A high-resolution double-focusing mass spectrometer analysis system

Abstract

This invention relates to isotope analysis technology, specifically a high-resolution dual-focusing mass spectrometer analysis system. It includes an electrostatic analyzer, a front-end flight tube mounted at the front of the electrostatic analyzer, a rear-end flight tube mounted at the rear of the electrostatic analyzer, a magnetic analysis flat tube connected to the rear-end flight tube, and a magnetic analyzer connected to the aforementioned magnetic analysis flat tube. The electrostatic analyzer includes an electrostatic shield, an outer electrode plate and an inner electrode plate mounted within the electrostatic shield, and a front grounding electrode and a rear grounding electrode respectively mounted at both ends of the outer and inner electrode plates. By designing a mutually matched electrostatic and magnetic analyzer, the instrument resolution is effectively improved, and its application range is expanded. The design of the insulating pads and grounding electrodes in the electrostatic analyzer effectively reduces the influence of the diffuse field at the end of the electrostatic analyzer on the ion trajectory.

Description

Technical Field

[0001] The present invention belongs to the field of isotope analysis technology, and particularly relates to a high-resolution double-focusing mass spectrometer analysis system. Background Art

[0002] The magnetic mass spectrometer only involves a single analysis system, namely the magnetic analysis system. This kind of analysis system has an unsatisfactory separation effect on ion sources with large energy dispersion. The large energy dispersion leads to a widened image, thus affecting the analysis results. In order to improve the instrument resolution, an electrostatic analysis system matching the magnetic field can be designed to focus the energy of ions before they enter the magnetic analyzer.

[0003] The electrostatic analyzer and the magnetic analyzer are the focusing systems coupled with each other in the double-focusing high-resolution mass spectrometer. The two analysis systems respectively perform energy focusing and mass focusing on the isotope ions of the sample to be measured. The principle is that the energy dispersion of ions in the electrostatic analyzer is exactly offset by the energy dispersion of the magnetic analyzer, so that charged particles with different energies and movement directions converge at one point. The double-focusing system effectively improves the instrument resolution and reduces the interference of isobars.

[0004] The electrostatic analyzer mainly consists of four parts: positive and negative electrode plates, a shielding cover, end insulating gaskets, and a grounding electrode. When a DC voltage is applied to the positive and negative electrode plates, a uniform electric field is generated between the two plates. Charged particles with different energies have different movement trajectories in the uniform electric field, and ions with the same energy converge at a certain point at the beam extraction end, and then drift through a section of path and enter the magnetic analyzer;

[0005] The magnetic analyzer mainly consists of three parts: a U-shaped magnetic yoke, pole shoes, and a pole shoe winding coil. The two pole shoes are respectively placed on the upper and lower sides of the U-shaped magnetic yoke. When the coil outside the pole shoes is energized, a uniform magnetic field exists in the gap between the upper and lower pole shoes. The difference in the movement trajectories of ions with different charge-to-mass ratios in the magnetic field forms a separation effect.

[0006] The advantages of high sensitivity and high resolution of the double-focusing mass spectrometer have enabled it to be widely used in many interdisciplinary fields, such as: earth science, paleometeorological science, extraterrestrial meteorites, and biological fossil analysis, nuclear power plant safety analysis, etc. Summary of the Invention

[0007] The purpose of the present invention is to provide a high-resolution double-focusing mass spectrometer analysis system, which can improve the instrument resolution and expand its application range.

[0008] The technical solution of the present invention is as follows:

[0009] A high-resolution double-focusing mass spectrometer analysis system, comprising an electrostatic analyzer, a front flight tube installed at the front end of the electrostatic analyzer, a rear flight tube installed at the rear end of the electrostatic analyzer, a magnetic analysis flat tube connected to the rear flight tube, and a magnetic analyzer connected to the magnetic analysis flat tube;

[0010] The electrostatic analyzer comprises an electrostatic shielding cover, an outer electrode plate and an inner electrode plate installed in the electrostatic shielding cover, and a front grounding electrode and a rear grounding electrode respectively installed at both ends of the outer electrode plate and the inner electrode plate.

