Neutral beam injection device multi-stage isolation high vacuum obtaining system and control method

Abstract

The invention discloses a multi-stage isolation high vacuum obtaining system of a neutral beam injection device and a control method, and relates to the field of nuclear fusion Tokamak vacuum pumping design. The low-temperature pump unit comprises a plug-in low-temperature pump in a neutral beam vacuum chamber, and the plug-in low-temperature pump is used for refrigerating and cooling liquid nitrogen and liquid helium to adsorb gas to realize vacuum pumping; the low-temperature pump preceding-stage air extractor unit comprises a molecular pump unit, a roots pump unit and a mechanical pump unit; an inlet of the molecular pump set is connected with the neutral beam vacuum chamber through a gate valve, and an outlet of the molecular pump set is connected with an inlet of the roots pump set through a forestage valve. An inlet of the roots pump set is connected with the neutral beam vacuum chamber through a preceding stage valve and a pre-pumping valve, and an outlet of the roots pump set is connected with the mechanical pump set through the preceding stage valve. By adopting a multi-stage vacuum shielding technology and a step-by-step start-stop strategy, step-by-step transition from low vacuum to high vacuum and from high vacuum to low vacuum can be efficiently, stably and reliably realized, and an air extractor unit and a vacuum environment are protected from being polluted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nuclear fusion tokamak vacuum pumping design, and particularly relates to a multi-stage isolation high vacuum obtaining system and control method for a neutral beam injection device. BACKGROUND

[0002] A new generation of high parameter controlled nuclear fusion tokamak device is designed to carry out high parameter and high confinement mode discharge experiments, and a neutral beam injection system is required to assist heating of the plasma. The neutral beam injection system needs to ensure ultra-high vacuum conditions (~10 -5 Pa) during operation to ensure that the plasma discharge basic vacuum conditions of the device are reliable and stable, the neutral beam injection heating pulse width is stable and persistent, and the plasma is effectively heated.

[0003] The vacuum pumping system is the basis for the operation of the neutral beam injection system, and its purpose is to reduce the gas pressure of the injection device and the experimental device to the required ultra-high vacuum state to ensure particle transmission and injection effect. However, the commonly used vacuum pumping technology directly uses several vacuum pump groups for vacuum pumping, but there is no mutual cooperation between the several vacuum pump groups, which cannot effectively and stably maintain the required vacuum state, and is easy to cause pollution of the vacuum environment. SUMMARY

[0004] The present application is to solve the problems of the prior art, and aims to provide a multi-stage isolation high vacuum obtaining system and control method for a neutral beam injection device, which uses multi-stage vacuum shielding technology and realizes efficient, stable and reliable step-by-step transition from low vacuum to high vacuum and from high vacuum to low vacuum through a step-by-step start-stop strategy, thereby protecting the vacuum environment and the pumping unit from pollution.

[0005] The present application is realized by the following technical solutions:

[0006] A multi-stage isolation high vacuum obtaining system for a neutral beam injection device, comprising:

[0007] A cryogenic pump unit, which comprises an insert-type cryogenic pump in the neutral beam vacuum chamber for liquid nitrogen, liquid helium refrigeration and adsorption of gas to realize vacuum pumping;

[0008] A low-temperature pump pre-pumping unit, which comprises a molecular pump group, a Roots pump group and a mechanical pump group;

[0009] The inlet of the molecular pump group is connected to the neutral beam vacuum chamber through a plug valve, and the outlet is connected to the inlet of the Roots pump group through a pre-stage valve;

[0010] The inlet of the Roots pump group is connected to the neutral beam vacuum chamber through a pre-stage valve and a pre-pumping valve, and the outlet is connected to the mechanical pump group through a pre-stage valve.

[0011] The application discloses a multi-stage isolation high-vacuum obtaining system and control method for a neutral beam injection device, and adopts a multi-stage vacuum isolation physical shielding technology and a step-by-step start-stop control strategy, so that step-by-step transition from low vacuum to high vacuum and from high vacuum to low vacuum can be realized efficiently, stably and reliably, and the vacuum environment and the air extraction unit are protected from pollution. -3 -5 Pa, and the super-high vacuum obtaining system of the neutral beam injection device mainly based on the insert cryopump is realized through multi-stage isolation.

