged thermal expansion module and avoids both ends of the thermal expansion module;

[0011] The thermal expansion module includes a temperature regulating component and an expansion component. The upper connecting arm is symmetrically connected to both ends of the expansion component. The temperature regulating component is arranged in the middle of the expansion component, and the length of the expansion component in the horizontal direction is adjusted by controlling the temperature of the temperature regulating component.

[0012] In the technical scheme, the second fixing component is used to tightly fix the thermal expansion module with the first fixing component, so as to realize the stable transmission of the linear deformation of the thermal expansion module. The second fixing component is arranged in the middle of the horizontally arranged thermal expansion module, and is used to fix the thermal expansion module. At the same time, the setting position of the second fixing component avoids the two ends of the thermal expansion module, so as to facilitate the occurrence and control of the deformation of the thermal expansion module in the horizontal direction. Preferably, the second fixing component adopts a hard material with a small linear expansion coefficient, including but not limited to ceramics. Further, in order to make the thermal expansion module conduct heat evenly and symmetrically adjust the spacing between the connecting arms, the thermal expansion component is designed to include a temperature adjustment component and an expansion component, wherein the upper connecting arm is symmetrically connected to the two ends of the expansion component, the temperature adjustment component is arranged in the middle of the expansion component, and the length of the expansion component in the horizontal direction is adjusted by controlling the temperature of the temperature adjustment component. Since the temperature adjustment component is arranged in the middle of the expansion component, when the components of the expansion component are uniform, the rate of heat conduction to the two ends of the expansion component is consistent, so that the amount of linear deformation of the expansion component to the two ends is consistent, thereby ensuring the symmetrical deformation of the expansion component from symmetrically adjusting the spacing between the connecting arms. Preferably, the expansion component is made of a hard material with a large linear expansion coefficient, including but not limited to aluminum.

[0013] Preferably, the temperature regulating component is an electric heating coil, and the electric heating coil uniformly wraps the expansion component. By setting the temperature regulating component as an electric heating coil uniformly wrapped on the expansion component, the contact area and uniformity of heat conduction are increased, thereby improving the uniformity of temperature change of the expansion component, and further improving the range and accuracy of symmetrical deformation of the expansion component.

[0014] Furthermore, the slit module includes a slit assembly and a slit adjustment assembly, the slit assemblies are symmetrically arranged, and the spacing between them constitutes the slit of a certain width, the slit adjustment assembly is fixed in the first fixing assembly, and the slit assembly is installed in the center of the slit adjustment assembly; the slit adjustment assembly is connected to the lower connecting arm and is driven by the lower connecting arm to deform, thereby driving the slit assembly to move in the horizontal direction to adjust the width of the slit.

[0015] In the present technical solution, in order to make the width of the slit adjustable, the slit module is set as a component that can partially elastically deform, and the slit module can be divided into a slit assembly and a slit adjustment assembly according to its function, wherein the slit adjustment assembly is a component that can undergo elastic deformation, and the slit adjustment assembly is symmetrically connected to the lower connecting arm and is deformed by the horizontal movement of the lower connecting arm; the slit assembly is symmetrically connected in the center of the slit adjustment assembly, and a gap is formed between the two slit assemblies. When the lower connecting arm symmetrically drives the slit adjustment assembly to move horizontally, the slit assembly is driven to move horizontally accordingly to adjust the width of the slit; preferably, the slit assembly is set to a rigid material or a material with negligible deformation to ensure symmetrical adjustment of the slit width.

[0016] Preferably, in order to further improve the quality of the slit and the accuracy of the slit width adjustment, the first fixing component is configured to be composed of two circular rings connected front and back, the slit component is two rectangles symmetrically arranged in the center of the circular ring, and a rectangular slit is formed between the rectangles; the slit adjustment component is fixed by the first fixing component and fills the other areas of the circular ring except the slit.

[0017] Preferably, the lower connecting arm is arranged to be parallel to the slit, and the connection position between the lower connecting arm and the slit adjustment assembly is close to the slit assembly, and has a consistent width with the slit assembly in the vertical direction, thereby improving the stability of the slit width adjustment; the slit adjustment assembly connected to the upper and lower ends of the slit assembly has a consistent width in the vertical direction, and when the lower connecting arm drives the slit adjustment assembly to move horizontally, the slit adjustment assemblies arranged above and below the slit assembly have a consistent stress-strain curve, thereby ensuring the horizontal adjustment of the slit width, thereby further improving the symmetry and stability of the slit width adjustment.

[0018] Preferably, the width of the slit is adjustable in the range of 1-1000 μm.

