Low-temperature vacuum irradiation in-situ electrical property testing system and method

Abstract

This invention relates to the field of fusion reactor material irradiation technology, and particularly to a low-temperature vacuum irradiation in-situ electrical performance testing system and method. The testing system includes: a first shell with a vacuum chamber inside; a second shell with its sidewalls extending outward to form an extension, making the shell L-shaped, the end of which connects to the first shell; a through-cavity between the second shell and the extension, which communicates with the vacuum chamber, located outside the second shell; a sample stage disposed within the vacuum chamber, the sample stage having a dielectric test sample holder, suitable for in-situ performance testing of insulating materials under low-temperature irradiation conditions; an irradiation source located within the irradiation chamber, suitable for irradiating the sample stage; and a cooling module suitable for adjusting the temperature range of the sample stage from 2.2K to 77K. This system simulates the actual service conditions of fusion reactor insulating materials under low-temperature vacuum conditions, solving the problem that irradiation devices cannot simultaneously handle both low-temperature and vacuum environments.

Description

Technical Field

[0001] This invention relates to the field of fusion reactor material irradiation technology, and in particular to a low-temperature vacuum irradiation in-situ electrical performance testing system and method. Background Technology

[0002] Insulating materials in fusion reactors face extreme conditions such as low temperatures, intense radiation, and strong magnetic fields. The degradation behavior of these materials within the reactor significantly restricts the safety and economic viability of fusion reactors. For the development of new fusion reactor insulating materials, irradiation testing is essential before they can be safely used in fusion reactors.

[0003] However, existing studies on the radiation resistance of insulating materials involve low-temperature performance testing after gamma-ray irradiation under normal air conditions at room temperature. This differs significantly from the actual low-temperature vacuum service conditions of insulating materials. Firstly, normal air contains various gases, and the insulating material inevitably reacts with gases such as oxygen during irradiation, introducing impurities and making it difficult to study the true damage mechanism of gamma-ray irradiation. Secondly, the low-temperature environment is difficult to simulate. Compared to room-temperature gamma-ray irradiation, the types and concentrations of gamma-ray-induced free radicals differ at low temperatures, and the limited thermal motion of free radicals directly alters the type of chemical reaction. Furthermore, gases (hydrogen, methane) generated during low-temperature irradiation-induced outgassing freeze within the material, forming defects such as pores upon reheating, directly affecting the material's macroscopic properties. Clearly, the performance of samples tested at low temperatures after gamma-ray irradiation differs greatly from that of samples irradiated at low temperatures in a real service environment, failing to provide accurate results regarding the degradation of insulating materials during service in fusion reactors. In summary, the existing technology lacks a low-temperature irradiation in-situ electrical performance testing system that can achieve the operating temperature range of insulating materials within a nuclear fusion vacuum chamber. Summary of the Invention

[0004] This invention provides a low-temperature vacuum irradiation in-situ electrical performance testing system and method to address one of the shortcomings of existing technologies. This invention achieves the combination of temperature regulation in the range of 2.2K to 77K and vacuum environment, which can accurately simulate the real service conditions of fusion reactor insulating materials under low temperature and vacuum conditions, and solves the problem that traditional irradiation devices cannot take into account both low temperature and vacuum environments.

[0005] This invention provides a low-temperature vacuum irradiation in-situ electrical performance testing system, applied to the electrical performance testing of superconducting magnet insulating materials in fusion reactors, comprising: The housing includes: A first housing, the first housing having a vacuum chamber inside; The second housing has a sidewall that extends outward to form an extension, giving the outer shell an L-shaped structure. The end of the extension is connected to the first housing. The second housing and the extension have a through-cavity that communicates with the vacuum chamber, which is located outside the second housing. The sample carrier module includes: The sample stage is made of oxygen-free copper and is disposed within the vacuum chamber. A dielectric test sample holder, which is disposed on the sample stage, is suitable for in-situ low-temperature irradiation testing of the electrical properties of superconducting magnet insulating materials in fusion reactors. Irradiation module, including: Irradiation chamber, wherein the outer shell is located within the irradiation chamber; An irradiation source is located inside the irradiation chamber and outside the outer shell, and is in close contact with the vacuum chamber. The irradiation source is used to irradiate the sample stage. A cooling module is provided, which is adapted to adjust the temperature range of the sample stage from 2.2K to 77K. The cooling module is connected to the upper end of the second housing, and the cooling pipeline of the cooling module passes through the inner cavity and the vacuum chamber in sequence and is connected to the sample stage.

[0006] A low-temperature vacuum irradiation in-situ electrical performance testing system according to an embodiment of the present invention includes a first housing comprising: Base; A first cover is disposed on the base and together with the base, forms the vacuum chamber; The second cover is disposed on the base and covers the outside of the first cover.

[0007] According to an embodiment of the present invention, a low-temperature vacuum irradiation in-situ electrical performance testing system is provided, wherein the first cover is provided with a first window, the second cover is provided with a second window, the first window and the second window are correspondingly arranged, and both the first window and the second window are titanium windows.

[0008] According to an embodiment of the present invention, a low-temperature vacuum irradiation in-situ electrical performance testing system is provided, wherein a vacuum extraction port is provided on the second housing, the vacuum extraction port is connected to the vacuum chamber through the inner cavity, and the vacuum extraction port is connected to a vacuum pump.

[0009] According to an embodiment of the present invention, a low-temperature vacuum irradiation in-situ electrical performance testing system is provided, wherein the outer wall of the second housing is provided with lead sheathing, or a lead partition is provided at the extension, the lead partition being adapted to separate the space where the second housing is located from that of the first housing.

[0010] A low-temperature vacuum irradiation in-situ electrical performance testing system according to an embodiment of the present invention is provided, wherein the irradiation source is... 60 Co, located in the irradiation chamber, is suitable for irradiating the sample stage with gamma rays.