[0011] The electrostatic shielding cover is an arc-shaped circular tube, inside which an outer electrode plate and an inner electrode plate of the same arc are installed; the outer electrode plate is installed on the outer side of the arc, and the outer electrode plate pad is fixedly installed on the middle position of the upper part; the inner electrode plate is installed on the inner side of the arc, and the inner electrode plate pad is fixedly installed on the middle position of the upper part.

[0012] Insulating gaskets are installed on the inner sides of the front-end grounding electrode and the rear-end grounding electrode respectively; ceramic gaskets are installed on the outer sides of the front-end grounding electrode and the rear-end grounding electrode respectively.

[0013] The outer side wall of the electrostatic shielding cover is also fixedly mounted with a terminal flange port, a vacuum pump flange port, and a terminal flange port.

[0014] The terminal flange port, vacuum pump flange port and terminal flange port are installed at the upper end of the outer side wall of the electrostatic shielding cover and are evenly distributed on the arc segment.

[0015] The front flight tube comprises a front tube and a front mounting flange, and is fixedly connected to the front end of the electrostatic analyzer via the front mounting flange.

[0016] The rear end flight tube includes a rear end mounting flange, a rear end tube, and a flange bellows fixedly mounted on the end of the rear end tube. It is fixedly connected to the rear end of the electrostatic analyzer through the rear end mounting flange and connected to the magnetic analysis flat tube through the flange structure of the flange bellows.

[0017] The magnetic analysis flat tube is an arc-shaped flat tube with a cavity inside and flanges installed at both ends.

[0018] The front-end grounding electrode and the rear-end grounding electrode have the same structure, including two mounting plates arranged in an L shape, wherein screw holes are processed on the upper and lower parts of one mounting plate respectively for fixing to the outer electrode plate and the inner electrode plate at the corresponding positions, and screw holes are processed on the other mounting plate for fixed connection to the inner wall of the electrostatic analyzer.

[0019] The described magnetic analyzer includes a U-shaped magnetic yoke, an upper pole shoe, a lower pole shoe, an upper winding package body, and a lower winding package body installed inside the U-shaped opening of the U-shaped magnetic yoke; the upper winding package body and the lower winding package body are respectively fixedly installed on the inner side wall of the U-shaped opening, and the upper pole shoe and the lower pole shoe are correspondingly installed inside the upper winding package body and the lower winding package body; there is a certain gap between the relative installation surfaces of the upper pole shoe and the lower pole shoe.

[0020] The size of the gap can accommodate the thickness of the magnetic analysis flat tube.

[0021] The upper pole shoe is parallel welded to the upper end of the upper winding package body, and the lower pole shoe is parallel welded to the lower end of the lower winding package body; the upper winding package body and the lower winding package body are respectively fixedly connected to the U-shaped magnetic yoke by screws.

[0022] Its ion deflection parameters are designed as follows: the ion orbit radius is 520 mm, the deflection angle is 63.7°, the magnetic field ion orbit radius is 250 mm, the deflection angle is 90°, the incident angle is 30°, and the exit angle is 24°.

[0023] The remarkable effects of the present invention are as follows:

[0024] By designing a mutually matching electrostatic analyzer and magnetic analyzer, the resolution of the instrument is effectively improved and its application range is increased;

[0025] The design of the insulating gasket and the grounding electrode in the electrostatic analyzer effectively reduces the influence of the end dispersion field of the electrostatic analyzer on the ion trajectory;

[0026] The inner electrode plate and the outer electrode plate are fixed in the shielding cover by using the grounding electrode, effectively saving the internal space of the electrostatic analyzer on the premise of ensuring stability;

