Transmission electron microscope sample positioning limiter

Abstract

The application discloses a transmission electron microscope sample feeding positioning limiter, which comprises a fixing part used for being fixed with a goniometer, a connecting part rotatably arranged with the fixing part, wherein the connecting part is provided with a first track and a second track, the first track is perpendicular to and communicates with the second track, the first track is in an arc shape, and the second track is in a straight line type; and a limiting part which is movable from the first track to the second track, two ends of the limiting part are respectively arranged outside the tracks, the limiting part is arranged towards the center of the first track, one end of the limiting part towards the center of the first track is provided with a limiting structure used for limiting a positioning pin of a sample rod. The transmission electron microscope internal ball valve damage and the reduction of the mirror tube vacuum degree caused by improper operation are avoided, the sample feeding success rate is improved, the sample rod and the ball valve are protected, and the service life of the equipment is prolonged. Meanwhile, the hand directly contacts the sample rod is avoided through the limiting part operation, and the influence of pollutants on the mirror tube vacuum environment, the sample and the vacuum pump is reduced.

Description

Technical Field

[0001] This application relates to the field of transmission electron microscope (TEM) sample introduction auxiliary technology, and in particular to a TEM sample introduction positioning limiter. Background Technology

[0002] In the testing procedure of transmission electron microscopy (TEM), the sample holder plays a crucial role, bearing the responsibility of introducing the sample into the high-vacuum environment of the electron microscope. Given that a high vacuum must be maintained inside the TEM to ensure stable electron beam operation and prevent sample contamination, the sample holder must perform both sealing and transition functions during sample transfer to ensure the vacuum environment is not disrupted, and also facilitate the safe and intact removal of the sample after observation, providing assurance for subsequent experiments or preservation.

[0003] The sample introduction process in transmission electron microscopy (TEM) mainly includes the following steps: First, the sample rod is inserted into the pre-evacuation chamber at a specific angle and pre-evacuated for 3-5 minutes using a molecular pump until the required high vacuum is achieved. Then, the sample rod rotates around its own axis by a specific angle. This rotation is mechanically linked to open the spherical vacuum isolation valve that separates the pre-evacuation chamber from the vacuum chamber of the TEM tube. Finally, the sample rod is pushed axially from the pre-evacuation chamber into the working position inside the TEM tube, completing the sample introduction. The reverse operation of the above steps is the sample rod removal process. All of the above processes are manual operations. For TEM operators, mastering the insertion and removal of the sample rod is an essential skill. Traditional manual operation requires operators to invest a significant amount of time in repeated practice to master, and the entire process is highly dependent on the operator's technique and experience. Even so, even experienced users cannot completely avoid sample chamber leakage due to misoperation, which can seriously damage the internal structure of the goniometer stage or shorten the lifespan of the sample rod.

[0004] The success rate of sample introduction operations highly depends on the operator's precise control over the insertion and rotation angles of the sample rod, as well as the stability of the arm's direction and force during advancement. Past training experience shows that almost every new trainee experiences an average of 2 to 5 mistakes before gradually mastering the correct operating technique when learning to insert and remove the sample rod. However, each mistake can lead to serious consequences such as vacuum breakage and high-pressure drop, causing irreversible damage to the instrument. Specifically, vacuum breakage significantly reduces the lifespan of molecular and ion pumps, and also compromises the cleanliness of the TEM tube. Moreover, once a vacuum breakage occurs, it takes several hours to restore the vacuum state, which undoubtedly severely impacts the normal lifespan and operational efficiency of the instrument. Utility Model Content

[0005] This application aims to solve one of the aforementioned technical problems in the prior art. To this end, embodiments of this application provide a transmission electron microscope sample introduction positioning limiter.

[0006] According to an embodiment of this application, a transmission electron microscope sample introduction positioning limiter is provided, including a fixing member for fixing to a goniometer stage;

[0007] The connector is configured to rotate with the fixing member. The connector is provided with a first track and a second track, wherein the first track is perpendicular to and connected to the second track, the first track is arc-shaped, and the second track is straight.