[0012] ​The application divides the vacuum chamber into independent pumping units by arranging multistage isolation valves such as pre-pumping valve, front-stage valve, plug-in valve, etc. in the vacuum system. When the local vacuum deteriorates due to the shutdown of the cryogenic pump, the adjacent isolation valves are quickly closed to form a local vacuum barrier, preventing the rapid diffusion of gas to pollute other areas or the working state of the regional equipment. By using the multistage vacuum physical shielding design, the gradual transition from low vacuum to high vacuum is efficiently, stably and reliably achieved through the step-by-step start-stop strategy, protecting the pumping unit and the vacuum environment from pollution. When the machine is shut down or the cryogenic machine is down, the gradual transition from ultra-high vacuum to low vacuum is efficiently, stably and reliably achieved through the step-by-step start-stop strategy, which also protects the pumping unit and the vacuum environment from pollution.

[0013] Further optimization, the low-temperature pump unit is also provided with a low-temperature system for inputting liquid nitrogen and liquid helium, and a molecular pump and a mechanical pump are sequentially connected to the multichannel delivery pipeline of the low-temperature system, so as to ensure that the vacuum degree of the low-temperature pipeline is not too high due to heat radiation, thereby reducing the refrigeration and cooling efficiency.

[0014] Further optimization, in order to obtain more accurate vacuum degree data in the vacuum chamber, a plurality of vacuum gauges for measuring the vacuum degree are distributed on the neutral beam vacuum chamber, and a vacuum gauge is connected to each vacuum gauge. This scheme uses multiple measurement of the average value of the vacuum degree, abnormality rejection for reference, improves the monitoring accuracy of the vacuum degree in the vacuum chamber, so as to ensure that the control protection instruction can be issued based on the actual vacuum degree, improves the timeliness and accuracy of the vacuum degree interlock protection in the vacuum chamber, ensures that the vacuum pumping unit works in a suitable operating vacuum environment, and ensures the safety of the beamline experiment environment and the vacuum equipment of the pumping unit.

[0015] Further optimization, as an optimal choice for detecting position, front-positioned vacuum gauges are arranged at the upper and lower positions of the front end of the neutral beam vacuum chamber, and rear-positioned vacuum gauges are arranged at the upper and lower positions of the rear end of the neutral beam vacuum chamber. The front-positioned vacuum gauges are connected to front-positioned vacuum gauges, and the rear-positioned vacuum gauges are connected to rear-positioned vacuum gauges. The front-positioned vacuum gauge and the rear-positioned vacuum gauge are signal-connected to the control unit.

[0016] Further optimization, in order to realize remote control and interlock protection, a control unit and a logic control action unit are further included. The control unit is used for receiving the vacuum degree signals of the vacuum gauges and outputting control signals to the logic control action unit according to the vacuum degree signals. The logic control action unit is used for controlling the operation of the low-temperature pump unit, the Roots pump group and the molecular pump group, and the opening and closing of the pre-pumping valve, the plug-in valve and the front-stage valve.

[0017] In a further optimization, when the cryogenic pump fails and causes local vacuum deterioration, in order to quickly close adjacent isolation valves, form a local vacuum barrier, prevent gas from spreading and contaminating other areas, and perform vacuum interlock protection, the control unit can also determine the magnitude of the vacuum level signal and the preset vacuum level limit, and send a protection signal to the logic control action unit. The logic control action unit can use the protection signal to control the opening and closing of all valves of the upstream pumping unit, as well as the opening and closing of its switch control contactor or relay. In this scheme, a pre-vacuum gauge is used to measure the vacuum level at the front end of the cryogenic pump in the vacuum chamber of the vacuum unit, and outputs a pre-vacuum level signal; a post-vacuum gauge is used to measure the vacuum level at the front end of the cryogenic pump in the vacuum chamber of the vacuum unit, and outputs a post-vacuum level signal; the pre-vacuum gauge converts the signal output by the pre-vacuum gauge into a signal readable by the control unit; thus, the signal measured by the pre-vacuum gauge is input into the control unit for logical judgment and feedback control; the post-vacuum gauge converts the signal output by the post-vacuum gauge into a signal readable by the control unit; thus, the signal measured by the post-vacuum gauge is input into the control unit for logical judgment and feedback control; the control unit performs logical judgment based on the pre-vacuum level signal output by the pre-vacuum gauge and the post-vacuum level signal output by the post-vacuum gauge, and issues corresponding vacuum level adjustment commands; the logic control protection action unit is used to receive the control commands issued by the control unit and execute the vacuum level logic protection action according to the adjustment commands. The cryogenic pump pre-stage pumping unit is used to receive the logic action commands from the logic protection unit to drive the action mechanism to execute the actual protection action. The control unit processes the input pre-vacuum and post-vacuum levels to determine the vacuum operating status within the vacuum chamber, including but not limited to: comparing the pre-vacuum and post-vacuum levels with their corresponding preset vacuum limits; if both the pre-vacuum and post-vacuum levels exceed their respective preset limits, an alarm is issued and protection actions are triggered. The protection actions issued by the control unit include the valve and pump unit switching control contactors or relays for all upstream units of the cryogenic pump. The control unit sends control signals to drive these protection actions to achieve vacuum interlock protection. The protection actions also include relays and operating nodes at the valve and pump unit upstream. The control unit drives the relays to open and close via trigger signals to achieve the switching of valves and pump units.

