Ion mobility tube and method of manufacturing the same

Abstract

The present application provides an ion migration tube, comprising a migration tube shell; an ionization source assembly arranged at one end of the migration tube shell; an ion gate assembly arranged between the ionization source assembly and the migration tube shell; a collector assembly arranged at the other end of the migration tube shell; and a suppression grid arranged between the collector assembly and the migration tube shell, wherein the ion gate assembly comprises a horn, 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 mouth portion of the horn, and 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 present application also provides a manufacturing method of an ion migration tube.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ion migration tube, and relates to a miniaturized ion migration tube and a manufacturing method thereof. BACKGROUND

[0002] The migration tube is the core component of the ion mobility spectrometer, which has the most direct influence on the detection result. The conventional migration tube is divided into two kinds, one of which is assembled by stacking metal electrodes and insulating material gaskets. This scheme is relatively simple, but has many defects, especially in harsh environments of 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 extreme harsh environments. The other is the migration tube formed by brazing and packaging the metal electrode and the ceramic. This migration tube has good shock resistance, strong anti-interference ability and wide working temperature range. However, the size of the current migration tube is relatively large, which leads to the overall size of the whole machine being too large. In addition, this kind of migration tube has two ion gates, which are assembled in a stacking manner. The assembly process is complex and the consistency and stability are poor. Therefore, it is necessary to develop a miniaturized, high-resolution handheld ion mobility spectrometer applicable ion migration tube system. SUMMARY

[0003] The present application aims to overcome at least one of the above and other problems in the prior art.

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

[0005] a migration tube housing;

[0006] an ion source assembly disposed at one end of the migration tube housing;

[0007] an ion gate assembly disposed between the ion source assembly and the migration tube housing;

[0008] a collector assembly disposed at the other end of the migration tube housing; and

[0009] a suppression grid disposed between the collector assembly and the migration tube housing;

[0010] wherein the ion gate assembly comprises a horn, 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 disposed at the larger mouth portion of the horn, and in the axial direction of the ion migration tube, the first insulating ring is disposed between the first ion gate and the second ion gate, and the second insulating ring is disposed 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 the larger mouth of the trumpet mouth.

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

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

[0014] In one embodiment, the ion drift tube further comprises a shield assembly, which surrounds the collector assembly and comprises an inner shield and an outer shield, fixed to the collector assembly and the drift tube shell respectively by a connecting piece.

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

[0016] In one embodiment, the drift tube shell comprises a plurality of ceramic rings and a plurality of metal ring electrodes, which are arranged alternately in sequence, and the adjacent ceramic rings and metal ring electrodes are sealed by welding.

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

[0018] In one embodiment, the thickness of the ceramic rings and the metal ring electrodes in the axial direction of the drift tube shell is 2mm and 0.5mm respectively.

[0019] According to another aspect of the present application, a method for manufacturing the ion drift tube is provided, which comprises:

[0020] providing a preform of a drift tube shell, which comprises a plurality of ceramic rings and a plurality of metal ring electrodes, which are arranged alternately in sequence, and the adjacent ceramic rings and metal ring electrodes are provided with solder,

[0021] a brazing step of the preform, in which the preform 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 cutting process, a second nitrogen passing process and a power-off process are sequentially performed,

[0022] The temperature rising process comprises raising the preform to a first preset temperature in a first preset time period and raising the preform from the first preset temperature to a second preset temperature in a second preset time period; the temperature falling process comprises lowering the preform from the second preset temperature to a third preset temperature in a third preset time period and lowering the preform from the third preset temperature to a fourth preset temperature in 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, in the brazing step, the pressure in the hydrogen brazing furnace is kept 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 in the second preset time period comprises:

[0025] raising the preform from the first preset temperature to a fifth preset temperature in a first preset sub-time period and keeping the fifth preset temperature for a second preset sub-time period,

[0026] raising the preform from the fifth preset temperature to the second preset temperature in a third preset sub-time period and keeping the second preset temperature for a fourth preset sub-time period, wherein the second preset sub-time period is greater than the fourth preset sub-time 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 lowering the preform from the third preset temperature to the fourth preset temperature in the fourth preset time period comprises:

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

[0030] lowering the preform from the first preset temperature to the fourth preset temperature in a sixth preset sub-time period, wherein the sixth preset sub-time period is at least 2 times the fifth preset sub-time period.

