Ion migration tube and manufacturing method thereof

Abstract

The invention provides an ion migration tube. The ion migration tube comprises a migration tube shell, the ionization source assembly is arranged at one end of the migration tube shell; the ion gate assembly is arranged between the ionization source assembly and the migration tube shell; the collector assembly is arranged at the other end of the migration tube shell; the ion gate assembly comprises a horn mouth, a first ion gate, a first insulating ring, a second ion gate, a second insulating ring and a third ion gate, the first ion gate, the second ion gate and the third ion gate are arranged at a larger opening part of the horn mouth, and the first insulating ring and the second insulating ring are arranged at the larger opening part of the horn mouth. In the axial direction of the ion migration tube, the first insulating ring is arranged between the first ion gate and the second ion gate, and the second insulating ring is arranged between the second ion gate and the third ion gate. The invention further provides a manufacturing method of the ion migration tube.

Description

Technical Field

[0001] The invention relates to the technical field of ion transfer tubes, and in particular to a miniaturized ion transfer tube and a manufacturing method thereof. Background Art

[0002] The migration tube is the core component of the ion mobility spectrometer, which has the most direct impact on the detection results. There are two types of conventional migration tubes. One is assembled by stacking metal electrodes and insulating material gaskets. This solution is relatively simple, but there are many defects. Especially in harsh environments with high temperature, high humidity and strong vibration, the migration tube formed by assembling multiple scattered parts together cannot meet the stability requirements and cannot adapt to extremely harsh environments; the other is a migration tube formed by brazing and packaging metal electrodes and ceramics. This migration tube has good shock resistance, strong anti-interference ability, and a wide operating temperature range, but the current size of this migration tube is large, resulting in an oversized overall size of the whole machine; in addition, this type of migration tube has two ion gates, which are assembled in a stacked manner, with a complex assembly process and poor consistency and stability. Therefore, it is necessary to develop an ion migration tube system suitable for a handheld ion mobility spectrometer that meets the requirements of miniaturization and high resolution. Summary of the invention

[0003] The object of the present invention is to overcome at least one of the above and other problems existing in the prior art.

[0004] According to one aspect of the present invention, there is provided an ion transfer tube, comprising:

[0005] Migration tube shell;

[0006] An ionization source assembly, the ionization source assembly being arranged at one end of the migration tube shell;

[0007] An ion gate assembly, wherein the ion gate assembly is disposed between the ionization source assembly and the migration tube shell;

[0008] A collector assembly, the collector assembly being disposed at the other end of the migration tube shell; and

[0009] A suppression grid, the suppression grid is arranged between the collector assembly and the migration tube shell;

[0010] Wherein, the ion gate assembly includes a bell mouth, a first ion gate, a first insulating ring, a second ion gate, a second insulating ring and a third ion gate, the first ion gate, the second ion gate and the third ion gate are arranged at the larger mouth of the bell mouth, and in the axial direction of the ion transfer tube, the first insulating ring is arranged between the first ion gate and the second ion gate, and the second insulating ring is arranged between the second ion gate and the third ion gate.

[0011] In one embodiment, the first ion gate, the first insulating ring, the second ion gate, the second insulating ring and the third ion gate are fixed together at a larger mouth of the bell mouth.

[0012] In one embodiment, the suppression grid is fixed to the other end of the migration tube shell of the ion migration tube by spot welding, and is sandwiched between the migration tube shell and the collector assembly.

[0013] In one embodiment, the spacing between the suppressor grid and the collector assembly is at least 0.5 mm.

[0014] In one embodiment, the ion transfer tube further comprises a shielding cover assembly, which surrounds the collector assembly and comprises an inner shielding cover and an outer shielding cover, which are respectively fixed to the collector assembly and the transfer tube shell through connectors.

[0015] In one embodiment, the connector fixes the outer shield cover to the migration tube shell of the ion migration tube in the radial direction, and the connector fixes the inner shield cover to the collector assembly in the axial direction.

