Positioning device for vertical cold finger vacuum interface valve of germanium detector

Abstract

The utility model discloses a positioning device for a vertical cold finger vacuum interface valve of a germanium detector, belongs to the technical field of cold fingers of nuclear radiation germanium detectors, and solves the technical problem that the vertical cold finger vacuum interface valve of the detector is difficult to position during installation. The device comprises a limiting plate, limiting screws, a limiting lower partition plate, a left fixing ring, a right fixing ring, a vacuum sealing gasket and left and right ring fixing screws. The limiting lower partition plate and the limiting plate are of an integrated structure. The limiting lower partition plate is fixedly connected with the left fixing ring through a limiting screw; and the limiting plate is in nested connection with the cold finger. The left fixing ring and the right fixing ring are connected and fixed through left and right ring fixing screws; the vacuum sealing gasket is connected with the left fixing ring and the right fixing ring and located on the inner sides of the left fixing ring and the right fixing ring. The left fixing ring and the right fixing ring are nested and sealed with the cold finger sealing and fixing section; and the vacuum interface valve is hermetically connected with the left fixing ring and is used for positioning and fixing the vacuum interface connection of the germanium detector.

Description

Technical Field

[0001] This utility model belongs to the field of cold finger technology for nuclear radiation germanium detectors, specifically relating to a positioning device for a vacuum interface valve of a vertical cold finger for germanium detectors. Background Technology

[0002] Semiconductor detectors are crucial equipment in radiometric measurements, with germanium detectors finding numerous applications in environmental radioactivity monitoring, spent fuel reprocessing, and uranium ore geological exploration. Because the germanium detector crystal is encapsulated in a vacuum chamber and operates at low temperatures, the cold is typically transferred to the germanium crystal via liquid nitrogen in a Dewar flask through a cold finger. During long-term use or transportation, the vacuum seal performance of the cold finger deteriorates, leading to a decrease in the detector's energy resolution and affecting its overall performance. However, instrument manufacturers do not provide positioning devices for the vacuum interface connection. Therefore, a corresponding vacuum interface valve and matching positioning device must be designed based on the structural characteristics of the cold finger vacuum interface for maintenance. The design must ensure that the cold finger vacuum interface valve and the cold finger vacuum sealing plug are aligned on an axis, allowing for the opening and closing of the cold finger vacuum sealing plug and thus maintaining the vacuum of the cold finger.

[0003] Due to the wide variety of detector types and the different structures of the cold finger vacuum interface, a special design for the cold finger interface valve positioning device is required, taking into account the structural characteristics of the cold finger vacuum interface. Currently, no relevant literature reports on positioning devices for the vertical cold finger vacuum interface valve of germanium detectors. Similar examples include "Repair System for Neutron Radiation Damage to HPGe Detectors" (Lei Xiangguo et al., Nuclear Electronics and Detection Technology, 1996, No. 3) and "A Vacuum Maintenance System for High-Purity Germanium Detectors with Thermal Purification Function" (CN103728651A, Zhang Xiaolin et al.). These documents show an interface valve in the structural diagram of the HPGe detector repair system, but do not discuss the composition of the interface valve. Furthermore, in the literature and patent CN103728651A (the first two types), the vacuum interface of the HPGe (high-purity germanium) detector is located on a circular plane at the bottom of the detector's vacuum chamber. Simultaneously, during detector fabrication, fixing screw holes are provided on the circular planes on both sides of the sealing plug. Therefore, the vacuum interface and interface valve of this type of HPGe (high-purity germanium) detector have planar contact surfaces, and the two are easily fixed and connected through the existing screw holes. Patent CN103728651A, Class 3, describes an interface valve for a thin-walled, externally mounted germanium detector with a vacuum interface. This valve is vertically fixed to a base plate, which is secured by screws to two U-shaped fixing plates. Installation requires aligning the screw holes of the two U-shaped fixing plates and the base plate, necessitating multiple operators and a cumbersome process. This invention addresses the structure of the vertical cold finger of a germanium detector and designs a positioning and fixing device for the vacuum interface valve on the arc surface of the cold finger. This device aligns the central axis of the fixing ring's central hole, the pull rod, and the cold finger vacuum sealing plug into a straight line. The axial movement of the pull rod opens and closes the vacuum chamber of the cold finger, enabling vacuum maintenance and restoring the working state and performance of this type of germanium detector experiencing a cold finger vacuum fault. Summary of the Invention