[0018] It is understandable that by real-time detection of the vacuum level at multiple locations within the vacuum chamber (such as the front and rear ends of the vacuum chamber), and then judging the actual vacuum level within the vacuum chamber based on the real-time vacuum levels at multiple locations, the accuracy of vacuum level monitoring within the vacuum chamber can be improved compared to measuring the vacuum level at a single measurement point. This ensures that the control unit can issue appropriate and correct vacuum interlock protection commands based on accurate vacuum level information.

[0019] In a further optimization, an injection valve is provided on one side of the neutral beam vacuum chamber. This injection valve is used to inject the neutral beam into other devices. Specifically, the injection valve is located at the connection point between the neutral beam vacuum chamber and other devices (such as a plasma chamber), and is used to control the injection of the neutral beam into the plasma. It allows selective interlocking of the activation of related neutral beam injection devices to open or close the neutral beam injection channel, thereby controlling the entry of the neutral beam into the plasma.

[0020] Secondly, the ion source gate valve can be installed near the outlet or connection port on the ion source side of the neutral beam vacuum chamber to control the neutralization and screening of the high-energy ion beam. By controlling the opening and closing state of the gate valve, the start and stop of related ion source equipment can be interlocked, thereby allowing or preventing the generation and entry of the high-energy ion beam. When the gate valve is closed, it provides effective isolation and sealing between the neutral beam vacuum chamber and the ion source vacuum system. This prevents gas leakage and the entry of impurities, thereby maintaining the vacuum partitioning and appropriate vacuum environment of the neutral beam vacuum chamber and the ion source vacuum chamber.

[0021] Further solutions:

[0022] This invention also provides a control method for a multi-stage isolated high vacuum acquisition system using a neutral beam injection device, including a step-by-step start-up control method and a step-by-step stop-up control method after the experiment is completed. The step-by-step start-up control method includes the following steps:

[0023] Start the mechanical pump unit, and open the fore-stage valve and the pre-evacuation valve in sequence. The mechanical pump unit evacuates the neutral beam vacuum chamber through the pre-evacuation pipeline of the Roots pump unit to make the vacuum level reach below 10000Pa, and then gradually decreases it to 1000Pa. This is the first stage of vacuum.

[0024] When the vacuum level reaches 1000Pa, the Roots pump group is started to evacuate the neutral beam vacuum chamber, so that the vacuum level is below 1000Pa, and then gradually reduced to 10Pa. This is the second stage of vacuum.

[0025] When the vacuum level reaches 10 Pa, close the pre-evacuation valve and open the fore-stage valve of the molecular pump assembly. Start the molecular pump assembly and open the gate valve. Use the molecular pump assembly to evacuate the neutral beam vacuum chamber until the vacuum level reaches below 10 Pa, and then gradually reduce it to 10 Pa. -3 Pa level, reaching the third level vacuum;

[0026] When the vacuum degree reaches 10 -3 At Pa levels, the neutral beam vacuum chamber is evacuated by gradually introducing cryogenic liquid nitrogen and liquid helium to lower the temperature and activate an insertion cryogenic pump, achieving a vacuum level of 10. -5 To achieve an ultra-high vacuum state, the Pa level is below.

[0027] Further optimization, the step-by-step stop control method includes the following steps:

[0028] First, the insertion cryogenic pump is stopped by gradually stopping the supply of liquid helium and liquid nitrogen, which releases the gas and reduces the vacuum level. Then, the gas inside the neutral beam vacuum chamber is continuously discharged through the molecular pump group.