[0016] In one embodiment, the migration tube shell includes a plurality of ceramic rings and a plurality of metal ring electrodes, the ceramic rings and the metal ring electrodes are alternately arranged in sequence, and adjacent ceramic rings and metal ring electrodes are sealed and welded.

[0017] In one embodiment, the inner diameter of the ceramic ring and the metal ring electrode is 9 mm.

[0018] In one embodiment, the thicknesses of the ceramic ring and the metal ring electrode along the axial direction of the migration tube shell are 2 mm and 0.5 mm respectively.

[0019] According to another aspect of the present invention, there is provided a method for manufacturing the above-mentioned ion transfer tube, the method comprising:

[0020] A preform of a migration tube shell is provided, wherein the preform comprises a plurality of ceramic rings and a plurality of metal ring electrodes, wherein the ceramic rings and the metal ring electrodes are alternately arranged in sequence, and solder is arranged between adjacent ceramic rings and metal ring electrodes.

[0021] The brazing step of the prefabricated part includes placing the prefabricated part in a hydrogen brazing furnace, and sequentially performing a first nitrogen passing process, a hydrogen passing process, an ignition process, a temperature rising process, a temperature falling process, a hydrogen shut-off process, a second nitrogen passing process, and a power off process.

[0022] The heating process includes heating the preform to a first preset temperature within a first preset time period, and heating the preform from the first preset temperature to a second preset temperature within a second preset time period; the cooling process includes cooling the preform from the second preset temperature to a third preset temperature within a third preset time period, and cooling the preform from the third preset temperature to a fourth preset temperature within a fourth preset time period; the sum of the lengths of the first preset time period and the second preset time period is less than the sum of the lengths of the third preset time period and the fourth preset time period.

[0023] In one embodiment, during the brazing step, the pressure in the hydrogen brazing furnace is maintained at a positive pressure of 0.1 MPa-0.4 MPa.

[0024] In one embodiment, the step of raising the preform from the first preset temperature to the second preset temperature within the second preset time period comprises:

[0025] The preform is heated from the first preset temperature to a fifth preset temperature within a first preset sub-period, and the fifth preset temperature is maintained for a second preset sub-period,

[0026] The preform is raised from the fifth preset temperature to the second preset temperature within a third preset sub-period, and the second preset temperature is maintained for a fourth preset sub-period, wherein the second preset sub-period is greater than the fourth preset sub-period.

[0027] In one embodiment, the fifth preset temperature is lower than the melting point of the solder, and the second preset temperature is higher than the melting point of the solder.

[0028] In one embodiment, the step of reducing the temperature of the preform from the third preset temperature to the fourth preset temperature within the fourth preset time period comprises:

[0029] reducing the preform from the third preset temperature to the first preset temperature within a fifth preset sub-time period,

[0030] The preform is cooled from the first preset temperature to the fourth preset temperature within a sixth preset sub-period, wherein the sixth preset sub-period is at least twice as long as the fifth preset sub-period.

[0031] In one embodiment, during the hydrogen passing process, the gas exhausted from the hydrogen brazing furnace is subjected to a hydrogen purification test.

[0032] In one embodiment, the method according to the present invention further comprises a pretreatment step for the preform, in which the ceramic ring and the metal ring electrode are subjected to surface treatment and cleaning; the pretreatment step comprises:

[0033] The brazing surface of the ceramic ring is metallized.

[0034] The surface of the metal ring electrode is subjected to nickel electroplating treatment.

[0035] The ceramic ring and the metal ring electrode are cleaned.

[0036] In one embodiment, the cleaning process of the ceramic ring and the metal ring electrode includes performing an acid cleaning step or a hydrogen burning step on the ceramic ring and the metal ring electrode.

[0037] In one embodiment, the method according to the present invention further comprises a step of mounting the preform, in which the ceramic ring and the metal ring electrode of the tube shell are assembled in place and centered using a tool, wherein the mounting step is performed in a clean fume hood.

