Laser lens group for mass spectrometer

Abstract

The utility model discloses a laser lens group for mass spectrometer, including setting up the bottom of vacuum ion source chamber's lens mounting bracket, be provided with with the first installation hole of coaxial arrangement of incident laser on the lens mounting bracket, the included angle of the central axis of first installation hole and the flying direction of ion in vacuum ion source chamber is acute angle, laser lens group inserts and installs into first installation hole, including lens barrel and lens, the lens barrel is the splicing structure, and the splicing surface of lens barrel is coplanar with the central axis of first installation hole or parallel setting, the inner wall of lens barrel is spaced apart and is provided with a plurality of positioning clamping groove along the central axis direction, and the outer edge size of positioning clamping groove is compatible with lens, when laser lens group installs into first installation hole, the inner wall of first installation hole restricts the outer wall of lens barrel of laser lens group, and the stable structure of laser lens group is ensured, the utility model discloses ingenious structure, convenient installation, easy maintenance, and the focusing effect of lens group is good, and the equipment measurement accuracy is high, and the overall safety factor is high.

Description

Technical Field

[0001] This utility model relates to the field of mass spectrometer detection technology, and in particular to a laser lens assembly for a mass spectrometer. Background Technology

[0002] A mass spectrometer, also known as a mass spectrometer, consists of an ion source, a mass analyzer, and an ion detector as its core components. Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a commonly used soft ionization mass spectrometer. Its ion source is typically installed in a vacuum ion source chamber. The laser emitted from the laser passes through a lens group consisting of multiple lenses and is incident on the sample site. Soft ionization of biomolecules is achieved through laser desorption / ionization of the matrix and sample, producing intact molecular ions. The lens group is coaxial with the laser incident direction and is mounted inside the microscope tube and fixed to a support within the ion source chamber. Existing microscope tubes use a one-piece structure, including a large cylinder, a small cylinder, and a variable-diameter section connecting the two. Two lenses are located inside the small cylinder, and the other lens is located inside the large cylinder. During installation, the operator pushes the lens into its predetermined position inside the microscope tube and then glues it in place. Afterward, the microscope tube is mounted obliquely on the support and glued in place again. Because the lenses are bonded with adhesive, they are difficult to replace. If lens damage or incorrect installation is not detected in time, the entire lens assembly will be rendered unusable. Secondly, the proper installation of the lenses relies entirely on the operator's experience; inaccurate installation will affect the focusing effect of the lens assembly. Furthermore, because the lens barrel is inserted at an angle into the mounting hole of the bracket, insufficient adhesive bonding can easily cause the lens position to shift, affecting the equipment's detection performance. Finally, because the lens assembly is located within the chamber, the adhesive used for installation can create dead volumes between adjacent lenses, prolonging the vacuuming time of the ion source chamber. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a laser lens assembly for mass spectrometers that offers accurate lens positioning and convenient disassembly and replacement. Specifically, the following technical solution can be adopted:

[0004] The present invention relates to a laser lens assembly for a mass spectrometer. The laser lens assembly is disposed within the vacuum ion source chamber of the mass spectrometer. A lens mounting bracket is provided at the bottom of the vacuum ion source chamber, and the lens mounting bracket has a first mounting hole. The first mounting hole is coaxially aligned with the incident laser beam within the vacuum ion source chamber, and the angle between the central axis of the first mounting hole and the flight direction of the ions within the vacuum ion source chamber is acute. The laser lens assembly is inserted into the first mounting hole. The laser lens assembly includes a lens barrel and lenses disposed within the lens barrel. The lens barrel has a spliced ​​structure, and the splicing surface of the lens barrel is coplanar or parallel to the central axis of the first mounting hole. Multiple positioning slots are spaced along the central axis of the lens barrel, and the positioning slots are adapted to the outer edge dimensions of the corresponding lenses. When the laser lens assembly is installed in the first mounting hole, the inner wall of the first mounting hole constrains the outer wall of the lens barrel of the laser lens assembly, ensuring the structural stability of the laser lens assembly.

[0005] The aforementioned laser lens assembly uses two opposing spliced ​​lens barrels with positioning slots on the inner side of the barrels to facilitate lens positioning and installation. After the lens barrels are aligned, they are interference-fitted into the angled mounting holes of the lens mounting bracket, effectively preventing them from falling off or shifting from the lens mounting bracket. This also avoids the drawback of using glue for fixing, which causes time for vacuuming the ion source chamber.

