Electron microscope gun valve

Abstract

This application relates to the field of field emission scanning electron microscopy (FET) technology, and in particular to an electron microscope gun valve. The electron microscope gun valve includes a valve seat and a second control valve disposed on the valve seat. The valve seat is sealed between the gun lens and the objective lens; the valve seat has a gas passage, including a first channel connecting to a molecular pump, a second channel connecting to an ion pump, and a third channel connecting to the gun lens, all three being interconnected. The second control valve can close the first channel to cut off its connection with the other two channels. Therefore, with the electron microscope gun valve of this application, which includes a gas passage and a second control valve, the molecular pump can be used to evacuate the microscope barrel and the ion pump first, allowing the ion pump to quickly reach the starting conditions before starting, thus avoiding forced start-up of the ion pump before the starting conditions are met, which would affect its service life, and effectively improving the efficiency of vacuum establishment in the microscope barrel.

Description

Technical Field

[0001] This application relates to the field of field emission scanning electron microscopy (FET), and in particular to an electron microscope gun valve. Background Technology

[0002] In the tube of a tabletop field emission scanning electron microscope (FE-SEM), an electron gun, a gun lens (also known as a condenser lens), and an objective lens are typically arranged in sequence, with an electron gun isolation valve (or gun valve) installed between the gun lens and the objective lens. The main function of the gun valve is to maintain the ultra-high vacuum state in the area where the electron gun is located, while preventing contaminants from spreading to the electron gun area from the sample chamber connected to the objective lens when changing samples or in case of accidental gas leakage.

[0003] In current gun valve designs, the gun valve also serves to connect the molecular pump and the ion pump, assisting in establishing a vacuum in the microscope tube. The process of establishing a vacuum in the microscope tube generally involves: first, starting the molecular pump to obtain a high vacuum level and reaching the vacuum conditions required for the ion pump to start; then, starting the ion pump to obtain an ultra-high vacuum level.

[0004] However, the existing gun valve structure design has limitations, which means that the vacuum level achieved by the molecular pump cannot meet the normal start-up conditions of the ion pump. The ion pump often needs to be forced to start even when the start-up conditions are not met. This forced start-up method not only significantly increases the workload of the ion pump and affects its service life, but also reduces the efficiency of vacuum build-up in the microscope tube. Utility Model Content

[0005] The purpose of this utility model is to provide a solution to the technical problems in the prior art to a certain extent.

[0006] This utility model provides an electron microscope gun valve, including a valve seat and a second control valve disposed on the valve seat;

[0007] The valve seat is used to be disposed between the scope and the objective lens of the scope barrel. The valve seat is provided with a gas passage, which includes a first passage, a second passage and a third passage.

[0008] The first channel is used to connect to the molecular pump, the second channel is used to connect to the ion pump, and the third channel is used to connect to the gun scope connecting valve on the gun scope;

[0009] The first channel, the second channel, and the third channel are interconnected, and the second control valve is capable of closing the first channel.

[0010] Furthermore, the electron microscope gun valve also includes a first control valve disposed on the valve seat;

[0011] The valve seat forms a through beam channel, which is coaxially disposed between the electron beam channel of the gun scope and the electron beam channel of the objective lens.

[0012] The first control valve is used to control the on / off state of the beam channel.

[0013] Furthermore, the valve seat has a valve cavity, and the beam channel passes through the valve cavity;

[0014] The first control valve includes an on / off control, which is disposed within the valve cavity. The on / off control includes a sealing valve disc and a beam conduit spaced apart along a first direction, wherein the first direction is perpendicular to the axial direction of the beam channel, and the axial direction of the beam conduit is parallel to the axial direction of the beam channel.

[0015] The on / off control can move along the first direction, so that the beam duct is coaxially opposite to the beam channel, or so that the sealing valve disc is opposite to the beam channel and seals against the opposite side walls of the valve cavity along the axial direction of the beam channel.

[0016] Furthermore, the first control valve includes a first drive element and a connecting rod;

[0017] The valve seat is provided with a first mounting hole, one end of which is connected to the valve cavity, and the other end of which extends along the first direction and penetrates the valve seat.

