Ion source lens assembly of thermal ionization mass spectrometer

Abstract

The invention discloses a thermal ionization mass spectrometer ion source lens assembly, which comprises a fixed frame, a Y-direction correction electrode assembly, a focusing electrode lens assembly, an extraction assembly and an outlet assembly, and is characterized in that the Y-direction correction electrode assembly is fixed below the fixed frame and is used for correcting ions; the focusing electrode lens assembly is coaxially fixed below the Y-direction correction electrode assembly and is used for focusing ions, the extraction assembly is coaxially fixed below the focusing electrode lens assembly and is used for extracting ions emitted by an ion source to the focusing electrode lens assembly, and the outlet assembly is fixed above the fixed frame and is used for extracting ions emitted by the ion source to the focusing electrode lens assembly. And the ion exporting module is used for exporting focused and corrected ions in sequence. Different from the prior art of first correction and then acceleration, acceleration and then correction are adopted, the narrow ion beam of the outlet ion beam is stable, and the risk of ion divergence after re-acceleration does not exist.

Description

Technical Field

[0001] The invention relates to the technical field of thermal ionization mass spectrometers, and in particular to an ion source lens assembly of a thermal ionization mass spectrometer. Background Art

[0002] The mass spectrometer is designed to determine the isotopic composition of chemical elements in a sample. The role of the ion source is to convert the elements into positive ion forms and accelerate and focus them into an ion beam for subsequent analysis of the charged ion magnetic field. The role of the ion receiver is to collect ions after electromagnet analysis. The movement of charged ions has an electric current. The current is amplified by an external device, and the ratio of the collected ions can be measured, thereby measuring the isotope ratio of different mass-to-charge ratios. The working principle of the thermal ionization magnetic mass spectrometer is based on the spatial separation of the elements of the analyte solid sample. These elements are ionized and form ion beams through different work functions, and then the content of each component is determined. To achieve this goal, the sample is placed on the sample holder, then ionized by current into the ion optical lens system of the mass spectrometer, collected into a narrow beam by the ion optical system of the ion source, and accelerated to an energy many times higher than the initial thermal energy propagation. The resulting single ion beam is guided into a transverse uniform magnetic field (analyzer), where it is divided into multiple beams, each containing ions with only one m / e value (ion mass / ion charge). By changing the induction of the magnetic field, the ion beam with the desired m / e value can be directed into the Faraday cup of the ion receiver. Each ion of the ion beam provides their charge to the ion collector, that is, they generate a current in its circuit. The magnitude of this current can be used as a measure of the content of the component in the sample gas.

[0003] For example, patent CN202210097473.2 provides an ion source of a magnetic mass spectrometer, whose lens assembly includes a turntable connecting base, a collimator assembly, an output lens assembly, a focusing pole X assembly, a separate focusing lens assembly, a focusing lens assembly, an extraction pole lens assembly, an insulating connecting column and a porcelain insulating column. One side of the turntable connecting base is connected to the collimator assembly through an insulating connecting column, and an output lens assembly is arranged on the outside of the collimator assembly. A focusing pole X assembly is installed between the turntable connecting base and the collimator assembly through a porcelain insulating column, a focusing lens assembly is installed in the middle of the focusing pole X assembly, a separate focusing lens assembly is arranged at one end of the porcelain insulating column, and an extraction pole lens assembly is arranged in the middle of the turntable connecting base.

[0004] However, there is a problem that in the prior art, the ion source lens assembly is generally calibrated first and then accelerated, but the calibrated narrow ion beam will diverge after acceleration. Summary of the invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies and to provide an ion source lens assembly for a thermal ionization mass spectrometer to solve the technical problem of narrow ion beam divergence in the prior art.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: The present invention provides an ion source lens assembly for a thermal ionization mass spectrometer, comprising: Fixed bracket, A Y-direction correction electrode assembly, fixed below the fixing frame, for correcting ions; A focusing electrode lens assembly is coaxially fixed below the Y-direction correction electrode assembly and is used for focusing ions; an extraction assembly, coaxially fixed below the focusing pole lens assembly, for extracting ions ejected from the ion source to the focusing pole lens assembly, and The outlet assembly is fixed above the fixing frame and is used to export the ions that have been focused and corrected in sequence.

[0007] In some embodiments, the fixed frame includes a frame body, a plurality of positioning pins and a plurality of ceramic positioning columns. A through hole is opened on the frame body along the axial direction. The positioning pins are fixed on the upper surface of the frame body to fix the outlet assembly. The ceramic positioning columns are fixed on the lower surface of the frame body to fix the Y-direction correction electrode assembly, the focusing pole lens assembly, and the lead-out assembly.