[0038] The advantages of the ion transfer tube and the method for manufacturing the ion transfer tube according to the present invention are that the ion transfer tube is small in size, light in weight, easy to use and has high resolution. The brazing preparation process in the method for manufacturing the ion transfer tube of the present invention is not only applicable to the welding of the tube shell of the transfer tube, but can also be extended to other applications involving ceramic metal welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic structural diagram of an ion transfer tube according to the present invention is shown;

[0040] Figure 2 A schematic structural diagram of an ion gate assembly of an ion transfer tube according to the present invention is shown;

[0041] Figure 3 A schematic structural diagram of a shielding cover of an ion transfer tube according to the present invention is shown;

[0042] Figure 4 A flow chart showing the steps of a method for manufacturing a tube housing for an ion transfer tube according to the present invention; and

[0043] Figure 5 A temperature variation curve diagram showing the temperature increase process and the temperature decrease process of the method for manufacturing a tube shell of an ion transfer tube according to the present invention. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is further specifically described below by examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals represent the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0045] According to the general concept of the present invention, an ion migration tube is provided, comprising a migration tube shell, an ion source assembly, an ion gate assembly, a suppression grid, a collector assembly and a shielding cover, wherein the ion source assembly is arranged at one end of the migration tube shell, the ion gate assembly is arranged between the ion source assembly and the migration tube shell, the collector assembly is arranged at the other end of the migration tube shell, and the suppression grid is arranged between the collector assembly and the migration tube shell, wherein the ion gate assembly comprises a bell mouth, a first ion gate, a first insulating ring, a second ion gate, a second insulating ring and a third ion gate, the first insulating ring is arranged between the first ion gate and the second ion gate, the first insulating ring is arranged between the second ion gate and the third ion gate, and the first ion gate, the second ion gate and the third ion gate are arranged at the larger mouth of the bell mouth.

[0046] In addition, in the following detailed description, for the purpose of explanation, numerous specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details.

[0047] Figure 1 A schematic structural diagram of an ion transfer tube according to the present invention is shown; Figure 2 A schematic structural diagram of an ion gate assembly of an ion transfer tube according to the present invention is shown.

[0048] As shown in the figure: the ion migration tube according to the present invention comprises a migration tube shell 1, an ion source assembly 2, an ion gate assembly 4, a suppression grid 5, a collector assembly 6 and a shielding cover, wherein the ion source assembly 2 is arranged at one end of the migration tube shell 1, the ion gate assembly 4 is arranged between the ion source assembly 2 and the migration tube shell 1, the collector assembly 6 is arranged at the other end of the migration tube shell 1, and the suppression grid 5 is arranged between the collector assembly 6 and the migration tube shell 1, wherein the ion gate assembly 4 comprises a bell mouth 15, and a first ion gate 131, a first insulating ring 141, a second ion gate 132, a second insulating ring 142 and a third ion gate 133 arranged in sequence along the axial direction of the ion migration tube, the first insulating ring 141 is arranged between the first ion gate 131 and the second ion gate 132, the second insulating ring 142 is arranged between the second ion gate 132 and the third ion gate 133, and the first ion gate 131, the second ion gate 132 and the third ion gate 133 are arranged at the larger mouth of the bell mouth 15.

[0049] Among them, the first ion gate 131, the first insulating ring 141, the second ion gate 132, the second insulating ring 142 and the third ion gate 133 can be fixed at the larger mouth of the bell mouth 15 by bolts. Specifically, the three ion gates 13 in the ion gate assembly 4 are isolated and positioned on the bell mouth 15 by two insulating rings 14, and then the ion gate assembly 4 including the three ion gates 13, the two insulating rings 14 and the bell mouth 15 is installed in the migration tube shell 1 as a whole. This installation method avoids the defects such as poor positioning and easy deformation in the method of directly installing the ion gate 13 and the insulating ring 14 to the shell in turn in the existing technical solution.

