Ultralow-temperature vacuum system of Tokamak or star imitator adaptive to nuclear fusion

Abstract

The invention discloses an ultra-low temperature vacuum system of a Tokamak or star imitator adaptive to nuclear fusion, and relates to the technical field of nuclear fusion equipment, the ultra-low temperature vacuum system comprises a vacuum chamber, a plasma state sensor is embedded in the inner wall of the vacuum chamber, the outer end of the vacuum chamber is provided with a sealing interface, the outer end of the sealing interface is provided with a primary filter, and the primary filter is provided with a secondary filter. A getter bin is installed at the outer end of the primary filter, an auxiliary pump is installed at the outer end of the getter bin, a stop valve is installed at the outer end of the auxiliary pump, a cold trap is installed at the outer end of the stop valve, the side wall of the cold trap is connected with a refrigerating machine through a pipeline, and a main pump is installed at the outer end of the cold trap. By arranging a series of structures, the pain point of decoupling of a traditional system and plasma operation is thoroughly solved, all the components cooperate to guarantee the ultrahigh vacuum environment, interference of impurity gas on plasma constraint is greatly reduced, and the stability and success rate of a nuclear fusion experiment are remarkably improved.

Description

A cryogenic vacuum system adapted for nuclear fusion tokamak or stellarator Technical Field

[0001] This invention relates to the field of nuclear fusion equipment technology, specifically to an ultra-low temperature vacuum system adapted to a tokamak or stellarator for nuclear fusion. Background Technology

[0002] The stable operation of magnetic confinement nuclear fusion devices (tokamak, stellarator) depends on an ultra-high vacuum environment to avoid energy loss or confinement failure caused by collisions between impurity gases and plasma.

[0003] The core defects of the existing system are concentrated in several aspects: First, it is decoupled from the plasma operating state and adopts a fixed vacuum degree control mode, which cannot adapt to the pulse cycle requirements of the plasma "before discharge - during discharge - between discharge", which easily causes vacuum degree fluctuations and leads to plasma confinement failure; Second, it is not resistant to radiation and has insufficient reliability. The radiation protection design of pipeline connection components and pump body is scattered, and the cooling system has no redundant configuration, which makes it easy to shut down due to high-energy particle bombardment or cooling failure. Summary of the Invention

[0004] The purpose of this invention is to provide an ultra-low temperature vacuum system adapted to a tokamak or stellarator for nuclear fusion, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an ultra-low temperature vacuum system adapted to a tokamak or stellarator for nuclear fusion, comprising a vacuum chamber with a plasma state sensor embedded in its inner wall, a sealed interface at the outer end of the vacuum chamber, a preliminary filter installed at the outer end of the sealed interface, a getter chamber installed at the outer end of the preliminary filter, an auxiliary pump installed at the outer end of the getter chamber, a shut-off valve installed at the outer end of the auxiliary pump, a cold trap installed at the outer end of the shut-off valve, a refrigerator connected to the side wall of the cold trap via a pipe, a main pump installed at the outer end of the cold trap, an exhaust gas filter installed at the outer end of the main pump, and the main pump, auxiliary pump, cold trap, refrigerator, shut-off valve, and plasma state sensor all electrically connected to a central control system.

[0006] Preferably, the outer end of the sealing interface is threadedly connected to a first bellows via a threaded groove, the outer end of the first bellows is sealed to the preliminary filter via a flange, and the outer end of the getter chamber is equipped with a second bellows, the outer end of the second bellows being connected to an auxiliary pump.

[0007] Preferably, the primary filter has an air outlet and an air inlet at its left and right ends, respectively. The primary filter has an inner filter tube connected to the air outlet inside. An outer filter tube is sleeved on the outside of the inner filter tube. The outer filter tube is fixedly connected to the inner wall of the primary filter by a fixing block. The primary filter, the outer filter tube, and the inner filter tube are all filled with activated carbon air absorbent.

[0008] Preferably, the getter compartment adopts a layered filling structure, a partition plate is installed at the center of the inside of the getter compartment, a through groove is opened at the center of the partition plate, and metal getter and activated carbon getter are respectively arranged inside the getter compartments on the left and right sides of the partition plate.