[0011] A low-temperature vacuum irradiation in-situ electrical performance testing system according to an embodiment of the present invention further includes: The base is height-adjustable and supports the second housing.

[0012] A low-temperature vacuum irradiation in-situ electrical performance testing system according to an embodiment of the present invention includes: A power supply, suitable for providing voltage for electrical testing, which causes leakage current to form in insulating materials; An electrometer is suitable for measuring the leakage current of insulating materials under voltage in order to calculate the conductivity of the insulating materials.

[0013] A low-temperature vacuum irradiation in-situ electrical performance testing system according to an embodiment of the present invention includes a dielectric test sample holder comprising: The base is provided with a vertical plate; A fixing plate is disposed opposite to the upright plate and is connected to the upright plate through an adjusting member. The space between the fixing plate and the upright plate is suitable for fixing the insulating material to be tested. A flat plate electrode is disposed on the surface of the upright plate facing the fixed plate, and the flat plate electrode is insulated from the base. A spherical electrode is disposed on the surface of the fixed plate facing the upright plate, and the spherical electrode is insulated from the fixed plate.

[0014] This invention also provides a method for in-situ electrical performance testing under low-temperature vacuum irradiation, applied to the low-temperature vacuum irradiation in-situ electrical performance testing system described above, comprising: The sample to be irradiated is divided into two parts. One part is placed in the dielectric test sample holder, and the other part is placed on the sample stage in a position other than the dielectric test sample holder. The vacuum chamber is evacuated by a vacuum pump, so that the vacuum level inside the vacuum chamber is within the set vacuum level range. The temperature of the sample stage is adjusted to the required irradiation temperature by the cooling module and maintained at the irradiation temperature for a set time. Irradiation is carried out according to the preset dose rate until the preset total dose is reached, while the electrical performance of the sample is tested in real time through the in-situ electrical testing platform. Stop irradiation, adjust the temperature of the sample stage to room temperature, turn off the vacuum pump, and remove the sample.

[0015] According to an embodiment of the present invention, a method for in-situ electrical performance testing under low-temperature vacuum irradiation is provided, wherein the time required to adjust the temperature of the sample stage from room temperature to 4K is less than or equal to 150 minutes.

[0016] The low-temperature vacuum irradiation in-situ electrical performance testing system of the present invention mainly consists of a shell, a sample carrier module, an irradiation module, and a cooling module. The shell, serving as the supporting base of the entire device, is mainly composed of a first shell and a second shell. The first shell has a reserved sealed space for setting up a vacuum chamber, providing an experimental environment isolated from external air for the sample. The sample stage of the sample carrier module is installed in the middle of the vacuum chamber. The placement surface of the sample stage forms a low-temperature irradiation area. The size of the placement surface is adapted to the size of the experimental sample, and different specifications of sample carrier plates can be replaced according to actual needs. A dielectric test sample holder can be installed on the placement surface of the sample stage. The dielectric test sample holder can hold superconducting magnet insulating material from a fusion reactor for in-situ low-temperature irradiation electrical performance testing; that is, the dielectric test sample holder can serve as the in-situ low-temperature irradiation testing area formed on the sample stage. The irradiation source of the irradiation module is located inside the irradiation chamber, outside the outer shell and close to the vacuum chamber. The irradiation source faces the vacuum chamber to ensure that the irradiation rays can accurately cover the bearing area of ​​the sample stage. A safe distance is maintained between the irradiation source and the cooling module to minimize the irradiation rays that the cooling module receives.

[0017] In this invention, both the second housing and the extension are designed as cylindrical structures with openings at both ends. That is, the interiors of the second housing and the extension are interconnected cavities. One end of the extension connects to the base, and the other end connects to the side wall opening of the second housing. The upper opening of the second housing connects to the cooling module, thereby connecting the sample stage and the cooling module through the outer shell. The inner cavity communicates with the bottom side of the vacuum chamber, and the inner wall of the inner cavity may be provided with a heat-insulating coating to reduce the loss of cooling energy during transmission.

[0018] The mounting bracket for the refrigeration module is bolted to the upper opening of the second housing. The cooling pipeline for the refrigeration module is made of oxygen-free copper. One end of the pipeline is sealed to the cold head of the refrigeration module, while the other end passes through the inner cavity of the second housing, extends into the inner cavity of the extension section, and finally enters the vacuum chamber, where it is welded to the center of the bottom of the sample stage. To ensure the sealing effect of the vacuum chamber, a sealing layer can be installed at the junction where the cooling pipeline enters the vacuum chamber from the inner cavity. This sealing layer separates the vacuum chamber from the inner cavity, leaving only an area for the cooling pipeline to pass through. A heat insulation sleeve can be installed on the cooling pipeline to effectively prevent cold air from being transferred to the housing, avoiding frost or deformation of the housing due to low temperatures.

[0019] The cooling pipeline is arranged in a straight line within the inner cavity, reducing heat loss caused by pipe bends and facilitating pipeline installation and maintenance. Furthermore, the structural design of the second shell, extension, base, two-layer casing, and cooling module also facilitates the disassembly and maintenance of the low-temperature vacuum irradiation in-situ electrical performance testing system.

[0020] The cooling module employs a cryogenic cooling system, with its cooling output fixedly connected to the center of the sample stage's bottom. The cooling module achieves precise temperature control of the sample stage through feedback regulation, ensuring a stable temperature range between 2.2K and 77K during cryogenic irradiation testing, meeting the irradiation temperature requirements. This invention combines temperature regulation within the 2.2K to 77K range with a vacuum environment, accurately simulating the real-world operating conditions of fusion reactor insulating materials under cryogenic vacuum conditions, thus solving the problem of traditional irradiation devices being unable to simultaneously handle cryogenic and vacuum environments.