[0050] The suppression grid 5 can be fixed to the other end of the migration tube shell 1 of the ion migration tube by, for example, spot welding, and is sandwiched between the migration tube shell 1 and the collector assembly 6. Specifically, the suppression grid 5 is a metal mesh with a hexagonal grid, which can be fixed to the other end of the migration tube shell 1 by spot welding. The spot welding fixation method avoids the technical difficulty of the spring assembly installation method used in the prior art solution. The spring assembly used in the prior art solution makes the metal mesh more easily deformed, resulting in defects that affect the effect.

[0051] The interval between the suppression grid 5 and the collector assembly 6 is at least 0.5 mm.

[0052] The ionization source assembly 2 may be composed of a nickel-63 radiation source and a source holder, and is fixed inside the migration tube shell 1 to achieve ionization of sample molecules.

[0053] The metal ring electrode 12 is a circular ring with a strip-shaped protrusion, such as Figure 1 As shown, the strip-shaped protrusion has a boss, and when a plurality of metal ring electrodes 12 and the ceramic ring 11 are brazed and packaged, the strip-shaped protrusion is located on the same side, which facilitates the fixation of the metal ring electrodes 12 and the voltage dividing plate 10.

[0054] Among them, the collector assembly 6 is made of a ceramic collecting plate, a metal sheath and a metal plug through brazing, and then fixed as a whole to the other end of the migration tube shell 1 by screws. The collecting plate has a gold-plated arc surface and maintains a minimum spacing of more than 0.5 mm with the suppression grid 5 to improve signal sensitivity.

[0055] Figure 3 A schematic structural diagram of a shielding cover of an ion transfer tube according to the present invention is shown.

[0056] The shielding cover surrounds the collector assembly 6, and the shielding cover includes an inner shielding cover 7 and an outer shielding cover 8, which are respectively fixed to the collector assembly 6 and the migration tube shell 1 through connectors (such as screws). Specifically, the shielding cover includes an inner shielding cover 7 and an outer shielding cover 8, which are respectively fixed to the collector and the migration tube shell 1 through connectors to shield external signal interference; the outer shielding cover 8 is fixed in a radial manner, which does not require the flange required for axial fixing, reducing the overall outer diameter of the ion migration tube. The inner shielding cover 7 is fixed in an axial manner.

[0057] like Figure 1 As shown, the ion transfer tube also includes a connection plate 3, which is arranged at the same end of the ion transfer tube as the ion source assembly 2 and surrounds the ion source assembly 2. The connection plate 3 is a high temperature resistant non-metallic material, has a sample inlet gas path, and is fixed to the transfer tube shell 1 by, for example, screws to achieve sample transportation, and can achieve heating and temperature control to meet the ionization temperature requirements of different samples. The figure shows a single-tube connection plate 3, which can also be implemented as a double-tube connection, with the shell 1 located on the same side or both sides of the connection plate 3, and both positive and negative dual-mode detection can be achieved.

[0058] The migration tube shell 1 includes a plurality of ceramic rings 11 and a plurality of metal ring electrodes 12, which are alternately arranged in sequence, and the adjacent ceramic rings 11 and metal ring electrodes 12 are sealed and welded. Specifically, the migration tube shell 1 is composed of a plurality of ceramic rings 11 and metal ring electrodes 12 alternately arranged in sequence, and two gas nozzles 9 are arranged on one side to meet the gas path requirements, and all parts are brazed and packaged to form an integral body.

[0059] The inner diameter of the ceramic ring 11 and the metal ring electrode 12 may be 9 mm. The thickness of the ceramic ring 11 and the metal ring electrode 12 along the axial direction of the migration tube shell 1 may be 2 mm and 0.5 mm respectively.

[0060] Figure 4 A flow chart showing the steps of a method for manufacturing a tube housing for an ion transfer tube according to the present invention; and Figure 5 A temperature variation curve diagram showing the temperature increase process and the temperature decrease process of the method for manufacturing a tube shell of an ion transfer tube according to the present invention.