[0018] One end of the connecting rod is connected to the on / off control, and the other end of the connecting rod extends out of the valve seat through the first mounting hole and is connected to the first driving member, so that it can reciprocate along the first direction under the drive of the first driving member.

[0019] Furthermore, the first control valve also includes a connecting sleeve, a first bellows, and a sliding connector;

[0020] The first driving member is fixed to the outside of the valve seat by the connecting sleeve. The connecting sleeve is sleeved on the outside of the connecting rod. One end of the connecting sleeve is sealed to the valve seat, and the other end of the connecting sleeve is sealed to the sliding connector. The connecting sleeve is slidably connected to the connecting rod through the sliding connector, so that the connecting rod can slide in the first direction within the connecting sleeve.

[0021] The first bellows is disposed inside the connecting sleeve and sleeved on the outside of the connecting rod. One end of the first bellows is sealed to the sliding connector, and the other end of the first bellows is sealed to the connecting rod.

[0022] Furthermore, the valve seat has a second mounting hole on one side along the second direction, the second direction being perpendicular to the axial direction of the beam channel, and the second direction intersecting with the first direction;

[0023] One end of the first channel penetrates the bottom wall of the second mounting hole to connect with the second mounting hole, and is connected to the second channel and the third channel through the second mounting hole;

[0024] The second control valve includes a seal and a second actuating element;

[0025] One end of the seal is connected to the driving end of the second driving member, and the other end of the seal extends into the second mounting hole. The second driving member can drive the seal to move along the second direction, so that the seal seals against the bottom wall of the second mounting hole, thereby cutting off the communication between the second mounting hole and the first channel.

[0026] Furthermore, the second driving component includes a connecting seat, a nut, and a screw;

[0027] The connecting seat is located outside the valve seat, and the connecting seat is arranged around the sealing element and sealed to the valve seat;

[0028] The connecting seat is provided with a limiting member, the screw is arranged along the second direction, one end of the screw is slidably connected to the limiting member along the second direction, and the other end of the screw is connected to the sealing member;

[0029] The nut is axially positioned on the connecting seat and screwed to the screw rod.

[0030] Furthermore, the second control valve also includes a second bellows, which is sleeved on the outside of the seal. One end of the second bellows is sealed to the connecting seat, and the other end of the bellows is sealed to the seal.

[0031] Furthermore, the valve seat has a recessed cavity at one end facing the gun scope to accommodate the electron beam channel of the gun scope, and the beam channel penetrates the bottom wall of the recessed cavity;

[0032] The second channel and the third channel are both connected to the cavity. The air passage also includes a fourth channel, one end of which is connected to the cavity, and the other end of which penetrates the side wall of the second mounting hole.

[0033] Furthermore, the electron microscope gun valve also includes a differential pressure aperture, which is fixed to the bottom wall of the cavity, and one end of the differential pressure aperture is coaxially inserted into the beam channel;

[0034] And / or, the electron microscope gun valve further includes a shielding ring, which is disposed within the cavity and surrounds the electron beam channel of the gun mirror.

[0035] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0036] The electron microscope gun valve provided by this utility model includes a valve seat and a second control valve disposed on the valve seat. For a benchtop field emission scanning electron microscope (FET), the tube includes a gun lens and an objective lens arranged sequentially. The valve seat of the electron microscope gun valve is sealed between the gun lens and the objective lens. The valve seat has a gas path, including a first channel, a second channel, and a third channel. The first channel is used to connect to a molecular pump, the second channel is used to connect to an ion pump, and the third channel is used to connect to a gun lens connecting valve on the gun lens, so as to control the connection between the third channel and the gun lens. The first, second, and third channels can be interconnected. The second control valve can close the first channel to cut off the connection between the first channel and the other two channels (i.e., the second and third channels).

