Discharge cleaning device and method for linear field antiform fusion device

Abstract

The invention provides a discharge cleaning device and method for a linear field antiform fusion device, and the device is characterized in that a glow electrode is arranged in a first end chamber connected with one end of a non-metal chamber as a positive electrode, and an insulating mounting table and a fixed frame are arranged below the first end chamber, so that the first end chamber is in a suspended state and is insulated from the ground. A second end chamber connected with the other end of the non-metal vacuum chamber is grounded to serve as a negative electrode, two sets of power supply systems of a first power supply and a second power supply are adopted to supply power in stages according to design, an electric field which is uniformly distributed in the axial direction is established in the non-metal cylindrical chamber, and plasmas which are uniformly distributed and high in fullness are excited and generated; no cleaning dead angle exists on the inner wall; stable discharge and uniform plasma enable ions to be effectively accelerated and guided to the whole cavity wall, so that the cleaning effect is maximized; according to the method, low maintaining voltage and stable discharging current are achieved, the current density is optimized, local overheating or arc damage is avoided, and system operation is safer and more energy-saving.

Description

Technical Field

[0001] This invention relates to the field of cleaning technology for the inner walls of fusion devices, specifically to a discharge cleaning device and method for linear field inversion fusion devices. It is particularly suitable for FRC fusion devices employing large non-metallic vacuum chambers, enabling efficient and uniform glow discharge cleaning of the inner walls of the vacuum chamber, reducing impurity content and gas load within the chamber, and providing a clean vacuum environment for fusion plasma experiments. Background Technology

[0002] DC glow discharge cleaning is commonly used for cleaning the inner walls of fusion devices. It is an effective means of reducing impurities and obtaining a clean vacuum. Ions generated by glow discharge bombard the inner wall of the vacuum chamber under the acceleration of the electric field, similar to "ion sputtering," stripping off impurities (such as carbon, oxygen, and metal atoms) and adsorbed gas molecules (mainly water vapor, carbon monoxide, and nitrogen) attached to the surface. This significantly reduces the impurity content and gas load in the vacuum chamber, laying the foundation for obtaining high-performance, high-purity fusion plasma. Clean walls reduce radiative energy loss and prevent premature cooling of the plasma.

[0003] Traditional fusion devices or large vacuum chambers are typically constructed from a continuous, monolithically conductive metallic material. Conventional implementations place two electrodes within the chamber—one positive and one negative—or both positive, with the chamber itself grounded as the negative electrode. In this configuration, the discharge current is uniformly conducted through the conductive chamber walls, creating a stable spatial electric field that excites a uniform and continuous glow discharge plasma throughout the chamber, effectively cleaning the inner walls. However, as fusion research advances towards compactness and high Beta values, designs employing large non-metallic (e.g., quartz tubes or ceramics) vacuum chambers, exemplified by linear field inversion (FRC) fusion devices, are increasingly common. While these structures offer physical advantages, they also expose fundamental technical shortcomings in traditional glow discharge methods. 1. Conductive circuit breakage: The non-metallic cavity itself is insulating and cannot serve as a current conduction medium. The grounding circuit that relies on the cavity's conductivity in traditional methods completely fails here, causing the discharge circuit to fail to form a closed loop.

[0004] 2. Distorted Electric Field Distribution and Uneven Discharge: Because the cavity is non-conductive, relying solely on isolated electrodes placed inside a non-metallic cavity with an inner diameter and length of several meters and a volume of several cubic meters will result in a severely distorted electric field, making it difficult to penetrate and uniformly cover the entire large space. This leads to a limited discharge area and uneven plasma density, making it impossible to achieve effective cleaning of the entire cavity wall.

[0005] 3: Difficult to initiate and maintain discharge: In a large insulating container, the gas breakdown voltage is high, and due to the lack of effective guidance and stable current path, it is extremely difficult to maintain the stability and continuity of the discharge even if it is briefly initiated, and it is easy to extinguish or change into a local arc.