[0021] In this invention, an irradiation chamber is established, and the entire low-temperature vacuum irradiation in-situ electrical performance testing system is placed inside the irradiation chamber. The irradiation source is located inside the irradiation chamber, which ensures a stable output of irradiation dose and facilitates equipment maintenance and safety protection. The outer shell mainly consists of a first shell and a second shell, wherein the sidewall of the second shell extends outward to form an extension, the end of which connects to the first shell, thus making the overall outer shell have an L-shaped structure. That is, the vacuum chamber formed by the first shell is located outside the second shell. During irradiation experiments, the position of the irradiation source in the irradiation chamber is relatively fixed and cannot be moved, and the position of the irradiation device in the irradiation chamber is also relatively fixed. Therefore, through the extension of the second shell, the first shell extends away from the second shell, allowing the first shell to be closer to the irradiation source, until the vacuum chamber is in close contact with the irradiation source. The sample stage in the vacuum chamber can be closer to the irradiation source. At the same time, through precise irradiation path calibration, it is ensured that the sample receives uniform irradiation, improving the repeatability of the experiment. It also allows the second shell and the cooling module to be kept as far away from the irradiation source as possible. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a front view of the low-temperature vacuum irradiation in-situ electrical performance testing system provided in an embodiment of the present invention; Figure 2 This is a side view of the low-temperature vacuum irradiation in-situ electrical performance testing system provided in an embodiment of the present invention; Figure 3This is a top view of the low-temperature vacuum irradiation in-situ electrical performance testing system provided in this embodiment of the invention; Figure 4 This is a side view of another embodiment of the low-temperature vacuum irradiation in-situ electrical performance testing system provided in this invention. Figure 5 This is a schematic diagram of the dielectric test sample holder of the low-temperature vacuum irradiation in-situ electrical performance testing system provided in an embodiment of the present invention.

[0024] Figure label: 100. Outer shell; 110. First housing; 111. Vacuum chamber; 120. Second housing; 121. Vacuum extraction port; 122. Wire connector; 123. Inner cavity; 124. Extension; 130. First cover; 131. First window; 140. Second cover; 141. Second window; 150. Base; 200. Sample stage; 210. Dielectric test sample holder; 211. Base; 212. Vertical plate; 213. Fixing plate; 214. Flat electrode; 215. Spherical electrode; 216. Bolt; 217. Spring; 300. Refrigeration module; 310. Cooling piping; 400, base; 500, lead partition. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," 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 the embodiments of the present 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 limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0028] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] like Figure 1 , Figure 2 and Figure 3As shown, the low-temperature vacuum irradiation in-situ electrical performance testing system of this invention is applied to the electrical performance testing of superconducting magnet insulating materials in fusion reactors. It includes a shell 100, a sample carrying module, an irradiation module, and a cooling module 300. The shell 100 includes a first shell 110 and a second shell 120. The first shell 110 has a vacuum chamber 111 inside. The sidewall of the second shell 120 extends outward to form an extension 124, making the shell 100 have an L-shaped structure. The end of the extension 124 is connected to the first shell 110. The second shell 120 and the extension 124 have a through-cavity 123, which communicates with the vacuum chamber 111. The vacuum chamber 111 is located... Located outside the second housing 120; the sample carrying module includes a sample stage 200 and a dielectric test sample holder 210. The sample stage 200 is made of oxygen-free copper and is located inside the vacuum chamber 111. The dielectric test sample holder 210 is located on the sample stage 200 and is suitable for in-situ low-temperature irradiation testing of insulating materials in fusion reactors. The irradiation module includes an irradiation chamber and an irradiation source. The outer shell 100 is located inside the irradiation chamber, and the irradiation source is located inside the irradiation chamber and outside the outer shell 100. The irradiation source is in close contact with the vacuum chamber 111 and is suitable for irradiating the sample stage 200. The cooling module 300 is suitable for adjusting the temperature range of the sample stage 200 from 2.2K to 77K. The cooling module 300 is connected to the second housing 120, and the cooling pipeline 310 of the cooling module 300 passes through the inner cavity 123 and the vacuum chamber 111 in sequence and is connected to the sample stage 200.

[0031] The low-temperature vacuum irradiation in-situ electrical performance testing system of this invention mainly consists of a shell 100, a sample carrier module, an irradiation module, and a cooling module 300. The shell 100, serving as the support base for the entire device, is mainly composed of a first shell 110 and a second shell 120. The first shell 110 has a reserved sealed space for setting up a vacuum chamber 111, providing an experimental environment isolated from external air for the sample. The sample stage 200 of the sample carrier module is installed in the middle of the vacuum chamber 111. The placement surface of the sample stage 200 forms a low-temperature irradiation area. The size of the placement surface is adapted to the size of the experimental sample, and different specifications of sample carrier plates can be replaced according to actual needs. A dielectric test sample holder 210 can be installed on the placement surface of the sample stage 200. The dielectric test sample holder 210 can hold superconducting magnet insulating materials from a fusion reactor for in-situ low-temperature irradiation electrical performance testing. That is, the dielectric test sample holder 210 can serve as an in-situ low-temperature irradiation testing area formed on the sample stage 200. The irradiation source of the irradiation module is located in the irradiation chamber, outside the outer shell 100 and close to the vacuum chamber 111. The irradiation source faces the vacuum chamber 111 to ensure that the irradiation rays can accurately cover the bearing area of ​​the sample stage 200. A safe distance is maintained between the irradiation source and the cooling module 300 to minimize the irradiation rays that the cooling module 300 receives.

[0032] In this embodiment, both the second housing 120 and the extension 124 are designed as cylindrical structures with openings at both ends. Specifically, the second housing 120 and the extension 124 have interconnected internal cavities 123. One end of the extension 124 is connected to the base 150, and the other end is connected to the side wall opening of the second housing 120. The upper opening of the second housing 120 is connected to the cooling module 300, thereby connecting the sample stage 200 and the cooling module 300 through the outer shell 100. The internal cavity 123 communicates with the bottom side of the vacuum chamber 111, and the inner wall of the internal cavity 123 may be provided with a heat-insulating coating to reduce the loss of cooling energy during transmission.