[0008] A limiting member is movable from the first track to the second track. Both ends of the limiting member are located outside the track. The limiting member is positioned towards the center of the first track. A limiting structure is provided at one end of the limiting member facing the center of the first track. The limiting structure is used to limit the positioning pin of the sample rod.

[0009] The aforementioned transmission electron microscope (TEM) sample insertion positioning limiter has at least the following beneficial effects: In use, the fixing component is fixed to the goniometer stage of the TEM, and the connecting component is adjusted so that the center of the first track is concentric with the sample insertion hole of the goniometer stage. Then, the limiting component is moved to the end of the first track away from the second track. The sample rod is then inserted into the sample insertion hole of the goniometer stage, and the positioning pin of the sample rod is engaged with the limiting structure. The limiting component rotates at a constant speed on the first track, causing the sample rod to move at a constant speed. When the sample rod rotates to its position, the limiting component faces the second track. At this time, the positioning pin of the sample rod aligns with the positioning hole of the goniometer stage, and the sample rod is axially pressed into the microscope tube by atmospheric pressure. The limiting component and the second track ensure that the sample rod does not rotate during the process of being pressed in by atmospheric pressure. After the positioning pin of the sample rod enters the positioning hole, the connecting component is rotated so that the limiting structure no longer restricts the positioning pin of the sample rod, allowing the sample rod to be inserted further. The transmission electron microscope (TEM) sample introduction positioning limiter of this application avoids damage to the internal ball valve and reduction of the vacuum level in the microscope tube caused by improper operation, thereby improving the sample introduction success rate, protecting the sample rod and ball valve, and extending the service life of the equipment. At the same time, the limiting device avoids direct hand contact with the sample rod, reducing the impact of contaminants on the vacuum environment of the microscope tube, the sample, and the vacuum pump.

[0010] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, the first track is provided with a damping structure on one or more sides that are in contact with the limiting member, and the pre-pressure provided by the damping structure acts on the limiting member.

[0011] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, the second track is provided with the damping structure on one or more sides that are in contact with the limiting member.

[0012] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, the damping structure includes a plurality of arrayed protrusions, and the protrusions are elastic.

[0013] According to the transmission electron microscope sample insertion positioning limiter described in the embodiments of this application, the damping structure is made of polytetrafluoroethylene.

[0014] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, the connecting member is provided with a first channel on the side facing the center of the first track. The first channel connects the first track and the second track so that the end of the limiting member can pass through the first channel.

[0015] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, a second channel is provided on the side of the connector facing away from the center of the first track. The second channel connects the first track and the second track, so that the end of the limiting member can pass through the second channel.

[0016] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, the limiting structure is provided with a slider portion adapted to the first track or the second track.

[0017] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, the limiting structure is a limiting groove, the groove opening is oriented towards the center of the first track, and the angle formed by the line connecting the bottom of the limiting groove and the center of the first track with the setting direction of the limiting groove is set to 30° to 45°. The distance between the bottom of the limiting groove and the center of the first track is equal to the distance between the sample introduction hole of the goniometer stage and the limiting hole.

[0018] According to the transmission electron microscope sample introduction positioning limiter described in the embodiments of this application, the rotatable range of the connecting member is set to 120°, the limiting member slides from one end of the first track to the other end, and the limiting member rotates 120° around the center of the first track.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The present application will be further described below with reference to the accompanying drawings and embodiments;

[0021] Figure 1 This is a schematic diagram of the structure of the transmission electron microscope sample entry positioning limiter according to an embodiment of this application. Figure 1 ;

[0022] Figure 2 This is a schematic diagram of the structure of the transmission electron microscope sample introduction positioning limiter in the embodiments of this application. Figure 2 ;

[0023] Figure 3 This is a schematic diagram of the sample rod structure in an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the structure of the transmission electron microscope sample introduction positioning limiter in the embodiments of this application. Figure 3 ;

[0025] Figure 5 This is a schematic diagram of the damping structure in an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of the structure of the limiting member in an embodiment of this application;

[0027] Figure 7 This is a schematic diagram of the structure of the transmission electron microscope sample introduction positioning limiter in the embodiments of this application. Figure 4 .