[0061] like Figure 4 As shown, the method for manufacturing a tube shell of an ion transfer tube according to the present invention comprises:

[0062] A preform of a migration tube shell 1 is provided, the preform comprising a plurality of ceramic rings 11 and a plurality of metal ring electrodes 12, the ceramic rings 11 and the metal ring electrodes 12 are alternately arranged in sequence, and solder is provided between adjacent ceramic rings 11 and metal ring electrodes 12,

[0063] The brazing step of the prefabricated part is as follows: in the brazing step, the prefabricated part is placed in a hydrogen brazing furnace, and the first nitrogen passing process, the hydrogen passing process, the ignition process, the temperature rising process, the temperature falling process, the hydrogen shut-off process, the second nitrogen passing process and the power off process are sequentially performed.

[0064] The heating process includes heating the preform to a first preset temperature within a first preset time period, and heating the preform from the first preset temperature to a second preset temperature within a second preset time period; the cooling process includes cooling the preform from the second preset temperature to a third preset temperature within a third preset time period, and cooling the preform from the third preset temperature to a fourth preset temperature within a fourth preset time period; the sum of the lengths of the first preset time period and the second preset time period is less than the sum of the lengths of the third preset time period and the fourth preset time period.

[0065] The step of raising the preform temperature from the first preset temperature to the second preset temperature within the second preset time period includes:

[0066] The preform is heated from the first preset temperature to the fifth preset temperature within the first preset sub-period, and the fifth preset temperature is maintained for a second preset sub-period,

[0067] The preform is heated from the fifth preset temperature to the second preset temperature within the third preset sub-time period, and the second preset temperature is maintained for a fourth preset sub-time period, wherein the second preset sub-time period is greater than the fourth preset sub-time period. Such a setting of the length of the temperature maintenance time period enables the ceramic ring, the metal ring electrode and the solder of the preform to be kept stable as a whole during the temperature increase process, and does not cause undesirable stress and solder melting degree due to temperature changes.

[0068] The fifth preset temperature is lower than the melting point of the solder, and the second preset temperature is higher than the melting point of the solder.

[0069] The step of reducing the preform temperature from the third preset temperature to the fourth preset temperature within the fourth preset time period comprises:

[0070] reducing the preform from the third preset temperature to the first preset temperature within a fifth preset sub-time period,

[0071] The preform is cooled from the first preset temperature to a fourth preset temperature within a sixth preset sub-period, wherein the sixth preset sub-period is at least twice as long as the fifth preset sub-period.

[0072] Specifically, the working process of the hydrogen brazing furnace includes: nitrogen filling, hydrogen filling, ignition, heating, welding, cooling, hydrogen closing, nitrogen filling and power off. During the process, the pressure in the furnace is kept positive. For example: after filling nitrogen at a flow rate of about 5L / min for 10 minutes, start filling hydrogen. The hydrogen filling flow rate is about 5L / min. During the hydrogen filling process, a gas pipe can be drawn out from the hydrogen outlet to directly introduce hydrogen into the outside. After 15 minutes of hydrogen filling, the hydrogen can be tested for purity. Take a hydrogen sample with a test tube and ignite it 4-5 meters outside the furnace. If the hydrogen is pure, there should be no explosion sound (the filling time depends on the size of the furnace). After the hydrogen purity is reached, ignite and burn hydrogen. Set the welding temperature process curve to carry out the heating, insulation and cooling process. After the furnace temperature drops to 200℃, turn off the hydrogen filling, turn on the nitrogen filling, and take out the prefabricated parts after the furnace temperature drops below 60℃. After taking out the parts, wipe the workpiece tray and then close the furnace body, turn off the power supply of each electrical appliance, and turn off the valves of the hydrogen and nitrogen bottles.