[0029] When the vacuum level reaches the 10Pa limit, the limit is triggered to automatically shut down the molecular pump group and the slide valve connecting the molecular pump group to the neutral beam vacuum chamber, open the pre-evacuation valve, and continuously discharge the gas inside the neutral beam vacuum chamber through the Roots pump group. When the molecular pump group stops and the speed drops to 0, the fore-stage valve is closed.

[0030] When the vacuum level reaches 1000Pa, shut down the Roots pump set and continuously discharge the gas inside the neutral beam vacuum chamber through the mechanical pump set until the initial standard is reached. Then, shut down the mechanical pump set, the fore-stage valve, and the pre-evacuation valve.

[0031] Further optimizations include a control unit and a logic control action unit. The control unit is used to issue a protection control strategy based on the vacuum level detected in real time inside the neutral beam vacuum chamber. The protection control strategy includes:

[0032] When the vacuum level inside the neutral beam vacuum chamber exceeds the preset vacuum level limit, the control unit sends a protection control signal to the logic control action unit, causing the logic control action unit to control all valves in the upstream pumping unit to close and all switch control contactors or relays to open.

[0033] Subsequently, the cryogenic system on the cryogenic pump unit was controlled to cool down and the water cooling system on the neutral beam vacuum chamber was controlled to maintain water pressure. Related anomaly repairs were performed to ensure that the vacuum level inside the neutral beam vacuum chamber was less than the preset vacuum level limit. Anomaly diagnosis and repair were performed on the components in the cryogenic pump pre-stage pumping unit.

[0034] After diagnosis and repair, the operation of the cryogenic pump pre-stage air extraction unit can be restored.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] 1. This invention provides a multi-stage isolation high vacuum acquisition system and control method for a neutral beam injection device, employing a multi-stage vacuum shielding design and incorporating multi-stage isolation valves (such as...) within the vacuum system. Figure 1 The vacuum chamber is divided into independent pumping units by components such as the pre-pump valve, fore-stage valve, gate valve, injection valve, and ion source gate valve. When the cryogenic pump fails, causing local vacuum deterioration, adjacent isolation valves are quickly closed to form a local vacuum barrier, preventing gas from spreading and contaminating other areas.

[0037] 2. This invention provides a multi-stage isolation high vacuum acquisition system and control method for a neutral beam injection device. It employs a multi-stage vacuum shielding design, and upon startup to reach an ultra-high vacuum environment, a step-by-step start-stop strategy is used to efficiently, stably, and reliably achieve a gradual transition from low to high vacuum, protecting the pumping unit and vacuum environment from contamination. Conversely, during shutdown or cryogenic failure, the step-by-step start-stop strategy is used to reduce the vacuum environment from ultra-high to low, or even to atmospheric pressure, achieving a efficient, stable, and reliable transition from ultra-high to low vacuum, again protecting the pumping unit and vacuum environment from contamination.

[0038] 3. The present invention provides a multi-stage isolation high vacuum acquisition system and control method for a neutral beam injection device. By using multiple vacuum gauge signals from the neutral beam injection beam injector to participate in the interlocking protection of the cryogenic pump operation, real-time monitoring and feedback control of the vacuum degree can be achieved. This improves the safety and reliability of the vacuum pumping interlocking protection system that revolves around the cryogenic pump as the main component and the upstream pumping unit as the auxiliary component. It can also detect changes in the vacuum degree in a timely and accurate manner, thereby interlocking the operation control of the cryogenic pump and its upstream pumping unit in a timely manner, which helps to improve the overall operational stability of the system.

[0039] 4. This invention provides a multi-stage isolation high vacuum acquisition system and control method for a neutral beam injection device. The participation of multiple vacuum gauge signals can provide vacuum level information for different parts of the neutral beam injection system. When abnormal vacuum levels or faults occur, the source of the problem can be quickly located by analyzing changes in different vacuum gauge signals. This helps to accelerate the fault diagnosis and repair process, and reduce system downtime and system losses. Integrating the cryogenic pump forestage pumping unit into the vacuum protection system and improving the timeliness of the protection action of the cryogenic pump forestage pumping unit through the control system's vacuum threshold interlock protection method improves the timeliness of the protection action of the cryogenic pump forestage pumping unit. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0041] Figure 1 A control diagram of a multi-stage isolation high vacuum acquisition system for a neutral beam injection device provided by the present invention;

[0042] Figure 2 A structural diagram of a multi-stage isolation high vacuum acquisition system for a neutral beam injection device provided by the present invention;

[0043] Figure 3This invention provides a flowchart of the interlocking protection control startup process for a multi-stage isolated high vacuum acquisition system using a neutral beam injection device.