[0037] Specifically, when establishing a vacuum in the scope barrel, the first channel is first opened via the second control valve, and the scope barrel connection valve is also opened, connecting the molecular pump to the ion pump through the gas path channel and then to the scope barrel. The molecular pump is then started; specifically, the mechanical pump connected to the molecular pump is started first to evacuate the vacuum. Once the vacuum level reaches the starting conditions for the molecular pump, the molecular pump is then started to evacuate the scope barrel, bringing both the scope barrel and the ion pump to a high vacuum environment (10). -4 The pressure is approximately 10 Pa to meet the starting conditions of the ion pump. Then, the first channel is closed via the second control valve, and the ion pump is started to continue evacuating the scope barrel (specifically the side with the gun scope) to an ultra-high vacuum environment (10 Pa). -6 (around pa).

[0038] Therefore, by using the electron microscope gun valve with a gas passage and a second control valve in this application, the molecular pump can be used to evacuate the microscope tube and the ion pump first, so that the ion pump can quickly reach the start-up conditions, avoiding the ion pump being forced to start before the start-up conditions are met, which would affect its service life, and effectively improving the efficiency of vacuum establishment in the microscope tube. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1A three-dimensional schematic diagram of an electron microscope gun valve provided for an embodiment of this utility model;

[0041] Figure 2 This is a cross-sectional schematic diagram of the electron microscope gun valve from a first-view perspective, provided for an embodiment of the present invention.

[0042] Figure 3 This is a cross-sectional schematic diagram of the electron microscope gun valve from a second perspective, provided for an embodiment of the present invention.

[0043] Figure 4 A schematic diagram of the structure of the first control valve provided in an embodiment of this utility model;

[0044] Figure 5 A cross-sectional schematic diagram of the first control valve provided for an embodiment of this utility model;

[0045] Figure 6 This is a schematic diagram of the structure of the second control valve provided in an embodiment of the present utility model;

[0046] Figure 7 A cross-sectional schematic diagram of the second control valve provided in an embodiment of this utility model.

[0047] Figure label:

[0048] 1-First control valve, 11-On / off control, 12-Sealing valve disc, 13-Beam conduit, 14-Connecting rod, 15-First bellows, 16-Connecting sleeve, 17-Sliding connector, 18-First drive component, 2-Second control valve, 21-Seal, 22-Second bellows, 23-Connecting seat, 24-Limiting component, 25-Screw, 26-Nut, 3-Valve seat, 31-First channel, 32-Second channel, 33-Third channel, 34-Fourth channel, 35-Valve cavity, 36-Concave cavity, 37-Beam channel, 4-Shielding ring, 5-Differential pressure aperture;

[0049] a - First direction, b - Second direction. Detailed Implementation

[0050] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0051] The components of the present invention embodiments described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0052] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0053] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0054] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0055] The following reference Figures 1 to 7 This application describes an electron microscope gun valve according to some embodiments.

[0056] This application provides an electron microscope gun valve, such as Figures 1 to 3 As shown, the electron microscope gun valve includes a valve seat 3 and a second control valve 2 disposed on the valve seat 3.

[0057] For the tube of a tabletop field emission scanning electron microscope, there are gun scope and objective lens arranged in sequence. The valve seat 3 of the electron microscope gun valve is sealed between the gun scope and the objective lens. The valve seat 3 is provided with a gas passage, which includes a first channel 31, a second channel 32 and a third channel 33. The first channel 31 is used to connect to a molecular pump, the second channel 32 is used to connect to an ion pump, and the third channel 33 is used to connect to a gun scope connecting valve on the gun scope, so as to control the connection between the third channel 33 and the gun scope through the gun scope connecting valve.

[0058] The first channel 31, the second channel 32, and the third channel 33 can be interconnected. The second control valve 2 can close the first channel 31 to cut off the connection between the first channel 31 and the other two channels (i.e., the second channel 32 and the third channel 33).