[0006] 4: Ion guidance failure: The physical basis of glow discharge cleaning is that ions are accelerated to hit the wall under the action of an electric field. In a non-metal chamber, the distorted and weak electric field cannot provide effective and directional guidance for ions, resulting in a sharp decline in cleaning efficiency. SUMMARY

[0007] The purpose of the present application is to provide a linear field-reversed configuration fusion device discharge cleaning device and method, which can solve the problems raised in the background art.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is: A linear field-reversed configuration fusion device discharge cleaning device, comprising a vacuum pumping device, a gas filling device, a first end chamber, a second end chamber, a non-metal chamber, an insulating mounting table, a power supply system, a fixing frame and a control system; A discharge electrode is arranged in the first end chamber, and the first end chamber and the second end chamber are both mounted on the fixing frame through the insulating mounting table, and the non-metal chamber is located between the first end chamber and the second end chamber, and the first end chamber and the second end chamber are both sealingly connected with two ends of the non-metal chamber; The vacuum pumping device is mounted on the first end chamber and used to change the air pressure in the non-metal chamber; The gas filling device is mounted on the second end chamber and used to fill gas into the non-metal chamber; The vacuum pumping device and the gas filling device are arranged opposite to each other at two ends of the non-metal chamber, so as to dynamically balance the vacuum pressure in the chamber, and uniform vacuum pressure gradient distribution can be realized, which is more conducive to generating uniform plasma; The positive electrode of the power supply system is connected with the discharge electrode, and the negative electrode of the power supply system is connected with the second end chamber and grounded; The control system is electrically connected with the vacuum pumping device, the gas filling device and the power supply system respectively.

[0009] Further, the vacuum pumping device comprises a dry pump Roots pump group and a molecular pump group, and the dry pump Roots pump group and the molecular pump group are both sealingly connected with the first end chamber.

[0010] Further, the vacuum pumping device further comprises a vacuum measuring device, and the vacuum measuring device is sealingly connected with the second end chamber.

[0011] Further, the power supply system comprises a first power supply and a second power supply, and the first power supply and the second power supply are connected in parallel.

[0012] Further, the first power supply works in a constant voltage mode, and is set to have an output voltage of 3000V, an output current of less than or equal to 0.1A, an output voltage adjustable, and a current limited.

[0013] Further, the second power supply works in a constant current mode, and is set to have an output current of 5A, an output voltage of less than or equal to 1000V, an output current adjustable, and a voltage limited.

[0014] Further, the insulation level of the insulation mounting table satisfies that when the direct current voltage is 2500V, the insulation resistance is greater than or equal to 500MΩ.

[0015] Further, the gas analysis system is connected with the first end chamber and electrically connected with the control system.

[0016] A linear field reversed configuration fusion device discharge cleaning method comprises the following steps: S1. A dry pump Roots pump set of a vacuum pumping device is started to perform vacuum pumping work on a nonmetallic chamber, when the internal vacuum degree of the nonmetallic chamber is less than or equal to 10pa, the dry pump Roots pump set is closed, and a molecular pump set of the vacuum pumping device is started to perform forced pumping to make the internal vacuum degree of the nonmetallic chamber reach 10 -3 Pa~10 -4 Pa order of magnitude; S2. A gas charging device is started to inject hydrogen / argon mixed gas into the nonmetallic chamber, the pressure in the nonmetallic chamber is maintained at 5~10pa, and a first power supply is simultaneously started to have an output voltage raised to a gas breakdown voltage; S3. When the injected mixed gas is broken down, the gas charging parameters are adjusted, a second power supply is started, the output power of the second power supply is simultaneously increased, and the output power of the first power supply is reduced, when the output voltage of the second power supply is raised to 1000V and the working voltage of the first power supply is lower than 1000V, the first power supply is closed, and stable and continuous glow can be realized; S4. After the gas analysis system feeds back the residual gas composition and content in the vacuum chamber, the control system analyzes and determines to send a stop command, and sequentially stops according to the operation procedures.

[0017] The present application has at least the following advantages or beneficial effects: This invention provides a discharge cleaning device for a linear field-reverse fusion device. By placing a glow discharge electrode as the positive electrode in a first end chamber connected to one end of a non-metallic chamber, and installing an insulating mounting platform and fixing frame below the first end chamber, the first end chamber is suspended and insulated from the ground. A second end chamber connected to the other end of the non-metallic vacuum chamber is grounded as the negative electrode, completely solving the loop problem under the non-metallic chamber and making continuous and stable glow discharge possible within an insulated space of several cubic meters. Two power supply systems, a first power supply and a second power supply, are used to provide power in stages according to the design. A uniformly distributed electric field is established along the axial direction within the non-metallic cylindrical chamber, exciting and generating a uniformly distributed plasma with high filling density, ensuring no cleaning dead zones on the inner wall. Stable discharge and uniform plasma effectively accelerate and guide ions to the entire cavity wall, maximizing the cleaning effect. Furthermore, this method achieves a lower holding voltage and a stable discharge current, optimizes the current density, avoids local overheating or arc damage, and makes the system safer and more energy-efficient. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the structure of a discharge cleaning device for a linear field inversion fusion device provided by the present invention; Figure 2 The flowchart illustrates a discharge cleaning method for a linear field inverse fusion device provided by this invention.