[0033] The mounting base of the refrigeration module 300 is bolted to the upper opening of the second housing 120. The cooling pipe 310 of the refrigeration module 300 is made of oxygen-free copper. One end of the cooling pipe 310 is sealed to the cold head of the refrigeration module 300, and the other end first passes through the inner cavity 123 of the second housing 120, then extends into the inner cavity 123 of the extension 124, and finally enters the vacuum chamber 111, where it is welded and fixed to the bottom center of the sample stage 200. To ensure the sealing effect of the vacuum chamber 111, a sealing layer can be provided at the junction where the cooling pipe 310 enters the vacuum chamber 111 from the inner cavity 123. This sealing layer separates the vacuum chamber 111 from the inner cavity 123, leaving only an area for the cooling pipe 310 to pass through. A heat insulation sleeve can be installed on the cooling pipe 310 to effectively block the transfer of cold energy to the second housing 120, preventing the second housing 120 from frosting or deforming due to low temperatures.

[0034] The portion of the cooling pipeline 310 within the inner cavity 123 is arranged in a straight line, reducing heat loss caused by pipeline bends and facilitating pipeline installation and maintenance. Furthermore, the structural design of the second housing 120, extension 124, base 150, two-layer casing, and cooling module 300 also facilitates the disassembly and maintenance of the low-temperature vacuum irradiation in-situ electrical performance testing system.

[0035] The cooling module 300 is a cryogenic cooling module, whose cooling output end is fixedly connected to the center of the bottom of the sample stage 200. The cooling module 300 achieves precise temperature control of the sample stage 200 through feedback adjustment, ensuring that the temperature of the sample stage 200 remains stable between 2.2K and 77K during cryogenic irradiation testing, meeting the irradiation temperature requirements. This invention achieves a combination of temperature regulation within the 2.2K to 77K range and a vacuum environment, accurately simulating the real-world operating conditions of fusion reactor insulating materials under cryogenic vacuum, solving the problem that traditional irradiation devices cannot simultaneously handle cryogenic and vacuum environments.

[0036] In this embodiment, an irradiation chamber is established, and the entire low-temperature vacuum irradiation in-situ electrical performance testing system is placed inside the irradiation chamber. The irradiation source is set inside the irradiation chamber, which not only ensures a stable output of irradiation dose, but also facilitates equipment maintenance and safety protection. The outer casing 100 mainly consists of a first casing 110 and a second casing 120. The sidewall of the second casing 120 extends outward to form an extension 124, the end of which connects to the first casing 110. This gives the outer casing 100 an overall L-shaped structure. Specifically, the vacuum chamber 111 formed by the first casing 110 is located outside the second casing 120. During irradiation experiments, the position of the irradiation source within the irradiation chamber is relatively fixed and cannot be moved. Similarly, the position of the irradiation device within the irradiation chamber is also relatively fixed. Therefore, through the extension 124 extending from the second casing 120, the first casing 110 extends away from the second casing 120, allowing it to get closer to the irradiation source until the vacuum chamber 111 is flush with the irradiation source. This allows the sample stage 200 within the vacuum chamber 111 to be closer to the irradiation source. Simultaneously, precise irradiation path calibration ensures that the sample receives uniform irradiation, improving experimental repeatability. It also allows the second casing 120 and the cooling module 300 to be kept as far away from the irradiation source as possible.

[0037] In this embodiment, the sample stage 200 is made entirely of oxygen-free copper. Oxygen-free copper has an excellent thermal conductivity, which can quickly conduct the cold or heat generated by the cooling module 300 or the heating device, ensuring the temperature uniformity of the sample stage 200 surface.

[0038] The excellent thermal conductivity of high-purity oxygen-free copper enables the sample stage 200 to respond quickly to temperature adjustment commands, shortening the time to reach the set temperature. The cooling time from room temperature to 4K can be controlled within 150 minutes, improving experimental efficiency. Simultaneously, it ensures the uniformity of the sample stage 200's surface temperature, preventing inconsistent irradiation damage to the samples due to temperature unevenness. The highly efficient thermally conductive connection between the oxygen-free copper sample stage 200 and the cooling module 300 ensures heat conduction under low-temperature conditions, minimizing cold loss and ensuring rapid and uniform temperature adjustment. This provides a stable temperature environment for material irradiation experiments, improving the reliability of experimental data.

[0039] According to one embodiment of the present invention, referring to Figure 3 As shown, the first housing 110 includes a base 150, a first cover 130 and a second cover 140. The first cover 130 is disposed on the base 150 and together with the base 150, forms a vacuum chamber 111. The second cover 140 is disposed on the base 150 and covers the outside of the first cover 130.

[0040] In this embodiment, the first housing 110 mainly consists of a base 150, a first cover 130, and a second cover 140. The first cover 130 is a rectangular dome structure, and its edges are fixedly connected to the opening at the end of the base 150 via a flange, forming a sealed connection between the flange and the base 150. The first cover 130 and the base 150 together form a sealed vacuum chamber 111, allowing the irradiation rays to penetrate the first cover 130 without reacting chemically with the sample. The second cover 140 is also a rectangular dome structure, but its dimensions are larger than the first cover 130. It is fixed to the base 150 with bolts and completely covers the outside of the first cover 130. A certain distance is reserved between the second cover 140 and the first cover 130. This space can be evacuated to form a vacuum interlayer or filled with insulation material to form a heat insulation layer, further isolating the internal space of the first cover 130 from the outside, reducing the outward loss of cold energy from the vacuum chamber 111, and improving the stability of temperature control. In addition, the second cover 140 can also provide physical protection for the first cover 130, preventing it from being damaged by external impacts.