[0027] For the bellows part of the flight tube at the rear end of the electrostatic analyzer, the tolerance rate of machining error and installation error is increased, and the bellows can be translated during the debugging process to make the focusing point match the magnetic analyzer;

[0028] The barbs design on the inner side of the magnetic analysis flat tube increases the probability of ions deviating from the orbit colliding with the inner wall and also achieves better heat dissipation conditions;

[0029] Welding the pole shoe and the winding package body and fixing them to the U-shaped magnetic yoke by screws effectively increases the stability of the magnetic analyzer and ensures the uniform distribution of the magnetic field. Description of the Drawings

[0030] Figure 1 It is a schematic diagram of the analysis system of a high-resolution double-focusing mass spectrometer;

[0031] Figure 2 It is a schematic diagram of the front-end flight tube;

[0032] Figure 3 It is a schematic diagram of an electrostatic analyzer;

[0033] Figure 4 It is a schematic diagram of the front-end grounding electrode and the rear-end grounding electrode structure;

[0034] Figure 5 It is a schematic diagram of the rear-end flight tube;

[0035] Figure 6 It is a schematic diagram of a magnetic analysis flat tube;

[0036] Figure 7 It is a schematic diagram of a magnetic analyzer;

[0037] Figure 8 It is a schematic diagram of the connection between the upper-side winding package and the U-shaped magnetic yoke in the magnetic analyzer;

[0038] In the figure: 1. Front-end flight tube; 101. Front-end tube barrel; 102. Front-end mounting flange; 2. Electrostatic analyzer; 3. Rear-end flight tube; 301. Rear-end flange; 302. Rear-end tube barrel; 303. Flange bellows; 4. Magnetic analysis flat tube; 5. Magnetic analyzer; 6. Terminal flange port; 7. Vacuum pump flange port; 8. Terminal flange port; 9. Outer electrode plate; 10. Inner electrode plate; 11. Electrostatic shielding cover; 12. Front-end grounding electrode; 13. Rear-end grounding electrode; 14. Insulating gasket a; 15. Insulating gasket b; 16. Insulating gasket c; 17. Insulating gasket d; 18. Ceramic gasket a; 19. Ceramic gasket b; 20. Ceramic gasket c; 21. Ceramic gasket d; 22. Outer electrode plate pad column; 23. Inner electrode plate pad column; 24. U-shaped magnetic yoke; 25. Upper-side pole shoe; 26. Lower-side pole shoe; 27. Upper-side winding package; 28. Lower-side winding package; 29. Screw hole. Specific embodiments

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0040] As Figure 1 shown in the high-resolution double-focusing mass spectrometer analysis system, which includes an electrostatic analyzer 2, a front-end flight tube 1 installed at the front end of the electrostatic analyzer 2, a rear-end flight tube 3 installed at the rear end of the electrostatic analyzer 2, a magnetic analysis flat tube 4 connected to the rear-end flight tube 3, and a magnetic analyzer 5 connected to the magnetic analysis flat tube 4;

[0041] As Figure 2 shown, the front-end flight tube 1 is installed at the front end of the electrostatic analyzer 2, and it includes a front-end tube barrel 101 and a front-end mounting flange 102. During installation, it is fixedly connected to the front end of the electrostatic analyzer 2 through the front-end mounting flange 102.

[0042] As Figure 3As shown, the electrostatic analyzer 2 includes an electrostatic shielding cover 11, an outer electrode plate 9 and an inner electrode plate 10 installed in the electrostatic shielding cover 11, and a front end grounding electrode 12 and a rear end grounding electrode 13 respectively installed at both ends of the outer electrode plate 9 and the inner electrode plate 10. In addition, a terminal flange port 6, a vacuum pump flange port 7, and a terminal flange port 8 are fixedly installed on the outer wall of the electrostatic shielding cover 11.