[0004] To overcome the difficulty in positioning the vertical cold finger vacuum interface valve during the installation of the detector, this utility model proposes a positioning device for the vertical cold finger vacuum interface valve of a germanium detector.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A positioning device for a vertical cold finger vacuum interface valve of a germanium detector, the structure of which consists of a central circular hole, left and right position limiting screw holes, a limiting plate, upper and lower position limiting screw holes, a limiting screw, a lower limiting partition, a left fixing ring, a right fixing ring, a limiting plate fixing screw hole, a vacuum interface valve fixing screw hole, a central hole, a vacuum sealing gasket, left and right ring fixing screw holes and left and right ring fixing screws;

[0007] The diameter of the central circular hole matches the outer diameter of the cold finger, allowing it to be nested into the cold finger.

[0008] The diameter and orientation of the left and right position limiting screw holes match the diameter and spatial layout of the cold finger fixing screw, so as to achieve nesting at the cold finger fixing screw, and when nested, the limiting lower partition and the cold finger vacuum sealing plug are in the same direction.

[0009] The lower limiting plate is located below the limiting plate, and the two are an integral structure with a certain thickness;

[0010] The radii of the left and right fixing rings are matched with the radius of the cold finger seal fixing section;

[0011] The left fixing ring is provided with a limiting plate fixing screw hole, and the limiting screw is used for the fixed connection between the left fixing ring and the limiting plate lower partition.

[0012] The right and left fixed rings are nested and sealed with the cold finger sealing section by a vacuum sealing gasket and left and right ring fixing screws.

[0013] The vacuum interface valve fixing screw holes are connected to each other by bolts to form a vacuum extraction pipeline.

[0014] Furthermore, in the positioning device for the vertical cold finger vacuum interface valve of the germanium detector, the central circular hole and left and right position limiting screw holes of the limiting plate are matched and nested with the cold finger and the cold finger fixing screw in terms of structure and spatial layout.

[0015] The radii of the left and right fixing rings are nested to match the radius of the cold finger sealing fixing section;

[0016] The lower partition of the limiting plate is provided with a certain thickness and is fixedly connected by upper and lower position limiting screw holes, limiting screws, fixing screw holes and left fixing ring. The thickness of the lower partition of the limiting plate makes the center hole and the center of the cold finger vacuum sealing plug form an axis.

[0017] The right fixing ring is connected and fixed to the left fixing ring by left and right ring fixing screws, and the left and right fixing rings are nested and sealed with the cold finger sealing fixing section by a vacuum sealing gasket;

[0018] The vacuum interface valve is connected to the left fixing ring by bolts passing through the fixing screw hole of the vacuum interface valve and the fixing screw hole, so that the center of the pull rod and the cold finger vacuum sealing plug are on the same axis.

[0019] Through the above operations, the positions of the left and right fixed ring centers were determined, ensuring that the central axis of the central hole, pull rod, and cold finger vacuum sealing plug are a straight line.

[0020] Furthermore, in the positioning device for the vertical cold finger vacuum interface valve of the germanium detector, the integral structure formed by the limiting plate and the limiting lower partition is connected to the left fixing ring by limiting the left, right and up and down positions.

[0021] The right fixing ring is fixedly connected to the left fixing ring by left and right ring fixing screws, and is sealed by a vacuum sealing gasket and a cold finger sealing fixing section.

[0022] The vacuum interface valve is connected to the left fixing ring by bolts passing through the fixing screw hole of the vacuum interface valve and the fixing screw hole, so that the center of the pull rod and the cold finger vacuum sealing plug are on the same axis, thereby controlling the opening or closing of the cold finger vacuum port.

[0023] The positioning device of the vacuum interface valve can be easily connected to the vacuum maintenance system to realize the vacuum maintenance treatment of the vertical cold finger of the germanium detector.

[0024] The beneficial effects of this utility model are:

[0025] A positioning device for a vertical cold finger vacuum interface valve of a germanium detector enables precise positioning of the vertical cold finger vacuum interface valve when it is installed on the arc surface of the cold finger.