[0041] The double-layered enclosure design achieves sealing and X-ray penetration of the vacuum chamber 111 through the first enclosure 130, while the second enclosure 140 provides insulation and protection. Together, they ensure the airtightness of the experimental environment while effectively reducing temperature loss, thus improving the efficiency and temperature control accuracy of the cooling module 300. The combination of the base 150 and the double-layered enclosure forms the first shell 110, enhancing the structural stability and durability of the entire device, adapting to long-term experimental operation needs, and reducing equipment maintenance costs.

[0042] In this embodiment, the first cover 130 may be made of aluminum, and the second cover 140 may be made of stainless steel.

[0043] According to one embodiment of the present invention, a first cover 130 is provided with a first window 131, and a second cover 140 is provided with a second window 141. The first window 131 and the second window 141 are correspondingly provided, and both the first window 131 and the second window 141 are titanium windows.

[0044] In this embodiment, the first window 131 is located at the center of the first housing 130. A titanium alloy sheet with a thickness of 0.5 mm is used as the window substrate, ensuring sufficient structural strength, excellent gamma-ray penetration, and chemical stability, preventing oxidation or deformation under low-temperature vacuum conditions. The second window 141 is located at the center of the second housing 140, corresponding to the first window 131, ensuring unobstructed passage of radiation rays through both windows. The second window 141 is also made of a titanium alloy sheet with a thickness of 0.5 mm to prevent air from entering the space between the two housings.

[0045] The corresponding arrangement of the first window 131 and the second window 141, both made of highly penetrating titanium, ensures that the gamma rays emitted from the irradiation source can efficiently and without attenuation penetrate into the sample stage 200 within the vacuum chamber 111. This solves the problem of traditional window materials blocking or attenuating rays, guaranteeing the effectiveness of the irradiation experiment. The titanium alloy material possesses excellent low-temperature resistance and corrosion resistance, enabling it to adapt to the low-temperature vacuum environment of the vacuum chamber 111. This avoids damage such as brittleness and oxidation of the window material during the experiment, improving the service life and reliability of the equipment. Furthermore, the high strength of the titanium window material allows for a thinner design, further reducing the obstruction and attenuation of ray intensity.

[0046] According to one embodiment of the present invention, the low-temperature vacuum irradiation in-situ electrical performance testing system further includes a heating device and a temperature sensor. The heating device is connected to the sample stage 200. The temperature sensor is disposed on the sample stage 200 and is adapted to be associated with the heating device and the cooling module 300 to detect the temperature of the sample stage 200 and control the heating device and the cooling module 300 to raise and lower the temperature.

[0047] In this embodiment, the low-temperature vacuum irradiation in-situ electrical performance testing system mainly consists of a housing 100, a sample stage 200, a cooling module 300, an irradiation source, a heating device, and a temperature sensor. The heating device is designed specifically for the sample stage 200 to heat it; the type of heating device can be selected according to actual needs. The temperature sensor is also installed on the sample stage 200, enabling real-time monitoring of its temperature.

[0048] The temperature sensor, heating device, and cooling module 300 form a closed-loop control circuit. The temperature sensor detects the temperature data of the sample stage 200 in real time and transmits the data to the control system. The control system compares the detected temperature with the set temperature. If the detected temperature is lower than the set temperature, the control system controls the cooling module 300 to reduce the cooling power or start the heating device. If the detected temperature is higher than the set temperature, the control system controls the heating device to turn off and increases the cooling power of the cooling module 300, thereby achieving precise control of the temperature of the sample stage 200.

[0049] The coordinated operation of the heating device and the cooling module 300 enables the sample stage 200 to not only achieve low-temperature regulation but also to heat up when needed, further expanding the temperature control range and meeting the irradiation experimental requirements of different materials under different temperature conditions. The tight thermally conductive connection between the temperature sensor and the sample stage 200 ensures the real-time performance and accuracy of temperature detection. The closed-loop control design enables automatic temperature adjustment, reducing human error and improving the stability of temperature control, keeping the temperature fluctuation of the sample stage 200 within ±50 mK.

[0050] In this embodiment, a thermocouple temperature sensor can be selected as the temperature sensor. Its sensing end is fixed to a pre-drilled mounting hole on the side of the sample stage 200 by threads. The mounting hole is filled with thermally conductive silicone grease to ensure good thermal contact between the sensor and the sample stage 200, thereby improving the accuracy of temperature detection. The heating device can be a thin-film resistance heater, which is attached to the bottom side of the sample stage 200 with high-temperature resistant adhesive to ensure uniform heating.

[0051] According to one embodiment of the present invention, the second housing 120 is provided with a vacuum extraction port 121, which is connected to the vacuum chamber 111 through the inner cavity 123 and is connected to a vacuum pump.

[0052] In this embodiment, the vacuum extraction port 121 is located on the side of the second housing 120 and has a circular interface structure, which facilitates quick connection with the pipeline of the vacuum pump and enables the vacuum level of the vacuum chamber 111 to be quickly evacuated to 5×10⁻⁶. -4 mbar to 5×10 -6 The range of mbars meets the high vacuum environment requirements of experiments and solves the problems of slow pumping speed and low ultimate vacuum of traditional single vacuum pumps.

[0053] The vacuum extraction port 121 is connected to the inner cavity 123 of the second housing 120 through an internal connecting pipe, and then connected to the vacuum chamber 111 through the inner cavity 123 of the extension 124. The structural design of the vacuum extraction port 121 being connected to the vacuum chamber 111 through the inner cavity 123 simplifies the pipeline layout and avoids the sealing risks caused by multiple pipelines directly passing through the vacuum chamber 111. At the same time, the heat insulation structure of the inner cavity 123 reduces the loss of cold energy during the extraction process and improves the stability of temperature control.