[0043] The electrostatic shielding cover 11 is an arc-shaped circular tube, and the outer electrode plate 9 and the inner electrode plate 10 installed inside the outer electrode plate 9 are also arc-shaped, and the curvature of all arcs is the same, and the outer electrode plate 9 is installed on the outer side of the arc, and the outer electrode plate pad column 22 is fixedly installed at the upper middle position, and the inner electrode plate 10 is installed on the inner side of the arc; and the inner electrode plate pad column 23 is fixedly installed at the upper middle position;

[0044] The front end grounding electrode 12 and the rear end grounding electrode 13 installed at both ends of the electrode plate are fixedly connected by screws. When connected, the inner sides of the front end grounding electrode 12 and the rear end grounding electrode 13 are respectively installed with insulating gaskets a14, insulating gaskets b15, insulating gaskets c16, and insulating gaskets d17; the outer sides of the front end grounding electrode 12 and the rear end grounding electrode 13 are respectively installed with ceramic gaskets a18, ceramic gaskets b19, ceramic gaskets c20, and ceramic gaskets d21.

[0045] The terminal flange port 6 , the vacuum pump flange port 7 , and the terminal flange port 8 may be installed at the upper end of the outer wall of the electrostatic shielding cover 11 , and the positions are evenly distributed on the arc segment.

[0046] The design of the insulating gasket effectively reduces the influence of the end diffuse field on the ion movement trajectory; the grounding electrode is fixed to the electrode plates at both ends with screws, which improves the stability of the electrode plates.

[0047] like Figure 4 The front end grounding electrode 12 and the rear end grounding electrode 13 shown in the figure have the same structure, including two mounting plates arranged in an L shape, one of which has screw holes 29 processed on the upper and lower parts respectively for fixing with the outer electrode plate 9 and the inner electrode plate 10 at the corresponding positions, and the other one has screw holes 29 processed on the upper and lower parts for fixing with the inner wall of the electrostatic analyzer 2.

[0048] like Figure 5 As shown, the rear end flight tube 3 includes a rear end mounting flange 301, a rear end tube 302, and a flange bellows 303 fixedly mounted on the end of the rear end tube 302. During installation, the rear end flight tube 3 is fixedly connected to the rear end of the electrostatic analyzer 2 through the rear end mounting flange 301, and then connected to the magnetic analysis flat tube 4 through the flange structure of the flange bellows 303.

[0049] The corrugated design effectively compensates for the deviation of the ion focusing point from the predetermined trajectory caused by workpiece processing errors or installation errors, thereby increasing the system fault tolerance.

[0050] As shown Figure 6 in Figure 6 , the magnetic analysis flat tube 4 is an arc-shaped flat tube with a cavity inside, and the flanges installed at both ends thereof. The flange at one end is used to connect with the rear flight tube 3, and the design of the flat tube facilitates the fixed connection with the magnetic analyzer 5.

[0051] The magnetic analysis flat tube 4 provides a good vacuum environment for the magnetic analyzer. Its inner cavity can be treated with barbs, increasing the absorption rate of ions deviating from the orbit.

[0052] As shown Figure 7 in Figure 7 , the magnetic analyzer 5 includes a U-shaped magnetic yoke 24, an upper pole shoe 25, a lower pole shoe 26, an upper winding package body 27, and a lower winding package body 28 installed on the inner side of the U-shaped opening of the U-shaped magnetic yoke 24.

[0053] Among them, the upper winding package body 27 and the lower winding package body 28 are respectively fixedly installed on the inner side wall of the U-shaped opening. The upper pole shoe 25 and the lower pole shoe 26 are correspondingly installed on the inner sides of the upper winding package body 27 and the lower winding package body 28; there is a certain gap between the relative mounting surfaces of the upper pole shoe 25 and the lower pole shoe 26, and the size of the gap can accommodate the thickness of the magnetic analysis flat tube 4. When installed, there is an installation gap of 0.5 mm between the upper and lower surfaces of the magnetic analysis flat tube 4 and the mounting surfaces of the corresponding upper pole shoe 25 and lower pole shoe 26 respectively;