[0019] The present technical solution also provides a magnetic mass spectrometer, which includes at least components such as an ion source, a mass analyzer and an ion detector. The ion source, the mass analyzer and the ion detector are connected in sequence. The ion source is used to provide an ion beam, and the ion beam enters the mass analyzer and is separated by the mass analyzer. The separated ion beam enters the ion detector in sequence to be collected; the ion source, the mass analyzer and the ion detector are all in a high vacuum state; the mass analyzer includes a main cavity, and the main cavity is provided with an inlet and an outlet, the inlet is used to receive the ion beam, and the outlet is provided with a slit system as described in the present technical solution, which is used to export the separated ion beam.

[0020] The beneficial effects of the utility model are:

[0021] 1. By taking advantage of the heat conduction in a vacuum and the effect of thermal expansion and contraction of materials, the thermal expansion module is driven by electricity to cause temperature changes and linear deformation, thereby achieving stepless adjustment of the slit width through the continuous linear deformation of the thermal expansion module.

[0022] 2. The thermal expansion module generates linear deformation through electric drive and can be connected and driven through the power system of the magnetic mass spectrometer without adding additional electric fields, magnetic fields and gas paths, etc., and does not affect the working accuracy of the magnetic mass spectrometer; at the same time, the control circuit of the thermal expansion module can be fully integrated with the electrical system of the magnetic mass spectrometer, and can be easily automatically controlled through the electrical system of the magnetic mass spectrometer, so that the slit width can be freely adjusted, and then the slit of the required slit width can be freely adopted, reducing the continuous impact of ions on the slit during long-term use, thereby protecting the slit as much as possible and ensuring the service life of the slit.

[0023] 3. The transmission is carried out through two cross-symmetrically arranged and movably hinged connecting arms, so that the horizontal spacing at both ends of the connecting arms can be changed and adjusted synchronously. Therefore, the thermal expansion module is arranged between one ends of the connecting arms, and the horizontal spacing at one end of the connecting arm is adjusted by the linear deformation of the thermal expansion module. The slit modules are symmetrically arranged between the other ends of the connecting arms, and a slit with a certain width is formed between the slit modules. When the thermal expansion module undergoes linear deformation to adjust the horizontal spacing between one ends of the connecting arms, the horizontal spacing between the other ends of the connecting arms changes accordingly, thereby symmetrically adjusting the horizontal spacing between the slit modules accordingly, thereby realizing precise adjustment of the slit width, so that the slit width adjustment has higher accuracy and a larger range. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the local structure of the slit module in the utility model.

[0025] Figure 2 It is a front view of the structure of a slit system with adjustable slit width according to the utility model.

[0026] Figure 3 The utility model is a side view of the structure of a slit system with adjustable slit width.

[0027] Description of the drawings: a first fixing component 101 , a second fixing component 102 , a fastener 103 , a temperature adjustment component 201 , an expansion component 202 , a connecting arm 300 , a rotating shaft 301 , a slit component 401 , a slit 402 , a slit adjustment component 403 , and an elastic retaining ring 5 . DETAILED DESCRIPTION

[0028] The drawings of the present invention are only used for illustrative purposes and cannot be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] Example 1

[0030] like Figure 1-Figure 3 As shown, the present embodiment provides a slit system with adjustable slit width, the slit system comprises a thermal expansion module, a connecting rod module, a slit module and a fixing module, the thermal expansion module drives the temperature change by electricity and generates linear deformation; the connecting rod module comprises two cross-symmetrically arranged and movably hinged connecting arms 300, the thermal expansion module is arranged between the upper ends of the connecting arms 300, the slit module is symmetrically arranged between the lower ends of the connecting arms 300, and a slit 402 with a certain width is formed between the slit modules, the thermal expansion module adjusts the horizontal spacing of the connecting arms 300 and the width of the slit 402 accordingly; the thermal expansion module, the connecting rod module and the slit module are integrally installed by the fixing module; specifically, the fixing module comprises a first fixing component 101 and a second fixing component 102, the connecting rod module and the slit module are supported by the first fixing component 101, the thermal expansion module is integrally fixed with the second fixing component 102 by a fastener 5, so that the thermal expansion module, the connecting rod module and the slit module are stably transmitted.