[0008] In some embodiments, the Y-direction correction electrode assembly includes a pair of Y-direction correction electrodes, which are fixed to the ceramic positioning column and arranged opposite to each other along the Y-axis direction. A notch is provided on one side of the Y-direction correction electrode facing the other Y-direction correction electrode, and the notch encloses a Y-direction correction channel coaxially arranged with the through hole.

[0009] In some embodiments, the Y-direction correction electrode assembly further includes a first positioning gasket, which is fixed on the edge of the correction electrode, and the first positioning gasket is sleeved on the ceramic positioning column and abuts against the lower surface of the frame.

[0010] In some embodiments, the focusing pole lens assembly includes a focusing pole seat and a focusing pole lens. The focusing pole seat is fixed to the ceramic positioning column, the middle of the focusing pole seat is hollow, and the focusing pole lens is fixed on the focusing pole seat and is coaxial with the through hole.

[0011] In some embodiments, the lead-out assembly includes a lead-out pole lens assembly and a lead-out slit assembly. The lead-out pole lens assembly is fixed to the ceramic positioning column and is located below the focusing pole lens assembly. The lead-out slit assembly is fixed to the ceramic positioning column and is located below the lead-out pole lens assembly.

[0012] In some embodiments, the extraction pole lens assembly includes a pair of extraction pole lens mounting seats and a pair of extraction pole lens pole pieces. The pair of extraction pole lens mounting seats are fixed to the ceramic positioning columns and are arranged opposite to each other. The pair of extraction pole lens pole pieces are respectively fixed on the pair of extraction pole lens mounting seats and are arranged opposite to each other. The extraction pole lens pole pieces are combined to form an extraction channel coaxial with the through hole.

[0013] In some embodiments, the lead-out slit assembly includes a lead-out slit mounting seat and a lead-out slit piece, the lead-out slit mounting seat is annular, the lead-out slit piece is fixed to the lead-out slit mounting seat, the lead-out slit piece is provided with a mounting hole for the ceramic positioning column to pass through and a slit coaxial with the through hole, and the lead-out slit piece is embedded with an accelerating electrode sheet.

[0014] In some embodiments, the exit assembly includes an X-direction correction pole lens assembly and an exit slit assembly. The X-direction correction pole lens assembly is fixed to the upper surface of the frame and is used to correct ions in the X direction. The exit slit assembly is fixed to the upper surface of the frame and is located above the X-direction correction pole lens assembly and is used to guide ion ejection.

[0015] In some embodiments, the X-direction correction pole lens assembly includes a pair of X-direction correction pole pieces, the pair of X-direction correction pole pieces are arranged opposite to each other along the X-axis direction, and the X-direction correction pole pieces are fixed to the exit slit assembly.

[0016] Compared with the prior art, the ion source lens assembly of the thermal ionization mass spectrometer provided by the present invention includes a fixed frame, a Y-direction correction electrode assembly, a focusing pole lens assembly, an extraction assembly and an outlet assembly, wherein the Y-direction correction electrode assembly is fixed below the fixed frame for correcting ions, the focusing pole lens assembly is coaxially fixed below the Y-direction correction electrode assembly for focusing ions, the extraction assembly is coaxially fixed below the focusing pole lens assembly for extracting ions ejected from the ion source to the focusing pole lens assembly, and the outlet assembly is fixed above the fixed frame for extracting ions that have been focused and corrected in sequence. The present invention is different from the prior art of first correcting and then accelerating, but adopts first accelerating and then correcting, and the narrow ion beam of the outlet ion beam is stable, and there is no risk of ion divergence after re-acceleration.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows with reference to the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the ion source lens assembly of the thermal ionization mass spectrometer provided by the present invention; Figure 2 This is a schematic diagram of the explosion structure of the ion source lens assembly of the thermal ionization mass spectrometer provided by the present invention: Figure 3 yes Figure 1 A schematic diagram of the structure of the middle fixing frame; Figure 4 yes Figure 1 A schematic diagram of the structure of the Y-direction correction electrode assembly; Figure 5 yes Figure 1 A schematic diagram of the structure of the central focusing lens assembly; Figure 6 yes Figure 2 A schematic diagram of the structure of the middle lead-out pole lens assembly; Figure 7 yes Figure 2 The schematic diagram of the structure of the slit assembly is shown in FIG. Figure 8 yes Figure 2 A schematic diagram of the structure of the X-direction correction polar lens assembly; Fig. 9 yes Figure 1 Schematic diagram of the structure of the middle outlet slit assembly; Fig.10 yes Figure 1 Schematic diagram of the structure of the grounding lens assembly.

