Sample stage for variable position large angle proton irradiation in vacuum environment

Abstract

The application discloses a variable-position large-angle proton irradiation sample table in a vacuum environment, which comprises a sample table arranged in an electronic comprehensive irradiation cabin, and the sample table comprises a motion turntable, a driving mechanism, a transmission shaft, a spline hollow shaft and a spline shaft. One end of the transmission shaft is in transmission connection with the driving mechanism, a fluid sealing device is rotatably sleeved on the transmission shaft, a first universal joint is connected to the fluid sealing device, the first universal joint is hinged to one end of the spline hollow shaft, the other end of the spline hollow shaft is slidably provided with the spline shaft, and the other end of the spline shaft away from the spline hollow shaft is hinged to a second universal joint. The motion turntable comprises a platform base, the platform base is rotatably provided with an X-direction turntable, an irradiation table is rotatably connected to the X-direction turntable through a turntable shaft, and one end of the second universal joint away from the spline hollow shaft is connected to the turntable shaft. When the sample receives the radiation, the uniformity of the absorbed dose of the irradiated object is maximally improved, and the irradiation source can be directly faced.

Description

Technical Field

[0001] This invention relates to the field of irradiation sample stage technology, specifically to a vacuum environment variable displacement large-angle proton irradiation sample stage. Background Technology

[0002] The development of aerospace technology is inseparable from the research and application of various irradiation environments. Currently, over 100 countries worldwide possess irradiation facilities for different purposes, simulating environments such as vacuum, heat sinks, high / low temperature / thermal cycling, charged particle irradiation, and solar electromagnetic radiation, as well as studying the effects of various space environments on materials, devices, and system components. Since the 1950s, my country's research-oriented irradiation facilities have developed rapidly, initially applied to agricultural radiation-induced mutagenesis and genetic breeding, but their application in aerospace has been limited. With the rapid development of my country's aerospace industry, sample testing under vacuum irradiation environments has significant research value. For proton irradiation chambers, the sample stage, while possessing a certain load-bearing capacity and the ability to load different types of samples, should be able to perform sample irradiation, measurement, and transfer functions. Considering the high cost, long development cycle, and extremely low fault tolerance inherent in the aerospace industry, it is essential to design an irradiation stage that ensures uniform radiation absorption by the irradiated product, has a high load-bearing capacity, reduces operator workload, adapts to the space environment, and can operate stably. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a vacuum environment variable displacement large-angle proton irradiation sample stage, which ensures that the uniformity of the absorbed dose of the irradiated object is maximized when the sample is receiving radiation, and can be directly facing different irradiation sources, while adapting to stable operation in high vacuum, high radiation, and high and low temperature environments.

[0004] The objective of this invention is achieved through the following technical solution: a vacuum environment variable displacement large-angle proton irradiation sample stage, comprising a sample stage disposed within an electron integrated irradiation chamber, the sample stage comprising a transmission mechanism and a rotating stage, the transmission mechanism comprising a drive mechanism, a transmission shaft, a splined hollow shaft and a splined shaft, one end of the transmission shaft being drively connected to the drive mechanism, a fluid sealing device being rotatably mounted on the transmission shaft, a first universal joint being connected to the fluid sealing device, the first universal joint being hinged to one end of the splined hollow shaft, the other end of the splined hollow shaft being slidably pierced by the splined shaft, and the other end of the splined shaft away from the splined hollow shaft being hinged to a second universal joint;

[0005] The rotating platform includes a platform base, an X-axis rotating platform, and an irradiation stage. The X-axis rotating platform is rotatably mounted on the platform base and rotates around the height axis of the platform base. The irradiation stage is rotatably connected to the X-axis rotating platform via a rotating platform shaft. The end of the second universal joint away from the hollow spline shaft is connected to the rotating platform shaft. The rotation axis of the irradiation stage is perpendicular to the rotation axis of the X-axis rotating platform.