[0031] Among them, in the connecting rod module, the connecting arm 300 is hinged by the rotating shaft 301, the rotating shaft 301 passes through the connecting arm 300 and the first fixed component 101, and an elastic retaining ring 5 is sleeved on the rotating shaft 301 protruding from the surface of the first fixed component 101; the first fixed component 101 fixes the edge of the slit module, and the connecting arm 300 is divided into an upper connecting arm (PK segment and QK segment) and a lower connecting arm (KM segment and KN segment) with the position of the rotating shaft 301 as the dividing line. The upper connecting arm is connected to the thermal expansion module, and the lower connecting arm extends into the first fixed component 101 and is connected to the slit module.

[0032] The thermal expansion module includes a temperature regulating component 201 and an expansion component 202, the upper connecting arm is symmetrically connected to the two ends of the expansion component 202, the temperature regulating component 201 is arranged in the middle of the expansion component 202, and the length of the expansion component 202 in the horizontal direction is adjusted by controlling the temperature of the temperature regulating component 201. The second fixed component 102 is arranged in the middle of the horizontally arranged thermal expansion module and avoids the two ends of the thermal expansion module. The thermal expansion module mainly changes the length of the expansion component 202 according to the thermal expansion and contraction effect, and this change is the driving force for the adjustment of the slit system. Preferably, the temperature regulating component 201 is an electric heating coil, and the electric heating coil evenly wraps the expansion component 202. The expansion component 202 is made of a material with a large linear expansion coefficient such as aluminum, and the second fixed component 102 is made of a ceramic material with a small linear expansion coefficient. There is sufficient margin of movement between the expansion component 202 and the second fixed component 102, so that the bracket does not completely hinder the thermal expansion and contraction of the expansion component 202 in the PQ direction. And because the heating environment is stable and unchanged, and there are no obvious interference factors, a certain heating power corresponds to a certain temperature of the expansion component 202, and then corresponds to a certain length of the expansion component 202, that is, the distance between PQ can be changed by changing the heating power.

[0033] The slit module is a component that can be partially elastically deformed, including a slit assembly 401 and a slit adjustment assembly 403. The slit assemblies 401 are symmetrically arranged, and the spacing between them forms a slit 402 of a certain width. The slit adjustment assembly 403 is fixed in the first fixing assembly 101, and the slit assembly 401 is installed in the center of the slit adjustment assembly 403; the slit adjustment assembly 403 is connected to the lower connecting arm and is driven by the lower connecting arm to deform, driving the slit assembly 401 to move in the horizontal direction to adjust the width of the slit 402. The first fixing assembly 101 is composed of two circular rings connected front and back, and the slit assembly 401 is two rectangles symmetrically arranged in the center of the circular ring, and a rectangular slit 402 is formed between the rectangles; the slit adjustment assembly 403 is fixed by the first fixing assembly 101 and fills the other areas of the circular ring except the slit 402. Preferably, the lower connecting arm is parallel to the slit 402, and the connection position between the lower connecting arm and the slit adjustment component 403 is close to the slit component 401, and has a consistent width with the slit component 401 in the vertical direction, thereby improving the stability of the slit width adjustment of the slit 402; the slit adjustment component 403 connected to the upper and lower ends of the slit component 401 has a consistent width in the vertical direction. When the lower connecting arm drives the slit adjustment component 403 to move horizontally, the slit adjustment component 403 arranged around the slit component 401 above and below has a consistent stress-strain curve, ensuring the horizontal adjustment of the slit width of the slit 402, thereby further improving the symmetry and stability of the slit width adjustment of the slit 402.

[0034] Preferably, if Figure 1-Figure 3As shown, the four sections AB, CD, EF, and GH are elastic deformation modules, and the rest are rigid or the deformation can be ignored. The four sections AB, CD, EF, and GH use exactly the same geometric dimensions. If the subtle differences in the material structure are ignored, the four sections have exactly the same stress-strain curves, that is, after being subjected to the same tensile force, the deformation of the four sections of material is the same. By adjusting the different heating powers of the electric heating coil, PQ has different lengths, which drives the lower connecting arm to apply pressure to BC and FG, so that the four sections AB, CD, EF, and GH produce elastic stretching, and finally realize the spacing change of the slit 402 after mechanical balance. Preferably, different heating temperature ranges and different ratios of the upper connecting arm to the lower connecting arm are configured, and the adjustable width range of the slit 402 can reach 1-1000μm; the adjustment accuracy of the width of the slit 402 can reach several microns.