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

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

[0033] metallizing the brazing surface of the ceramic ring,

[0034] electroplating nickel on the surface of the metal ring electrode,

[0035] cleaning the ceramic ring and the metal ring electrode.

[0036] In one embodiment, the cleaning the ceramic ring and the metal ring electrode includes pickling or hydrogen firing the ceramic ring and the metal ring electrode.

[0037] In one embodiment, the method according to the present application further comprises a jiggling step in which the ceramic ring and the metal ring electrode of the tube shell are assembled in place and centered using a jig, wherein the jiggling step is performed in a clean bench.

[0038] The ion mobility tube and the method for manufacturing the ion mobility tube according to the present application have the advantages of small volume, light weight, easy to use, and high resolution. The brazing preparation process in the manufacturing method of the ion mobility tube according to the present application is not only suitable for the welding of the tube shell of the mobility tube, but also can be extended to other applications involving ceramic metal welding. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 shows a structural schematic diagram of an ion mobility tube according to the present application;

[0040] Figure 2 shows a structural schematic diagram of an ion gate assembly of an ion mobility tube according to the present application;

[0041] Figure 3 shows a structural schematic diagram of a shield of an ion mobility tube according to the present application;

[0042] Figure 4 shows a flowchart of steps of a method for manufacturing a tube shell of an ion mobility tube according to the present application; and

[0043] Figure 5 shows a temperature change curve diagram of a temperature rising process and a temperature falling process of a method for manufacturing a tube shell of an ion mobility tube according to the present application. DETAILED DESCRIPTION

[0044] The technical solutions of the present application will be further specifically explained below by embodiments and in conjunction with the drawings. In the description, the same or similar reference numerals represent the same or similar components. The following description of the embodiments of the present application with reference to the drawings is intended to explain the overall inventive concept of the present application, and should not be understood as a limitation of the present application.

[0045] According to the general concept of the present application, there is provided an ion mobility tube comprising a mobility tube housing, an ionization source assembly, an ion gate assembly, a suppression grid, a collector assembly and a shield, wherein the ionization source assembly is arranged at one end of the mobility tube housing, the ion gate assembly is arranged between the ionization source assembly and the mobility tube housing, the collector assembly is arranged at the other end of the mobility tube housing, the suppression grid is arranged between the collector assembly and the mobility tube housing, wherein the ion gate assembly comprises a trumpet, a first ion gate, a first insulator ring, a second ion gate, a second insulator ring and a third ion gate, the first insulator ring is arranged between the first ion gate and the second ion gate, the first insulator ring is arranged between the second ion gate and the third ion gate, the first ion gate, the second ion gate and the third ion gate are arranged at the larger mouth of the trumpet.

[0046] Additionally, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent to one skilled in the art that one or more embodiments can be practiced without these specific details.

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

[0048] As shown: an ion mobility tube according to the present application, comprising a mobility tube housing 1, an ionization source assembly 2, an ion gate assembly 4, a suppression grid 5, a collector assembly 6 and a shield, wherein the ionization source assembly 2 is arranged at one end of the mobility tube housing 1, the ion gate assembly 4 is arranged between the ionization source assembly 2 and the mobility tube housing 1, the collector assembly 6 is arranged at the other end of the mobility tube housing 1, the suppression grid 5 is arranged between the collector assembly 6 and the mobility tube housing 1, wherein the ion gate assembly 4 comprises a trumpet 15, and a first ion gate 131, a first insulator ring 141, a second ion gate 132, a second insulator ring 142 and a third ion gate 133 arranged in sequence along the axial direction of the ion mobility tube, the first insulator ring 141 is arranged between the first ion gate 131 and the second ion gate 132, the second insulator ring 142 is arranged between the second ion gate 132 and the third ion gate 133, the first ion gate 131, the second ion gate 132 and the third ion gate 133 are arranged at the larger mouth of the trumpet 15.