[0059] Specifically, when establishing a vacuum in the scope barrel, firstly, the first channel 31 is opened via the second control valve 2, and the scope barrel connection valve is opened, connecting the molecular pump to the ion pump through the gas path channel and to the scope barrel. Then, the molecular pump is started. Specifically, the mechanical pump connected to the molecular pump is started first to evacuate the vacuum. Once the vacuum level reaches the starting condition of the molecular pump, the molecular pump is started to evacuate the scope barrel, bringing both the scope barrel and the ion pump to a high vacuum environment (10). -4 The pressure is adjusted to approximately 10 Pa to meet the ion pump's start-up conditions. Then, the first channel 31 is closed via the second control valve 2, and the ion pump is started to continue evacuating the endoscope barrel (specifically the side with the gun lens) to an ultra-high vacuum environment (10 Pa). -6 (around pa).

[0060] Therefore, by using the electron microscope gun valve provided with a gas passage and a second control valve 2 in this application, the molecular pump can be used to evacuate the microscope tube and the ion pump first, so that the ion pump can quickly reach the start-up conditions, avoiding the ion pump being forced to start before the start-up conditions are met, which would affect its service life, and effectively improving the efficiency of vacuum establishment in the microscope tube.

[0061] In one embodiment of this application, preferably, as shown below, Figure 1 and Figure 2 As shown, the valve seat 3 is provided with a through beam channel 37. Both the gun lens and the objective lens of the scope barrel are provided with an electron beam channel for the electron beam to pass through. The beam channel 37 of the valve seat 3 is coaxially disposed between the electron beam channel of the gun lens and the electron beam channel of the objective lens, so as to utilize the beam flow to reach the electron beam channel connecting the gun lens and the objective lens.

[0062] The electron microscope gun valve also includes a first control valve 1 disposed on the valve seat 3. The first control valve 1 is used to control the opening and closing of the beam channel 37. That is, the first control valve 1 can open the beam channel 37 so that the electron beam channels of the gun lens and the objective lens are connected through the beam channel 37. The first control valve 1 can also close the beam channel 37 so that the connection between the electron beam channel of the gun lens and the electron beam channel of the objective lens is disconnected.

[0063] During the use of the scope barrel (with the second control valve 2 closed), the ultra-high vacuum environment on the side of the scope barrel gun lens can be sealed by closing the first control valve 1. This effectively prevents contaminants from spreading to the ultra-high vacuum environment on the side of the gun lens lens when the sample chamber connected to the objective lens is changed or when there is an accidental gas leak.

[0064] Regarding the first control valve 1, in one embodiment of this application, preferably, as shown in... Figure 2 As shown, the valve seat 3 has a valve cavity 35, and the beam channel 37 passes through the valve cavity 35, so that the beam channel 37 is divided into two sections by the valve cavity 35.

[0065] Combination Figure 4 and Figure 5 As shown, the first control valve 1 includes a control 11 for opening and closing within the valve chamber 35. The control 11 includes a sealing valve disc 12 and a beam conduit 13 spaced apart along a first direction a. The first direction a is perpendicular to the axial direction of the beam channel 37, and the axial direction of the beam conduit 13 is parallel to the axial direction of the beam channel 37.

[0066] The valve chamber 35 has a first sidewall and a second sidewall opposite to each other along the axial direction of the beam channel 37. The on / off control 11 can be driven to reciprocate between a first position and a second position along a first direction a. When the on / off control 11 moves to the first position, the sealing valve disc 12 is opposite to the beam channel 37, and one side of the sealing valve disc 12 seals against the first sidewall, while the other side of the sealing valve disc 12 seals against the second sidewall, thereby cutting off the connection between the two beam channels 37 through the sealing valve disc 12. When the on / off control 11 moves to the second position, the beam conduit 13 is coaxially opposite to the beam channel 37, so that the two beam channels 37 are connected through the beam conduit 13.

[0067] In this embodiment, preferably, the beam channel 37 has through holes formed on both the first and second side walls. When the sealing valve disc 12 is opposite to the beam channel 37, one side of the sealing valve disc 12 is sealed against the first side wall by a first sealing ring, and the other side of the sealing valve disc 12 is sealed against the second side wall by a second sealing ring. The first sealing ring surrounds the outside of the through hole on the first side wall, and the second sealing ring surrounds the outside of the through hole on the second side wall.