[0054] As shown Figure 8 in Figure 8 , the upper pole shoe 25 is parallel welded to the upper end of the upper winding package body 27, and then fixed to the U-shaped magnetic yoke 24 by using screws through the screw holes machined on the upper end surface of the U-shaped magnetic yoke 24 respectively;

[0055] Similarly, after the lower pole shoe 26 is parallel welded to the lower end of the lower winding package body 28, it is fixed to the lower end surface of the U-shaped magnetic yoke 24 by screws, and its fixing method is the same as that of the upper end surface.

[0056] The winding package body forms an integral body with the pole shoe through the welding process. Both the upper and lower pole shoes are fixed to the U-shaped magnetic yoke by two M14 screws. This invention enhances the stability of the magnetic analyzer and effectively solves the problem of uneven magnetic field distribution caused by asymmetric installation of the pole shoes.

[0057] When installing this device,

[0058] First, the screws at the beam inlet end (front end) of the electrostatic analyzer 2 are sequentially passed through the ceramic gaskets, then inserted into the screw holes of the front grounding electrode 12 respectively, and then the insulating gaskets are sleeved respectively, and finally fully screwed into the electrode plate; at the beam outlet end (rear end) of the electrostatic analyzer, the installation scheme of the rear grounding electrode 13 is the same as that of the beam inlet end.

[0059] Then, place the outer electrode plate pad post 22 and the inner electrode plate pad post 23 at the bottoms of the outer electrode plate 9 and the inner electrode plate 10 respectively, and fix them with M6 countersunk head screws.

[0060] After that, use screws to pass through the screw holes of the front end grounding electrode 12 of the electrostatic analyzer 2 respectively, and tighten and fix them to the electrostatic shielding cover 11; the installation scheme of the rear end grounding electrode 13 is the same as that at the beam inlet end.

[0061] The flange port 6, the connection vacuum pump port 7, and the flange port 8 are respectively connected to their corresponding installation positions through screws.

[0062] The front end flight tube 1, the electrostatic analyzer 2, the rear end flight tube 3, and the magnetic analysis flat tube 4 are sequentially connected by corresponding flange ports with screws.

[0063] Then, weld the upper pole shoe 25 parallel to the upper end of the upper winding package body 27, and then use two M14 screws to fix it on the C-shaped magnetic yoke 24 through the screw holes respectively. After the lower pole shoe 26 is welded parallel to the lower end of the lower winding package body 28, it is fixed to the lower end of the C-shaped magnetic yoke 24 by two M14 screws, and its fixing method is the same as that of the upper side.

[0064] Finally, translate the magnetic analyzer 5 to the ion deflection path (arc-shaped flat tube) of the magnetic analysis flat tube 4. The gap between the upper pole shoe 25 and the lower pole shoe 26 just allows the magnetic analysis flat tube 4 to pass through, and there is a surplus position of 0.5 mm on both the upper and lower sides.

[0065] The preferred ion deflection parameters in this embodiment are: the ion orbital radius is 520 mm, the deflection angle is 63.7°; the magnetic field ion orbital radius is 250 mm, the deflection angle is 90°, the incident angle is 30°, and the exit angle is 24°.