[0006] The advantages of the above technical solution are as follows: The transmission mechanism drives the irradiation stage to rotate around the turntable axis, causing the irradiated object on the irradiation stage to rotate around the Z-axis. When rotation around the X-axis is required, the transmission mechanism is locked to ensure rotational accuracy. During rotation around the X-axis, the relative displacement between the spline shaft and the spline hollow shaft, along with the transmission characteristics of the first and second universal joints on both sides, ensures that the torque around the Z-axis is not lost. This maximizes the uniformity of the absorbed dose when the sample receives radiation, and allows for direct contact with different irradiation sources to meet irradiation requirements from different directions. Secondly, regarding adaptability to high vacuum, high radiation, and high / low temperatures, since torque transmission requires penetration through the chamber, a fluid sealing device is installed to seal the internal mechanisms to prevent damage to the chamber environment. The fluid sealing device uses a magnetohydrodynamic seal, and simultaneously isolates the drive mechanism from the chamber, forming a magnetohydrodynamic seal at the drive mechanism. This allows the transmission mechanism to adapt to the high vacuum, high radiation, and high / low temperature environment within the comprehensive irradiation chamber.

[0007] Furthermore, the drive mechanism includes a stepper motor, a reducer, and a worm gear transmission pair. The output shaft of the stepper motor is connected to the input shaft of the reducer, and the output shaft of the reducer is connected to the worm shaft of the worm gear transmission pair. The worm shaft of the worm gear transmission pair is connected to the drive shaft via a coupling. The end of the fluid sealing device away from the first universal joint is connected to the worm wheel of the worm gear transmission pair.

[0008] Furthermore, the first universal joint and the spline hollow shaft, as well as the spline shaft and the second universal joint, are both connected by Hooke hinges.

[0009] Furthermore, the X-axis turntable is U-shaped, and the irradiation station is located in the U-shaped opening of the X-axis turntable. Both ends of the irradiation station are fixed with the turntable shafts, which are rotatably connected to the X-axis turntable via bearings. One of the turntable shafts is equipped with an encoder, which is connected to the X-axis turntable via a flange. The other turntable shaft is equipped with a Z-axis scale.

[0010] Furthermore, a turntable spindle is connected to the bottom of the X-axis turntable, and the turntable spindle is rotatably connected to the platform base through a turntable bearing.

[0011] Furthermore, the platform base is provided with an X-axis scale, which is coaxial with the turntable spindle. A turntable locking mechanism is provided on the X-axis turntable to restrict the rotation of the X-axis turntable.

[0012] Furthermore, the turntable locking mechanism includes a handwheel, a screw, and a brake disc. The screw is threadedly connected to the X-axis turntable, and the handwheel is fixed to the top of the screw. The handwheel is located within the U-shaped opening of the X-axis turntable. The brake disc is disposed between the X-axis turntable and the platform base, and the brake disc is located on the screw's screw path.

[0013] Furthermore, the bottom of the platform base is connected to multiple bow-shaped lifting brackets, which are installed inside the integrated electron irradiation chamber by anchor bolts.

[0014] The beneficial effects of this invention are:

[0015] 1. The irradiation stage is driven to rotate around the turntable shaft by the transmission mechanism, causing the irradiated object on the irradiation stage to rotate around the Z-axis. When rotation around the X-axis is required, the transmission mechanism is locked to ensure rotational accuracy. When the turntable rotates around the X-axis, the relative displacement between the spline shaft and the spline hollow shaft and the transmission characteristics of the first and second universal joints on both sides can ensure that the torque around the Z-axis is not lost. This ensures that the uniformity of the absorbed dose of the irradiated object is maximized when the sample receives radiation. It can also be aligned with different irradiation sources to meet the irradiation requirements of different orientations.