[0006] The splicing surfaces of the lens barrels are either planar or mortise and tenon joints. Planar structures facilitate lens barrel assembly; mortise and tenon joints not only facilitate assembly but also help create a light-blocking environment.

[0007] The positioning slot is composed of a pair of limiting plates arranged on the inner surface of the lens barrel. The limiting plates have multiple or continuous annular structures spaced apart along the circumferential surface of the lens barrel. This structure is suitable for situations where the lens barrel wall is relatively thin.

[0008] The positioning slot is a circumferential groove provided on the inner wall of the lens barrel. This structure can be used when the lens barrel wall thickness is sufficient.

[0009] The lens barrel is made of insulating material, and an annular groove is formed on the outer surface of the lens barrel. In the vacuum ion source chamber, the annular groove can increase the creepage distance and reduce the risk of damage to components caused by high voltage discharge. Secondly, the annular groove can increase the surface roughness of the lens barrel, which can change the refraction angle of light, reduce the risk of light pollution, and avoid blurring of the camera window in the vacuum chamber.

[0010] An ion-passing channel is provided at the center of the lens mounting bracket. The ion-passing channel is connected to the lens mounting bracket through an insulating sleeve fitted on its outer side. The folded edge at the bottom of the insulating sleeve is fixedly connected to the lens mounting bracket by a bolt that passes vertically downward. The end of the bolt extends into the first mounting hole and presses against the outer wall of the lens barrel located in the first mounting hole.

[0011] The bolts used to fix the ion passage channel to the lens mounting bracket are long bolts. Based on the spatial characteristics of the laser lens group being inclined on one side of the vertical ion passage channel, the tail of the long bolts is cleverly used to press against the outer wall of the lens tube, further fixing the lens tube and enhancing the anti-detachment effect of the lens tube.

[0012] The outer surface of the lens barrel is a light-scattering surface.

[0013] The aforementioned surface treatment of the outer wall of the lens barrel, such as frosting or matte finish, can increase the roughness of the lens barrel surface, thereby causing diffuse reflection of the light incident on the outer wall of the lens barrel, reducing light pollution and ensuring a clear view of the camera window.

[0014] The lens mounting bracket is also provided with a second mounting hole, which is coaxially arranged with the camera tube. The second mounting hole is used to install the camera lens group. The lower end of the camera tube is connected to the camera lens group. The second mounting hole and the first mounting hole are respectively located on both sides of the ion flight direction.

[0015] The aforementioned camera mechanism is used to monitor the operating status of the mass spectrometer and record experimental procedures. The laser lens assembly for the mass spectrometer provided by this invention allows for precise lens mounting via a positioning slot. Because the lens and positioning slot are sized to fit each other, displacement is prevented. The lens barrel is interference-fitted with the first mounting hole and secured with bolts, ensuring it won't detach due to vibration even during bumpy transport, thus guaranteeing the overall stability of the system and the focusing effect of the lens assembly. Furthermore, the two-piece lens barrel of this invention allows for easy placement of the lens into the positioning slot before closing and securing it. During routine maintenance, simply loosen the bolts, remove the lens barrel, and open it for lens disassembly and replacement. Compared to traditional one-piece lens barrels, this operation is more convenient and faster. Since no glue is used throughout the process, the vacuum ion source chamber does not require additional time for evacuation. This invention features a clever structure, convenient installation, easy maintenance, excellent focusing effect of the lens assembly, high measurement accuracy, and a high overall safety factor. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 yes Figure 1A schematic diagram of the structure of the middle lens mounting bracket.

[0018] Figure 3 yes Figure 2 A schematic diagram of the middle half of the lens tube.

[0019] Figure 4 yes Figure 2 A schematic diagram of the mounting structure of the central lens barrel and lens.

[0020] Figure 5 yes Figure 4 Schematic diagram of the structure of the middle lens splicing surface Figure 1 .

[0021] Figure 6 yes Figure 4 Schematic diagram of the structure of the middle lens splicing surface Figure 2 . Detailed Implementation

[0022] The embodiments of this utility model will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific working processes. However, the protection scope of this utility model is not limited to the following embodiments.