[0049] 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 opening of the horn mouth 15 by bolts. Specifically, the three ion gates 13 in the ion gate assembly 4 are isolated and positioned by the two insulating rings 14 and are installed on the horn mouth 15, and then the ion gate assembly 4 including the three ion gates 13, the two insulating rings 14 and the horn mouth 15 is installed as a whole in the migration tube shell 1, which 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 in the shell in the prior art.

[0050] The suppression grid 5 can be fixed at the other end of the migration tube shell 1 of the ion migration tube by spot welding, for example, and is clamped 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 at the other end of the migration tube shell 1 by spot welding. The spot welding avoids the technical difficulty in the method of assembling and installing the clamping spring in the prior art, and the metal mesh is more likely to be deformed in the method of assembling and installing the clamping spring in the prior art, which affects the effect.

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

[0052] The ionization source assembly 2 can be composed of a nickel-63 radioactive source and a source seat, and is fixed inside the migration tube shell 1 to realize ionization of sample molecules.

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

[0054] The collector assembly 6 is integrally formed by brazing a ceramic collector disc and a metal sheath and a metal plug, and is then integrally fixed at the other end of the migration tube shell 1 by screws. The collector disc has a gold-plated arc-shaped 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 structure diagram of a shielding cover of an ion migration tube according to the present application is shown.

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

[0057] As shown in Figure 1 The ion migration tube further includes a connecting disc 3, which is arranged at the same end of the ion migration tube as the ionization source assembly 2 and surrounds the ionization source assembly 2. The connecting disc 3 is made of a high-temperature-resistant non-metallic material, has a sample gas inlet channel, and is fixed on the migration tube shell 1 through, for example, screws, to realize sample delivery and heating and temperature control, thereby meeting the ionization temperature requirements of different samples. The connecting disc 3 shown in the figure is for a single tube, and can also be realized for double tubes, with the migration tube shell 1 located on the same side or both sides of the connecting disc 3, and both positive and negative double-mode detection can be realized.

[0058] The migration tube shell 1 includes 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 arranged alternately in sequence, and adjacent ceramic rings 11 and metal ring electrodes 12 are sealingly welded. Specifically, the migration tube shell 1 is made of a plurality of ceramic rings 11 and metal ring electrodes 12 arranged alternately in sequence, and at the same time, two gas nozzles 9 are arranged on one side to meet the gas channel requirements, and all parts are made into an integrated body by brazing packaging.

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

[0060] Figure 4 a flow chart showing the steps of the method for manufacturing the shell of the ion migration tube according to the present application; and Figure 5 a temperature change curve diagram showing the temperature rising process and the temperature falling process of the method for manufacturing the shell of the ion migration tube according to the present application.

[0061] As shown in Figure 4 The method for manufacturing the shell of the ion migration tube according to the present application includes:

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

[0063] The brazing step of the preform, in which the preform is placed into a hydrogen brazing furnace, and sequentially a first nitrogen passing process, a hydrogen passing process, an ignition process, a temperature rising process, a temperature lowering process, a hydrogen closing process, a second nitrogen passing process, and a power-off process are performed,

[0064] The temperature rising process includes raising the preform to a first preset temperature in a first preset time period and raising the preform from the first preset temperature to a second preset temperature in a second preset time period; the temperature lowering process includes lowering the preform from the second preset temperature to a third preset temperature in a third preset time period and lowering the preform from the third preset temperature to a fourth preset temperature in a fourth preset time period; and 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 from the first preset temperature to the second preset temperature in the second preset time period includes:

[0066] raising the preform from the first preset temperature to a fifth preset temperature in a first preset sub-time period and maintaining the fifth preset temperature for a second preset sub-time period,