[0054] The vacuum evacuation port 121 is equipped with a filter screen to prevent impurities in the vacuum chamber 111 from entering the vacuum pump and affecting its performance. This facilitates control of the evacuation process, protects the vacuum pump from contamination, and extends its service life. The real-time monitoring function of the vacuum gauge allows operators to accurately monitor the vacuum state within the vacuum chamber 111, ensuring that experiments are conducted under the set vacuum conditions.

[0055] like Figure 4 As shown, according to one embodiment of the present invention, the outer wall of the second housing 120 is provided with lead sheathing, or a lead partition 500 is provided at the extension 124, the lead partition 500 being adapted to separate the space where the second housing 120 is located from that of the first housing 110.

[0056] In this embodiment, to ensure the stable operation of the low-temperature vacuum irradiation in-situ electrical performance testing system in the radiation space, the structures of other components besides the first housing 110 are treated with radiation protection. For example, lead is coated on the outside of the second housing 120, or a lead layer is wrapped around it to form a lead sheath, thus blocking radiation from the second housing 120 and the cooling module 300. Alternatively, the first housing 110 and the second housing 120 can be spatially separated by using a lead partition 500 on the outside of the extension 124. The lead partition 500 extends vertically, thereby separating the space where the first housing 110 and the second housing 120 are located, thereby blocking radiation from the space where the first housing 110 is located from reaching the second housing 120. In one embodiment of the present invention, the irradiation source is... 60 Co, located in the irradiation chamber, is suitable for irradiating the sample stage 200 with gamma rays.

[0057] In this embodiment, the irradiation source is selected as follows: 60 The Co-γ-ray irradiation source is equipped with a protective shield to prevent radiation leakage and potential safety hazards. The window of the first housing 110 is vertically positioned, facing the irradiation source, and the surface of the sample stage 200 also faces the irradiation source. This irradiation device, in conjunction with an in-situ electrical performance testing platform, enables in-situ testing of changes in the electrical properties of sample materials under 4K low-temperature vacuum γ-ray irradiation conditions.

[0058] According to one embodiment of the present invention, the low-temperature vacuum irradiation in-situ electrical performance testing system further includes a base 400, the height of which is adjustable, and the base 400 is supported by a second housing 120.

[0059] In this embodiment, the base 400 is a height-adjustable base 400. The base 400 is mainly connected to and supports the second housing 120, thereby realizing the height adjustment of the sample stage 200, the cooling module 300, etc.

[0060] In this embodiment, the height adjustment range of the base 400 does not exceed 30cm.

[0061] According to one embodiment of the present invention, the low-temperature vacuum irradiation in-situ electrical performance testing system further includes a high-voltage power supply and an electrometer. The high-voltage power supply is adapted to provide high voltage for electrical testing, and the high voltage causes leakage current to form in the insulating material. The electrometer is adapted to measure the leakage current of the insulating material under high voltage in order to calculate the conductivity of the insulating material.

[0062] In this embodiment, the placement surface of the sample stage 200 can be structurally divided into a non-in-situ testing area and an in-situ testing area. The in-situ testing area is the location where the dielectric test sample holder 210 is installed, and the non-in-situ testing area is the location other than where the dielectric test sample holder 210 is installed. The test samples placed in both areas can be guaranteed to be independent of each other and will not interfere with each other.

[0063] The design of the sample stage 200 and the dielectric test sample holder 210 enables the simultaneous conduction of simple irradiation experiments and irradiation-in-situ electrical testing experiments of samples under the same irradiation environment and temperature conditions. The samples in the non-in-situ test area on the sample stage 200 and the samples on the dielectric test sample holder 210 receive completely consistent irradiation doses and temperature environments, facilitating comparative analysis and improving experimental efficiency and data comparability.

[0064] The second housing 120 is provided with a wire connector 122 adapted to the in-situ electrical testing device. This serves as a connection structure between the electrodes of the in-situ electrical testing device and external testing instruments. The wire connector 122 enables the wires to be led out, ensuring the airtightness of the vacuum chamber 111 and enabling real-time transmission of electrical signals. This allows for real-time monitoring of changes in the electrical properties of the sample during irradiation, solving the problem that traditional testing methods require interruption of irradiation for detection, and obtaining dynamic performance data of the material during irradiation.

[0065] In this embodiment, the dielectric test sample holder 210 can be a Cryo-4K-SMA sample holder, matched with a 4K cooling module, and equipped with two low-temperature high-voltage coaxial cables. Two high-voltage BNC through-holes are installed on the cooling module. The high-voltage power supply can be a 3kV~10kV / 0.5W~2W / ultra-low ripple precision high-voltage power supply. The electrometer can be a Keithley 6517B electrometer.

[0066] like Figure 5 As shown, according to one embodiment of the present invention, the dielectric test sample holder 210 includes a base 211, a fixing plate 213, a flat electrode 214, and a spherical electrode 215. The base 211 is provided with a vertical plate 212; the fixing plate 213 is disposed opposite to the vertical plate 212 and is connected to the vertical plate 212 through an adjusting member, and the space between the fixing plate 213 and the vertical plate 212 is suitable for fixing the insulating material to be tested; the flat electrode 214 is disposed on the surface of the vertical plate 212 facing the fixing plate 213, and the flat electrode 214 is insulated from the base 211; the spherical electrode 215 is disposed on the surface of the fixing plate 213 facing the vertical plate 212, and the spherical electrode 215 is insulated from the fixing plate 213.