[0073] In particular, if Figure 5 As shown in the figure, the tube shell is welded by burning hydrogen in the heating process and the cooling process, wherein the heating process and the cooling process are the following continuous processes: from the beginning to the 20th minute (in the first preset time period), the temperature is linearly increased from 20°C to 200°C (the first preset temperature), from the 20th minute to the 60th minute (in the first preset sub-time period), the temperature is linearly increased from 200°C to 780°C (the fifth preset temperature), from the 60th minute to the 75th minute (in the second preset sub-time period), the temperature is maintained at 780°C, and from the 75th minute to the 85th minute (in the third preset sub-time period), the temperature is linearly increased from 200°C to 780°C (the fifth preset temperature). The temperature is linearly increased from 780°C to 820°C (the second preset temperature), maintained at 820°C from the 85th minute to the 86th minute (the fourth preset sub-time period), linearly reduced from 820°C to 500°C (the third preset temperature) from the 86th minute to the 146th minute (the third preset sub-time period), linearly reduced from 500°C to 200°C from the 146th minute to the 186th minute (the fifth preset sub-time period), and linearly reduced from 200°C to 80°C (the fourth preset temperature) from the 186th minute to the 286th minute (the sixth preset sub-time period). Usually, the temperature control is terminated after the temperature is reduced to 500°C (the third preset temperature), and the temperature is reduced to 80°C (the fourth preset temperature) by natural cooling or air cooling in the fourth preset time period.

[0074] In the brazing step, the pressure in the hydrogen brazing furnace is maintained at a positive pressure of 0.1 MPa to 0.4 MPa.

[0075] In addition, if Figure 4As shown, before the brazing step of the preform, the method for manufacturing the tube shell of the ion migration tube of the present invention may also include a pretreatment step of the preform and a racking step of the preform. The pretreatment step of the preform may include: metallizing the brazing surfaces of all ceramic rings, electroplating nickel on the surfaces of all metal ring electrodes, and cleaning the ceramic rings and metal ring electrodes before brazing, and the cleaning method is not limited to pickling, hydrogen burning, etc. It should be noted that the "hydrogen burning" here is used to clean impurities, while the hydrogen burning in the heating process and the cooling process is used for brazing, and the temperature control curves of the two are different.

[0076] Generally speaking, the structure of the migration tube determines that it is sealed in two forms: flat seal and sleeve seal. Flat seal is composed of dozens of ceramic rings 11 and dozens of metal ring electrodes 12 arranged alternately in sequence, with a sheet of ring solder of appropriate size placed between each piece. The sleeve seal is a metal gas nozzle 9 assembled on the tube shell through a positioning hole, and a filament solder of appropriate diameter is placed. The solder selection mechanism is to use the gravity and capillary action of the solder to promote the solder to fill the gap; the solder material can be silver-copper alloy (Ag72Cu28).

[0077] In the step of mounting the preform, the ceramic ring 11 and the metal ring electrode 12 of the tube shell are assembled in place and aligned using a tool, wherein the mounting step is performed in a clean fume hood.

[0078] The mounting process is guaranteed by tooling. In a small-diameter, long-length tube shell, dozens of welds are formed at one time. Its positioning accuracy, brazing process and welding quality are all guaranteed by tooling. The tooling adopts an internal positioning and external centering design. The internal positioning core column is made of graphite that is not easily wetted and adhered by liquid, which is convenient for positioning and removal after welding. The external centering is composed of two semicircular external ferrules less than 180 degrees to ensure that the bosses of all metal ring electrodes 12 are in a straight line. After all parts are assembled in place and positioned and centered, tighten the fastening screws of the tooling. The entire mounting process is carried out in a clean fume hood to ensure that all parts are not contaminated;

[0079] The brazing process includes transferring the mounted and fixed workpiece to a hydrogen brazing furnace, adjusting the position height so that it is in a constant temperature area in the furnace body, pressing an appropriate weight (the size of the weight varies according to the size of the part), and after the solder melts, all the stacked ceramic rings 11 and metal ring electrodes 12 are tightly sealed and firmly under the pressure of the weight.