[0044] Figure 4 The present invention provides a flowchart of the interlocking protection control shutdown process for a multi-stage isolated high vacuum acquisition system of a neutral beam injection device.

[0045] The attached diagram shows the markings and corresponding component names:

[0046] 1-Control unit, 2-Logic control action unit, 3-Cryogenic pump pre-stage pumping unit, 4-Injection valve, 6-Pre-vacuum gauge, 7-Post-vacuum gauge, 8-Pre-vacuum gauge, 9-Post-vacuum gauge, 10-Insertion-type cryogenic pump, 11-Neutral beam vacuum chamber. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0048] Example 1: This Example 1 provides a multi-stage isolated high vacuum acquisition system for neutral beam injection devices, such as... Figures 1-2 As shown, it includes:

[0049] The cryogenic pump unit includes an insertion cryogenic pump 10 inside a neutral beam vacuum chamber 11 for cooling and adsorbing gases using liquid nitrogen or liquid helium to achieve vacuum pumping.

[0050] The cryogenic pump fore-stage pumping unit 3 includes a molecular pump group, a Roots pump group and a mechanical pump group.

[0051] The inlet of the molecular pump assembly is connected to the neutral beam vacuum chamber 11 via a gate valve, and the outlet is connected to the inlet of the Roots pump assembly via a pre-stage valve.

[0052] The inlet of the Roots pump unit is connected to the neutral beam vacuum chamber 11 via a pre-vacuum valve and a pre-evacuation valve, and the outlet is connected to the mechanical pump unit via a pre-vacuum valve.

[0053] Compared to existing technologies where multiple vacuum pumps lack coordination, making it difficult to effectively and stably maintain the required vacuum state and easily causing vacuum environment contamination, this invention discloses a multi-stage isolation high vacuum acquisition system and control method for a neutral beam injection device. It employs multi-stage vacuum isolation physical shielding technology and a step-by-step start-stop control strategy to efficiently, stably, and reliably achieve a step-by-step transition from low vacuum to high vacuum and from high vacuum to low vacuum, protecting the pumping unit and vacuum environment from contamination. Specifically, the system includes a cryogenic pump unit and a cryogenic pump pre-pump pumping unit 3, both used to change the vacuum level within the neutral beam vacuum chamber 11. The cryogenic pump pre-pump pumping unit 3 further includes a mechanical pump group, a Roots pump group, and a molecular pump group. During the experiment, a neutral particle beam needs to be injected into the plasma and interact with particles in the plasma. If the vacuum distribution gradient at the injection valve 4, during beam transmission, or within the injector vacuum chamber is insufficient (i.e., large gas molecules or particles exist during beam transmission), they may collide or interact with the neutral particle beam, interfering with the transmission and injection process of the neutral beam, reducing the neutral beam injection energy and efficiency. Therefore, it is necessary to maintain a certain vacuum level in the neutral beam vacuum chamber 11 to avoid malfunctions. The neutral beam vacuum chamber 11 is a square cavity with appropriate geometry and dimensions, providing a reasonable vacuum gradient distribution for the transmission and injection of neutral particle beams, ensuring the transmission and control of the neutral beam. Insertion-type cryogenic pumps 10 are located on both sides of the square cavity, and beam-laying equipment is installed within the cavity. The pre-pump unit of the cryogenic pump is located at the lower end of the square cavity. The inlet of the mechanical pump is connected to the outlet of the Roots pump unit. The inlet of the Roots pump unit is connected to the neutral beam vacuum chamber 11 via a pre-pump valve and a pre-pumping pipeline. When the Roots pump is not running, opening the pre-pump valve allows the mechanical pump unit to extract gas through the channel on the Roots pump unit, i.e., the pre-pumping pipeline. The mechanical pump achieves a first-stage vacuum isolation of 1000Pa to 10000Pa. The Roots pump unit enables a second-stage vacuum isolation of 10 Pa to 1000 Pa. The inlet of the molecular pump unit is isolated via a gate valve and the neutral beam vacuum chamber 11, while the outlet is isolated in sections via a fore-stage valve and the Roots pump unit's extraction port, facilitating gradual pressure increase or decrease. Closing the pre-evacuation valve and opening the gate valve allows for a third-stage vacuum isolation of less than 10 Pa via the molecular pump unit. The insertion cryogenic pump 10 has a pumping speed of megaliters per second. After the cryogenic start / stop of the insertion cryogenic pump 10, the pump 10 is activated. -3 Vacuum below the Pa level up to 10 Pa -5 Ultra-high vacuum below Pa is achieved through multi-stage isolation, thereby realizing an ultra-high vacuum system for a neutral beam injection device mainly composed of an insertion cryogenic pump 10.