[0009] Preferably, the cold trap has a double-layer nested structure, with an inner cavity inside the cold trap, two rotating shafts symmetrically installed inside the inner cavity, and spiral fins on the surface of the rotating shafts. A vacuum outer cavity is provided outside the inner cavity of the cold trap.

[0010] Preferably, the cold trap is equipped with a multi-threshold pressure sensor, the detection threshold of which corresponds to the pre-discharge, during-discharge, and inter-discharge stages of the plasma. The cold trap is equipped with an electric throttle valve at its inlet, and the central control system adjusts the opening of the electric throttle valve according to the sensor signal to maintain the target vacuum range.

[0011] Preferably, both the main pump and the auxiliary pump are connected to an external water-cooling device via pipelines.

[0012] Preferably, the vacuum chamber, main pump, auxiliary pump, preliminary filter, getter chamber, cold trap, and refrigerator are all provided with radiation protection layers.

[0013] Preferably, the exhaust gas filter is filled with activated carbon, and the exhaust gas filter is provided with a stainless steel protective layer on the outside.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. This cryogenic vacuum system, adapted for nuclear fusion tokamak or stellarator, constructs a closed loop through plasma state sensors and control systems, linking various components to achieve dynamic adaptive operation of pre-discharge pumping, ultra-high vacuum maintenance during discharge, and discharge gap maintenance. It completely solves the pain point of decoupling between traditional systems and plasma operation. All components work together to ensure the ultra-high vacuum environment, greatly reducing the interference of impurity gases on plasma confinement, and significantly improving the stability and success rate of nuclear fusion experiments.

[0016] 2. This cryogenic vacuum system, adapted for nuclear fusion tokamak or stellarator, achieves full-link interception and adsorption of impurities from large particles to trace amounts of active gases through a multi-level purification design including a preliminary filter, getter chamber, and cold trap. The purification efficiency is improved compared to traditional single purification structures, effectively ensuring the purity of the vacuum environment and providing key support for stable plasma confinement.

[0017] 3. This cryogenic vacuum system, adapted to nuclear fusion tokamak or stellarator, significantly improves the system's adaptability to extreme radiation and high-temperature conditions of nuclear fusion through a comprehensive radiation protection layer design and water-cooled configuration of main and auxiliary pumps. It avoids component aging or overheating failures and ensures the system's ability to operate continuously for long periods.

[0018] 4. This cryogenic vacuum system, adapted for nuclear fusion tokamak or stellarator, is fully automated and controlled by the control system. No manual intervention is required for operation switching and maintenance at each stage, reducing operational complexity and human error. At the same time, it reduces the frequency of downtime maintenance, significantly improves experimental efficiency and reduces operation and maintenance costs. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 is a schematic diagram of the first bellows structure of the present invention;

[0021] Figure 3 is a schematic diagram of the internal structure of the preliminary filter of the present invention;

[0022] Figure 4 is a schematic diagram of the internal structure of the getter chamber of the present invention;

[0023] Figure 5 is a schematic diagram of the internal structure of the cold trap of the present invention.