[0020] Icons: 1. Fixture; 2. First end chamber; 21. Discharge electrode; 3. Second end chamber; 4. Vacuum pumping device; 41. Dry pump Roots pump assembly; 42. Molecular pump assembly; 43. Vacuum measuring device; 5. Gas filling device; 6. Non-metallic chamber; 7. Power supply system; 71. First power supply; 72. Second power supply; 8. Control system; 9. Gas analysis system. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Please refer toFigure 1 As shown, a linear field inversion position fusion device discharge cleaning device, comprising a fixed frame 1, a first end chamber 2, a second end chamber 3, a vacuum pumping device 4, a gas filling device 5, a non-metal chamber 6, an insulating mounting table, a power supply system 7 and a control system 8.

[0023] The fixed frame 1 is arranged at the bottom of the entire cleaning device, and is used to fix and support the above-mentioned device components. The top surface of the two ends of the fixed frame 1 is a plane, and is used to mount the insulating mounting table. The middle part of the fixed frame is a convex placement table, which is used to temporarily place the non-metal chamber 6 when the non-metal chamber 6 is mounted.

[0024] The insulating mounting table is provided with two, which are fixedly mounted at the two ends of the fixed frame by bolts, and are respectively used to fix the first end chamber 2 and the second end chamber 3. The height and shape of the insulating mounting table are not limited, as long as the coaxiality of the first end chamber 2, the second end chamber 3 and the non-metal chamber 6 can be ensured after the first end chamber 2 and the second end chamber 3 are mounted on the insulating mounting table. The insulating mounting table is made of insulating material, and the insulation level should meet the requirement that the insulation resistance is greater than or equal to 500MΩ when the direct current voltage is 2500V.

[0025] The non-metal chamber 6 is located between the first end chamber 2 and the second end chamber 3, and the first end chamber 2 and the second end chamber 3 are respectively sealedly connected with the two ends of the non-metal chamber 6.

[0026] The first end chamber 2 is in a cylindrical structure. One end of the first end chamber 2 is provided with a discharge electrode 21, and the one end of the discharge electrode extends into the interior of the first end chamber 2 as a positive electrode. It should be noted that the outer periphery of the discharge electrode 21 needs to be sleeved or coated with an insulating material, which is connected with the first end chamber 2 to realize insulation. The other end of the first end chamber 2 is provided with a flange or a connecting pipe, which is used to be sealedly connected with one end of the non-metal chamber 6. A connecting port for mounting the vacuum pumping device 4 is formed on the peripheral wall of the first end chamber 2. The connecting port is in communication with the interior space of the non-metal chamber 6 through the interior space of the first end chamber 2, the flange or the connecting pipe.

[0027] The vacuum pumping device 4 includes a dry pump Roots pump group 41 and a molecular pump group 42, and the dry pump Roots pump group 41 and the molecular pump group 42 are both sealedly connected with the connecting port on the side wall of the first end chamber 2. The vacuum pumping device 4 is used to pump out the gas in the non-metal chamber 6 to provide a vacuum environment for discharge cleaning. In the embodiment, the vacuum degree in the interior of the non-metal chamber 6 needs to reach the order of magnitude of 10 -3 Pa~10 -4 Pa. In the embodiment, the dry pump Roots pump group 41 and the molecular pump group 42 are provided with electromagnetic valves. If the dry pump Roots pump group 41 and the molecular pump group 42 used do not have electromagnetic valves, electromagnetic valves need to be installed at the gas pumping end of the dry pump Roots pump group 41 and the molecular pump group 42, and then connected with the first end chamber 2.

[0028] The vacuum pumping device 4 further comprises a vacuum measuring device 43, which is a conventional vacuum gauge. The vacuum measuring device 43 is in sealed connection with the second end chamber 3, and is used to measure the air pressure value in the non-metal chamber 6.