[0028] Reference numerals: angle measuring stage 100, sample inlet 110, positioning hole 120, sample rod 200, positioning pin 210, fixing part 310, connecting part 320, first track 321, second track 322, limiting part 330, limiting groove 331, slider part 332, damping structure 340. Detailed Implementation

[0029] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.

[0030] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0031] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0032] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0033] In microscopic research within materials science and life sciences, transmission electron microscopy (TEM) plays an irreplaceable role as a crucial characterization tool. The human eye has relatively limited resolving power, with a resolution of approximately 0.2 mm, while optical microscopes can achieve a resolution of 0.2 μm. However, for submicroscopic structures that are difficult to resolve with optical microscopes, TEM, with its superior resolution, can provide clear observations. TEM resolution typically ranges from 0.1 to 0.2 nm, and its specific performance is influenced by factors such as accelerating voltage and the presence or absence of spherical aberration correctors. Advanced TEM instruments equipped with spherical aberration correctors can even achieve atomic-level resolution, revealing the intricate structures of the microscopic world to researchers.

[0034] The high resolution of TEM primarily stems from its use of an electron beam as the light source. The wavelength of the electron beam is significantly shorter than that of visible and ultraviolet light, and is inversely proportional to the square root of the accelerating voltage. As the accelerating voltage increases, the wavelength of the electron beam decreases accordingly, further enhancing the instrument's resolution and providing strong support for the analysis of nanoscale microstructures.

[0035] In the field of materials science, TEM plays a crucial role, especially in the research of semiconductor materials and nanomaterials (such as carbon nanotubes and graphene). TEM can provide key information on the morphology, structure, and composition of materials at the nanoscale. This high-precision observational data is of vital importance for a deeper understanding of the physical and chemical properties of materials, as well as for optimizing material design and fabrication processes, thus powerfully promoting the development of materials science.

[0036] As a sample carrier in the TEM, the design and function of the sample holder 200 are crucial to the success of the experiment. The sample holder 200 is typically club-shaped and used to carry the sample to be observed. In routine operation, the sample is placed on a support mesh (usually a 3 mm diameter copper mesh), and then the support mesh carrying the sample is fixed to the front end of the sample holder 200. One sample holder 200 can carry 1 to 5 samples to meet different experimental needs. The front end of the sample holder 200 is compact, small in size, and occupies little space. When inserted into the TEM, the sample holder 200 is precisely positioned between the upper and lower pole shoes of the objective lens, ensuring that the copper mesh is on the central axis of the electron optical path for optimal observation conditions.

[0037] The main function of the sample holder 200 is to provide stable and reliable support for the sample to be observed. Simultaneously, a rubber sealing ring seals the interface between the sample holder 200 and the microscope tube, maintaining a high vacuum (1 x 10⁻⁶) in the microscope tube after sample introduction. -6 Samples used in TEM are typically extremely thin and tiny, such as ultrathin slices of biological cells and nanomaterial particles. These samples are both fragile and small, placing stringent demands on the performance of the support equipment. The Sample Rod 200, with its ingenious design and stable performance, ensures that samples can be accurately placed into the TEM's sample chamber, enabling high-precision observation and providing strong support for researchers to obtain high-quality experimental data.