[0026] A positioning device for the vertical cold finger vacuum interface valve of a germanium detector uses a limiting plate and a fixing ring to position the vertical cold finger vacuum interface valve in all directions, ensuring that the central axis of the cold finger vacuum sealing plug is aligned with the central axis of the interface valve rod. The vacuum sealing plug of the cold finger can be easily opened and closed without vacuum leakage, enabling vacuum maintenance of the cold finger and restoring the performance of the germanium detector with a cold finger vacuum fault.

[0027] A positioning device for a vertical cold finger vacuum interface valve of a germanium detector is provided. The limiting plate, the lower limiting partition, and the fixing ring are easy to disassemble and can be widely used for positioning and fixing of vacuum interface connections of germanium detectors with similar structures. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the vertical cold finger structure of a germanium detector;

[0029] Figure 2 This is a schematic diagram of the limiting plate structure;

[0030] Figure 3 This is a schematic diagram of the left and right fixed ring structure;

[0031] Figure 4 This is a cross-sectional view of the pull rod of the vacuum interface valve and the vacuum extraction pipeline.

[0032] Reference numerals: 1. Cold finger, 2. Cold finger fixing screw, 3. Cold finger sealing fixing section, 4. Cold finger vacuum sealing plug, 21. Central circular hole, 22. Left and right position limiting screw holes, 23. Limiting plate, 24. Up and down position limiting screw holes, 25. Limiting screw, 26. Lower limiting partition, 31. Left fixing ring, 32. Right fixing ring, 33. Limiting plate fixing screw hole, 34. Vacuum interface valve fixing screw hole, 35. Central hole, 36. Vacuum sealing gasket, 37. Left and right ring fixing screw holes, 38. Left and right ring fixing screws, 41. Pull rod, 42. Fixing screw hole. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] A positioning device for a vertical cold finger vacuum interface valve of a germanium detector includes a central circular hole 21, left and right position limiting screw holes 22, a limiting plate 23, upper and lower position limiting screw holes 24, a limiting screw 25, a lower limiting partition 26, a left fixing ring 31, a right fixing ring 32, a limiting plate fixing screw hole 33, a vacuum interface valve fixing screw hole 34, a central hole 35, a vacuum sealing gasket 36, left and right ring fixing screw holes 37, and left and right ring fixing screws 38.

[0036] The diameter of the central circular hole 21 matches the outer diameter of the cold finger 1, so that it can be nested on the cold finger 1.

[0037] The diameter and orientation of the left and right position limiting screw holes 22 match the diameter and spatial layout of the cold finger fixing screw 2, so as to achieve nesting at the cold finger fixing screw 2, and when nested, the limiting lower partition 26 and the cold finger vacuum sealing plug 4 are in the same direction.

[0038] The lower limiting plate 26 is located below the limiting plate 23. The two are an integral structure and have a certain thickness.

[0039] The radii of the left fixing ring 31 and the right fixing ring 32 are matched with the radius of the cold finger seal fixing section 3.

[0040] The left fixing ring 31 is provided with a limiting plate fixing screw hole 33, and the limiting screw 25 is used for the fixed connection between the left fixing ring 31 and the limiting plate 23 and the limiting lower partition 26.

[0041] The right fixing ring 32 and the left fixing ring 31 are nested and sealed with the cold finger sealing fixing section 3 through the vacuum sealing gasket 36, the left and right ring fixing screw holes 37 and the left and right ring fixing screws 38.

[0042] The vacuum interface valve fixing screw hole 34 and fixing screw hole 42 are connected by bolts to form a vacuum extraction pipeline.

[0043] The center hole 21 and the left and right position limiting screw holes 22 of the limiting plate 23 are nested together with the cold finger 1 and the cold finger fixing screw 2 in terms of diameter and layout.

[0044] The radii of the left fixing ring 31 and the right fixing ring 32 are matched with the radius of the cold finger seal fixing section 3.

[0045] The lower partition 26 of the limiting plate has a certain thickness and is fixedly connected by the upper and lower position limiting screw holes 24, the limiting screws 25, the fixing screw holes 33 and the left fixing ring 31. The thickness of the lower partition 26 of the limiting plate makes the central hole 35 and the central axis of the cold finger vacuum sealing plug 4 form a straight line.