[0080] Those skilled in the art know that the temperature curve of the workpiece directly affects whether the solder can fully fill the joint gap, whether it can form a strong bond with the base metal, and form a good weld. Set a suitable temperature curve for temperature control. The temperature selection, heating, insulation, and cooling speed selection are determined according to the characteristics of the solder used. Special attention should be paid to the fact that the cooling speed should not be too fast to prevent the ceramic parts from cracking due to temperature stress. The basic brazing process curve is as follows: Figure 5 As shown, in actual operation, flexible adjustments need to be made based on the size of the workpiece, the number of welds, etc.

[0081] The advantages of the ion transfer tube according to the present invention are: the ion transfer tube according to the present invention is small in size, light in weight, easy to use, and has high resolution. In addition, the brazing preparation process in the manufacturing method of the ion transfer tube of the present invention is not only applicable to the welding of the tube shell of the transfer tube, but can also be extended to other applications involving ceramic metal welding.

[0082] Although the present invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the accompanying drawings are intended to exemplify the preferred implementations of the present invention and should not be construed as limiting the present invention.

[0083] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. An ion transfer tube, comprising: Migration tube shell (1); An ionization source component (2), the ionization source component (2) being arranged at one end of the migration tube shell (1); An ion gate component (4), the ion gate component (4) being arranged between the ionization source component (2) and the migration tube shell (1); A collector assembly (6), the collector assembly (6) being arranged at the other end of the migration tube shell (1); and A suppression grid (5), the suppression grid (5) being arranged between the collector assembly (6) and the migration tube shell (1); The ion gate assembly (4) comprises a bell mouth (15), a first ion gate (131), a first insulating ring (141), a second ion gate (132), a second insulating ring (142) and a third ion gate (133); the first ion gate (131), the second ion gate (132) and the third ion gate (133) are arranged at a larger mouth of the bell mouth (15); and in the axial direction of the ion migration tube, the first insulating ring (141) is arranged between the first ion gate (131) and the second ion gate (132); the second insulating ring (142) is arranged between the second ion gate (132) and the third ion gate (133); the bell mouth (15), the first ion gate (131), the first insulating ring (141), the second ion gate (132), the second insulating ring (142) and the third ion gate (133) of the ion gate form an integral body and are arranged between the ion source assembly (2) and the migration tube shell (1).

2. The ion transfer tube according to claim 1, characterized in that: The first ion gate (131), the first insulating ring (141), the second ion gate (132), the second insulating ring (142) and the third ion gate (133) are fixed together at the larger mouth of the bell mouth (15).

3. The ion transfer tube according to claim 1 or 2, characterized in that: The suppression grid (5) is fixed to the other end of the migration tube shell (1) of the ion migration tube by spot welding, and is sandwiched between the migration tube shell (1) and the collector assembly (6).

4. The ion transfer tube according to claim 1, characterized in that: The spacing between the suppression grid (5) and the collector assembly (6) is at least 0.5 mm.

5. The ion transfer tube according to claim 1, characterized in that: The ion transfer tube further comprises a shielding cover assembly, which surrounds the collector assembly (6) and comprises an inner shielding cover (7) and an outer shielding cover (8), which are respectively fixed to the collector assembly (6) and the transfer tube shell (1) via connecting pieces.

6. The ion transfer tube according to claim 5, characterized in that: The connecting piece fixes the outer shielding cover (8) to the migration tube shell (1) of the ion migration tube in the radial direction, and the connecting piece fixes the inner shielding cover (7) to the collecting electrode assembly (6) in the axial direction.

7. The ion transfer tube according to claim 1, characterized in that: The migration tube shell (1) comprises a plurality of ceramic rings (11) and a plurality of metal ring electrodes (12), wherein the ceramic rings (11) and the metal ring electrodes (12) are arranged alternately in sequence, and adjacent ceramic rings (11) and metal ring electrodes (12) are sealed and welded.