[0067] raising the preform from the fifth preset temperature to the second preset temperature in a third preset sub-time period and maintaining the second preset temperature 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 temperature maintaining time period length setting enables the overall stability of the ceramic ring, the metal ring electrode, and the solder of the preform in the temperature rising process, and avoids undesirable stress and solder melting degree caused by 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 lowering the preform from the third preset temperature to the fourth preset temperature in the fourth preset time period includes:

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

[0071] lowering the preform from the first preset temperature to the fourth preset temperature in a sixth preset sub-time period, wherein the sixth preset sub-time period is at least 2 times the fifth preset sub-time period.

[0072] Specifically, the hydrogen brazing furnace working process includes: nitrogen, hydrogen, ignition, heating, welding, cooling, hydrogen, nitrogen and power off the entire process, the process of the furnace pressure to maintain positive pressure. For example: with 5L / min or so flow of nitrogen after 10 min, start filling hydrogen, hydrogen flow is about 5L / min, hydrogen process can be introduced in a gas pipe hydrogen gas directly introduced into the outdoor. Hydrogen 15 min after the hydrogen test pure, hydrogen samples in the furnace 4-5 meters outside the ignition, such as hydrogen has been pure should be no explosion sound (charge time length to adjust the size of the hearth). After the hydrogen purity point ignition hydrogen. Set the welding temperature process curve, the process of heating, holding, cooling. When the furnace temperature drops to 200 ℃, close the hydrogen, open the nitrogen, when the furnace temperature drops to 60 ℃ below the preform. Take the piece, wipe the workpiece disc after closing the furnace, close the power, hydrogen, nitrogen cylinder valve.

[0073] In particular, as shown in Figure 5 the heating process and the cooling process are continuous processes as follows: the temperature is linearly increased from 20 ℃ to 200 ℃ (first preset temperature) during the period from the start to the 20th minute (first preset time period), the temperature is linearly increased from 200 ℃ to 780 ℃ (fifth preset temperature) during the period from the 20th minute to the 60th minute (first preset sub-period), the temperature is maintained at 780 ℃ during the period from the 60th minute to the 75th minute (second preset sub-period), the temperature is linearly increased from 780 ℃ to 820 ℃ (second preset temperature) during the period from the 75th minute to the 85th minute (third preset sub-period), the temperature is maintained at 820 ℃ during the period from the 85th minute to the 86th minute (fourth preset sub-period), the temperature is linearly decreased from 820 ℃ to 500 ℃ (third preset temperature) during the period from the 86th minute to the 146th minute (third preset time period), the temperature is linearly decreased from 500 ℃ to 200 ℃ during the period from the 146th minute to the 186th minute (fifth preset sub-period), and the temperature is linearly decreased from 200 ℃ to 80 ℃ (fourth preset temperature) during the period from the 186th minute to the 286th minute (sixth preset sub-period). Generally, the temperature control is ended after the temperature is decreased to 500 ℃ (third preset temperature), and the temperature is decreased to 80 ℃ (fourth preset temperature) by natural cooling or air cooling or the like during 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, as shown in 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 application can further include a pre-treatment step of the preform and a mounting step of the preform. The pre-treatment step of the preform can include: metallizing treatment of the brazing surfaces of all ceramic rings, and nickel plating treatment of the surfaces of all metal ring electrodes, the ceramic rings and the metal ring electrodes being cleaned before brazing, the cleaning method not being limited to pickling, hydrogen burning, etc. It is to be noted that "hydrogen burning" herein is used for cleaning impurities, and hydrogen burning in the heating process and the cooling process is used for brazing, the temperature control curves of the two being different.