[0038] The insertion and removal of the sample rod 200 is a crucial and high-risk step in the entire transmission electron microscope (TEM) operation. Even slight errors can break the vacuum in the microscope tube, leading to damage to the instrument hardware. Whether it's the early top-insertion type or the current mainstream side-insertion type, the current operating mode requires manual insertion and removal by the experimenter. The key operations and influencing factors are as follows: 1. The angle and depth at which the sample rod 200 is inserted into the goniometer stage 100 during the pre-vacuuming stage; 2. The angle at which the ball valve opens after the pre-vacuuming is completed by rotating the sample rod 200; 3. The control force and depth at which the sample rod 200 probes into the objective pole shoe after the ball valve opens. It is evident that this traditional operating method is highly prone to error and extremely dependent on the operator's skill level.

[0039] Transmission electron microscopes (TEMs) are expensive, often costing millions or even tens of millions of dollars, and are mostly imported equipment. Therefore, extreme caution must be exercised when inserting and removing samples from the sample holder 200: First, as an extremely delicate component inside the instrument, the sample holder 200 must be handled with care, and rough handling must be strictly avoided; second, when changing samples or inserting / removing the sample holder 200, it is strictly forbidden to touch any part of the sample holder 200 from the sealing ring to the top. Once it comes into contact with grease or other organic matter, it is very likely to affect the vacuum level of the instrument, thus causing irreversible contamination inside the instrument; third, when inserting or removing the sample holder 200, the established operating procedures must be strictly followed, and the insertion angle, force, and depth must be precisely controlled. Otherwise, the internal vacuum environment of the instrument can be easily damaged, and in severe cases, it may even damage the vacuum pump.

[0040] in, Figure 3 This is a schematic diagram of the sample rod 200. A positioning pin 210 for positioning the sample rod 200 is provided at the end of the sample rod 200 away from the insertion end.

[0041] in, Figure 1 , Figure 2 and Figure 4The schematic diagram of the goniometer stage 100 shown is a part of the transmission electron microscope. The goniometer stage 100 has a sample inlet 110 in the middle and a positioning hole 120 for the positioning pin 210 of the sample rod 200 to be inserted near the sample inlet 110.

[0042] Reference Figures 1 to 3 This application provides a transmission electron microscope (TEM) sample introduction positioning limiter, which includes a fixing member 310, a connecting member 320, and a limiting member 330.

[0043] like Figure 1 , Figure 2 and Figure 4 As shown, the fixing member 310 is used to fix it to the goniometer stage 100. The connecting member 320 is configured to rotate with the fixing member 310. The connecting member 320 is provided with a first track 321 and a second track 322. The first track 321 and the second track 322 are perpendicular and connected. The first track 321 is arc-shaped and the second track 322 is straight. The limiting member 330 can be set on the first track 321 or the second track 322, and the limiting member 330 can move from the first track 321 to the second track 322. The two ends of the limiting member 330 are respectively outside the track. The limiting member 330 is set towards the center of the first track 321. The end of the limiting member 330 facing the center of the first track 321 is provided with a limiting structure. The limiting structure is used to limit the positioning pin 210 of the sample rod 200. When the limiting member 330 slides from one end of the first track 321 to the other end, the limiting member 330 rotates around the center of the first track 321.

[0044] In use, fix the fixing member 310 to the goniometer stage 100 of the transmission electron microscope, adjust the connecting member 320 so that the center of the first track 321 is concentric with the sample inlet 110 of the goniometer stage 100, then move the limiting member 330 to the end of the first track 321 away from the second track 322, then insert the sample rod 200 into the sample inlet 110 of the goniometer stage 100, and make the positioning pin 210 of the sample rod 200 lock into the limiting structure. The limiting member 330 drives the sample rod 200 to move at a constant speed by rotating the first track 321 at a constant speed. When the sample rod 200 rotates to After positioning, the limiting component 330 is aligned with the second track 322. At this time, the positioning pin 210 of the sample rod 200 is aligned with the positioning hole 120 of the goniometer stage 100. Under the limiting of the limiting component 330 and the second track 322, the sample rod 200 is ensured not to rotate during atmospheric pressure pressing. After the sample rod 200 is pressed until the positioning pin 210 enters the positioning hole 120, the connecting component 320 is rotated so that the limiting structure no longer restricts the positioning pin 210 of the sample rod 200. Then, the sample rod 200 can continue to be fully pressed into the goniometer stage 100 by atmospheric pressure until it is tightly fitted.