[0035] Example 2

[0036] The utility model also provides a magnetic mass spectrometer, which at least includes an ion source, a mass analyzer, an ion detector and other components. The ion source, the mass analyzer and the ion detector are connected in sequence, wherein the ion source is used to provide an ion beam, the emitted ion beam enters the mass analyzer and is separated by the mass analyzer, and the separated ion beam enters the ion detector in sequence to be collected; when the magnetic mass spectrometer is working, the ion source, the mass analyzer and the ion detector are all in a high vacuum state. The mass analyzer includes a main cavity, which is provided with an inlet and an outlet, the inlet is used to receive the ion beam emitted by the ion source, and the outlet is provided with a slit system as described in Example 1, which is used to guide out the separated ion beam.

[0037] Obviously, the above embodiments of the utility model are only examples for clearly explaining the technical solution of the utility model, and are not intended to limit the specific implementation methods of the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the utility model shall be included in the protection scope of the claims of the utility model.

Claims

1. A slit system with adjustable slit width, characterized in that: The slit system includes a thermal expansion module, a connecting rod module, a slit module and a fixing module. The thermal expansion module drives the temperature change by electricity and generates linear deformation. The connecting rod module includes two connecting arms that are cross-symmetrically arranged and movably hinged. The thermal expansion module is arranged between the upper ends of the connecting arms, and the slit modules are symmetrically arranged between the lower ends of the connecting arms. A slit with a certain width is formed between the slit modules. The thermal expansion module adjusts the horizontal spacing of the connecting arms and correspondingly adjusts the width of the slit. The thermal expansion module, the connecting rod module and the slit module are integrally installed by the fixing module.

2. The slit system according to claim 1, characterized in that: The fixing module includes a first fixing component and a second fixing component, the connecting rod module and the slit module are supported by the first fixing component, and the thermal expansion module is integrally fixed to the first fixing component through the second fixing component.

3. The slot system according to claim 2, characterized in that In the connecting rod module, the connecting arm is hinged by a rotating shaft, and the rotating shaft passes through the connecting arm and the first fixing component, and the first fixing component fixes the edge of the slit module; the connecting arm is divided into an upper connecting arm and a lower connecting arm with the position of the rotating shaft as a dividing line, the upper connecting arm is connected to the thermal expansion module, and the lower connecting arm extends into the first fixing component and is connected to the slit module.

4. The slot system according to claim 3, characterized in that The second fixing assembly is arranged in the middle of the horizontally arranged thermal expansion module and avoids the two ends of the thermal expansion module; The thermal expansion module includes a temperature regulating component and an expansion component. The upper connecting arm is symmetrically connected to both ends of the expansion component. The temperature regulating component is arranged in the middle of the expansion component, and the length of the expansion component in the horizontal direction is adjusted by controlling the temperature of the temperature regulating component.

5. The slot system according to claim 4, characterized in that The temperature regulating component is an electric heating coil, and the electric heating coil uniformly wraps the expansion component.

6. The slot system according to claim 3, characterized in that The slit module includes a slit assembly and a slit adjustment assembly. The slit assemblies are symmetrically arranged, and the spacing between them constitutes the slit of a certain width. The slit adjustment assembly is fixed in the first fixing assembly, and the slit assembly is installed in the center of the slit adjustment assembly; the slit adjustment assembly is connected to the lower connecting arm and is driven by the lower connecting arm to deform, thereby driving the slit assembly to move in the horizontal direction to adjust the width of the slit.

7. The slot system according to claim 6, characterized in that The first fixing component is composed of two circular rings connected front and back, and the slit component is two rectangles symmetrically arranged in the center of the circular ring, and a rectangular slit is formed between the rectangles; the slit adjustment component is fixed by the first fixing component and fills the other areas of the circular ring except the slit.

8. The slot system according to claim 7, characterized in that The lower connecting arm is parallel to the slit, and the connection position between the lower connecting arm and the slit adjustment component is close to the slit component and has the same width as the slit component in the vertical direction; the slit adjustment component connected to the upper and lower ends of the slit component has the same width in the vertical direction.

9. The slit system according to any one of claims 1 to 8, characterized in that: The width of the slit can be adjusted in the range of 1-1000 μm.

10. A magnetic mass spectrometer, comprising at least an ion source, a mass analyzer and an ion detector, wherein the ion source, the mass analyzer and the ion detector are connected in sequence, the ion source is used to provide an ion beam, the ion beam enters the mass analyzer and is separated by the mass analyzer, and the separated ion beam enters the ion detector in sequence to be collected; characterized in that: The ion source, the mass analyzer and the ion detector are all in a high vacuum state; the mass analyzer includes a main cavity, the main cavity is provided with an inlet and an outlet, the inlet is used to receive the ion beam, and the outlet is provided with a slit system as described in any one of claims 1-9, for exporting the separated ion beam.

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