[0024] In the diagram: 1. Vacuum chamber; 2. Sealing interface; 3. First bellows; 4. Preliminary filter; 5. Getter chamber; 6. Auxiliary pump; 7. Shut-off valve; 8. Cold trap; 9. Refrigeration unit; 10. Main pump; 11. Exhaust gas filter; 12. Second bellows; 13. Threaded groove; 14. Air inlet; 15. Inner filter tube; 16. Outer filter tube; 17. Air outlet; 18. Fixing block; 19. Spiral fins; 20. Partition plate; 21. Inner cavity; 22. Outer cavity; 23. Rotating shaft. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] As shown in Figures 1 to 5, this embodiment is adapted to an ultra-low temperature vacuum system for a tokamak or stellarator used in nuclear fusion. It includes a vacuum chamber 1 with a plasma state sensor embedded in its inner wall. Vacuum chamber 1 serves as the nuclear fusion reaction site. The plasma state sensor on the inner wall collects discharge stage, density, and temperature parameters in real time and transmits them to the central control system. A sealing interface 2 is provided at the outer end of vacuum chamber 1. The sealing interface 2 ensures an ultra-high vacuum seal between the chamber and the pipelines. The sealing interface 2 is made of radiation-resistant material. A preliminary filter 4 is installed at the outer end of the sealing interface 2. A getter chamber 5 is installed at the outer end of the preliminary filter 4. The preliminary filter 4 intercepts large particulate impurities and some reactive gases. The getter chamber 5 deeply adsorbs H₂. 2. For reactive impurities such as CO, an auxiliary pump 6 is installed at the outer end of the getter chamber 5, and a shut-off valve 7 is installed at the outer end of the auxiliary pump 6. The auxiliary pump 6 is responsible for pre-evacuating to a preliminary vacuum before discharge and extracting regenerated impurities during the discharge gap. The shut-off valve 7 controls the gas path opening and closing. A cold trap 8 is installed at the outer end of the shut-off valve 7. A refrigerator 9 is connected to the side wall of the cold trap 8 through a pipe. A main pump 10 is installed at the outer end of the cold trap 8, and an exhaust gas filter 11 is installed at the outer end of the main pump 10. The cold trap 8, together with the refrigerator 9, achieves low-temperature impurity capture. The main pump 10 performs deep evacuation to maintain an ultra-high vacuum, and the exhaust gas filter 11 completes the final exhaust gas purification. The main pump 10, auxiliary pump 6, cold trap 8, refrigerator 9, shut-off valve 7, and plasma state sensor are all electrically connected to the central control system. All core components are uniformly controlled by the control system, and its operation process is deeply adapted to the plasma pulse cycle: Before discharge, the control system links the auxiliary pump 6 and shut-off valve 7 to start pre-evacuation, and the preliminary filter 4 works synchronously; during discharge, the control system regulates the cold trap 8 and the main pump 10 to maintain the vacuum. to Ultra-high vacuum; discharge gap, complete the control of component regeneration, thereby breaking the pain point of decoupling between traditional system and plasma operation, improving the stability and purity of vacuum environment, adapting to the needs of long-term continuous experiment, attention should be paid to the sealing performance of each connection to avoid leakage affecting the vacuum level, while ensuring the coordinated response efficiency of the control system and each component to match the dynamic operation requirements of plasma.

[0028] Specifically, the outer end of the sealing interface 2 is threadedly connected to the first bellows 3 via the threaded groove 13. The outer end of the first bellows 3 is sealed to the primary filter 4 via a flange. The outer end of the getter chamber 5 is equipped with a second bellows 12, and the outer end of the second bellows 12 is connected to the auxiliary pump 6. The threaded connection facilitates disassembly and maintenance, and the flange structure ensures ultra-high vacuum sealing performance. The first bellows 3 can compensate for the thermal expansion displacement of the vacuum chamber 1 and the filter due to temperature changes, avoiding pipeline stress fracture or sealing failure. This structure not only strengthens the vacuum sealing performance of the connection parts, but also improves the system's adaptability to the extreme temperature change environment of nuclear fusion, ensuring the continuity and reliability of the gas passage during long-term operation.

[0029] Furthermore, the primary filter 4 is provided with an outlet 17 and an inlet 14 at its left and right ends, respectively. The primary filter 4 is provided with an inner filter tube 15 connected to the outlet 17. An outer filter tube 16 is sleeved on the outside of the inner filter tube 15. The outer filter tube 16 is fixedly connected to the inner wall of the primary filter 4 by a fixing block 18. The primary filter 4, the outer filter tube 16 and the inner filter tube 15 are all filled with activated carbon getter. The gas discharged from the vacuum chamber 1 will enter through the inlet 14, pass between the outer filter tube 16 and the primary filter 4, then pass between the outer filter tube 16 and the inner filter tube 15, and finally enter the interior of the inner filter tube 15, forming a multi-stage reciprocating cycle. This fully contacts the internal activated carbon and can effectively intercept impurities discharged from the vacuum chamber 1, preventing them from entering subsequent auxiliary pumps 6, cold traps 8 and other components and causing pollution or malfunctions, thus laying the foundation for the subsequent construction of ultra-high vacuum.