[0016] 2. In terms of adapting to high vacuum, high radiation, and high and low temperatures, since the transmission of torque requires passing through the chamber, a fluid sealing device is set up to seal the internal mechanism in order to ensure that the internal environment is not damaged. The fluid sealing device adopts a magnetic fluid seal. At the same time, the drive mechanism is isolated from the chamber through the fluid sealing device, forming a magnetic fluid seal at the drive mechanism, so that the transmission mechanism can adapt to the high vacuum, high radiation, and high and low temperature environment inside the comprehensive irradiation chamber. Attached Figure Description

[0017] Figure 1 This is a perspective view of the sample stage in a vacuum environment variable position large angle proton irradiation sample stage of the present invention.

[0018] Figure 2 This is a top view of the sample stage in a vacuum environment variable position large angle proton irradiation sample stage of the present invention;

[0019] Figure 3 This is a schematic diagram of the internal structure of the sample stage in the vacuum environment variable position large angle proton irradiation sample stage of the present invention;

[0020] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0021] Figure 5 This is a schematic diagram of the sample stage installed inside the electron irradiation chamber in this invention;

[0022] Figure 6 This is a schematic diagram of the structure of the integrated electron irradiation chamber in this invention;

[0023] Figure 7 This is a motion posture diagram of the transmission mechanism when the sample stage of the present invention rotates around the X direction;