[0019] Description of reference numerals: 1-fixed frame, 11-frame, 12-positioning pin, 13-ceramic positioning column, 2-Y direction correction electrode assembly, 21-Y direction correction electrode, 22-first positioning gasket, 3-focusing pole lens assembly, 31-focusing pole seat, 32-focusing pole lens, 33-second positioning gasket, 4-lead-out assembly, 41-lead-out pole lens assembly, 411-lead-out pole lens mounting seat, 412-lead-out pole lens pole piece, 42-lead-out slit assembly, 421-lead-out slit mounting seat, 422-lead-out slit piece, 5-exit assembly, 51-X direction correction pole lens assembly, 511-X direction correction pole piece, 52-exit slit assembly, 521-exit slit seat, 522-exit slit piece, 6-grounding pole lens assembly, 61-grounding pole lens body, 62-distance positioning gasket. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] See also Figure 1-10 The present invention provides an ion source lens assembly of a thermal ionization mass spectrometer, comprising: a fixed frame 1, a Y-direction correction electrode assembly 2, a focusing pole lens assembly 3, an extraction assembly 4 and an outlet assembly 5, wherein the Y-direction correction electrode assembly 2 is fixed below the fixed frame 1 for correcting ions, the focusing pole lens assembly 3 is coaxially fixed below the Y-direction correction electrode assembly 2 for focusing ions, the extraction assembly 4 is coaxially fixed below the focusing pole lens assembly 3 for extracting ions emitted from the ion source to the focusing pole lens assembly 3, and the outlet assembly 5 is fixed above the fixed frame 1 for extracting ions that have been focused and corrected in sequence.

[0022] In the present invention, the ion source lens assembly of the thermal ionization mass spectrometer includes a fixed frame, a Y-direction correction electrode assembly, a focusing pole lens assembly, an extraction assembly and an outlet assembly, wherein the Y-direction correction electrode assembly is fixed below the fixed frame for correcting ions, the focusing pole lens assembly is coaxially fixed below the Y-direction correction electrode assembly for focusing ions, the extraction assembly is coaxially fixed below the focusing pole lens assembly for extracting ions emitted from the ion source to the focusing pole lens assembly, and the outlet assembly is fixed above the fixed frame for extracting ions that have been focused and corrected in sequence. The present invention is different from the prior art of first correcting and then accelerating, but adopts first accelerating and then correcting, and the narrow ion beam of the outlet ion beam is stable, and there is no risk of ion divergence after re-acceleration.

[0023] Specifically, the fixed frame 1 includes a frame body 11, a plurality of positioning pins 12 and a plurality of ceramic positioning columns 13. A through hole is opened on the frame body 11 along the axial direction. The positioning pins 12 are fixed on the upper surface of the frame body 11 to fix the outlet assembly 5. The ceramic positioning columns 13 are fixed on the lower surface of the frame body 11 to fix the Y-direction correction electrode assembly 2, the focusing pole lens assembly 3 and the lead-out assembly 4.

[0024] Specifically, the Y-direction correction electrode assembly 2 includes a pair of Y-direction correction electrodes 21, which are fixed to the ceramic positioning column 13 and arranged opposite to each other along the Y-axis direction. A notch is provided on one side of the Y-direction correction electrode 21 facing the other Y-direction correction electrode 21, and the notch is surrounded to form a Y-direction correction channel coaxially arranged with the through hole. When the Y-direction correction electrode 21 is powered on, it can form an electric field in the Y-axis direction to correct the passing ions in the Y-axis direction.

[0025] Furthermore, the Y-direction correction electrode assembly 2 further includes a first positioning gasket 22, which is fixed on the edge of the correction electrode 21, and is sleeved on the ceramic positioning column 13 and abuts against the lower surface of the frame 11. The spacing between the correction electrode 21 and the frame 11 depends on the thickness of the first positioning gasket 22. When the spacing between the correction electrode 21 and the frame 11 needs to be adjusted, the first positioning gasket 22 of different thicknesses can be selected.

[0026] Specifically, the focusing pole lens assembly 3 includes a focusing pole seat 31 and a focusing pole lens 32. The focusing pole seat 31 is fixed to the ceramic positioning column 13. The middle of the focusing pole seat 31 is hollowed out. The focusing pole lens 32 is fixed on the focusing pole seat 31 and is coaxial with the through hole. The focusing pole lens 32 focuses the passing ions.