[0068] Regarding the actuation of the sealing valve disc 12, in one embodiment of this application, preferably, as follows: Figure 4 and Figure 5 As shown, the first control valve 1 also includes a first drive element 18 and a connecting rod 14.

[0069] A first mounting hole is provided on the valve seat 3. The axis of the first mounting hole extends along the first direction a. One end of the first mounting hole is connected to the valve cavity 35, and the other end of the first mounting hole passes through the valve seat 3. A connecting rod 14 is slidably disposed in the first mounting hole along the first direction a. One end of the connecting rod 14 extends into the valve cavity 35 and is connected to the on / off control 11. The other end of the connecting rod 14 extends out of the valve seat 3 and is connected to the first driving member 18 outside the valve seat 3. The first driving member 18 can drive the connecting rod 14 to reciprocate along the first direction a, so as to drive the on / off control 11 to reciprocate between a first position and a second position along the first direction a in the valve cavity 35.

[0070] In this embodiment, preferably, as follows: Figure 4 and Figure 5 As shown, the first control valve 1 also includes a connecting sleeve, a first bellows 15, and a sliding connector 17.

[0071] The connecting sleeve is disposed on the outside of the valve seat 3 along the first direction a. One end of the connecting sleeve is wrapped around the outside of the first mounting hole and sealed to the valve seat 3, for example, by welding or flange structure to achieve a sealed connection; the sliding connector 17 and the first driving member 18 are both provided with the other end of the connecting sleeve.

[0072] The inner diameter of the connecting sleeve is larger than the outer diameter of the connecting rod 14, allowing the connecting rod 14 to extend into the connecting sleeve and connect with the first driving member 18. The connecting rod 14 is slidably connected to the connecting sleeve via a sliding connector 17, so that when the first driving member 18 drives the connecting rod 14 to move along the first direction a, the sliding connector 17 can guide the movement of the connecting rod 14. Preferably, the sliding connector 17 is a linear bearing.

[0073] The first bellows 15 is sleeved on the outside of the connecting rod 14. The first bellows 15 can also be movably extended into the connecting sleeve. One end of the first bellows 15 is sealed to the sliding connector 17, and the other end is sealed to the connecting rod 14. This allows the first bellows 15 to extend and retract without affecting the movement of the connecting rod 14 when the connecting rod 14 moves. At the same time, the first bellows 15 also achieves a seal, so that gas outside the valve seat 3 can only enter between the bellows and the connecting rod 14, and will not enter between the bellows and the connecting sleeve 16, and thus into the valve cavity 35.

[0074] Regarding the second control valve 2, in one embodiment of this application, preferably, as shown below... Figure 3 , Figure 6 and Figure 7 As shown, the valve seat 3 is provided with a second mounting hole, the axis of which extends along the second direction b, so that a bottom wall is formed on one side of the second mounting hole along the second direction b, and the second mounting hole penetrates the valve seat 3 along the other side of the second direction b. The second direction b is perpendicular to the axis of the beam channel 37, and the second direction b intersects the first direction a (for example, perpendicularly).

[0075] One end of the first channel 31 penetrates the bottom wall of the second mounting hole to communicate with it, and through the second mounting hole, it communicates with the second channel 32 and the third channel 33. The second control valve 2 includes a seal 21 and a second drive member. The second drive member is disposed outside the valve seat 3. One end of the seal 21 is connected to the drive end of the second drive member, and the other end of the seal 21 (denoted as the sealing end) can be movably inserted into the second mounting hole. The seal 21 can reciprocate along the second direction b under the drive of the second drive member, so that the seal 21 moves away from the bottom wall of the second mounting hole, or seals against the bottom wall of the second mounting hole. When the seal 21 moves away from the bottom wall of the second mounting hole, the first channel 31 communicates with the second mounting hole, and through the second mounting hole, it communicates with the second channel 32 and the third channel 33. When the seal 21 seals against the bottom wall of the second mounting hole, the communication between the first channel 31 and the second mounting hole is cut off, thereby cutting off the communication between the first channel 31 and the second channel 32 (and the third channel 33).