[0076] Generally speaking, the migration tube structure form determines the two forms of flat sealing and sleeve sealing. The flat sealing is that tens of ceramic rings 11 and tens of metal ring electrodes 12 are alternately arranged in sequence, and a sheet-shaped annular solder of a suitable size is placed between each piece. The sleeve sealing is that the metal gas nozzle 9 is assembled to the tube shell through the positioning hole, and a wire-shaped solder of a suitable diameter is arranged, and the solder selection mechanism is to promote the solder to fill the gap by using the gravity and capillary action of the solder; the solder material can be silver-copper alloy (Ag72Cu28).

[0077] In the mounting step of the preform, the ceramic rings 11 and the metal ring electrodes 12 of the tube shell are assembled in place and centered by using a tool, and the mounting step is performed in a clean bench.

[0078] The mounting process is guaranteed by the tool. In a small-diameter and large-length tube shell, tens of welds are formed at one time. The positioning accuracy, brazing process and welding quality are all guaranteed by the tool. The tool adopts the design of inner positioning and outer centering, the inner positioning core column selects graphite which is not easy to be wetted and adhered by liquid, facilitating positioning and post-welding stripping. The outer centering is composed of two semicircular outer sleeves less than 180 degrees, which ensures that the bosses of all metal ring electrodes 12 are on a straight line. After all the parts are assembled in place and positioned and centered, the tightening screw of the tool is tightened. The entire mounting process is carried out in a clean bench to ensure that all parts are not contaminated;

[0079] In the brazing process, the workpiece fixed by mounting is transferred to a hydrogen brazing furnace, the position height is adjusted so that it is in the constant temperature area of the furnace body, and a suitable weight (the weight size is different according to the size of the part) is pressed. After the solder is melted, all the stacked ceramic rings 11 and metal ring electrodes 12 are tightly sealed and firmly connected under the pressure of the weight.

[0080] As known by those skilled in the art, the temperature curve of the workpiece directly affects whether the solder can fully fill the joint gap and whether it can form a firm bond with the base metal to form a good weld. A suitable temperature curve is set for temperature control execution, and the temperature selection, heating, holding, and cooling speed selection are determined according to the characteristics of the brazing filler metal used, and special attention is paid to the fact that the cooling speed must not be too fast to prevent the ceramic part from cracking due to temperature stress. The basic brazing process curve is as followsFigure 5 As shown, the actual operation process needs to be flexibly adjusted according to the workpiece size, the number of welds and the like.

[0081] The ion migration tube according to the present application has the advantages of small volume, light weight, convenient use and high resolution. In addition, the brazing preparation process in the manufacturing method of the ion migration tube can not only be applied to the welding of the tube shell of the migration tube, but also can be extended to other applications involving ceramic metal welding.

[0082] Although the present application has been described in conjunction with the preferred embodiments thereof, the embodiments disclosed in the drawings are intended to illustrate, rather than limit, the preferred embodiments of the present application.

[0083] Although some embodiments of the general inventive concept have been shown and described, it is to be understood that changes can be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the claims and their equivalents.

Claims

1. An ion mobility tube comprising: a mobility tube housing (1); an ionization source assembly (2) disposed at one end of the mobility tube housing (1); an ion gate assembly (4) disposed between the ionization source assembly (2) and the mobility tube housing (1); a collector assembly (6) disposed at the other end of the mobility tube housing (1); and a suppression grid (5) disposed between the collector assembly (6) and the mobility tube housing (1); wherein the ion gate assembly (4) comprises a horn (15), a first ion gate (131), a first insulator ring (141), a second ion gate (132), a second insulator 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 disposed at the larger mouth of the horn (15), and, in the axial direction of the ion mobility tube, the first insulator ring (141) is disposed between the first ion gate (131) and the second ion gate (132), the second insulator ring (142) is disposed between the second ion gate (132) and the third ion gate (133), the horn (15), the first ion gate (131), the first insulator ring (141), the second ion gate (132), the second insulator ring (142), and the third ion gate (133) of the ion gate form an integral whole disposed between the ionization source assembly (2) and the mobility tube housing (1). The first ion gate (131), the first insulator ring (141), the second ion gate (132), the second insulator ring (142), and the third ion gate (133) are fixed together at the larger mouth of the horn (15).

