Miniature electron ionization source hot cathode structure

Abstract

The utility model relates to a small-sized electron ionization source hot cathode structure, which comprises insulating glass provided with a plurality of through holes; the connecting column penetrates through the through hole of the insulating glass; the metal fixing plate is arranged at the joint of the insulating glass and the connecting column; the metal fixing plate and the insulating glass are sintered to form a glass-gold sealing area, and the glass-gold sealing area is used for fixing the connecting column; the lamp filaments are welded to the fixing columns, and the number of the lamp filaments is two; a filament grating is fixedly arranged in the middle of the insulating glass; the two ends of the lamp filament grating are provided with the folded edges, so that electrons are more uniformly released in the middle of the lamp filament and are distributed to the lamp filament grating area. According to the utility model, the connecting column is fixed by sealing the sealing area through the glass gold, so that the stability and durability of the whole structure are enhanced; the lamp filaments are arranged into two groups, and the two lamp filaments are lightened at the same time in a vacuum environment so as to release electrons to the maximum extent.

Description

TECHNICAL FIELD

[0001] The utility model belongs to mass spectrum detection technical field, mainly be applied to high vacuum environment (10 -1 Pa~10 -5 Pa) in, specifically a small electron ionization source hot cathode structure. BACKGROUND

[0002] Electron ionization source is also called EI source (Electron Ionization), is the most widely used ion source so far. Electron ionization source is mainly composed of: ionization chamber, hot cathode, ion focusing lens etc. The main function of ionization chamber is to provide stable acceleration field for the hot electron emitted to the cathode material to obtain electron flow, and then the electron accelerated by electric field collides with gas phase molecules in the ionization chamber, such as water (H2O), carbon dioxide (CO2) molecules, and the outer electrons of the nucleus are violently impacted by the hot electrons, and then lose electrons to form cations. In the electron ionization source, the hot cathode material releases hot electrons, which is called hot cathode. The material of hot cathode is generally tungsten (W), or other elements plus tungsten, and its principle is similar to that of incandescent lamp, so it can also be called "filament".

[0003] In the mechanical design of electron ionization source, the main points include the design of hot cathode: hot cathode structure, hot cathode fixing method, hot cathode bottom plate processing technology, etc. In the design, the two ends of the metal cathode are fixed on the connecting piece, and the electrons in the cathode can move freely, but on the surface of the cathode, due to the electrostatic force between the electrons and the metal lattice ions, a potential barrier is formed, so that the electrons cannot leave the surface of the electrode. In order to overcome the hindrance of the surface potential barrier and move the electrons outside the cathode, the escape work (or called work function) eφ needs to be applied. The escape work is determined by the material and surface state of the cathode. When the temperature of the hot cathode reaches more than 900 degrees Celsius, a large number of electrons will be excited at this time. In the usual mechanical design, it is necessary to meet the normal excitation of hot cathode electrons and the insulation design of cathode connection in the fixing plate, and also to consider the product installation environment and other factors to meet the design size parameter requirements.

[0004] The main difficulties of the current hot cathode filament technology are the fixation of the connecting column, the installation method of the filament, and the short service life of the single filament, and the high labor cost when replacing, so a small electron ionization source hot cathode structure is needed to ensure the stability of the connecting column, the good fixation of the filament and the service life of the filament. SUMMARY

[0005] The utility model aims at providing a small electron ionization source hot cathode structure, which solves the problems of poor fixation of the connecting column, installation method of the filament, short service life of the single filament and high labor cost when replacing.

[0006] In order to solve the above problems, the utility model provides a small -size electronic ion source hot cathode structure, including

[0007] Insulating glass, a plurality of through holes are formed on the insulating glass;

[0008] Connecting post, the connecting post passes through the through -hole of the insulating glass;

[0009] Metal fixing plate, the metal fixing plate is arranged at the connecting place of insulating glass and connecting post;

[0010] The metal fixing plate and the insulating glass are formed by sintering treatment glass -metal sealing sealing area, and the glass -metal sealing sealing area fixes the connecting post;

[0011] Lamp filament, the lamp filament is welded on the fixed column, and the lamp filament is provided with two groups.