[0027] Furthermore, the focusing electrode lens assembly 3 further includes a second positioning gasket 33, which is fixed on the edge of the focusing electrode seat 31. The second positioning gasket 33 is sleeved on the ceramic positioning column 13 and abuts against the lower surface of the correction electrode 21. The distance between the focusing electrode seat 31 and the correction electrode 21 depends on the thickness of the second positioning gasket 33. When the distance between the focusing electrode seat 31 and the correction electrode 21 needs to be adjusted, the second positioning gasket 33 of different thicknesses can be selected.

[0028] Specifically, the lead-out component 4 includes a lead-out pole lens component 41 and a lead-out slit component 42. The lead-out pole lens component 41 is fixed to the ceramic positioning column 13 and is located below the focusing pole lens component 3. The lead-out slit component 42 is fixed to the ceramic positioning column 13 and is located below the lead-out pole lens component 41.

[0029] Furthermore, the lead-out pole lens assembly 41 includes a pair of lead-out pole lens mounting seats 411 and a pair of lead-out pole lens pole pieces 412. The pair of lead-out pole lens mounting seats 411 are fixed to and arranged opposite to the ceramic positioning columns 13. The pair of lead-out pole lens pole pieces 412 are respectively fixed on the pair of lead-out pole lens mounting seats 411 and arranged opposite to each other. The lead-out pole lens pole pieces 412 are enclosed to form a lead-out channel coaxial with the through hole.

[0030] Furthermore, the extraction slit assembly 42 includes an extraction slit mounting seat 421 and an extraction slit member 422, wherein the extraction slit mounting seat 421 is annular, and the extraction slit member 422 is fixed to the extraction slit mounting seat 421, and the extraction slit member 422 is provided with a mounting hole for the ceramic positioning column 13 to pass through and a slit coaxial with the through hole, and an accelerating electrode sheet is embedded in the extraction slit member 422. When the accelerating electrode sheet is powered on, the ions are accelerated and pass through the slit.

[0031] Specifically, the outlet assembly 5 includes an X-direction correction pole lens assembly 51 and an outlet slit assembly 52. ​​The X-direction correction pole lens assembly 51 is fixed to the upper surface of the frame 11 and is used to correct ions in the X direction. The outlet slit assembly 52 is fixed to the upper surface of the frame 11 and is located above the X-direction correction pole lens assembly 51 and is used to guide ion ejection.

[0032] Furthermore, the X-direction correction pole lens assembly 51 includes a pair of X-direction correction pole pieces 511, which are arranged opposite to each other along the X-axis direction, and the X-direction correction pole pieces 511 are fixed to the exit slit assembly 52. ​​When the X-direction correction pole pieces 511 are powered on, an electric field is formed in the X-axis direction to correct ions on the X-axis.

[0033] Furthermore, the exit slit assembly 52 includes an exit slit seat 521 and a pair of exit slit pieces 522. The exit slit seat 521 is fixed to the positioning pin 12 and the X-direction correction polar lens assembly 51. An exit is opened in the center of the exit slit seat 521. A pair of exit slit pieces 522 are relatively fixed on the exit slit seat 521 and partially block the exit. An exit slit is formed between the exit slit pieces 522.

[0034] Furthermore, the spacing between the outlet slits is 0.2 mm.

[0035] Specifically, the thermal ionization mass spectrometer ion source lens assembly further includes a grounding electrode lens assembly 6 , which is fixed to the lower surface of the frame 11 and is located between the Y-direction correction electrode assembly 2 and the focusing electrode lens assembly 3 .

[0036] Furthermore, the grounding electrode lens assembly 6 includes a grounding electrode lens body 61 and a distance positioning gasket 62. One end of the distance positioning gasket 62 is fixed to the grounding electrode lens body 61, and the other end is fixed to the frame 11. The grounding electrode lens body 61 is coaxially arranged with the through hole.

[0037] Beneficial effects of the present invention: The ion source lens assembly of the thermal ionization mass spectrometer provided by the present invention includes a fixed frame, a Y-direction correction electrode assembly, a focusing pole lens assembly, an extraction assembly and an outlet assembly, wherein the Y-direction correction electrode assembly is fixed below the fixed frame for correcting ions, the focusing pole lens assembly is coaxially fixed below the Y-direction correction electrode assembly for focusing ions, the extraction assembly is coaxially fixed below the focusing pole lens assembly for extracting ions emitted from the ion source to the focusing pole lens assembly, and the outlet assembly is fixed above the fixed frame for extracting ions that have been focused and corrected in sequence. The present invention is different from the prior art of first correcting and then accelerating, but instead adopts the method of first accelerating and then correcting. The narrow ion beam of the outlet ion beam is stable, and there is no risk of ion divergence after re-acceleration.