[0029] The second end chamber 3 is coaxially arranged with the first end chamber 2, and is in sealed connection with the end of the non-metal chamber 6. A plurality of connecting ports are arranged on the peripheral wall of the second end chamber 3, and the gas charging device 5 and the vacuum measuring device 43 are both mounted on the second end chamber 3 through the connecting ports, and are in communication with the internal space of the non-metal chamber 6 through the connecting ports.

[0030] The gas charging device 5 is a conventional gas storage tank, and stores the hydrogen / argon mixed gas required for the discharge cleaning. The tank opening is connected with the connecting port on the second end chamber 3 through a pipeline, and the gas is injected into the non-metal chamber 6. An electromagnetic valve and / or a manual valve are arranged on the pipeline to open and close the pipeline.

[0031] The power supply system 7 comprises a first power supply 71 and a second power supply 72, which are connected in parallel. The positive poles of the first power supply 71 and the second power supply 72 are electrically connected with the discharge electrode 21, and the negative poles of the first power supply 71 and the second power supply 72 are electrically connected with the second end chamber 3 and grounded. The first power supply 71 works in a constant voltage mode, and the output voltage is set to 3000V, the output current is ≤0.1A, the output voltage is adjustable, and the current is limited. The second power supply 72 works in a constant current mode, and the output current is set to 5A, the output voltage is ≤1000V, the output current is adjustable, and the voltage is limited.

[0032] The control system 8 is electrically connected with the vacuum pumping device 4, the gas charging device 5 and the power supply system 7, and is used to control the operation of the above-mentioned devices. The control system 8 comprises a PLC controller, a primary power distribution circuit and a secondary relay circuit. The PLC controller serves as the master control, automatically coordinates the switching logic control of each part, monitors the working state of each part in real time, and performs emergency treatment of the overall system in abnormal state. The primary power distribution circuit is responsible for providing the working power supply of each part. The secondary relay circuit assists the PLC to control and perform safety protection actions on each device. This part is a conventional technology, and will not be described in detail.

[0033] Preferably, the cleaning device further comprises a gas analysis system 9, which is a conventional residual gas analyzer. The gas analysis system 9 is connected with the first end chamber, and is electrically connected with the control system 8. The gas analysis system 9 is used to analyze the gas composition and content in the non-metal chamber 6, and the control system 8 compares the preset value according to the analysis result, so as to dynamically adjust the parameters of the gas charging device, realize stable glow discharge cleaning operation, and stop each subsystem according to the control logic of the control system 8 in sequence until the discharge cleaning instruction is received.

[0034] The application further provides a linear field inversion position fusion device discharge cleaning method, comprising the following steps. S1. Check the connection state of each component of the device, and confirm that each connection of the cleaning device is in a sealed state without leakage.

[0035] Each system of the device is turned on for inspection, and the electromagnetic valve of the vacuum pumping device is opened, and the vacuum measuring device is started to monitor the vacuum degree in real time; the measurement data of the vacuum measuring device is transmitted to the control system in real time; the vacuum pumping device adjusts the pump group configuration according to the design: first, the dry pump Roots pump group is started to pump to ≤10 Pa, the dry pump Roots pump group is closed, the molecular pump group of the vacuum pumping device is started to pump to make the internal vacuum degree of the non-metallic chamber reach 10 -3 Pa~10 -4 Pa order of magnitude; S2. Set the parameters of the gas filling device, start the gas filling device to inject hydrogen / argon mixed gas into the non-metallic chamber, and the molecular pump group is always in an open state, the pumping and the gas filling are in dynamic balance, the vacuum pressure is maintained at 5~10 Pa, the first power supply is started at the same time, and the voltage is gradually increased to 3000 V to realize glow discharge breakdown; S3. Adjust the gas filling parameters of the gas filling device to maintain the vacuum pressure in the vacuum chamber at 5×10 -1 ~5×10 -2 Pa, start the second power supply, synchronously increase the output power of the second power supply, and reduce the output power of the first power supply, when the output voltage of the second power supply is increased to 1000 V and the working voltage of the first power supply is lower than 1000 V, the first power supply is closed, and stable and continuous glow can be realized, in the process of continuous glow, real-time gas pressure feedback, flow control, temperature feedback, parameter adjustment, and stable long-time glow discharge are realized.