[0045] The transmission electron microscope sample introduction positioning limiter of this application integrates a series of ingenious limiting and locking measures, successfully transforming the insertion and removal process, which previously relied heavily on the operator's personal experience and technique, into a mechanized and streamlined operation mode. When used in conjunction with sample introduction operations, it significantly improves the accuracy and reliability of the operation, reducing reliance on the user's experience.

[0046] In some embodiments, the first track 321 is provided with a damping structure 340 on one or more sides that are in contact with the limiting member 330, and the pre-pressure provided by the damping structure 340 acts on the limiting member 330.

[0047] In this embodiment, the goniometer 100 is vertically arranged, and the sample rod 200 is inserted into the sample inlet 110 in a horizontal direction. Therefore, at least one side of the first track 321 is in contact with the limiting member 330. By adding a damping structure 340 between the first track 321 and the limiting member 330, the damping structure 340 can provide pre-pressure to the limiting member 330, thereby increasing the sliding friction of the damping structure 340 in the first track 321, making the process of manually moving the limiting member 330 more uniform and gentle.

[0048] In some specific embodiments, the opposite sides of the limiting member 330 are in contact with the first track 321 through the damping structure 340, so that the sliding speed of the limiting member 330 is controllable.

[0049] In some embodiments, the second track 322 is provided with a damping structure 340 on one or more sides that contact the limiting member 330. By adding a damping structure 340 between the second track 322 and the limiting member 330, the damping structure 340 can provide pre-pressure to the limiting member 330, thereby increasing the sliding friction of the damping structure 340 within the second track 322, making the process of manually moving the limiting member 330 more uniform and gentle.

[0050] In some specific embodiments, the opposite sides of the limiting member 330 are in contact with the second track 322 through the damping structure 340, so that the sliding speed of the limiting member 330 is controllable.

[0051] In the embodiments of this application, such as Figure 5 As shown, the damping structure 340 includes a plurality of arrayed protrusions, which are elastic. The elastic protrusions apply a pre-pressure to the limiting member 330 to increase the sliding friction of the damping structure 340. When the limiting plate is rotated counterclockwise, the sample rod 200 can be rotated at a uniform speed, ensuring the stability and accuracy of the operation process.

[0052] The damping structure 340 is made of polytetrafluoroethylene.

[0053] In some embodiments, such as Figure 4 and Figure 7 As shown, the connector 320 has a first channel on the side facing the center of the first track 321. The first channel connects the first track 321 and the second track 322, allowing the end of the limiting member 330 to pass through the first channel. This facilitates docking between the limiting structure at the end of the limiting member 330 and the sample rod 200.

[0054] In addition, a second channel is provided on the side of the connector 320 facing away from the center of the first track 321. The second channel connects the first track 321 and the second track 322 so that the end of the limiting member 330 can pass through the second channel, making it convenient for manual operation to rotate the end of the limiting member 330.

[0055] In some embodiments, such as Figure 6 As shown, the limiting structure is provided with a slider part 332 that is adapted to the first track 321 or the second track 322.

[0056] In the embodiments shown in this application, such as Figure 1 , Figure 2 , Figure 4 and Figure 7 As shown, the connector 320 is sickle-shaped and can be fixedly installed on the surface of the goniometer stage 100 by the fastener 310. It is mainly used to achieve positioning, limiting and uniform speed functions when changing TEM samples.

[0057] The sickle-shaped connector 320 has an inner arc of 225° centered on the sample inlet 110. It includes a first arc portion with an arc of 165° and a second arc portion with an arc of 60°. A first track 321 is disposed on the first arc portion, and a fixing member 310 is rotatably connected to the second arc portion. The second track 322 is disposed at the end of the first arc portion. Through the fixing member 310, the transmission electron microscope sample inlet positioning limiter of this application can rotate away from the sample inlet 110 in a fixed-point rotation manner.