[0012] Further, the insulating glass is fixedly provided with a lamp filament grid in the middle.

[0013] Further, the lamp filament grid is provided with a hem at both ends.

[0014] Further, the two connecting posts fix a lamp filament.

[0015] Further, the lamp filament is multiple.

[0016] Further, the cross section of the connecting post is rectangular.

[0017] Further, the cross section of the connecting post can also be oval or circular.

[0018] Further, the metal fixing plate is rectangular.

[0019] Further, the metal fixing plate can also be oval or circular.

[0020] Further, the lamp filament is circular ring shape, spiral line.

[0021] The utility model has the advantages of:

[0022] (1) the utility model is fixed to the connecting post through glass -metal sealing sealing area, strengthens the stability and durability of whole structure, makes hot cathode structure still can keep accurate positioning and stability under high vacuum and high temperature environment, forms glass -metal sealing sealing area through sintering treatment, simplifies manufacturing technology, reduces production cost, and at the same time, keeps the performance and reliability of structure, and the lamp filament is provided with two groups, and two lamp filaments are ignited simultaneously in vacuum environment, so that the electron is released to the maximum extent.

[0023] (2) The filament grid is fixedly arranged in the middle of the insulating glass, which can uniformly distribute gas molecules to the hot cathode radiation area, providing protection for subsequent gas molecule ionization. In addition, the two ends of the filament grid are designed with a folded edge, which has the advantage of more uniform release of electrons in the middle of the filament, thereby distributing to the filament grid area.

[0024] (3) The connecting column and the metal fixing plate can be circular, oval or rectangular, providing diversified design options to adapt to different installation environments and space requirements; the filament can be set in different shapes, so that the hot cathode structure can adapt to different electric field distribution and electron emission requirements, enhancing its adaptability in different application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Fig. 1 It is a perspective view of the small electronic ionization source hot cathode structure in the embodiment of the present application.

[0027] Fig. 2 It is a top view of the small electronic ionization source hot cathode structure in the embodiment of the present application.

[0028] Fig. 3 It is a front view of the small electronic ionization source hot cathode structure in the embodiment of the present application.

[0029] Fig. 4 It is a side view of the small electronic ionization source hot cathode structure in the embodiment of the present application.

[0030] Explanation of reference signs: 1-insulating glass; 2-metal fixing plate; 3-connecting column; 4-filament; 5-filament grid; 6-folded edge. DETAILED DESCRIPTION

[0031] In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features known in the art are not described.

[0032] In order to thoroughly understand the utility model, the detailed steps and detailed structure will be proposed in the following description, so as to explain the technical scheme of the utility model. The preferred embodiment of the utility model is described in detail as follows, however, in addition to these detailed descriptions, the utility model can also have other implementation manners.

[0033] As Figs. 1 to 4 The small electronic ionization source hot cathode structure of the utility model in one embodiment shown in the figure, the small electronic ionization source hot cathode structure includes: insulating glass 1, a plurality of through holes are formed on the insulating glass 1;Connecting column 3, the connecting column 3 passes through the through hole of the insulating glass 1;Metal fixed plate 2, the metal fixed plate 2 is arranged at the connecting place of insulating glass 1 and connecting column 3;The metal fixed plate 2 and the insulating glass 1 are formed by sintering treatment Glass-metal sealing area, glass-metal sealing area fixes connecting column 3.The specific process is as follows: the metal fixed plate 2 and connecting column 3 are processed into the designed size, the parts are polished, cleaned and deoiled;Metal fixed plate 2, insulating glass 1 and connecting column 3 are combined and fixed, and sintering treatment is carried out under nitrogen protection to form glass-metal sealing area.