[0046] The right fixing ring 32 is connected and fixed to the left fixing ring 31 by the left and right ring fixing screws 38. The left and right fixing rings 31 and 32 achieve nested sealing with the cold finger sealing fixing section 3 through the vacuum sealing gasket 36.

[0047] The vacuum interface valve is sealed to the left fixing ring 31 by bolts passing through the vacuum interface valve fixing screw hole 34 and fixing screw hole 42, so that the center of the pull rod 41 and the cold finger vacuum sealing plug 4 are on the same axis.

[0048] Through the above operations, the installation positions of the left and right fixing rings 31 and 32 in the up, down, left and right directions were determined, so that the central axis of the central hole 35, the pull rod 41 and the cold finger vacuum sealing plug 4 are a straight line.

[0049] The overall structure formed by the limiting plate 23 and the lower limiting partition 26 positions and fixes the left fixing ring 31 in the left, right, up, and down positions during installation and connection.

[0050] The right fixing ring 32 is fixedly connected to the left fixing ring 31 by the left and right ring fixing screws 38, and is sealed by the vacuum sealing gasket 36 nested with the cold finger sealing fixing section 3.

[0051] The vacuum interface valve is sealed to the left fixing ring 31 by bolts passing through the fixing screw hole 34 and fixing screw hole 42 of the vacuum interface valve, so that the center of the pull rod 41 and the cold finger vacuum sealing plug 4 are on the same axis, thereby controlling the opening or closing of the cold finger vacuum port.

[0052] Example 2

[0053] The working process of this invention:

[0054] 1. For example Figure 1 The germanium detector is shown being removed from the liquid nitrogen in the Dewar jar and allowed to stand and warm up.

[0055] 2. For example Figure 2As shown, the central circular hole 21 of the limiting plate 23 is nested in the cold finger 1, and the limiting screw hole 22 is nested in the cold finger fixing screw 2. When nesting, the lower limiting partition 26 and the cold finger vacuum sealing plug 4 are in the same direction.

[0056] 3. For example Figure 3 As shown, the left fixing ring 31 is fixedly connected to the limiting plate 23 by passing through the limiting screw 24 at the upper and lower positions of the limiting plate and the fixing screw 33 of the limiting plate through the limiting screw 25.

[0057] 4. For example Figure 3 As shown, the right fixing ring 32 is nested in the cold finger sealing fixing section 3, and is fixedly connected to the left fixing ring 31 through the left and right ring fixing screw holes 37 and the left and right ring fixing screws 38;

[0058] 5. For example Figure 3 , Figure 4 As shown, the vacuum interface valve fixing screw hole 34 and fixing screw hole 42 are connected by bolts to form a vacuum extraction pipeline;

[0059] 6. After Figure 1 , Figure 2 , Figure 3 and Figure 4 The structure shown forms a positioning device for the vacuum interface valve. The cold finger vacuum sealing plug 4 is pulled out and closed by the threaded structure at the top of the pull rod 41, thereby maintaining the vacuum of the cold finger.

[0060] Example 3

[0061] A positioning device for a vertical cold finger vacuum interface valve of a germanium detector includes a limiting plate 23, a limiting screw 25, a lower limiting partition 26, a left fixing ring 31, a right fixing ring 32, a vacuum sealing gasket 36, and left and right ring fixing screws 38.

[0062] The lower limiting plate 26 is located below the limiting plate 23, and the two are an integral structure; the lower limiting plate 26 and the left fixing ring 31 are fixedly connected by the limiting screw 25; the limiting plate 23 is nested and connected to the cold finger 1.

[0063] The left fixing ring 31 and the right fixing ring 32 are connected and fixed by left and right ring fixing screws 38; the vacuum sealing gasket 36 is connected to the left fixing ring 31 and the right fixing ring 32 respectively, and is located inside the left fixing ring 31 and the right fixing ring 32; the left fixing ring 31 and the right fixing ring 32 are nested and sealed with the cold finger sealing fixing section 3; the vacuum interface valve is sealed and connected to the left fixing ring 31.

[0064] The limiting plate 23 is provided with a central circular hole 21, left and right position limiting screw holes 22, and upper and lower position limiting screw holes 24. The upper and lower position limiting screw holes 24 are matched with the limiting screws 25.