[0058] In this embodiment, the rotatable range of the connector 320 is set to 120°, the limiting member 330 slides from one end of the first track 321 to the other end, and the limiting member 330 rotates 120° around the center of the first track 321.

[0059] In some embodiments, the limiting structure is a limiting groove 331, with the groove opening of the limiting groove 331 facing the center of the first track 321. The angle formed by the line connecting the bottom of the limiting groove 331 and the center of the first track 321 with the setting direction of the limiting groove 331 is set to 30° to 45°. The distance between the bottom of the limiting groove 331 and the center of the first track 321 is equal to the distance between the sample inlet 110 and the limiting hole 120 of the goniometer stage 100.

[0060] In this embodiment, the width of the limiting groove 331 is machined to 4 mm, perfectly matching the size of the positioning pin 210 at the rear end of the sample rod 200, ensuring that the positioning pin 210 can be smoothly inserted. Simultaneously, the angle formed by the line connecting the bottom of the limiting groove 331 and the center of the first track 321 with the setting direction of the limiting groove 331 is set to 35°. The limiting groove 331 is annular in shape, allowing the positioning pin 210 to easily disengage before the sample rod 200 is fully inserted into the goniometer stage 100. The height of the limiting member 330 from the surface of the goniometer stage 100 is accurately controlled at 6 cm, consistent with the precise insertion position in the first step of the operation, providing a precise positioning basis for the insertion of the sample rod 200.

[0061] In the embodiment shown in this application, the first track 321 forms a 120° arc groove with a width of 1.7 cm and a thickness of 1.7 cm, centered on the sample inlet hole 110. When the first track 321 is fixed to the goniometer stage 100, it is parallel to the surface of the goniometer stage 100. The interior of the first track 321 is carefully provided with a ring-shaped or sheet-shaped damping element made of polytetrafluoroethylene. When the limiting member 330 is rotated counterclockwise, the sample rod 200 can be driven to rotate at a uniform speed through the limiting groove 331, ensuring the stability and accuracy of the operation process.

[0062] The second track 322 is perpendicular to the surface of the goniometer stage 100, with a precisely set length of approximately 6 cm. It also incorporates a ring-shaped or sheet-shaped damping element made of polytetrafluoroethylene (PTFE) to ensure a tight fit with the slider portion 332 of the limiting member 330. This ingenious design allows the sample rod 200 to move at a uniform speed when inserted into the microscope tube, further improving the accuracy and smoothness of the operation and effectively avoiding sample damage or positioning deviations that may result from speed fluctuations.

[0063] All components in this application embodiment do not contain metallic materials and are mainly manufactured using non-metallic materials such as polytetrafluoroethylene (PTFE). PTFE has excellent wear resistance, a low coefficient of friction, and good chemical stability, ensuring stable performance of the device during long-term use. Furthermore, the entire device can be produced using 3D printing technology. This advanced manufacturing process not only enables precise molding of complex structures but also effectively reduces costs and improves production efficiency.

[0064] Furthermore, the advantage of using non-metallic materials lies in effectively controlling component weight and avoiding adverse effects on the instrument's counterweight, thereby ensuring the overall balance and stability of the instrument. More importantly, non-metallic materials do not generate magnetic fields, fundamentally avoiding interference with the normal operation of electromagnetic lenses. This is crucial for ensuring the imaging quality and testing accuracy of TEM equipment.

[0065] This application employs a limiting component 330 to drive the sample rod 200, replacing the traditional direct manual operation. This design not only cleverly utilizes the damping structure 340 to achieve uniform movement of the sample rod 200, but also effectively avoids the risk of contamination from direct hand contact with the sample rod 200. Hand contact can lead to contaminants affecting the vacuum environment of the microscope tube, contaminating the sample, and even increasing the load on the vacuum pump. In this way, this patent significantly improves the reliability and service life of the equipment while ensuring operational accuracy.