[0076] Preferably, the first channel 31 has a through hole formed on the bottom wall of the second mounting hole, and the sealing end of the sealing member 21 can be sealed against the bottom wall of the second mounting hole by a sealing ring, and the sealing ring surrounds the outside of the through hole.

[0077] In this embodiment, preferably, as follows: Figure 6 and Figure 7 As shown, the second driving component includes a connecting seat 23, a nut 26, and a screw 25. The connecting seat 23 is located outside the valve seat 3, surrounds the sealing element 21, and is sealed to the valve seat 3, for example, through welding or a flange structure. A limiting element 24 is provided on the connecting seat 23. The screw 25 is positioned along the second direction b, with one end of the screw 25 slidably connected to the limiting element 24 along the second direction b, and the other end connected to the sealing element 21. The nut 26 is axially limited on the connecting seat 23, preventing it from moving along its own axial direction. The nut 26 is screwed onto the screw 25, so that by rotating the nut 26, the screw 25 can drive the sealing element 21 to move along the second direction b.

[0078] In this embodiment, preferably, as follows: Figure 6 and Figure 7 As shown, the second control valve 2 also includes a second bellows 22, which is sleeved on the outside of the seal 21. One end of the second bellows 22 is sealed to the connecting seat 23, and the other end is sealed to the seal 21, for example, by welding. Thus, the second bellows 22 achieves a seal, and the gas outside the valve seat 3 can only enter between the second bellows 22 and the seal 21, and cannot enter the second mounting hole to contaminate the inside of the valve seat 3.

[0079] In this embodiment, preferably, as follows: Figures 1 to 3As shown, the valve seat 3 has a recess 36 at one end facing the gun scope, the electron beam channel of the gun scope extends into the recess 36, the valve cavity 35 is located on the side of the recess 36 away from the gun scope, and the beam channel 37 at one end facing the gun scope penetrates the bottom wall of the recess 36 to communicate with the electron beam channel of the gun scope.

[0080] The second channel 32 and the third channel 33 are connected to the uniform concave cavity 36. The air passage also includes a fourth channel 34. One end of the fourth channel 34 is connected to the concave cavity 36, and the other end of the fourth channel 34 penetrates the side wall of the second mounting hole. Thus, the second channel 32 and the third channel 33 are connected to the fourth channel 34 through the concave cavity 36, and are connected to the second mounting hole through the fourth channel 34, so that they can be connected to the first channel 31.

[0081] In this embodiment, preferably, the electron microscope gun valve further includes a differential pressure aperture 5, which is coaxially arranged with the beam channel 37 and fixed to the bottom wall of the cavity 36, so as to control the pressure difference between the gun lens side and the objective lens side through the differential pressure aperture 5.

[0082] In this embodiment, preferably, the electron microscope gun valve also includes a shielding ring 4, which is coaxially disposed in the cavity 36 and surrounds the electron beam channel of the gun lens and the outside of the differential pressure aperture 5. The shielding ring 4 is installed in the cavity 36 by means of non-magnetic fasteners, thereby isolating the electron beam from external magnetic fields and reducing burrs in the electron microscope image.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An electron microscope gun valve, characterized by Includes a valve seat and a second control valve disposed on the valve seat; The valve seat is used to be disposed between the scope and the objective lens of the scope barrel. The valve seat is provided with a gas passage, which includes a first passage, a second passage and a third passage. The first channel is used to connect to the molecular pump, the second channel is used to connect to the ion pump, and the third channel is used to connect to the gun scope connecting valve on the gun scope; The first channel, the second channel, and the third channel are interconnected, and the second control valve is capable of closing the first channel.

2. The electron microscope gun valve of claim 1, wherein, The electron microscope gun valve also includes a first control valve disposed on the valve seat; The valve seat forms a through beam channel, which is coaxially disposed between the electron beam channel of the gun scope and the electron beam channel of the objective lens. The first control valve is used to control the on / off state of the beam channel.