[0030] Furthermore, the getter chamber 5 adopts a layered filling structure. A partition plate 20 is installed in the center of the getter chamber 5, and a through groove is opened in the center of the partition plate 20. Activated carbon getter and metal getter are respectively placed in the getter chamber 5 on the left and right sides of the partition plate 20. After the gas enters through the gas inlet, the main active gas is first adsorbed by the metal getter, and then the gas flows through the through groove to the activated carbon getter to adsorb residual trace impurities. The layered design allows different getters to perform their respective functions, improving the overall adsorption efficiency and adsorption capacity.

[0031] Furthermore, the cold trap 8 has a double-layer nested structure. The cold trap 8 has an inner cavity 21 inside, and two rotating shafts 23 are symmetrically installed inside the inner cavity 21. The surface of the rotating shafts 23 is provided with spiral fins 19. The outer vacuum cavity 22 is provided outside the inner cavity 21 of the cold trap 8. The cold trap 8 has a built-in driving device. The two driving devices drive the two rotating shafts 23 to rotate. The rotating shafts 23 drive the spiral fins 19 to rotate. In the low temperature environment, the impurities inside the gas will liquefy or solidify and then be adsorbed by the spiral fins. At the same time, the outer vacuum cavity 22 can isolate the transmission of temperature to a certain extent.

[0032] Furthermore, the cold trap 8 is equipped with a multi-threshold pressure sensor. The detection threshold of the multi-threshold pressure sensor corresponds to the pre-discharge, during-discharge, and inter-discharge stages of the plasma. The air inlet 14 of the cold trap 8 is equipped with an electric throttle valve. The central control system adjusts the opening of the electric throttle valve according to the sensor signal to maintain the target vacuum range. Before discharge, the opening is increased to ensure rapid pre-pumping. During discharge, the opening is decreased to maintain ultra-high vacuum stability. During the inter-discharge stage, the opening is appropriately widened to adapt to maintenance needs. This design achieves precise layered control of vacuum, avoiding the shortcomings of a single control mode that cannot adapt to the needs of different stages, effectively reducing vacuum fluctuations and improving plasma confinement stability.

[0033] Furthermore, both the main pump 10 and the auxiliary pump 6 are connected to an external water-cooling device through pipelines. During system operation, the water-cooling device continuously provides cooling medium to the pump body, carrying away the large amount of heat generated by the pump body during operation. This cooling design can effectively control the pump body temperature and avoid pump performance degradation, shortened lifespan, or shutdown due to high temperature.

[0034] Furthermore, the vacuum chamber 1, main pump 10, auxiliary pump 6, preliminary filter 4, getter chamber 5, cold trap 8, and refrigerator 9 are all equipped with radiation shielding layers. In the nuclear fusion environment, there are a large number of high-energy particles. The radiation shielding layers can effectively shield the bombardment of these high-energy particles and prevent the components from aging, degrading in performance, or being damaged.

[0035] Furthermore, the exhaust gas filter 11 is filled with activated carbon, and the exterior of the exhaust gas filter 11 is equipped with a stainless steel protective layer. After the gas discharged from the main pump 10 enters the filter, the activated carbon can adsorb residual impurities and fine particles, thereby purifying the exhaust gas. The stainless steel protective layer can resist external environmental corrosion and radiation, protecting the internal structure of the filter. This design ensures that the exhaust gas meets environmental protection standards and avoids environmental pollution.

[0036] The usage method of this embodiment is as follows: Before use, check the connection and sealing of components such as vacuum chamber 1, preliminary filter 4, and getter chamber 5, and confirm that the radiation protection layer is intact. Ensure that the water-cooling equipment and refrigerator 9 connected to the main pump 10 and auxiliary pump 6 are in a ready state. Start the central control system and initialize the parameters, set the vacuum threshold for each stage of plasma operation, and the plasma state sensor starts synchronously and collects parameters in real time. In the pre-discharge stage, the control system opens the shut-off valve 7 and auxiliary pump 6 in conjunction to pre-evacuate the system, and the preliminary filter 4 simultaneously performs impurity adsorption and purification. After the vacuum level reaches the standard, the discharge stage begins. The control system starts the refrigerator 9 to cool the cold trap 8, starts the main pump 10 for deep evacuation, and adjusts the opening of the electric throttle valve of the cold trap 8 according to the sensor signal. The getter chamber 5 and the cold trap 8 work together to complete deep purification. In the discharge gap stage, the control system automatically triggers maintenance actions such as cold trap 8 regeneration, and the auxiliary pump 6 simultaneously extracts desorbed impurities. During operation, the operating status of each component and vacuum level data are monitored in real time. After the experiment, first turn off the main pump 10 and refrigerator 9, then close the shut-off valve 7, then stop the auxiliary pump 6, and finally turn off the control system.