[0066] The main operations for assisting with the sample rod 200 in this application are as follows:

[0067] The first step, precise positioning and insertion of the sample rod 200, optimizes the insertion process of the sample rod 200 through ingenious mechanical design. After the positioning pin 210 is fully inserted into the positioning hole 120, the insertion angle and depth of the sample rod 200 can be precisely determined, ensuring accurate matching of the sealing ring position and achieving reliable sealing. This eliminates the need for repeated manual fine-tuning of the sample rod 200 position, simplifying the operation, reducing operational difficulty, and minimizing problems such as poor sealing caused by inaccurate insertion.

[0068] The second step, pre-vacuum optimization: The purpose of pre-vacuum is to evacuate the transition chamber containing the sample and the front end of the sample rod 200 to achieve a certain vacuum level before the sample can be smoothly transferred into the high-vacuum microscope tube. In traditional operation, even if the sample rod 200 is not inserted to the correct depth, the vacuum sensor will be triggered. However, in reality, due to poor sealing of the sealing ring, the molecular pump may be overloaded and damaged, or even the vacuum in the microscope tube may be broken. This patent, through the precise limitation of the limiting groove 331, ensures the accuracy of the insertion angle and depth of the sample rod 200, avoiding the problem of insufficient vacuuming caused by positional deviation, and improving the efficiency and reliability of pre-vacuum.

[0069] Step 3: Improved Rotation and Insertion Operations: In traditional operation, rotating the sample rod 200 to open the ball valve and inserting the sample rod 200 requires the operator to manually rotate it at a constant speed and precisely control the force to balance atmospheric pressure and vacuum suction, making the operation quite difficult. This application introduces a track with a mechanical friction damping system. The uniform movement of the sample rod 200 is achieved through the friction between the damping material and the slider 332 of the limiting member 330. The operator only needs to manually turn the limiting member 330 counterclockwise to rotate and insert the sample rod 200 at a constant speed, eliminating the need for experience or skill. This design avoids damage to the ball valve and a decrease in the vacuum level of the microscope tube due to improper operation, improves the sample introduction success rate, protects the sample rod 200 and the ball valve, and extends the service life of the equipment. Simultaneously, the lever operation avoids direct hand contact with the sample rod 200, reducing the impact of contaminants on the vacuum environment of the microscope tube, the sample, and the vacuum pump.

[0070] Without the transmission electron microscope sample placement device described in this application, the rotation and insertion steps are highly susceptible to external atmospheric pressure, causing the operation to deviate into "rotation and insertion simultaneously." In this case, the ball valve may not be fully open before the sample rod 200 is inserted, thereby damaging the ball valve and reducing the vacuum level inside the microscope tube. Because this operation is highly dependent on the operator's experience and skill, improper operation can not only significantly reduce the success rate of sample introduction but may also damage the sample rod 200 and the ball valve.

[0071] The advantage of this application lies in the fact that the rotation position and angle are strictly limited by the first track 321, thereby ensuring precise and controllable rotation of the sample rod 200 and avoiding problems such as reverse rotation, over-rotation, or under-rotation. Furthermore, the uniform rotation is achieved thanks to the damping structure 340 cleverly arranged inside the tracks (first track 321 and second track 322). By configuring damping material inside the tracks that contacts the sample rod 200, the friction between the material and the slider 332 is used to dissipate the pushing energy, thus allowing for stable control of the sample rod 200's movement speed. When the operator manually pushes the limiting member 330, causing the sample rod 200 to move, the friction provided by the damping material and the applied thrust reach a dynamic balance, thereby achieving uniform motion.

[0072] The working process of the transmission electron microscope sample entry positioning limiter in this application is as follows:

[0073] Step 1: Insert the sample rod 200, hold the end of the sample rod 200 horizontally, and roughly align the positioning pin 210 with the limiting groove 331 on the sample stage. The positioning pin 210 will automatically align with the limiting groove 331. Gently push the sample rod 200 until the positioning pin 210 is fully inserted into the limiting groove 331.