[0067] In this embodiment, the dielectric test sample holder 210 mainly consists of a base 211, a fixing plate 213, a flat electrode 214, and a spherical electrode 215. A vertical plate 212 is provided on the upper surface of the base 211. The fixing plate 213 is opposite to and parallel to the vertical plate 212. The space between the fixing plate 213 and the vertical plate 212 can be used to place the insulating material to be tested, thereby clamping and fixing the insulating material to be tested between the fixing plate 213 and the vertical plate 212. The fixing plate 213 is connected to the vertical plate 212 through an adjusting member so that the vertical distance between the fixing plate 213 and the vertical plate 212 can be flexibly adjusted to adapt to insulating materials of different sizes and shapes.

[0068] When the fixing plate 213 and the upright plate 212 clamp and fix the insulating material, the spherical electrode 215 on the fixing plate 213 and the flat plate electrode 214 on the upright plate 212 directly contact the surface of the insulating material. Thus, the spherical electrode 215 and the flat plate electrode 214 serve as test electrodes for the performance testing of the insulating material, and the insulating material is energized during the test.

[0069] The base 211, fixing plate 213, upright plate 212, and adjusting components are all made of oxygen-free copper. To ensure the normal power supply of the spherical electrode 215 and the flat plate electrode 214 and to avoid short circuits, the connection between the spherical electrode 215 and the fixing plate 213 is insulated, and the connection between the flat plate electrode 214 and the upright plate 212 is also insulated.

[0070] In this embodiment, the adjusting component consists of a bolt 216 and a spring 217. The spring 217 is sleeved on the bolt 216. A through hole is provided on the fixing plate 213, and a threaded hole corresponding to the through hole is provided on the upright plate 212. The bolt 216 passes through the through hole of the fixing plate 213 and is screwed into the threaded hole of the upright plate 212. One end of the spring 217 abuts against the nut of the bolt 216, and the other end abuts against the fixing plate 213. Through the extension and retraction of the spring 217, on the one hand, the position of the fixing plate 213 on the bolt 216 is adjusted, thereby adjusting the distance between the fixing plate 213 and the upright plate 212. On the other hand, an elastic force is applied to the fixing plate 213, so that it and the upright plate 212 work together to generate a clamping force to fix the insulating material.

[0071] The low-temperature irradiation simulation method provided by the present invention is described below. The low-temperature irradiation simulation method described below can be referred to in correspondence with the in-situ electrical performance testing system described above.

[0072] This invention also provides a method for in-situ electrical performance testing under low-temperature vacuum irradiation, applied to the low-temperature vacuum irradiation in-situ electrical performance testing system as described above, comprising: The sample to be irradiated is divided into two parts. One part is placed in the dielectric test sample holder 210, and the other part is placed on the sample stage 200 in a position other than the dielectric test sample holder 210. The vacuum chamber 111 is evacuated by a vacuum pump so that the vacuum level inside the vacuum chamber 111 is within the set vacuum level range; The temperature of the sample stage 200 is adjusted to the required irradiation temperature by the cooling module 300, and the irradiation temperature is maintained for a set time or longer. Irradiation is carried out according to the preset dose rate until the preset total dose is reached, while the electrical performance of the sample is tested in real time through the in-situ electrical testing platform. Stop irradiation, adjust the temperature of sample stage 200 to room temperature, turn off the vacuum pump, and remove the sample.

[0073] The low-temperature vacuum irradiation in-situ electrical performance testing method of this invention first involves a sample preparation stage. A fusion reactor insulating material sample to be irradiated is selected; in this embodiment, it is epoxy resin. The sample is cut into two identical samples to ensure consistent initial performance. One sample is placed in the non-in-situ testing area of ​​the sample stage 200, and the other sample is placed in the dielectric test sample holder 210. The sample positions are adjusted to ensure precise contact between the electrodes of the dielectric test sample holder 210 and the sample surface. Next, a vacuuming stage is performed. A vacuum pump is started, and the vacuum chamber 111 is evacuated through the vacuum extraction port 121 until the vacuum level in the vacuum chamber 111 reaches a set range. The vacuum level is monitored in real time using a vacuum gauge to maintain the vacuum environment. Then, in the temperature regulation stage, the required irradiation temperature is set through the control system of the cooling module 300, which is 4.2K in this embodiment. The cooling module 300 is activated to cool the sample stage 200. The temperature sensor provides real-time feedback on the temperature data of the sample stage 200. Once the temperature reaches the set value, the cooling module 300 is kept in operation for at least 15 minutes to ensure the temperature of the sample stage 200 and the sample is stable, avoiding the impact of temperature fluctuations on the irradiation effect. Next, in the irradiation and in-situ testing stage, the irradiation dose rate and total dose are set according to experimental requirements. The irradiation source is activated to irradiate the sample in the non-in-situ testing area of ​​the sample stage 200 and the sample in the dielectric test sample holder 210. During the irradiation process, the electrical performance data (such as resistivity, capacitance, etc.) of the sample on the dielectric test sample holder 210 are collected in real time through the electrodes of the dielectric test sample holder 210. The test data is recorded every 1 minute until the set total dose is reached. Finally, after the experiment concluded and the preset total dose was reached, the irradiation source was turned off, and irradiation was stopped. The temperature of the sample stage 200 was gradually increased until it returned to room temperature (25°C). After the temperature stabilized, the cooling module 300 and the vacuum pump were turned off, allowing the vacuum chamber 111 to be connected to the atmosphere. Then, the first cover 130 and the second cover 140 of the vacuum chamber 111 were opened, and two samples were removed for subsequent offline performance testing.

[0074] Two samples were processed simultaneously within the same system. The sample from the non-in-situ testing area was used for subsequent offline performance testing and related characterization, studying the changes in material properties after low-temperature irradiation damage. The sample from the dielectric testing sample holder 210 was used for real-time electrical performance monitoring, enabling a comprehensive analysis of the dynamic changes in material properties during irradiation and the static properties after irradiation, providing comprehensive data support for studying the irradiation damage mechanism of materials. Maintaining a set vacuum level and temperature for a certain duration after vacuuming ensured the stability of the experimental environment and reduced the impact of environmental fluctuations on the experimental results. Precise control of the preset dose rate and total dose ensured the consistency of irradiation conditions and improved experimental repeatability.