[0065] The diameter of the central circular hole 21 matches the outer diameter of the cold finger 1 and is used for the nesting of the limiting plate 23 and the cold finger 1; the diameter and orientation of the left and right position limiting screw holes 22 match the diameter and spatial layout of the cold finger fixing screw 2 and are matched with the cold finger fixing screw 2.

[0066] The left fixing ring 31 is provided with a limit plate fixing screw hole 33, a vacuum interface valve fixing screw hole 34, a central hole 35, and left and right ring fixing screw holes 37. The right fixing ring 32 is provided with left and right ring fixing screw holes 37.

[0067] The radii of the left fixing ring 31 and the right fixing ring 32 match the radius of the cold finger sealing fixing section 3. The limiting screw 25 passes through the fixing screw hole 33 of the limiting plate, so that the left fixing ring 31 is fixedly connected to the lower limiting partition 26. The right fixing ring 32 and the left fixing ring 31 are fixedly connected through the left and right ring fixing screw holes 37 and the left and right ring fixing screws 38. The right fixing ring 32 and the left fixing ring 31 are nested and sealed with the cold finger sealing fixing section 3 through the vacuum sealing gasket 36. The central axis of the central hole 35 is on the same line as the central axis of the cold finger vacuum sealing plug 4. The vacuum interface valve is sealed and connected to the left fixing ring 31 through the fixing screw hole 34 and the fixing screw hole 42 of the vacuum interface valve by bolts, so that the center line of the pull rod 41 and the center line of the cold finger vacuum sealing plug 4 are on the same axis.

Claims

1. A positioning device for a vertical cold finger vacuum interface valve of a germanium detector, characterized in that, Includes a limiting plate (23), a limiting screw (25), a lower limiting partition (26), a left fixing ring (31), a right fixing ring (32), a vacuum sealing gasket (36), and left and right ring fixing screws (38); The lower limiting plate (26) is located below the limiting plate (23), and the two are an integral structure; the lower limiting plate (26) and the left fixing ring (31) are fixedly connected by the limiting screw (25); the limiting plate (23) and the cold finger (1) are nested together. The left fixing ring (31) and the right fixing ring (32) are connected and fixed by left and right ring fixing screws (38); the vacuum sealing gasket (36) is connected to the left fixing ring (31) and the right fixing ring (32) respectively, and is located inside the left fixing ring (31) and the right fixing ring (32); the left fixing ring (31) and the right fixing ring (32) are nested and sealed with the cold finger sealing fixing section (3); the vacuum interface valve is sealed and connected to the left fixing ring (31).

2. The positioning device according to claim 1, characterized in that, The limiting plate (23) is provided with a central circular hole (21), left and right position limiting screw holes (22), and upper and lower position limiting screw holes (24), and the upper and lower position limiting screw holes (24) are matched with the limiting screws (25); The diameter of the central circular hole (21) matches the outer diameter of the cold finger (1) and is used for the nesting of the limiting plate (23) and the cold finger (1); the diameter and orientation of the left and right position limiting screw holes (22) match the diameter and spatial layout of the cold finger fixing screw (2) and are matched with the cold finger fixing screw (2).

3. The positioning device according to claim 1, characterized in that, The left fixing ring (31) is provided with a limiting plate fixing screw hole (33), a vacuum interface valve fixing screw hole (34), a central hole (35), and left and right ring fixing screw holes (37), and the right fixing ring (32) is provided with left and right ring fixing screw holes (37); The radii of the left fixing ring (31) and the right fixing ring (32) match the radius of the cold finger sealing fixing section (3). The limiting screw (25) passes through the fixing screw hole (33) of the limiting plate, so that the left fixing ring (31) is fixedly connected to the lower limiting partition (26). The right fixing ring (32) and the left fixing ring (31) are fixedly connected through the left and right ring fixing screw holes (37) and the left and right ring fixing screws (38). The right fixing ring (32) and the left fixing ring (31) are nested and sealed with the cold finger sealing fixing section (3) through the vacuum sealing gasket (36). The central axis of the central hole (35) is in the same line as the central axis of the cold finger vacuum sealing plug (4). The vacuum interface valve is sealed to the left fixing ring (31) by bolts passing through the vacuum interface valve fixing screw hole (34) and fixing screw hole (42), so that the center line of the pull rod (41) and the center line of the cold finger vacuum sealing plug (4) are in the same axis.

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