8. The ion transfer tube according to claim 7, characterized in that: The inner diameters of the ceramic ring (11) and the metal ring electrode (12) are 9 mm.

9. The ion transfer tube according to claim 7, characterized in that: The thicknesses of the ceramic ring (11) and the metal ring electrode (12) along the axial direction of the migration tube shell (1) are 2 mm and 0.5 mm respectively.

10. A method for manufacturing an ion transfer tube according to any one of claims 1 to 9, the method comprising: A preform of a migration tube shell (1) is provided, the preform comprising a plurality of ceramic rings (11) and a plurality of metal ring electrodes (12), the ceramic rings (11) and the metal ring electrodes (12) being arranged alternately in sequence, and solder is provided between adjacent ceramic rings (11) and metal ring electrodes (12). The brazing step of the prefabricated part, in which the prefabricated part is placed in a hydrogen brazing furnace, and a first nitrogen passing process, a hydrogen passing process, an ignition process, a temperature rising process, a temperature falling process, a hydrogen shut-off process, a second nitrogen passing process and a power off process are sequentially performed. Wherein, the heating process includes heating the preform to a first preset temperature within a first preset time period, and heating the preform from the first preset temperature to a second preset temperature within a second preset time period; the cooling process includes cooling the preform from the second preset temperature to a third preset temperature within a third preset time period, and cooling the preform from the third preset temperature to a fourth preset temperature within a fourth preset time period; wherein the sum of the lengths of the first preset time period and the second preset time period is less than the sum of the lengths of the third preset time period and the fourth preset time period.

11. The method according to claim 10, characterized in that In the brazing step, the pressure in the hydrogen brazing furnace is maintained at a positive pressure of 0.1 MPa to 0.4 MPa.

12. The method according to claim 10, characterized in that The step of raising the preform from a first preset temperature to a second preset temperature within a second preset time period comprises: The preform is heated from the first preset temperature to a fifth preset temperature within a first preset sub-period, and the fifth preset temperature is maintained for a second preset sub-period, The preform is raised from the fifth preset temperature to the second preset temperature within a third preset sub-period, and the second preset temperature is maintained for a fourth preset sub-period, wherein the second preset sub-period is greater than the fourth preset sub-period.

13. The method according to claim 10, characterized in that The fifth preset temperature is lower than the melting point of the solder, and the second preset temperature is higher than the melting point of the solder.

14. The method according to claim 10, characterized in that The step of reducing the preform temperature from the third preset temperature to the fourth preset temperature within the fourth preset time period comprises: reducing the preform from the third preset temperature to the first preset temperature within a fifth preset sub-time period, The preform is cooled from the first preset temperature to the fourth preset temperature within a sixth preset sub-period, wherein the sixth preset sub-period is at least twice as long as the fifth preset sub-period.

15. The method according to claim 10, characterized in that Also includes: During the hydrogen passing process, the gas exhausted from the hydrogen brazing furnace is subjected to a hydrogen purification test.

16. The method according to claim 10, characterized in that The method further comprises a pretreatment step for the preform, in which the ceramic ring (11) and the metal ring electrode (12) are surface treated and cleaned; the pretreatment step comprises: The brazing surface of the ceramic ring (11) is subjected to metallization treatment. The surface of the metal ring electrode (12) is subjected to nickel electroplating treatment. The ceramic ring (11) and the metal ring electrode (12) are cleaned.

17. The method according to claim 16, characterized in that The cleaning process for the ceramic ring (11) and the metal ring electrode (12) comprises performing an acid washing step or a hydrogen burning step on the ceramic ring (11) and the metal ring electrode (12).

18. The method according to claim 10, characterized in that The method further comprises a step of mounting the prefabricated part, in which the ceramic ring (11) and the metal ring electrode (12) of the tube shell are assembled in place and aligned using a tool, wherein the mounting step is performed in a clean fume hood.

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