[0074] Step 2: Vacuum pretreatment. When the positioning pin 210 is fully inserted into the limiting groove 331, the red light on the sample stage illuminates, triggering the sensor and automatically starting the mechanical pump to pre-vacuum the transition chamber for approximately 3 minutes.

[0075] Step 3: Rotate the sample rod 200 and complete the insertion. After 3 minutes, the red light on the sample stage will turn off. At this time, manually turn the limiting member 330 counterclockwise, causing the sample rod 200 to rotate counterclockwise by approximately 120° to the end of the first track 321. Due to the strong suction inside the microscope tube, the sample rod 200 slides smoothly and evenly into the electron microscope along the second track 322. When the sample rod 200 reaches the bottom of the second track 322, rotate the connecting member 320 counterclockwise to disengage the positioning pin 210 from the limiting groove 331, completing the full insertion of the sample rod 200.

[0076] Finally, after confirming that the sample rod 200 is fully inserted, the positioning limiter is positioned below the sample rod 200, the red indicator light is off, the sample rod 200 is flush with the goniometer stage 100 without any protrusions, and the instrument vacuum level is good (better than 1 x 10⁻⁶). -6 Pa).

[0077] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A sample introduction positioning limiter for transmission electron microscopes, characterized in that: include Fasteners are used to fix the device to the goniometer. The connector is configured to rotate with the fixing member. The connector is provided with a first track and a second track, wherein the first track is perpendicular to and connected to the second track, the first track is arc-shaped, and the second track is straight. A limiting member is movable from the first track to the second track. Both ends of the limiting member are located outside the track. The limiting member is positioned towards the center of the first track. A limiting structure is provided at one end of the limiting member facing the center of the first track. The limiting structure is used to limit the positioning pin of the sample rod.

2. The transmission electron microscope sample entry positioning limiter according to claim 1, characterized in that: The first track is provided with a damping structure on one or more sides that are in contact with the limiting member, and the pre-pressure provided by the damping structure is applied to the limiting member.

3. The transmission electron microscope sample introduction positioning limiter according to claim 2, characterized in that: The second track is provided with the damping structure on one or more sides that are in contact with the limiting member.

4. The transmission electron microscope sample introduction positioning limiter according to claim 3, characterized in that: The damping structure includes a plurality of arrayed protrusions, which are elastic.

5. The transmission electron microscope sample introduction positioning limiter according to claim 4, characterized in that: The damping structure is made of polytetrafluoroethylene.

6. The transmission electron microscope sample entry positioning limiter according to any one of claims 1 to 5, characterized in that: The connector has a first channel on one side facing the center of the first track, the first channel connecting the first track and the second track, so that the end of the limiting member can pass through the first channel.

7. The transmission electron microscope sample introduction positioning limiter according to claim 6, characterized in that: The connector has a second channel on the side facing away from the center of the first track. The second channel connects the first track and the second track so that the end of the limiting member can pass through the second channel.

8. The transmission electron microscope sample entry positioning limiter according to claim 7, characterized in that: The limiting structure is provided with a slider portion that is adapted to the first track or the second track.

9. The transmission electron microscope sample entry positioning limiter according to any one of claims 1 to 5, characterized in that: The limiting structure is a limiting groove, with the groove opening facing the center of the first track. The angle formed by the line connecting the bottom of the limiting groove and the center of the first track with the setting direction of the limiting groove is set to 30° to 45°. The distance between the bottom of the limiting groove and the center of the first track is equal to the distance between the sample inlet of the angle measuring stage and the limiting hole.

10. The transmission electron microscope sample entry positioning limiter according to claim 1, characterized in that: The rotatable range of the connector is set to 120°, the limiting member slides from one end of the first track to the other end, and the limiting member rotates 120° around the center of the first track.

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