[0024] In the diagram, 1-transmission mechanism, 2-motion turntable, 3-drive shaft, 4-spline hollow shaft, 5-spline shaft, 6-first universal joint, 7-second universal joint, 8-platform base, 9-turntable around X-axis, 10-irradiation station, 11-turntable shaft, 12-stepper motor, 13-reducer, 14-worm gear transmission pair, 15-fluid sealing device, 16-encoder, 17-flange, 18-turntable spindle, 19-turntable bearing, 20-scale dial around Z-axis, 28-scale dial around X-axis, 29-handwheel, 30-screw, 31-brake disc, 32-arched lifting bracket. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0026] like Figures 1 to 7As shown, a vacuum environment variable-position large-angle proton irradiation sample stage includes a sample stage disposed within an electron integrated irradiation chamber. The sample stage includes a transmission mechanism 1 and a moving turntable 2. The transmission mechanism 1 includes a drive mechanism, a transmission shaft 3, a splined hollow shaft 4, and a splined shaft 5. One end of the transmission shaft 3 is connected to the drive mechanism. A fluid sealing device 15 is rotatably mounted on the transmission shaft 3. A first universal joint 6 is connected to the fluid sealing device 15. The first universal joint 6 is hinged to one end of the splined hollow shaft 4. The other end of the splined hollow shaft 4 is slidably connected to the splined shaft 5. The other end of the splined shaft 5, away from the splined hollow shaft 4, is hinged to a second universal joint 7. The moving turntable 2 includes a platform base 8, an X-axis turntable 9, and an irradiation stage 10. The X-axis turntable 9 is rotatably disposed on the platform base 8, and the X-axis turntable 9 revolves around the platform base 8. The irradiation stage 10 rotates along the height axis and is rotatably connected to the X-axis turntable 9 via the turntable shaft 11. The end of the second universal joint 7 away from the spline hollow shaft 4 is connected to the turntable shaft 11. The rotation axis of the irradiation stage 10 is perpendicular to the rotation axis of the X-axis turntable 9. To improve the irradiation uniformity of the irradiated sample, the sample stage adopts two degrees of freedom: rotation around the X-axis and rotation around the Z-axis. The drive mechanism includes a stepper motor 12, a reducer 13, and a worm gear transmission pair 14. The output shaft of the stepper motor 12 is connected to the input shaft of the reducer 13. The output shaft of the reducer 13 is connected to the worm shaft of the worm gear transmission pair 14. The worm shaft of the worm gear transmission pair 14 is connected to the drive shaft 3 via a coupling. The end of the fluid sealing device 15 away from the first universal joint 6 is connected to the worm wheel of the worm gear transmission pair 14. To improve the irradiation uniformity of the irradiated sample, the sample stage employs two degrees of freedom: rotation around the X-axis and rotation around the Z-axis. The rotational degree of freedom around the Z-axis is achieved by the rotation of the irradiation stage 10. The irradiation stage 10 has a 12x12 irradiation hole to facilitate the passage of the irradiation source. The specific rotation process is as follows: the stepper motor 12 drives the reducer 13 to start, the reducer 13 drives the worm gear pair 14 to rotate, the worm gear pair 14 drives the transmission shaft 3 and the fluid sealing device 15 on the transmission shaft 3 to rotate, the fluid sealing device 15 drives the first universal joint 6 on it to rotate, the first universal joint 6 drives the splined hollow shaft 4 to rotate, and the splined hollow shaft 4 drives the second universal joint through the splined shaft 5. The rotation of the 7th universal joint drives the rotation of the turntable shaft 11 through the second universal joint 7, thereby driving the irradiation stage 10 on the turntable shaft 11 to rotate, realizing the rotation of the sample stage around the Z-axis. Its rotation range is 0-90°. When rotation around the X-axis is required, the transmission mechanism 1 is locked to ensure rotational accuracy. When the turntable 9 rotates around the X-axis, the relative displacement between the spline shaft 5 and the spline hollow shaft 4 and the transmission characteristics of the first universal joint 6 and the second universal joint 7 on both sides can ensure that the torque around the Z-axis is not lost. This ensures that the uniformity of the absorbed dose of the irradiated object is maximized when the sample receives radiation. It can also face different irradiation sources to meet the irradiation requirements of different directions.In terms of adapting to high vacuum, high radiation, and high and low temperatures, since torque transmission requires penetration through the chamber, a fluid sealing device 15 is installed to seal the internal mechanisms to ensure that the internal environment of the integrated electron irradiation chamber is not damaged. Simultaneously, the fluid sealing device 15 isolates the drive mechanism from the chamber, forming a magnetohydrodynamic seal at the drive mechanism. This allows the transmission mechanism to adapt to the high vacuum, high radiation, and high and low temperature environment within the integrated electron irradiation chamber. Specifically, the fluid sealing device 15 employs a magnetohydrodynamic seal. A magnetic circuit composed of a ring-shaped permanent magnet, pole shoes, and a rotating shaft, under the influence of a magnetic field, concentrates the magnetohydrodynamic fluid placed in the gap between the shaft and the top of the pole shoes, forming a so-called "O" ring to prevent damage to the high vacuum, high radiation, and high and low temperature experimental environment within the chamber. Secondly, regarding lubrication, for bearings, the first universal joint 6, and the second universal joint 7, and other parts requiring lubrication, using ordinary grease would be volatile and disrupt the experimental environment. Therefore, this application adopts a fixed lubrication method to ensure that the experimental environment within the chamber is not affected, allowing the sample stage to operate safely and stably. In practice, the internal dimensions of the electron irradiation chamber are 1500mm × 1500mm × 1500mm (length × width × height). One end of the container is a flat-topped head, and the other end is a hinged door with a manual clamp for pre-tightening the sealing ring. The door is sealed with a φ20mm sealing ring installed in the trapezoidal sealing groove of the flange. Reinforcing ribs are welded to the outer shell of the container, and the material is carbon steel. The container is supported by four carbon steel supports. Guide rails are installed inside the shell for the installation and movement of the sample stage and specimens. The container has a CF300 flange interface for connection to a 6MV tandem accelerator, and also reserves interfaces for a 1MeV electron accelerator and a low-energy electron accelerator, with included angles of 15°, 28°, and 30° respectively. Figures 5 to 7 As shown, the container and vacuum system interface flange are sealed with O-rings. The displacement in three directions can be achieved through the relative movement between the spline shaft 5 and the spline hollow shaft 4, and the deflection of the first universal joint 6 and the second universal joint 7. This allows the sample to be irradiated at the interfaces of the electron, low-energy electron, and proton accelerators. To compensate for a certain displacement error, the first universal joint 6 and the spline hollow shaft 4, and the spline shaft 5 and the second universal joint 7 are both connected by Hooke hinges. The self-locking of the drive mechanism is achieved through the worm gear transmission pair 14. The stepper motor 12 is a dual-output stepper motor, with one end connected to the reducer 13 and the other end equipped with a handwheel, which can realize both electric and manual operation.

