Liquid nitrogen test Dewar for large-area-array detector

Abstract

The liquid nitrogen testing Dewar comprises a cold end cold head, a variable-temperature cold head, a variable-temperature rotating block, a transition block, a loading cold head, the large-area-array detector, an optical window, a liquid nitrogen storage cavity and a shell. The cold energy of the liquid nitrogen storage cavity forms a solid conduction path through the cold-end cold head, the variable-temperature cold head and the loading cold head, and the variable-temperature cold head and the loading cold head adopt a low-heat-conduction hollow structure to construct a basic temperature difference; the variable-temperature rotating block is connected with the variable-temperature cold head and the transition block in a threaded fit mode, and the cooling capacity obtaining degree of the object carrying cold head is changed by means of position adjustment. According to the invention, flexible and accurate temperature control within the range of 80K-180K can be realized, the cooling capacity transmission is efficient, the use is convenient, and the device is suitable for testing and screening of large-area-array detectors with different temperature requirements.

Description

Technical Field

[0001] This invention relates to the field of liquid nitrogen testing dewar technology for large-area detectors, specifically to a liquid nitrogen testing dewar for large-area detectors. Background Technology

[0002] Large-area detectors are core components in infrared imaging, astronomical observation, and remote sensing, and their performance directly determines the detection accuracy, imaging quality, and environmental adaptability of the entire system. During the research, development, production, and acceptance of large-area detectors, comprehensive testing of their photoelectric performance under different temperature environments is necessary to verify their operational stability and reliability over a wide temperature range. To improve the yield rate of the components, large-area detectors must undergo spectral and electrical performance testing before entering the component packaging stage. Liquid nitrogen, as a commonly used refrigerant in cryogenic fields, is widely used in cryogenic performance testing in materials physics, electronic devices, and other fields due to its low cost and high cooling efficiency. Therefore, the need to provide large-area detectors with wide-range variable-temperature testing conditions is becoming increasingly urgent.

[0003] Existing liquid nitrogen testing methods, such as the Dewar's system, have a single temperature zone structure, making it difficult to achieve precise temperature control in the medium and low temperature ranges, thus presenting significant limitations. Meanwhile, large-area detectors suffer from mismatched temperature control components and structural designs, resulting in low temperature control accuracy and slow response speeds during wide temperature range adjustments, failing to meet the testing requirements of precision devices.

[0004] In summary, the existing liquid nitrogen testing Dewar structures suffer from deficiencies in temperature range adaptability, thermal insulation performance, and temperature control accuracy, making them unsuitable for the practical needs of wide-temperature-range liquid nitrogen testing. Therefore, a liquid nitrogen testing Dewar structure that combines wide-temperature-range adaptability, excellent thermal insulation performance, and precise temperature control is of great significance for improving testing efficiency and ensuring testing accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a liquid nitrogen testing dewar for large-area array detectors, which solves the problem that existing liquid nitrogen testing dewars can only provide a single liquid nitrogen temperature range and cannot meet the wide temperature range testing requirements of large-area array detectors.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A liquid nitrogen test dewar for a large-area array detector has a housing, inside which is disposed a liquid nitrogen storage chamber, a cold energy conduction mechanism, and a cold head for placing the detector. An optical window is disposed above the cold head in the housing. The liquid nitrogen storage chamber is disposed in the lower part of the housing, the cold energy conduction mechanism is connected to the liquid nitrogen storage chamber, and the cold head is connected to the cold energy conduction mechanism.

[0008] The cold energy transfer mechanism includes a cold end head, a variable temperature head, a variable temperature rotary block, and a transition component. The cold end head is fixedly connected to the liquid nitrogen storage chamber. The variable temperature head is connected to the load-carrying head for cold energy transfer through the variable temperature rotary block and the transition component. The load-carrying head is fixedly connected to the transition component. By operating the variable temperature rotary block, the matching position between the variable temperature head and the transition component can be adjusted, thereby changing the degree of cold energy acquisition by the load-carrying head.

[0009] The cold end cold head, variable temperature swivel block, and transition components are made of high thermal conductivity materials; the variable temperature cold head and the carrier cold head are made of low thermal conductivity materials, and the liquid nitrogen storage chamber is vacuum insulated from the shell.