[0054] This invention, through the aforementioned scheme, incorporates multi-stage isolation valves in the vacuum system, such as pre-evacuation valves, fore-stage valves, and gate valves, dividing the vacuum chamber into independent evacuation units. When the cryogenic pump fails, causing local vacuum deterioration, adjacent isolation valves are quickly closed, forming a local vacuum barrier to prevent rapid gas diffusion and contamination of other areas or the operational status of equipment in those areas. Employing a multi-stage vacuum physical shielding design, the system achieves a high vacuum environment through a step-by-step start-stop strategy, efficiently, stably, and reliably transitioning from low to high vacuum, protecting the evacuation unit and the vacuum environment from contamination. Conversely, during shutdown or cryogenic failure, the system uses a step-by-step start-stop strategy to descend from the high vacuum environment to a low vacuum environment or even atmospheric pressure, efficiently, stably, and reliably transitioning from high to low vacuum, again protecting the evacuation unit and the vacuum environment from contamination.

[0055] In this embodiment, the cryogenic pump unit is also equipped with a cryogenic system for inputting liquid nitrogen and liquid helium. A molecular pump and a mechanical pump are connected in sequence on the multi-channel delivery pipeline of the cryogenic system to ensure that the vacuum degree of the cryogenic pipeline is not too high due to heat radiation, which would reduce the cooling efficiency.

[0056] In this embodiment, to obtain more accurate vacuum level data within the vacuum chamber, several vacuum gauges for measuring vacuum level are distributed on the neutral beam vacuum chamber 11, each connected to a vacuum meter. This scheme utilizes the average of multiple measured vacuum levels for processing and anomaly removal as a reference, improving the accuracy of vacuum level monitoring within the vacuum chamber. This ensures that control and protection commands are issued based on the actual vacuum level, improving the timeliness and accuracy of vacuum level interlocking protection within the vacuum chamber. It also ensures that the vacuum chamber pumping unit operates in a suitable vacuum environment, guaranteeing the safety of the beamline experimental environment and the vacuum equipment of the pumping unit.

[0057] In this embodiment, as an optimal choice for detection location, a front vacuum gauge 6 is provided at both the upper and lower positions of the front end of the neutral beam vacuum chamber 11, and a rear vacuum gauge 7 is provided at both the upper and lower positions of the rear end of the neutral beam vacuum chamber 11. The front vacuum gauge 6 is connected to a front vacuum meter 8, and the rear vacuum gauge 7 is connected to a rear vacuum meter 9. Both the front vacuum meter 8 and the rear vacuum meter 9 are signal-connected to the control unit 1.

[0058] In this embodiment, to achieve remote control and interlocking protection, a control unit 1 and a logic control action unit 2 are also included. The control unit 1 is used to receive vacuum degree signals from several vacuum gauges and output control signals to the logic control action unit 2 according to the vacuum degree signals. The logic control action unit 2 is used to control the operation of the cryogenic pump unit, the Roots pump unit and the molecular pump unit, as well as the opening and closing of the pre-evacuation valve, the slide gate valve and the fore-stage valve.