Claims

1. A high-resolution double-focusing mass spectrometer analysis system, characterized in that: It includes an electrostatic analyzer (2), a front flight tube (1) installed at the front end of the electrostatic analyzer (2), a rear flight tube (3) installed at the rear end of the electrostatic analyzer (2), a magnetic analysis flat tube (4) connected to the rear flight tube (3), and a magnetic analyzer (5) connected to the magnetic analysis flat tube (4); The electrostatic analyzer (2) includes an electrostatic shielding cover (11), an outer electrode plate (9) and an inner electrode plate (10) installed inside the electrostatic shielding cover (11), and a front grounding electrode (12) and a rear grounding electrode (13) respectively installed at both ends of the outer electrode plate (9) and the inner electrode plate (10); The electrostatic shielding cover (11) is an arc-shaped circular tube, and the outer electrode plate (9) and the inner electrode plate (10) with the same radian are installed inside it; the outer electrode plate (9) is installed on the arc-shaped outer side, and an outer electrode plate pad column (22) is fixedly installed at the middle position of the upper part thereof, and the inner electrode plate (10) is installed on the arc-shaped inner side, and an inner electrode plate pad column (23) is fixedly installed at the middle position of the upper part thereof; Insulating gaskets are respectively installed on the inner sides of the front grounding electrode (12) and the rear grounding electrode (13); ceramic gaskets are respectively installed on the outer sides of the front grounding electrode (12) and the rear grounding electrode (13); The magnetic analyzer (5) includes a U-shaped magnetic yoke (24), an upper pole shoe (25), a lower pole shoe (26), an upper winding package body (27) and a lower winding package body (28) installed inside the U-shaped opening of the U-shaped magnetic yoke (24); the upper winding package body (27) and the lower winding package body (28) are respectively fixedly installed on the inner side walls of the U-shaped opening, and the upper pole shoe (25) and the lower pole shoe (26) are correspondingly installed inside the upper winding package body (27) and the lower winding package body (28); a certain gap is provided between the relative installation surfaces of the upper pole shoe (25) and the lower pole shoe (26).

2. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 1, characterized in that: A terminal flange port (6), a vacuum pump flange port (7), and a terminal flange port (8) are also fixedly installed on the outer side wall of the electrostatic shielding cover (11).

3. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 2, characterized in that: The terminal flange port (6), the vacuum pump flange port (7), and the terminal flange port (8) are installed at the upper end of the outer side wall of the electrostatic shielding cover (11), and their positions are evenly distributed on the arc section.

4. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 1, characterized in that: The front flight tube (1) includes a front tube barrel (101) and a front mounting flange (102), and is fixedly connected to the front end of the electrostatic analyzer (2) through the front mounting flange (102).

5. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 1, characterized in that: The rear flight tube (3) includes a rear mounting flange (301), a rear tube barrel (302), and a flange bellows (303) fixedly installed at the end of the rear tube barrel (302), and is fixedly connected to the rear end of the electrostatic analyzer (2) through the rear mounting flange (301), and is connected to the magnetic analysis flat tube (4) through the flange structure of the flange bellows (303).

6. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 1, characterized in that: The magnetic analysis flat tube (4) is an arc-shaped flat tube with a cavity inside, and flanges installed at both ends thereof.

7. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 1, characterized in that: The front grounding electrode (12) and the rear grounding electrode (13) have the same structure, including two mounting plates arranged in an L shape. Screw holes are respectively machined in the upper and lower parts of one mounting plate for fixing to the outer electrode plate (9) and the inner electrode plate (10) at the corresponding positions, and screw holes are machined in the other mounting plate for fixedly connecting to the inner wall of the electrostatic analyzer (2).

8. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 1, characterized in that: The size of the gap can accommodate the thickness of the magnetic analysis flat tube (4).

9. A high-resolution double-focusing mass spectrometer analysis system as claimed in claim 1, characterized in that: The upper pole shoe (25) is welded in parallel with the upper end of the upper winding package body (27), and the lower pole shoe (26) is welded in parallel with the lower end of the lower winding package body (28); the upper winding package body (27) and the lower winding package body (28) are respectively fixedly connected to the C-shaped magnetic yoke (24) by screws.

10. The high-resolution double-focusing mass spectrometer analysis system according to claim 1, characterized in that: Its ion deflection parameters are designed as follows: the ion orbit radius is 520 mm, the deflection angle is 63.7°, the magnetic field ion orbit radius is 250 mm, the deflection angle is 90°, the incident angle is 30°, and the exit angle is 24°.

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