[0010] The variable-temperature cold head includes a fixed part and a hollow cylindrical connecting part, the outer wall of which is provided with external threads; the fixed part of the variable-temperature cold head is fixedly connected to the cold end cold head; the loading cold head includes a loading platform and a support part, the support part is located on the lower surface of the loading platform, and the support part is a hollow cylindrical structure; the transition piece is a hollow cylindrical assembly, the outer wall of which is provided with external threads; the support part of the loading cold head is inserted into the transition piece and fixedly connected to the transition piece; the variable-temperature rotary block is a hollow cylindrical structure, the inner wall of which is provided with internal threads, and the variable-temperature rotary block is screwed onto the outer wall of the variable-temperature cold head and the transition piece; rotating the variable-temperature rotary block adjusts its height relative to the fixed part of the variable-temperature cold head, thereby changing the amount of cooling obtained by the loading cold head through the variable-temperature rotary block and the transition piece.

[0011] The cold end cold head is connected and fixed to the liquid nitrogen storage chamber by brazing; the support part of the load-carrying cold head is inserted into the connecting part of the variable temperature cold head, and the outer wall of the support part is in contact with the inner wall of the connecting part.

[0012] The temperature-changing rotary block is provided with internal threads on the hot end and internal threads on the cold end. The internal thread on the cold end is screwed into the external thread of the connection part of the temperature-changing cold head, and the internal thread on the hot end is screwed into the external thread of the transition piece.

[0013] The loading head and the transition piece are connected by a soft metal.

[0014] The cold end cold head and transition components use copper or molybdenum as high thermal conductivity materials; the variable temperature cold head and the load-carrying cold head use titanium alloy, polyimide or polytetrafluoroethylene as low thermal conductivity materials.

[0015] The temperature adjustment range of the loading cold head is 80K-180K.

[0016] In view of the above technical features, the present invention has the following beneficial effects: 1. The present invention enables the liquid nitrogen test Dewar to achieve wide temperature range (80K-180K) by adjusting the temperature-changing rotary block, which is suitable for testing and screening large array detectors with different temperature requirements in the liquid nitrogen test Dewar; 2. The present invention has efficient cold energy transfer. Through the design of the cold end cold head, the temperature-changing cold head, the temperature-changing rotary block, the transition component, and the object-carrying cold head, the cold energy transfer path is optimized, the cold energy loss is reduced, and the efficiency of maintaining the low temperature environment is improved; 3. The present invention has high temperature control accuracy. By adjusting the temperature-changing rotary block and the temperature-changing cold head, the temperature of the object-carrying cold head can be controlled to meet the different temperature requirements during the testing of infrared detector modules. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the liquid nitrogen testing Dewar structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the variable temperature cold head structure of the present invention;

[0019] Figure 3 This is a schematic diagram of the variable temperature rotary block structure of the present invention;

[0020] Figure 4 This is a schematic diagram of the transition component structure of the present invention;

[0021] Figure 5 This is a schematic diagram of the material-carrying cold head structure of the present invention;

[0022] In the diagram: 1-Cold end cold head; 2-Variable temperature cold head; 21-Fixing part; 22-Connecting part; 3-Variable temperature rotating block; 31-Hot end internal thread; 32-Cold end internal thread; 4-Transition part; 41-Counterhead hole; 5-Load-carrying cold head; 51-Load-carrying stage; 52-Supporting part; 6-Large area array detector; 7-Optical window; 8-Liquid nitrogen storage chamber; 9-Shell. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that some components well-known to those skilled in the art but not related to the main content of the present invention may be omitted in the drawings or description. Additionally, for ease of description, some components in the drawings may be omitted, enlarged, or reduced, but this does not represent the actual size or complete structure of the product.

[0024] A liquid nitrogen test dewar for a large-area detector, such as Figure 1-5As shown, it has a housing 9, inside which is a liquid nitrogen storage chamber 8, a cold energy conduction mechanism and a cold head 5 for placing the detector. An optical window 7 is provided above the cold head 5 in the housing 9. A large-area array detector 6 is placed on the cold head 5, and the large-area array detector 6 is tested through the optical window 7.

[0025] The liquid nitrogen storage chamber 8 is located in the lower part of the shell 9, and the liquid nitrogen storage chamber 8 is vacuum insulated from the shell 9.

[0026] The cold energy transfer mechanism is connected to the liquid nitrogen storage chamber 8, and the cold head 5 is connected to the cold energy transfer mechanism.

[0027] The cold energy transfer mechanism includes a cold end head 1, a variable temperature cold head 2, a variable temperature rotating block 3, and a transition component 4. The cold end head 1 is fixedly connected to the liquid nitrogen storage chamber 8, and the two are connected and fixed by brazing.

[0028] The cold end cold head 1, the variable temperature swivel block 3, and the transition component 4 are made of high thermal conductivity materials; the variable temperature cold head 2 and the load-carrying cold head 5 are made of low thermal conductivity materials.