[0038] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A thermal ionization mass spectrometer ion source lens assembly, characterized in that: It includes: Fixed frame; A Y-direction correction electrode assembly, fixed below the fixing frame, for correcting ions; A focusing electrode lens assembly is coaxially fixed below the Y-direction correction electrode assembly and is used for focusing ions; An extraction assembly, coaxially fixed below the focusing pole lens assembly, for extracting ions ejected from the ion source to the focusing pole lens assembly; as well as The outlet assembly is fixed above the fixing frame and is used to export the ions that have been focused and corrected in sequence.

2. The thermal ionization mass spectrometer ion source lens assembly according to claim 1, characterized in that: The fixed frame includes a frame body, a plurality of positioning pins and a plurality of ceramic positioning columns. A through hole is opened on the frame body along the axial direction. The positioning pins are fixed on the upper surface of the frame body to fix the outlet assembly. The ceramic positioning columns are fixed on the lower surface of the frame body to fix the Y-direction correction electrode assembly, the focusing pole lens assembly, and the lead-out assembly.

3. The thermal ionization mass spectrometer ion source lens assembly according to claim 2, characterized in that: The Y-direction correction electrode assembly includes a pair of Y-direction correction electrodes, which are fixed to the ceramic positioning columns and arranged opposite to each other along the Y-axis direction. A notch is provided on one side of the Y-direction correction electrode facing the other Y-direction correction electrode, and the notch encloses a Y-direction correction channel coaxially arranged with the through hole.

4. The thermal ionization mass spectrometer ion source lens assembly according to claim 3, characterized in that: The Y-direction correction electrode assembly further includes a first positioning gasket, which is fixed on the edge of the correction electrode. The first positioning gasket is sleeved on the ceramic positioning column and abuts against the lower surface of the frame.

5. The thermal ionization mass spectrometer ion source lens assembly according to claim 2, characterized in that: The focusing pole lens assembly comprises a focusing pole seat and a focusing pole lens. The focusing pole seat is fixed to the ceramic positioning column. The middle of the focusing pole seat is hollowed out. The focusing pole lens is fixed on the focusing pole seat and is coaxial with the through hole.

6. The thermal ionization mass spectrometer ion source lens assembly according to claim 2, characterized in that: The lead-out assembly includes a lead-out pole lens assembly and a lead-out slit assembly. The lead-out pole lens assembly is fixed to the ceramic positioning column and is located below the focusing pole lens assembly. The lead-out slit assembly is fixed to the ceramic positioning column and is located below the lead-out pole lens assembly.

7. The thermal ionization mass spectrometer ion source lens assembly according to claim 6, characterized in that: The lead-out pole lens assembly includes a pair of lead-out pole lens mounting seats and a pair of lead-out pole lens pole pieces. The pair of lead-out pole lens mounting seats are fixed to the ceramic positioning columns and are arranged opposite to each other. The pair of lead-out pole lens pole pieces are respectively fixed on the pair of lead-out pole lens mounting seats and are arranged opposite to each other. The lead-out pole lens pole pieces enclose and form a lead-out channel coaxial with the through hole.

8. The thermal ionization mass spectrometer ion source lens assembly according to claim 7, characterized in that: The lead-out slit assembly includes a lead-out slit mounting seat and a lead-out slit piece, the lead-out slit mounting seat is annular, the lead-out slit piece is fixed to the lead-out slit mounting seat, the lead-out slit piece is provided with a mounting hole for the ceramic positioning column to pass through and a slit coaxial with the through hole, and the lead-out slit piece is embedded with an accelerating electrode sheet.

9. The thermal ionization mass spectrometer ion source lens assembly according to claim 8, characterized in that: The outlet assembly comprises an X-direction correction pole lens assembly and an outlet slit assembly. The X-direction correction pole lens assembly is fixed to the upper surface of the frame and is used to correct ions in the X direction. The outlet slit assembly is fixed to the upper surface of the frame and is located above the X-direction correction pole lens assembly and is used to guide ion ejection.

10. The thermal ionization mass spectrometer ion source lens assembly according to claim 9, characterized in that: The X-direction correction pole lens assembly comprises a pair of X-direction correction pole pieces, the pair of X-direction correction pole pieces are arranged opposite to each other along the X-axis direction, and the X-direction correction pole pieces are fixed to the exit slit assembly.

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