3. The electron microscope gun valve of claim 2, wherein, The valve seat has a valve cavity, and the beam channel passes through the valve cavity; The first control valve includes an on / off control, which is disposed within the valve cavity. The on / off control includes a sealing valve disc and a beam conduit spaced apart along a first direction, wherein the first direction is perpendicular to the axial direction of the beam channel, and the axial direction of the beam conduit is parallel to the axial direction of the beam channel. The on / off control can move along the first direction, so that the beam duct is coaxially opposite to the beam channel, or so that the sealing valve disc is opposite to the beam channel and seals against the opposite side walls of the valve cavity along the axial direction of the beam channel.

4. The electron microscope gun valve of claim 3, wherein The first control valve includes a first drive element and a connecting rod; The valve seat is provided with a first mounting hole, one end of which is connected to the valve cavity, and the other end of which extends along the first direction and penetrates the valve seat. One end of the connecting rod is connected to the on / off control, and the other end of the connecting rod extends out of the valve seat through the first mounting hole and is connected to the first driving member, so that it can reciprocate along the first direction under the drive of the first driving member.

5. The electron microscope gun valve of claim 4, wherein, The first control valve further includes a connecting sleeve, a first bellows, and a sliding connector; The first driving member is fixed to the outside of the valve seat by the connecting sleeve. The connecting sleeve is sleeved on the outside of the connecting rod. One end of the connecting sleeve is sealed to the valve seat, and the other end of the connecting sleeve is sealed to the sliding connector. The connecting sleeve is slidably connected to the connecting rod through the sliding connector, so that the connecting rod can slide in the first direction within the connecting sleeve. The first bellows is disposed inside the connecting sleeve and sleeved on the outside of the connecting rod. One end of the first bellows is sealed to the sliding connector, and the other end of the first bellows is sealed to the connecting rod.

6. The electron microscope gun valve of claim 3, wherein, The valve seat has a second mounting hole on one side along the second direction, the second direction being perpendicular to the axial direction of the beam channel, and the second direction intersecting with the first direction; One end of the first channel penetrates the bottom wall of the second mounting hole to communicate with the second mounting hole, and communicates with the second channel and the third channel through the second mounting hole; The second control valve includes a seal and a second actuating element; One end of the seal is connected to the driving end of the second driving member, and the other end of the seal extends into the second mounting hole. The second driving member can drive the seal to move along the second direction, so that the seal seals against the bottom wall of the second mounting hole, thereby cutting off the communication between the second mounting hole and the first channel.

7. The electron microscope gun valve of claim 6, wherein, The second driving component includes a connecting seat, a nut, and a screw; The connecting seat is located outside the valve seat, and the connecting seat is arranged around the sealing element and sealed to the valve seat; The connecting seat is provided with a limiting member, the screw is arranged along the second direction, one end of the screw is slidably connected to the limiting member along the second direction, and the other end of the screw is connected to the sealing member; The nut is axially positioned on the connecting seat and screwed to the screw rod.

8. The electron microscope gun valve of claim 7, wherein, The second control valve further includes a second bellows, which is sleeved on the outside of the seal. One end of the second bellows is sealed to the connecting seat, and the other end of the bellows is sealed to the seal.

9. The electron microscope gun valve of claim 6, wherein, The valve seat has a recessed cavity at one end facing the gun scope to accommodate the electron beam channel of the gun scope, and the beam channel penetrates the bottom wall of the recessed cavity; The second channel and the third channel are both connected to the cavity. The air passage also includes a fourth channel, one end of which is connected to the cavity, and the other end of which penetrates the side wall of the second mounting hole.

10. The electron microscope gun valve of claim 9, wherein, The electron microscope gun valve also includes a differential pressure aperture, which is fixed to the bottom wall of the cavity, and one end of the differential pressure aperture is coaxially inserted into the beam channel; And / or, the electron microscope gun valve further includes a shielding ring, which is disposed within the cavity and surrounds the electron beam channel of the gun mirror.

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