[0029] Preferably, the cold end cold head 1 and the transition component 4 are made of copper or molybdenum, which are high thermal conductivity materials; the variable temperature cold head 2 and the load-carrying cold head 5 are made of titanium alloy, polyimide or polytetrafluoroethylene, which are low thermal conductivity materials.

[0030] The variable temperature cold head 2 achieves the cold energy conduction connection with the load-carrying cold head 5 through the variable temperature rotary block 3 and the transition piece 4. By operating the variable temperature rotary block 3 to adjust its matching position with the variable temperature cold head 2 and the transition piece 4, the degree of cold energy acquisition of the load-carrying cold head 5 can be changed.

[0031] like Figure 2 As shown, the variable temperature cold head 2 includes a fixing part 21 and a hollow cylindrical connecting part 22. The outer wall of the connecting part 22 is provided with external threads. The fixing part 21 of the variable temperature cold head 2 is fixedly connected to the cold end cold head 1. Preferably, the variable temperature cold head 2 and the cold end cold head 1 are fixed by bolts.

[0032] like Figure 5 As shown, the cooling head 5 includes a stage 51 and a support 52. The support 52 is disposed on the lower surface of the stage 51 and has a cylindrical hollow structure. Figure 4 As shown, the transition piece 4 is a cylindrical, hollow assembly with external threads on its outer wall; the support portion 52 of the loading head 5 is inserted into the transition piece 4 and fixedly connected to it; the transition piece 4 is fitted around the outside of the support portion 52 of the loading head 5, and bolts are screwed into the loading head 5 through four countersunk holes 41. The loading head 5 and the transition piece 4 are connected by a soft metal.

[0033] like Figure 3As shown, the variable temperature rotary block 3 is a cylindrical hollow structure. The inner wall of the variable temperature rotary block 3 is provided with internal threads. The internal threads of the variable temperature rotary block 3 are the hot end internal thread 31 and the cold end internal thread 32.

[0034] The variable temperature rotary block 3 is screwed onto the outer wall of the variable temperature cold head 2 and the transition piece 4. The internal thread 32 of the cold end is screwed into the external thread of the connecting part 22 of the variable temperature cold head 2, and the internal thread 31 of the hot end is screwed into the external thread of the transition piece 4.

[0035] Screw the external thread of the transition piece 4 into the internal thread 31 of the hot end of the temperature-changing rotary block 3 until the lower part of the support part 52 of the load-carrying cold head 5 is inserted into the connecting part 22 of the temperature-changing cold head 2, and the outer wall of the support part 52 and the inner wall of the connecting part 22 are attached and fully matched.

[0036] The variable temperature cold head 2 and the transition piece 4 achieve heat transfer through the screw connection with the variable temperature rotary block 3; the height of the variable temperature rotary block 3 relative to the fixing part 21 of the variable temperature cold head 2 is adjusted by rotating the variable temperature rotary block 3, thereby changing the amount of heat obtained by the load-bearing cold head 5 through the variable temperature rotary block 3 and the transition piece 4.

[0037] The principle is that cold energy will preferentially be conducted through a high thermal conductivity path. The cold end head 1 is made of high thermal conductivity metal materials such as copper and molybdenum, which can quickly conduct the cold energy of liquid nitrogen to the variable temperature head 2. The variable temperature head 2 is screwed to the variable temperature swivel block 3, which is also screwed to the transition piece 4. Since the variable temperature head 2 and the carrier head 5 are both made of low thermal conductivity materials, while the variable temperature swivel block 3 and the transition piece 4 are both made of high thermal conductivity materials, although the connecting part 22 of the variable temperature head 2 is in contact with the supporting part 52 of the carrier head 5, the cold energy will still preferentially be conducted through the high thermal conductivity path of the connecting part 22, the variable temperature swivel block 3, and the transition piece 4, rather than through the low thermal conductivity path of the connecting part 22 and the supporting part 52.

[0038] Therefore, rotating the temperature-regulating rotary block 3 can adjust the amount of cold energy transfer. When the temperature-regulating rotary block 3 rotates upward, that is, towards the cold head 5, the distance between it and the cold end 1 increases, the time for cold energy transfer increases, and the amount of cold energy transferred per unit time decreases. Conversely, when the temperature-regulating rotary block 3 rotates downward, that is, towards the cold end 1, the distance between it and the cold end 1 decreases, the time for cold energy transfer decreases, and the amount of cold energy transferred per unit time increases. By cleverly utilizing the heat-conducting material to adjust the cold energy, the temperature adjustment range of the cold head 5 is 80K-180K.