[0036] S4. During the continuous operation of the cleaning device, the gas analysis system measures the gas composition and content in the vacuum chamber in real time, confirms the cleaning effect and feeds back the control system, and the control system controls each subsystem to monitor the gas pressure in the vacuum chamber and the running state of the power supply system in real time, dynamically adjusts the gas injection system parameters, realizes stable glow discharge cleaning operation, and until the gas analysis system detects that the gas composition reaches the preset value, the control system controls each subsystem to stop in turn.

[0037] The above is only a preferred embodiment of the application and is not used to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A linear field-reversed configuration fusion device discharge cleaning apparatus, characterized by, The device comprises a vacuumizing device, a gas filling device, a first end chamber, a second end chamber, a non-metal chamber, an insulating mounting table, a power supply system, a fixing frame and a control system. The first end chamber is provided with a discharge electrode, and the first end chamber and the second end chamber are both mounted on the fixing frame through the insulating mounting table, with the non-metal chamber being located between the first end chamber and the second end chamber and being in sealed connection with both ends of the non-metal chamber. The vacuumizing device is mounted on the first end chamber and used for changing the air pressure in the non-metal chamber and monitoring the air pressure. The gas filling device is mounted on the second end chamber and used for filling gas into the non-metal chamber. The positive pole of the power supply system is connected with the discharge electrode, and the negative pole of the power supply system is connected with the second end chamber and grounded. The control system is electrically connected with the vacuumizing device, the gas filling device and the power supply system.

2. The linear field-reversed configuration fusion device discharge cleaning apparatus of claim 1, wherein, The vacuumizing device comprises a dry pump Roots pump group and a molecular pump group, both of which are in sealed connection with the first end chamber.

3. The linear field-reversed configuration fusion device discharge cleaning apparatus of claim 2, wherein, The vacuumizing device further comprises a vacuum measuring device, which is in sealed connection with the second end chamber.

4. The linear field-reversed configuration fusion device discharge cleaning apparatus of claim 1, wherein, The power supply system comprises a first power supply and a second power supply, which are connected in parallel.

5. A linear field-reversed configuration fusion device discharge cleaning apparatus as defined in claim 4, wherein The first power supply works in a constant voltage mode, with a set output voltage of 3000V, an output current of ≤0.1A, an adjustable output voltage and a limited current.

6. A linear field-reversed configuration fusion device discharge cleaning apparatus as defined in claim 4, wherein The second power supply works in a constant current mode, with a set output current of 5A, an output voltage of ≤1000V, an adjustable output current and a limited voltage.

7. The linear field-reversed configuration fusion device discharge cleaning apparatus of claim 1, wherein, The insulating level of the insulating mounting table meets the requirement that the insulating resistance is ≥500MΩ when the direct current voltage is 2500V.

8. The linear field-reversed configuration fusion device discharge cleaning apparatus of claim 1, wherein, The device further comprises a gas analysis system, which is connected with the first end chamber and electrically connected with the control system.

9. A linear field-reversed configuration fusion device discharge cleaning method, comprising: applying a voltage to a first electrode of the device; applying a voltage to a second electrode of the device; and applying a voltage to a third electrode of the device. The device comprises the following steps: S1. Start the dry pump roots pump group of the vacuum pumping device to perform vacuumizing work on the nonmetallic chamber, when the internal vacuum degree of the nonmetallic chamber is less than or equal to 10 Pa, the dry pump roots pump group is closed, and the molecular pump group of the vacuum pumping device is started to perform force vacuumizing so that the internal vacuum degree of the nonmetallic chamber reaches 10 -3 Pa~10 -4 Pa order of magnitude; S2. The gas filling device is started to inject hydrogen / argon mixed gas into the non-metal chamber, so that the pressure in the non-metal chamber is maintained at 5-10pa, the first power supply is started, and the output voltage is raised to the breakdown voltage of the gas; S3. When the injected mixed gas is broken down, the gas filling parameters are adjusted, the second power supply is started, the output power of the second power supply is simultaneously increased, and the output power of the first power supply is reduced. When the output voltage of the second power supply is raised to 1000V and the working voltage of the first power supply is lower than 1000V, the first power supply is turned off, and stable and continuous glow can be realized; S4. After the feedback of the residual gas composition and content in the vacuum chamber by the gas analysis system, the control system analyzes and determines to issue a stop command, and the operation procedures are sequentially stopped.

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