[0023] like Figure 1-6 As shown, the laser lens assembly for a mass spectrometer described in this utility model includes a vacuum ion source chamber 1. A lens mounting bracket 2 is provided at the bottom of the vacuum ion source chamber 1. The lens mounting bracket 2 is provided with a first mounting hole. The first mounting hole is coaxially arranged with the incident laser in the vacuum ion source chamber 1. The angle between the central axis of the first mounting hole and the flight direction of the ions in the vacuum ion source chamber 1 is an acute angle. The laser lens assembly is inserted into the first mounting hole. The laser lens assembly includes a lens barrel 8 and a lens 10 disposed in the lens barrel. The lens barrel 8 is a spliced ​​structure. The splicing surface of the lens barrel is coplanar or parallel to the central axis of the first mounting hole. The inner wall of the lens barrel 8 is provided with multiple positioning slots 9 at intervals along its central axis direction. The positioning slots 9 are adapted to the outer edge dimensions of the corresponding lens 10. When the laser lens assembly is installed in the first mounting hole, the inner wall of the first mounting hole constrains the outer wall of the lens barrel 8 of the laser lens assembly to ensure the structural stability of the laser lens assembly.

[0024] In one embodiment of this utility model, a lens barrel 8 is interference-fitted into the first mounting hole, and the lens barrel 8 is inclined outward from bottom to top on the lens mounting bracket 2. The lens barrel 8 is a two-piece spliced ​​structure, and the splicing surface of the lens barrel 8 is coplanar with the central axis of the first mounting hole. The splicing surface of the lens barrel 8 can be a planar structure (see...). Figure 5 This facilitates the assembly of the lens barrel 8. The joint surfaces of the lens barrel 8 can also be mortise and tenon joints (see...). Figure 6 This not only improves the accuracy of assembly, but also helps to create a light-blocking environment when the two parts overlap during assembly.

[0025] Multiple positioning slots 9 are arranged from top to bottom on the inner wall of the lens barrel 8. These slots 9 are used to mount the lens 10. Each positioning slot 9 is adapted to the outer edge size of the lens 10 installed within it, thus firmly fixing the lens 10 in place. Even without glue, it will not easily shift. The positions of these positioning slots 9 are carefully designed according to the focusing requirements of the lens group. Therefore, as long as the lens 10 is installed in the positioning slot 9 according to the design scheme, a good focusing effect can be achieved.

[0026] The lens barrel 8 is made of insulating material. When the wall thickness of the lens barrel 8 is relatively thin, a raised limiting plate is usually provided on the inner surface of the lens barrel 8 to form a positioning groove 9. The limiting plates are provided in pairs and can adopt an intermittent structure along the circumferential surface of the lens barrel 8 or a continuous annular structure along the inner wall of the lens barrel 8. When the wall thickness of the lens barrel 8 is sufficiently thick, an circumferential groove can be formed on the inner wall of the lens barrel 8 as a positioning groove 9. Regardless of the form, its size must be adapted to the outer edge size of the lens 10.

[0027] Since the lens barrel 8 is located inside the vacuum ion source chamber 1, an annular groove 11 is provided on the outer surface of the lens barrel 8 to increase the creepage distance and reduce the risk of component damage caused by high-voltage discharge. Secondly, the annular groove 11 can increase the surface roughness of the lens barrel 8, thereby changing the refraction angle of light, reducing the risk of light pollution, and preventing the camera (located at the top of the camera barrel 7) inside the vacuum chamber 1 from becoming blurry. In other embodiments of this utility model, the outer surface of the lens barrel 8 can also be set as a light scattering surface, for example, the outer wall of the lens barrel 8 can be treated with frosted, matte, or other surface treatments, so that the light incident on the outer wall of the lens barrel 8 undergoes diffuse reflection, reducing light pollution and ensuring a clear camera window.

[0028] An ion-passing channel 3 is provided at the center of the lens mounting bracket 2. The central axis of the ion-passing channel 3 coincides with the ion flight direction. The ion-passing channel 3 is connected to the lens mounting bracket 2 through an insulating sleeve 4 sleeved on its outer side. The folded edge at the bottom of the insulating sleeve 4 is fixedly connected to the lens mounting bracket 2 by a bolt 5 that passes vertically downward. The end of the bolt 5 extends into the first mounting hole and presses against the outer wall of the lens barrel 8 located in the first mounting hole, thereby further fixing the laser lens assembly in the first mounting hole.