[0075] In-situ electrical testing was conducted simultaneously with the irradiation process, avoiding the secondary impact on material properties caused by changes in temperature, vacuum, and other conditions during the transfer of samples from the irradiation environment to the testing environment, which is common in traditional testing methods. This yielded electrical performance data of the material under real irradiation conditions, making the experimental results closer to actual working conditions.

[0076] According to one embodiment of the present invention, the time required to adjust the temperature of the sample stage 200 from room temperature to 4K is less than or equal to 150 minutes.

[0077] In this embodiment, the time required to adjust the temperature of the sample stage 200 from room temperature to 4K is less than or equal to 150 minutes, which greatly shortens the experimental preparation cycle, improves experimental efficiency, solves the problem of excessive cooling time and lengthy experimental cycle in traditional low-temperature vacuum irradiation in-situ electrical performance testing systems, and meets the needs of batch experiments or rapid verification.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-temperature vacuum irradiation in-situ electrical performance testing system, characterized in that, Electrical performance testing of insulating materials for superconducting magnets used in fusion reactors includes: The housing includes: A first housing, the first housing having a vacuum chamber inside; The second housing has a sidewall that extends outward to form an extension, giving the outer shell an L-shaped structure. The end of the extension is connected to the first housing. The second housing and the extension have a through-cavity that communicates with the vacuum chamber, which is located outside the second housing. The sample carrier module includes: A sample stage, wherein the sample stage is disposed within the vacuum chamber; A dielectric test sample holder, which is disposed on the sample stage, is suitable for in-situ low-temperature irradiation testing of the electrical properties of superconducting magnet insulating materials in fusion reactors. Irradiation module, including: Irradiation chamber, wherein the outer shell is located within the irradiation chamber; An irradiation source is located inside the irradiation chamber and outside the outer shell, with the irradiation source in close contact with the vacuum chamber, and is used to irradiate the sample stage; A cooling module is provided, which is adapted to adjust the temperature range of the sample stage from 2.2K to 77K. The cooling module is connected to the upper end of the second housing, and the cooling pipeline of the cooling module passes through the inner cavity and the vacuum chamber in sequence and is connected to the sample stage.

2. The low-temperature vacuum irradiation in-situ electrical performance testing system according to claim 1, characterized in that, The first housing includes: Base; A first cover is disposed on the base and together with the base, forms the vacuum chamber; A second cover is disposed on the base and covers the outside of the first cover.

3. The low-temperature vacuum irradiation in-situ electrical performance testing system according to claim 2, characterized in that, The first cover has a first window, and the second cover has a second window. The first window and the second window are provided correspondingly, and both the first window and the second window are titanium windows.

4. The low-temperature vacuum irradiation in-situ electrical performance testing system according to claim 1, characterized in that, The second housing is provided with a vacuum extraction port, which is connected to the vacuum chamber through the inner cavity and is also connected to a vacuum pump.

5. The low-temperature vacuum irradiation in-situ electrical performance testing system according to any one of claims 1 to 4, characterized in that, The outer wall of the second housing is provided with lead sheathing, or a lead partition is provided at the extension, the lead partition being adapted to separate the space where the second housing is located from that of the first housing.

6. The low-temperature vacuum irradiation in-situ electrical performance testing system according to any one of claims 1 to 4, characterized in that, The irradiation source is 60 Co, located in the irradiation chamber, is suitable for irradiating the sample stage with gamma rays.

7. The low-temperature vacuum irradiation in-situ electrical performance testing system according to any one of claims 1 to 4, characterized in that, Also includes: The base is height-adjustable and supports the second housing.

8. The low-temperature vacuum irradiation in-situ electrical performance testing system according to any one of claims 1 to 4, characterized in that, Also includes: A power supply, suitable for providing voltage for electrical testing, which causes leakage current to form in insulating materials; An electrometer is suitable for measuring the leakage current of insulating materials under voltage in order to calculate the conductivity of the insulating materials.

9. The low-temperature vacuum irradiation in-situ electrical performance testing system according to any one of claims 1 to 4, characterized in that, The dielectric test sample holder includes: The base is provided with a vertical plate; A fixing plate is disposed opposite to the upright plate and is connected to the upright plate through an adjusting member. The space between the fixing plate and the upright plate is suitable for fixing the insulating material to be tested. A flat plate electrode is disposed on the surface of the upright plate facing the fixed plate, and the flat plate electrode is insulated from the base; A spherical electrode is disposed on the surface of the fixed plate facing the upright plate, and the spherical electrode is insulated from the fixed plate.

10. A method for in-situ electrical performance testing under low-temperature vacuum irradiation, characterized in that, The low-temperature vacuum irradiation in-situ electrical performance testing system according to any one of claims 1 to 9 comprises: The sample to be irradiated is divided into two parts. One part is placed in the dielectric test sample holder, and the other part is placed on the sample stage in a position other than the dielectric test sample holder. The vacuum chamber is evacuated by a vacuum pump, so that the vacuum level inside the vacuum chamber is within the set vacuum level range. The temperature of the sample stage is adjusted to the required irradiation temperature by the cooling module and maintained at the irradiation temperature for a set time. Irradiation is carried out according to the preset dose rate until the preset total dose is reached, while the electrical performance of the sample is tested in real time through the in-situ electrical testing platform. Stop irradiation, adjust the temperature of the sample stage to room temperature, turn off the vacuum pump, and remove the sample.

11. The method for in-situ electrical performance testing under low-temperature vacuum irradiation according to claim 10, characterized in that, The time required to adjust the temperature of the sample stage from room temperature to 4K is less than or equal to 150 minutes.

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