[0039] The aforementioned structure allows the large-area detector 6 to maintain a temperature of 180K during testing, thanks to the thermal insulation design of the variable-temperature cold head 2 and the object-carrying cold head 5. The degree of cooling acquisition by the object-carrying cold head 5 can be adjusted by rotating the variable-temperature knob 3, enabling flexible wide-range temperature regulation. The stable assembly of all components ensures efficient cooling and structural reliability, guaranteeing stable operation of the infrared detector module 6 in different temperature environments (80K-180K).

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. All equivalent changes and modifications made within the scope of the claims of this invention should be considered within the technical scope of this invention.

Claims

1. A liquid nitrogen testing dewar for a large-area array detector, characterized in that: It has a housing (9), inside which is a liquid nitrogen storage chamber (8), a cold energy conduction mechanism and a cold head (5) for placing the detector. An optical window (7) is provided above the cold head (5) in the housing (9). The liquid nitrogen storage chamber (8) is located in the lower part of the housing (9), the cold energy conduction mechanism is connected to the liquid nitrogen storage chamber (8), and the cold head (5) is connected to the cold energy conduction mechanism. The cold energy transfer mechanism includes a cold end cold head (1), a variable temperature cold head (2), a variable temperature rotary block (3), and a transition piece (4). The cold end cold head (1) is fixedly connected to the liquid nitrogen storage chamber (8). The variable temperature cold head (2) is connected to the cold head (5) through the variable temperature rotary block (3) and the transition piece (4). The cold head (5) is fixedly connected to the transition piece (4). The variable temperature rotary block (3) is operated to adjust its matching position with the variable temperature cold head (2) and the transition piece (4), thereby changing the degree of cold energy acquisition of the cold head (5). The cold end cold head (1), the variable temperature swivel block (3) and the transition piece (4) are made of high thermal conductivity materials; the variable temperature cold head (2) and the carrier cold head (5) are made of low thermal conductivity materials; the liquid nitrogen storage chamber (8) and the shell (9) are vacuum insulated.

2. The liquid nitrogen testing Dewar as described in claim 1, characterized in that: The variable temperature cold head (2) includes a fixing part (21) and a hollow cylindrical connecting part (22), the outer wall of which is provided with external threads; the fixing part (21) of the variable temperature cold head (2) is fixedly connected to the cold end cold head (1); the loading cold head (5) includes a loading platform (51) and a support part (52), the support part (52) is provided on the lower surface of the loading platform (51), and the support part (52) is a cylindrical hollow structure; the transition part (4) is a cylindrical hollow kit, the outer wall of which is provided with external threads. The support part (52) of the cold head (5) is inserted into the transition piece (4) and fixedly connected to the transition piece (4); the variable temperature rotary block (3) is a cylindrical hollow structure, and the inner wall of the variable temperature rotary block (3) is provided with internal threads. The variable temperature rotary block (3) is screwed to the outer wall of the variable temperature cold head (2) and the transition piece (4); the variable temperature rotary block (3) is rotated to adjust its height relative to the fixing part (21) of the variable temperature cold head (2), thereby changing the amount of cold energy obtained by the cold head (5) through the variable temperature rotary block (3) and the transition piece (4).

3. The liquid nitrogen testing Dewar as described in claim 2, characterized in that: The cold end cold head (1) is connected and fixed to the liquid nitrogen storage chamber (8) by brazing; the support part (52) of the load cold head (5) is inserted into the connecting part (22) of the variable temperature cold head (2), and the outer wall of the support part (52) is in contact with the inner wall of the connecting part (22).

4. The liquid nitrogen testing Dewar as described in claim 2, characterized in that: The variable temperature rotary block (3) is provided with a hot end internal thread (31) and a cold end internal thread (32). The cold end internal thread (32) is screwed into the external thread of the connection part (22) of the variable temperature cold head (2), and the hot end internal thread (31) is screwed into the external thread of the transition piece (4).

5. The liquid nitrogen testing Dewar as described in claim 1, characterized in that: The cold head (5) and the transition piece (4) are connected by soft metal.

6. The liquid nitrogen testing Dewar as described in claim 1, characterized in that: The high thermal conductivity materials used in the cold end cold head (1) and transition part (4) are copper or molybdenum; the low thermal conductivity materials used in the variable temperature cold head (2) and carrier cold head (5) are titanium alloy, polyimide or polytetrafluoroethylene.

7. The liquid nitrogen testing Dewar as described in claim 1, characterized in that: The temperature adjustment range of the cold head (5) is 80K-180K.

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