A closed Faraday receiving cup structure

Abstract

The present invention belongs to the technical field of mass spectrometry instruments, and particularly relates to a closed Faraday receiving cup structure. The present invention includes a T-shaped ceramic part, a square ceramic pad, a shielding box, a graphite cup, a slit piece, a positioning ceramic piece, a positioning ceramic column, a suppression grid, a first ceramic tube, and a second ceramic tube. A step is provided inside the shielding box, and a step is provided on the side at the bottom of the step, and the suppression grid is installed on the step; the slit piece is installed on the side of the shielding box; the graphite cup is installed at the bottom of the shielding box through the T-shaped ceramic part, and a square ceramic pad is provided between the graphite cup and the shielding box; a positioning ceramic piece is installed on the upper surface of the graphite cup, and a positioning ceramic column is provided on the positioning ceramic piece; first lead holes and second lead holes are provided on the side of the shielding box, and the first ceramic tube and the second ceramic tube are respectively installed. The present invention effectively eliminates the influence of scattered ions on the detection of effective ions by the receiving cup and improves the performance of the instrument.

Description

Technical Field

[0001] The present invention belongs to the technical field of mass spectrometry instruments, and particularly relates to a closed Faraday receiving cup structure. Background Art

[0002] The receiver of a mass spectrometer is a key component of a mass spectrometry instrument. The receiver of a mass spectrometer generally mainly consists of a Faraday receiving cup, a receiving cup adjusting mechanism, a receiver cylinder, etc. Generally, there is a shielding box, a graphite cup, a suppression grid and a slit plate in a receiving cup, and each component is connected and fixed by screws and ceramic parts. After assembling each receiving cup to the theoretical position, the isotope ions separated and dispersed by the mass analyzer will be accurately focused on each receiving cup. A magnetic mass spectrometer utilizes the principle that ions with different mass-to-charge ratios will be separated in an electromagnetic field, and then the abundances and contents of the separated isotopes or different elements are precisely determined by the intensity of the ion signals received by the receiving cups. The Faraday receiving cup is the core component for a mass spectrometer to achieve precise detection of different substances to be measured. In the prior art, generally, the entrance of the shielding box and the entrance of the receiving cup are on the same plane. The suppression grid and the slit plate are assembled outside the shielding box, separated by ceramic columns respectively, and fixed by screws. Such a structure will make the entrance of the receiving cup in an open state, and scattered ions will enter the receiving cup through the gap between the suppression grid and the receiving cup, thus affecting the measurement accuracy of the instrument. Summary of the Invention

[0003] The technical problem solved by the present invention is to provide a closed Faraday receiving cup structure in view of the defects in the structure of the receiving cup of the existing mass spectrometer, effectively eliminating the influence of scattered ions on the effective ions detected by the receiving cup and improving the performance of the instrument.

[0004] The technical solution adopted by the present invention:

[0005] A closed Faraday receiving cup structure includes a T-shaped ceramic part, a square ceramic pad, a shielding box, a graphite cup, a slit plate, a positioning ceramic piece, a positioning ceramic column, a suppression grid, a first ceramic tube, and a second ceramic tube. A step is provided inside the shielding box, and a step is provided on the side at the bottom of the step, and the suppression grid is installed on the step; the slit plate is installed on the side of the shielding box; the graphite cup is installed at the bottom of the shielding box through the T-shaped ceramic part, and a square ceramic pad is provided between the graphite cup and the shielding box; a positioning ceramic piece is installed on the upper surface of the graphite cup, and a positioning ceramic column is provided on the positioning ceramic piece; first lead holes and second lead holes are provided on the side of the shielding box, and the first ceramic tube and the second ceramic tube are respectively installed.

[0006] The material of the graphite cup is graphite material, effectively reducing the generation of secondary ions;

[0007] The step is provided with a first assembly hole. The suppression grid includes a suppression grid support, a suppression grid side, and a third assembly hole. Two suppression grid supports and two suppression grid sides are connected by spot welding, and a gap is left between the two suppression grid supports. The position of the third assembly hole is matched with the position of the first assembly hole. The suppression grid is installed on one side of the shielding box through a suppression grid mounting post;

[0008] The side of the shielding box is provided with a threaded hole. Both sides of the slit plate are provided with second assembly holes, and the positions of the second assembly holes are matched with the threaded hole. The slit plate is installed on the shielding box through screws;

[0009] A through hole matching the gap above the suppression grid is opened in the middle of the slit plate;

[0010] A suppression grid support post and a cover plate are arranged between the slit plate and the suppression grid mounting post.

[0011] The suppression grid mounting post is made of ceramic material and is matched with a suppression grid washer.