[0027] Furthermore, such as Figures 1 to 3As shown, to reduce the load torque, the radius of rotation of the X-axis turntable 9 should be as small as possible while avoiding interference. The X-axis turntable 9 is shaped like a U. The irradiation station 10 is placed within the U-shaped opening of the X-axis turntable 9. Turntable shafts 11 are fixed at both ends of the irradiation station 10. The turntable shafts 11 are rotatably connected to the X-axis turntable 9 via bearings. One turntable shaft 11 is equipped with an encoder 16, which is connected to the X-axis turntable 9 via a flange 17. The other turntable shaft 11 is equipped with a Z-axis scale 20. Through the cooperation of the encoder 16 and the Z-axis scale 207, the rotation angle of the irradiation station 10 is controlled, achieving precise positioning of the irradiation station 10. The bottom of the X-axis turntable 9... The sample stage is connected to a turntable spindle 18, which is rotatably connected to the platform base 8 via a turntable bearing 19. The turntable spindle 18 allows the turntable 9 to rotate around the X-axis on the platform base 8. The platform base 8 is equipped with an X-axis scale 28, which is coaxial with the turntable spindle 18. A turntable locking mechanism is provided on the X-axis turntable 9 to restrict its rotation around the X-axis. This allows the sample stage to have two degrees of freedom: a 0-60° range of rotation around the X-axis and a 0-90° range of rotation around the Z-axis. The relative displacement between the spline shaft 5 and the spline hollow shaft 4, along with the first universal joint 6 and the second universal joint 7 on both sides, enables synchronous rotation of both degrees of freedom.

[0028] Furthermore, such as Figure 1 and Figure 4 As shown, the turntable locking mechanism includes a handwheel 29, a screw 30, and a brake disc 31. The screw 30 is threadedly connected to the X-axis turntable 9. The handwheel 29 is fixed to the top of the screw 30 and is located in the U-shaped opening of the X-axis turntable 9. The brake disc 31 is provided between the X-axis turntable 9 and the platform base 8. The brake disc 31 is located on the screw 30's screwing path. By rotating the handwheel 29, the screw 30 is screwed downwards and abuts against the brake disc 31, thereby restricting the rotational freedom of the X-axis turntable 9 and achieving precise overall positioning of the sample stage.

[0029] Furthermore, such as Figure 1 As shown, the bottom of the platform base 8 is connected to multiple bow-shaped lifting brackets 32. The bow-shaped lifting brackets 32 are installed inside the electron integrated irradiation chamber by anchor bolts. Since the bottom space of the X-axis turntable 9 is lower than the bottom surface of the bearing seat when placed vertically, in order to avoid interference between the X-axis turntable 9 and the internal installation bracket of the electron integrated irradiation chamber during installation, an additional bow-shaped lifting bracket 32 ​​is added to the bottom of the bearing seat. Then, the bow-shaped lifting bracket 32 ​​is installed onto the internal installation bracket by anchor bolts. Both the X-axis turntable 9 and the bearing seat for mounting the turntable bearing 19 are designed with reinforced ribs, which not only meet the strength requirements but also reduce the weight of the mechanism.

[0030] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," and "both ends," 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 invention 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 limiting this invention. Furthermore, those skilled in the art will understand that the beneficial effects to be achieved by this invention are merely to achieve better beneficial effects compared with the current embodiments in the prior art under specific conditions, rather than to directly achieve the best use effect in the industry.