[0029] After the lens 10 is installed inside the lens barrel 8, the lens barrel 8 is tilted into the first mounting hole of the lens mounting bracket 2, with its end extending below the folded edge of the insulating sleeve 4. The lens barrel 8 and the first mounting hole are interference-fitted, making it difficult for the lens barrel 8 to change position easily. Multiple vertically downward bolts 5 are installed on the bottom folded edge of the insulating sleeve 4. The bolts 5 pass through the insulating sleeve 4 and are screwed onto the lens mounting bracket 2, fixing the two together. The bolts 5 are long enough that their ends press against the outer wall of the lens barrel 8 to secure it, further preventing the lens barrel 8 from shifting and avoiding it from coming out of the first mounting hole due to vibration during transportation.

[0030] The lens mounting bracket 2 is also provided with a second mounting hole, which is coaxially arranged with the camera tube 7. The second mounting hole is used to install the camera lens group. The lower end of the camera tube 7 is connected to the camera lens group. The second mounting hole and the first mounting hole are located on both sides of the ion flight direction (i.e., ions pass through the channel 3).

[0031] It should be noted that in the description of this utility model, terms such as "front", "rear", "left", "right", "vertical", "horizontal", "inner", and "outer" indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

Claims

1. A laser lens assembly for a mass spectrometer, the laser lens assembly being disposed within the vacuum ion source chamber of the mass spectrometer, characterized in that: A lens mounting bracket is provided at the bottom of the vacuum ion source chamber. The lens mounting bracket has a first mounting hole, which is coaxially arranged with the incident laser in the vacuum ion source chamber. The angle between the central axis of the first mounting hole and the flight direction of the ions in the vacuum ion source chamber is an acute angle. The laser lens assembly is inserted into the first mounting hole. The laser lens assembly includes a lens barrel and lenses disposed within the lens barrel. The lens barrel has a spliced ​​structure, and the splicing surface of the lens barrel is coplanar or parallel to the central axis of the first mounting hole. The inner wall of the lens barrel has multiple positioning slots spaced along its central axis, and the positioning slots are adapted to the outer edge dimensions of the corresponding lenses. When the laser lens assembly is installed in the first mounting hole, the inner wall of the first mounting hole constrains the outer wall of the lens barrel of the laser lens assembly, ensuring the structural stability of the laser lens assembly.

2. The laser lens assembly for a mass spectrometer according to claim 1, characterized in that: The splicing surface of the lens tube is either a planar structure or a mortise and tenon structure for splicing together.

3. The laser lens assembly for a mass spectrometer according to claim 1, characterized in that: The positioning slot is composed of a pair of limiting plates arranged on the inner surface of the lens barrel. The limiting plates are provided with multiple or continuous annular structures at intervals along the annular surface of the lens barrel.

4. The laser lens assembly for a mass spectrometer according to claim 1, characterized in that: The positioning slot is a circumferential groove set on the inner wall of the lens barrel.

5. The laser lens assembly for a mass spectrometer according to claim 1, characterized in that: The lens barrel is made of insulating material, and an annular groove is formed on the outer surface of the lens barrel.

6. The laser lens assembly for a mass spectrometer according to claim 1, characterized in that: An ion-passing channel is provided at the center of the lens mounting bracket. The ion-passing channel is connected to the lens mounting bracket through an insulating sleeve fitted on its outer side. The folded edge at the bottom of the insulating sleeve is fixedly connected to the lens mounting bracket by a bolt that passes vertically downward. The end of the bolt extends into the first mounting hole and presses against the outer wall of the lens barrel located in the first mounting hole.

7. The laser lens assembly for a mass spectrometer according to claim 1, characterized in that: The outer surface of the lens barrel is a light-scattering surface.

8. The laser lens assembly for a mass spectrometer according to claim 1, characterized in that: The lens mounting bracket is also provided with a second mounting hole, which is coaxially arranged with the camera barrel. The second mounting hole is used to install the camera lens group. The lower end of the camera barrel is connected to the camera lens group. The second mounting hole and the first mounting hole are located on opposite sides of the ion flight direction.

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