[0012] The ceramic tube is placed in the first lead hole to ensure that the lead of the suppression grid is connected to the outside of the receiving cup, and it can be insulated from the shielding box through the function of the ceramic tube; the ceramic tube is placed in the second lead hole to ensure that the lead of the graphite cup is connected to the outside of the receiving cup, and it can be insulated from the shielding box through the function of the ceramic tube.

[0013] The surface roughness of the inner surface of the slit plate is required to be within 0.8.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] (1) A closed Faraday receiving cup structure provided by the present invention effectively eliminates the influence of scattered ions on the detection of effective ions by the receiving cup and improves the performance of the instrument.

[0016] (2) A closed Faraday receiving cup structure provided by the present invention improves the ion receiving stability and the performance of the instrument.

[0017] (3) A closed Faraday receiving cup structure provided by the present invention improves the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a closed Faraday receiving cup structure provided by the present invention;

[0019] Figure 2 is a schematic structural diagram of the shielding box;

[0020] Figure 3 is a schematic structural diagram of the receiving cup;

[0021] Figure 4Schematic diagram of the slit sheet structure;

[0022] Figure 5 Schematic diagram of the inhibitory grid assembly post structure;

[0023] Figure 6 Schematic diagram of the inhibitory grid structure;

[0024] In the figure: 1 - T-shaped ceramic part, 2 - square ceramic pad, 3 - cover plate, 4 - shielding box, 5 - graphite cup, 6 - slit sheet, 7 - inhibitory grid washer, 8 - inhibitory grid mounting post, 9 - inhibitory grid support post, 10 - positioning ceramic piece, 11 - positioning ceramic post, 12 - inhibitory grid, 13 - screw, 14 - first ceramic tube, 15 - second ceramic tube, 16 - first assembly hole, 17 - first lead hole, 18 - threaded hole, 19 - groove, 20 - threaded hole, 21 - second lead hole, 22 - lead hole, 23 - cover plate groove, 24 - threaded hole, 19 - groove, 25 - assembly hole, 26 - lead hole groove, 27 - second assembly hole, 28 - limit hole, 29 - inhibitory grid support, 30 - inhibitory grid side, 31 - third assembly hole. Specific implementation mode

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the protection scope of the present invention.

[0026] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0028] As Figure 1-6 shown, a closed Faraday receiving cup structure provided by the present invention is connected to an L-shaped connecting rod and connected to an adjustment motor module through the L-shaped connecting rod, and includes a T-shaped ceramic part 1, a square ceramic pad 2, a cover plate 3, a shielding box 4, a graphite cup 5, a slit piece 6, a suppression grid washer 7, a suppression grid mounting post 8, a suppression grid support post 9, a positioning ceramic piece 10, a positioning ceramic post 11, a suppression grid 12, a screw 13, a first ceramic tube 14, and a second ceramic tube 15;

[0029] The shielding box 4 is internally provided with a step, and the bottom side of the step is provided with a step, and a first assembly hole 16 is provided on the step. The suppression grid 12 includes a suppression grid support 29, a suppression grid side 30, and a third assembly hole 31. The material is 304 stainless steel material, and the structure is that two suppression grid supports 29 and two suppression grid sides 30 are connected by spot welding, and a gap is left between the two suppression grid supports 29. The position of the third assembly hole 31 is matched with the position of the first assembly hole 16, and the suppression grid 12 is installed on one side of the shielding box 4 through the suppression grid mounting post 8; the suppression grid mounting post 8 is made of ceramic material, and the suppression grid mounting post 8 is matched with the suppression grid washer 7;

[0030] The side of the shielding box 4 is provided with a threaded hole 18. The two sides of the slit piece 6 are provided with second assembly holes 27, and the positions of the second assembly holes 27 are matched with the threaded hole 18. The slit piece 6 is installed on the shielding box 4 through the screw 13; a through hole matching the gap in the suppression grid 12 is opened in the middle of the slit piece 6; a suppression grid support post 9 and a cover plate 3 are provided between the slit piece 6 and the suppression grid mounting post 8; both sides of the shielding box 4 are sealed by the cover plate 3, and the entrance is sealed by the slit piece 6, so as to achieve the purpose that only ions passing through the exit slit can enter the receiving cup.

[0031] The graphite cup 5 is installed at the bottom of the shielding box 4 through the T-shaped ceramic part 1, and a square ceramic pad 2 is provided between the graphite cup 5 and the shielding box 4; a positioning ceramic piece 10 is installed on the upper surface of the graphite cup 5, and a positioning ceramic post 11 is provided on the positioning ceramic piece 10; the first ceramic tube 14 and the second ceramic tube 15 are respectively installed on the side of the shielding box 4;

[0032] Since the suppression grid 12 needs to be assembled inside the shielding box 4, in order to ensure the size of the slit, the thickness of both sides is very thin. Therefore, the design adopts separate processing of the suppression grid support 29 and the suppression grid side 30, and finally uses a mold for spot welding connection. A lead hole 17 is designed on the shielding box 4, and the leads of the shielding box 4 are led outside the shielding box by using the insulation method of the ceramic tube.