[0059] In this embodiment, when the cryogenic pump fails and causes local vacuum deterioration, in order to quickly close the adjacent isolation valves, form a local vacuum barrier, prevent gas from spreading and contaminating other areas, and perform vacuum interlock protection, the control unit 1 can also determine the magnitude of the vacuum level signal and the preset vacuum level limit, and send a protection signal to the logic control action unit 2. The logic control action unit 2 can use the protection signal to control the opening and closing of all valves of the upstream pumping unit, and the opening and closing of its switch control contactor or relay. In this scheme, the pre-vacuum gauge 6 is used to measure the vacuum level at the front end of the cryogenic pump in the vacuum chamber of the vacuum unit and outputs a pre-vacuum level signal; the post-vacuum gauge 7 is used to measure the vacuum level at the front end of the cryogenic pump in the vacuum chamber of the vacuum unit and outputs a post-vacuum level signal; the pre-vacuum gauge 8 converts the signal output by the pre-vacuum gauge 6 into a signal readable by the control unit 1; thus realizing the input of the signal measured by the pre-vacuum gauge 6 into the control unit 1 for logical judgment and feedback control; the post-vacuum gauge 9 converts the signal output by the post-vacuum gauge 7 into a signal readable by the control unit 1; thus realizing the input of the signal measured by the post-vacuum gauge 7 into the control unit 1 for logical judgment and feedback control; the control unit 1 performs logical judgment based on the pre-vacuum level signal output by the pre-vacuum gauge 8 and the post-vacuum level signal output by the post-vacuum gauge 9, and issues corresponding vacuum level adjustment commands; the logic control protection action unit is used to receive the control commands issued by the control unit 1 and execute the vacuum level logic protection action according to the adjustment commands. The cryogenic pump pre-stage pumping unit 3 is used to receive the logic action commands from the logic protection unit to drive the action mechanism to execute the actual protection action. Control unit 1 processes the input pre-vacuum and post-vacuum levels to determine the vacuum operating status within the vacuum chamber, including but not limited to: comparing the pre-vacuum and post-vacuum levels with their corresponding preset vacuum limits; if both the pre-vacuum and post-vacuum levels exceed their respective preset limits, an alarm is issued and a protection action is triggered. The protection action issued by control unit 1 includes the valve and pump unit switching control contactors or relays for all upstream units of the cryogenic pump. Control unit 1 sends control signals to drive the protection action devices to achieve vacuum interlock protection. The protection action devices also include relays and operating nodes at the front end of the valves and pump units. Control unit 1 drives the relays to open and close via trigger signals to achieve the switching of valves and pump units.

[0060] It is understandable that by real-time detection of the vacuum level at multiple locations within the vacuum chamber (such as the front and rear ends of the vacuum chamber), and then judging the actual vacuum level within the vacuum chamber based on the real-time vacuum levels at multiple locations, the accuracy of vacuum level monitoring within the vacuum chamber can be improved compared to measuring the vacuum level at a single vacuum level measurement point. This ensures that the control unit 1 can issue appropriate and correct vacuum interlock protection commands based on accurate vacuum level information.

[0061] In this embodiment, an injection valve 4 is provided on one side of the neutral beam vacuum chamber 11. The injection valve 4 is used to inject a neutral beam into other devices. The injection valve 4 is located at the connection point between the neutral beam vacuum chamber 11 and other devices (such as a plasma chamber), and is used to control the injection of the neutral beam into the plasma. The injection valve 4 controls the injection time and position of the neutral beam; it allows selective interlocking of the activation of related neutral beam injection devices to open or close the neutral beam injection channel, thereby controlling the entry of the neutral beam into the plasma.

[0062] Secondly, the ion source gate valve can be installed near the outlet or connection port on the ion source side of the neutral beam vacuum chamber 11 to control the neutralization and screening of the neutral beam high-energy ion beam. By controlling the opening and closing state of the gate valve, the start and stop of related ion source equipment can be interlocked, thereby allowing or preventing the generation and entry of high-energy ion beams. When the gate valve is closed, it provides effective isolation and sealing between the neutral beam vacuum chamber 11 and the ion source vacuum system. This prevents gas leakage and the entry of impurities, thereby maintaining the vacuum partitioning and appropriate vacuum environment of the neutral beam vacuum chamber 11 and the ion source vacuum chamber.

[0063] Example 2: This Example 2 further optimizes Example 1 and provides a control method for a multi-stage isolated high vacuum acquisition system of a neutral beam injection device, including a stage-by-stage start-up control method and a stage-by-stage stop-up control method after the experiment is completed, such as... Figures 3-4 As shown, the step-by-step start-up control method includes the following steps:

[0064] Start the mechanical pump unit, and open the fore-stage valve and the pre-evacuation valve in sequence. The mechanical pump unit evacuates the neutral beam vacuum chamber 11 through the pre-evacuation pipeline of the Roots pump unit to make the vacuum level reach below 10000Pa, and then gradually decreases it to 1000Pa. This is the first stage of vacuum.

[0065] When the vacuum level reaches 1000Pa, the Roots pump group is started to evacuate the neutral beam vacuum chamber 11 to bring the vacuum level below 1000Pa, and then gradually reduce it to 10Pa. This is the second-stage vacuum.