[0034] Lamp filament 4 is welded on connecting column 3, and lamp filament 4 is provided with two groups, and two connecting columns 3 fix a lamp filament 4.In the fixed design of hot cathode filament 4, the scheme adopts the fixed mode of connecting column 3, and the lamp filament 4 is welded on the connecting column 3, and the four connecting columns 3 of glass-metal sealing area ensure the firm fixation of the connecting column 3, and then the lamp filament 4 is welded on the connecting column 3, which ensures the stability of the installation of the lamp filament 3;Two lamp filaments 4 are designed in the design of lamp filament 4, that is, two connecting columns 3 fix a lamp filament 4, as shown in the figure, four connecting columns 3 are arranged on the left and right sides, and two lamp filaments 4 are fixed on the upper parts, and the two lamp filaments 4 are lit at the same time in the vacuum environment to release electrons to the maximum extent.

[0035] The middle part of the insulating glass 1 is fixedly provided with a filament grid 5, and the two ends of the filament grid 5 are provided with a folding edge 6.

[0036] In the design of lamp filament 4, the filament grid 5 is also designed, and the filament grid 5 can uniformly distribute gas molecules to the hot cathode radiation area, which provides guarantee for the subsequent gas molecule ionization.In addition, the two ends of the filament grid 5 adopt the design of folding edge 6, and the design has the advantages that the electrons are more uniformly released in the middle part of the lamp 4, so as to be distributed to the filament grid area.

[0037] The part of the lamp filament 4 in the utility model can also adopt a multi-lamp filament design, such as three lamp filaments, which can meet the replacement requirements in experiments.

[0038] The cross section of the connecting column 3 in the utility model is rectangular, and other styles of design can also be adopted, such as oval, circular and the like.

[0039] The metal fixing plate 2 at the bottom of the filament 4 is rectangular, and other styles such as oval and circular can also be adopted.

[0040] The filament 4 can be designed into any shape, such as a circular ring shape or a spiral line shape.

[0041] The preferred embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and is not limited to the small electronic ionization source hot cathode structure. The equipment and structures not fully described should be understood as being implemented in the ordinary way in the art; any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of the present application, which does not affect the essential content of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the content of the technical solutions of the present application, still belongs to the scope of protection of the technical solutions of the present application.

Claims

1. A small electronic ionization source thermionic cathode structure, characterized by, Include: Insulating glass (1), a plurality of through holes are formed on the insulating glass (1); Connecting column (3), the connecting column (3) passes through the through hole of the insulating glass (1); Metal fixing plate (2), the metal fixing plate (2) is arranged at the connecting place of the insulating glass (1) and the connecting column (3); The metal fixing plate (2) and the insulating glass (1) are formed by sintering treatment to form a glass-metal sealing area, and the glass-metal sealing area fixes the connecting column (3); Filament (4), the filament (4) is welded on the connecting column (3), and the filament (4) is provided with two groups.

2. The small electronic ionization source thermionic cathode structure of claim 1, wherein: The middle part of the insulating glass (1) is fixedly provided with a filament grid (5).

3. The small electron ionization source thermionic cathode structure of claim 2, wherein: The two ends of the filament grid (5) are provided with a folded edge (6).

4. The small electron ionization source thermionic cathode structure of claim 1, wherein: The two connecting columns (3) fix a filament (4).

5. The small electron ionization source thermionic cathode structure of claim 1, wherein: The filament (4) can also be multiple.

6. The small electron ionization source thermionic cathode structure of claim 1, wherein: The cross section of the connecting column (3) is rectangular.

7. The small electron ionization source thermionic cathode structure of claim 6, wherein: The cross section of the connecting column (3) can also be elliptical or circular.

8. The small electron ionization source thermionic cathode structure of claim 1, wherein: The metal fixing plate (2) is rectangular.

9. The small electron ionization source thermionic cathode structure of claim 8, wherein: The metal fixing plate (2) can also be elliptical or circular.

10. The small electron ionization source thermionic cathode structure of claim 1 or 4 or 5, wherein: The filament (4) is a circular ring shape, a spiral line shape.

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