[0037] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cryogenic vacuum system adapted for nuclear fusion tokamak or stellarator, comprising a vacuum chamber (1) with plasma state sensors embedded in its inner wall, characterized in that: The vacuum chamber (1) is provided with a sealing interface (2) at its outer end. A preliminary filter (4) is installed at the outer end of the sealing interface (2). A getter chamber (5) is installed at the outer end of the preliminary filter (4). An auxiliary pump (6) is installed at the outer end of the getter chamber (5). A shut-off valve (7) is installed at the outer end of the auxiliary pump (6). A cold trap (8) is installed at the outer end of the shut-off valve (7). A refrigerator (9) is connected to the side wall of the cold trap (8) through a pipe. A main pump (10) is installed at the outer end of the cold trap (8). A tail gas filter (11) is installed at the outer end of the main pump (10). The main pump (10), auxiliary pump (6), cold trap (8), refrigerator (9), shut-off valve (7), and plasma state sensor are all electrically connected to the central control system.

2. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion as described in claim 1, characterized in that: The outer end of the sealing interface (2) is threadedly connected to the first bellows (3) through the threaded groove (13). The outer end of the first bellows (3) is sealed to the primary filter (4) through the flange. The outer end of the getter chamber (5) is equipped with a second bellows (12). The outer end of the second bellows (12) is connected to the auxiliary pump (6).

3. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion as described in claim 1, characterized in that: The primary filter (4) has an air outlet (17) and an air inlet (14) at its left and right ends, respectively. The primary filter (4) has an inner filter tube (15) connected to the air outlet (17) inside. An outer filter tube (16) is sleeved on the outside of the inner filter tube (15). The outer filter tube (16) is fixedly connected to the inner wall of the primary filter (4) by a fixing block (18). The primary filter (4), the outer filter tube (16) and the inner filter tube (15) are all filled with activated carbon air absorbent.

4. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion as described in claim 1, characterized in that: The getter chamber (5) adopts a layered filling structure. A partition plate (20) is installed in the center of the inside of the getter chamber (5). A through groove is opened in the center of the partition plate (20). Metal getter and activated carbon getter are respectively arranged in the inside of the getter chamber (5) on the left and right sides of the partition plate (20).

5. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion as described in claim 1, characterized in that: The cold trap (8) has a double-layer nested structure. An inner cavity (21) is provided inside the cold trap (8). Two rotating shafts (23) are symmetrically installed inside the inner cavity (21). The surface of the rotating shafts (23) is provided with spiral fins (19). A vacuum outer cavity (22) is provided outside the inner cavity (21) inside the cold trap (8).

6. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion according to claim 1, characterized in that: The cold trap (8) is equipped with a multi-threshold pressure sensor. The detection threshold of the multi-threshold pressure sensor corresponds to the plasma discharge pre-discharge, discharge during discharge, and discharge gap stages. The air inlet (14) of the cold trap (8) is equipped with an electric throttle valve. The central control system adjusts the opening of the electric throttle valve according to the sensor signal to maintain the target vacuum range.

7. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion according to claim 1, characterized in that: Both the main pump (10) and the auxiliary pump (6) are connected to an external water-cooling device via pipelines.

8. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion according to claim 1, characterized in that: The vacuum chamber (1), main pump (10), auxiliary pump (6), preliminary filter (4), getter chamber (5), cold trap (8), and refrigerator (9) are all equipped with radiation protection layers.

9. The cryogenic vacuum system for a tokamak or stellarator adapted for nuclear fusion according to claim 1, characterized in that: The exhaust gas filter (11) is filled with activated carbon, and the exhaust gas filter (11) is provided with a stainless steel protective layer on the outside.

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