[0031] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A vacuum environment variable-position large-angle proton irradiation sample stage, comprising a sample stage disposed within an electron integrated irradiation chamber, characterized in that, The sample stage includes a transmission mechanism (1) and a rotating stage (2). The transmission mechanism (1) includes a drive mechanism, a transmission shaft (3), a spline hollow shaft (4), and a spline shaft (5). One end of the transmission shaft (3) is connected to the drive mechanism. A fluid sealing device (15) is rotatably mounted on the transmission shaft (3). A first universal joint (6) is connected to the fluid sealing device (15). The first universal joint (6) is hinged to one end of the spline hollow shaft (4). The other end of the spline hollow shaft (4) is slidably connected to the spline shaft (5). A second universal joint (7) is hinged to the other end of the spline shaft (5) away from the spline hollow shaft (4). The rotating turntable (2) includes a platform base (8), an X-axis turntable (9), and an irradiation stage (10). The X-axis turntable (9) is rotatably mounted on the platform base (8) and rotates around the height axis of the platform base (8). The irradiation stage (10) is rotatably connected to the X-axis turntable (9) via a turntable shaft (11). The end of the second universal joint (7) away from the spline hollow shaft (4) is connected to the turntable shaft (11). The rotation axis of the irradiation stage (10) is perpendicular to the rotation axis of the X-axis turntable (9). The bottom of the X-axis turntable (9) is connected to a turntable spindle (18), and the turntable spindle (18) is rotatably connected to the platform base (8) through a turntable bearing (19). The platform base (8) is provided with an X-axis scale (28), which is coaxial with the turntable spindle (18). The turntable (9) is provided with a turntable locking mechanism, which is used to restrict the rotation of the turntable (9). The turntable locking mechanism includes a handwheel (29), a screw (30), and a brake disc (31). The screw (30) is threadedly connected to the X-axis turntable (9). The handwheel (29) is fixed to the top of the screw (30). The handwheel (29) is located in the U-shaped opening of the X-axis turntable (9). The brake disc (31) is provided between the X-axis turntable (9) and the platform base (8). The brake disc (31) is located on the screw (30)'s screw path.

2. The vacuum environment variable displacement large-angle proton irradiation sample stage according to claim 1, characterized in that, The drive mechanism includes a stepper motor (12), a reducer (13), and a worm gear transmission pair (14). The output shaft of the stepper motor (12) is connected to the input shaft of the reducer (13). The output shaft of the reducer (13) is connected to the worm shaft of the worm gear transmission pair (14). The worm shaft of the worm gear transmission pair (14) is connected to the drive shaft (3) through a coupling. The end of the fluid sealing device (15) away from the first universal joint (6) is connected to the worm wheel of the worm gear transmission pair (14).

3. The vacuum environment variable displacement large-angle proton irradiation sample stage according to claim 2, characterized in that, The first universal joint (6) and the spline hollow shaft (4) are both connected by Hooke hinges, as are the spline shaft (5) and the second universal joint (7).

4. The vacuum environment variable-position large-angle proton irradiation sample stage according to claim 1, characterized in that, The X-axis turntable (9) is U-shaped. The irradiation station (10) is located in the U-shaped opening of the X-axis turntable (9). The turntable shafts (11) are fixed at both ends of the irradiation station (10). The turntable shafts (11) are rotatably connected to the X-axis turntable (9) through bearings. An encoder (16) is provided on one of the turntable shafts (11). The encoder (16) is connected to the X-axis turntable (9) through a flange (17). A Z-axis scale (20) is provided on the other turntable shaft (11).

5. The vacuum environment variable displacement large-angle proton irradiation sample stage according to claim 1, characterized in that, The bottom of the platform base (8) is connected to a plurality of bow-shaped lifting brackets (32), which are installed in the electronic integrated irradiation chamber by anchor bolts.

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