[0033] The shielding box 4 has a structure as shown in the appendix Figure 2As shown, it includes a first assembly hole 16, a lead hole 17, a threaded hole 18, a groove 19, a threaded hole 20, a lead hole 21, a lead hole 22, a cover plate groove 23, and a threaded hole 24. The shielding box and its cover plate are both made of 304 stainless steel, and their thickness is designed according to the width of the outlet slit. The height of the internal step is designed according to the required distance between the graphite cup 5, the suppression grid 12, and the slit sheet 6. The thickness of the cover plate 3 and the depth of the cover plate groove 23 are both designed to be 0.1 mm to meet the assembly requirements. The height of the lead hole 17 is designed according to the assembly height of the suppression grid, and the ceramic tube 14 is placed in the lead hole 17 to ensure that the lead of the suppression grid can be smoothly connected to the outside of the receiving cup, and can be insulated from the shielding box through the action of the ceramic tube 14. The lead hole 21 is designed to match the position and size of the lead hole groove 26 on the graphite cup. The ceramic tube 15 is placed in the lead hole 21 to ensure that the lead of the graphite cup 5 can be smoothly connected to the outside of the receiving cup and can be insulated from the shielding box by the ceramic tube 15 .

[0034] The graphite cup 5 has a structure as follows Figure 3 As shown, it includes a groove 19, an assembly hole 25, and a lead hole slot 26. The material is selected as graphite material, which can effectively reduce the generation of secondary ions. Its thickness is designed to have an assembly gap of 0.2mm with the cover plate.

[0035] The slit sheet 6 has a structure as follows Figure 4 As shown, it includes a second assembly hole 27, the slit sheet is made of 304 stainless steel, and the surface roughness of the inner surface of the slit is required to be within 0.8 to avoid hindering the passage of ions as much as possible.

[0036] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A closed Faraday receiving cup structure, characterized in that It includes a T-shaped ceramic part (1), a square ceramic pad (2), a shielding box (4), a graphite cup (5), a slit piece (6), a positioning ceramic piece (10), a positioning ceramic column (11), a suppression grid (12), a first ceramic tube (14), and a second ceramic tube (15). There is a step inside the shielding box (4), and a step is provided on the side at the bottom of the step. The suppression grid (12) is installed on the step. The slit piece (6) is installed on the side of the shielding box (4). The graphite cup (5) is installed at the bottom of the shielding box (4) through the T-shaped ceramic part (1), and a square ceramic pad (2) is provided between the graphite cup (5) and the shielding box (4). A positioning ceramic piece (10) is installed on the upper surface of the graphite cup (5), and a positioning ceramic column (11) is provided on the positioning ceramic piece (10). First lead holes (17) and second lead holes (21) are provided on the side of the shielding box (4), and the first ceramic tube (14) and the second ceramic tube (15) are respectively installed in them. The material of the graphite cup (5) is graphite material, which effectively reduces the generation of secondary ions. A first assembly hole (16) is provided on the step. The suppression grid (12) includes a suppression grid support (29), a suppression grid side (30), and a third assembly hole (31). Two suppression grid supports (29) and two suppression grid sides (30) are connected by spot welding. There is a gap between the two suppression grid supports (29). The position of the third assembly hole (31) matches the position of the first assembly hole (16). The suppression grid (12) is installed on one side of the shielding box (4) through a suppression grid mounting column (8). Threaded holes (18) are provided on the side of the shielding box (4). Second assembly holes (27) are provided on both sides of the slit piece (6). The position of the second assembly hole (27) matches the position of the threaded hole (18). The slit piece (6) is installed on the shielding box (4) through screws (13). A through hole matching the gap above the suppression grid (12) is opened in the middle of the slit piece (6). A suppression grid support column (9) and a cover plate (3) are provided between the slit piece (6) and the suppression grid mounting column (8).

2. The closed Faraday receiving cup structure according to claim 1, characterized in that, The suppression grid mounting column (8) is made of ceramic material, and the suppression grid mounting column (8) cooperates with a suppression grid washer (7).

3. The closed Faraday receiving cup structure according to claim 1, characterized in that, The first ceramic tube (14) is placed in the first lead hole (17) to ensure that the lead of the suppression grid is connected to the outside of the receiving cup, and it can be insulated from the shielding box through the function of the first ceramic tube (14). The second ceramic tube (15) is placed in the second lead hole (21) to ensure that the lead of the graphite cup (5) is connected to the outside of the receiving cup, and it can be insulated from the shielding box through the function of the second ceramic tube (15).

4. The closed Faraday receiving cup structure according to claim 1, characterized in that, The inner surface of the slit piece (6) requires a surface roughness within 0.8.

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