2. The ion transfer tube of claim 1, wherein, The suppression grid (5) is fixed to the other end of the mobility tube housing (1) of the ion mobility tube by spot welding, clamped between the mobility tube housing (1) and the collector assembly (6).

3. The ion transfer tube according to claim 1 or 2, characterized in that, The spacing between the suppression grid (5) and the collector assembly (6) is at least 0.5 mm.

4. The ion transfer tube of claim 1, wherein, The ion mobility tube further comprises a shield assembly, the shield assembly surrounds the collector assembly (6) and comprises an inner shield (7) and an outer shield (8), respectively fixed on the collector assembly (6) and the mobility tube housing (1) by a connecting piece.

5. The ion transfer tube of claim 1, wherein, The connecting piece fixes the outer shield (8) on the mobility tube housing (1) of the ion mobility tube in the radial direction, and fixes the inner shield (7) on the collector assembly (6) in the axial direction.

6. The ion transfer tube of claim 5, wherein, The mobility tube housing (1) comprises 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 arranged alternately in sequence, and the adjacent ceramic rings (11) and metal ring electrodes (12) are sealed welded.

7. The ion transfer tube of claim 1, wherein, ​ 8. The ion transfer tube of claim 7, wherein, The inner diameter of the ceramic rings (11) and the metal ring electrodes (12) is 9 mm.

9. The ion transfer tube of claim 7, wherein, The thickness of the ceramic rings (11) and the metal ring electrodes (12) in the axial direction of the migration tube shell (1) is 2 mm and 0.5 mm, respectively.

10. A method for manufacturing the ion migration tube according to any one of claims 1-9, the method comprising: providing a preform of a migration tube shell (1), 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 a solder being arranged between adjacent ceramic rings (11) and metal ring electrodes (12), a brazing step of the preform, in which the preform 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 lowering process, a hydrogen cutting process, a second nitrogen passing process, and a power-off process are performed in sequence, wherein the temperature rising process comprises raising the preform to a first preset temperature in a first preset time period, and raising the preform from the first preset temperature to a second preset temperature in a second preset time period; the temperature lowering process comprises lowering the preform from the second preset temperature to a third preset temperature in a third preset time period, and lowering the preform from the third preset temperature to a fourth preset temperature in a fourth preset time period; and 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 of claim 10, wherein, In the brazing step, the pressure in the hydrogen brazing furnace is kept as a positive pressure of 0.1-0.4 MPa.

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

13. The method according to claim 12, wherein 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 of claim 10, wherein, The step of lowering the preform from the third preset temperature to the fourth preset temperature in the fourth preset time period comprises: lowering the preform from the third preset temperature to the first preset temperature in a fifth preset sub-time period, lowering the preform from the first preset temperature to the fourth preset temperature in a sixth preset sub-time period, wherein the sixth preset sub-time period is at least 2 times the fifth preset sub-time period.

15. The method of claim 10, wherein, Further comprising: In the hydrogen passing process, purifying the gas discharged from the hydrogen brazing furnace.

16. The method of claim 10, wherein, It also comprises a pre-treatment step of said preform, in which said ceramic ring (11) and said metal ring electrode (12) are surface treated and cleaned; said pre-treatment step comprises: - a metallization treatment of the brazing surface of said ceramic ring (11), - an electroplating nickel treatment of the surface of said metal ring electrode (12), - a cleaning treatment of said ceramic ring (11) and said metal ring electrode (12).

17. The method of claim 16, wherein, The cleaning treatment of said ceramic ring (11) and said metal ring electrode (12) comprises an acid pickling step or a hydrogen burning step of said ceramic ring (11) and said metal ring electrode (12).

18. The method of claim 10, wherein, It also comprises a jacking step of said preform, in which said ceramic ring (11) and said metal ring electrode (12) of said tube shell are assembled in position and centered by means of a tooling, wherein said jacking step is performed in a clean bench.

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