[0066] When the vacuum level reaches 10 Pa, close the pre-evacuation valve and open the fore-stage valve of the molecular pump assembly. Start the molecular pump assembly and open the molecular pump assembly gate valve to evacuate the neutral beam vacuum chamber 11 through the molecular pump assembly, bringing the vacuum level below 10 Pa, and then gradually reducing it to 10 Pa. -3 Pa level, reaching the third level vacuum;

[0067] When the vacuum degree reaches 10 -3At the Pa level, the temperature is gradually lowered by introducing cryogenic liquid nitrogen and liquid helium, and the insertion cryogenic pump 10 is activated to evacuate the neutral beam vacuum chamber 11, achieving a vacuum level of 10. -5 To achieve an ultra-high vacuum state, the Pa level is below.

[0068] In this embodiment, the step-by-step stop control method includes the following steps:

[0069] First, the insertion cryogenic pump 10 is stopped by gradually stopping the supply of liquid helium and liquid nitrogen, which causes the gas vacuum to deteriorate. Then, the gas inside the neutral beam vacuum chamber 11 is continuously discharged through the molecular pump group.

[0070] When the vacuum level reaches the limit of 10Pa, the limit is triggered to automatically shut down the molecular pump group and the slide valve connecting the molecular pump group to the neutral beam vacuum chamber, open the pre-evacuation valve, and continuously discharge the gas inside the neutral beam vacuum chamber 11 through the Roots pump group. When the molecular pump group stops and the speed drops to 0, the fore-stage valve is closed.

[0071] When the vacuum level reaches 1000Pa, shut down the Roots pump set and continuously discharge the gas inside the neutral beam vacuum chamber 11 through the mechanical pump set until the initial standard is reached. Then, shut down the mechanical pump set, the fore-stage valve, and the pre-evacuation valve.

[0072] In this embodiment, a control unit 1 and a logic control action unit 2 are also included. The control unit 1 is used to issue a protection control strategy based on the vacuum level detected in real time inside the neutral beam vacuum chamber 11. The protection control strategy includes:

[0073] When the vacuum level inside the neutral beam vacuum chamber 11 is greater than the preset vacuum level limit, the control unit 1 sends a protection control signal to the logic control action unit 2, causing the logic control action unit 2 to control all valves in the front-stage pumping unit to close, and all switch control contactors or relays to open.

[0074] Subsequently, the cryogenic system on the cryogenic pump unit was controlled to cool down and the water cooling system on the neutral beam vacuum chamber 11 was controlled to maintain water pressure. Related abnormal repairs were performed to make the vacuum level inside the neutral beam vacuum chamber 11 less than the preset vacuum level limit. Abnormal diagnosis and repair were performed on the components in the cryogenic pump pre-stage pumping unit 3.

[0075] After diagnosis and repair, the operation of the cryogenic pump pre-stage extraction unit 3 can be restored.

[0076] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-stage isolation high vacuum acquisition system for neutral beam injection, characterized in that, include: The cryogenic pump unit includes an insertion cryogenic pump (10) inside a neutral beam vacuum chamber (11) for cooling and adsorbing gases using liquid nitrogen and liquid helium to achieve vacuum pumping. The cryogenic pump pre-stage pumping unit (3) includes a molecular pump group, a Roots pump group and a mechanical pump group. The inlet of the molecular pump assembly is connected to the neutral beam vacuum chamber (11) via a gate valve, and the outlet is connected to the inlet of the Roots pump assembly via a pre-stage valve. The inlet of the Roots pump unit is connected to the neutral beam vacuum chamber (11) through a pre-vacuum valve and a pre-evacuation valve, and the outlet is connected to the mechanical pump unit through a pre-vacuum valve.

2. The multi-stage isolation high vacuum acquisition system for neutral beam injection according to claim 1, characterized in that, The cryogenic pump unit is also equipped with a cryogenic system for inputting liquid nitrogen and liquid helium, and a molecular pump and a mechanical pump are connected in sequence on the multi-channel delivery pipeline of the cryogenic system.

3. The multi-stage isolation high vacuum acquisition system for neutral beam injection according to claim 1, characterized in that, The neutral beam vacuum chamber (11) is equipped with several vacuum gauges for measuring the vacuum level, and each vacuum gauge is connected to a vacuum meter.

4. The multi-stage isolation high vacuum acquisition system for neutral beam injection according to claim 3, characterized in that, The front end of the neutral beam vacuum chamber (11) is provided with a front vacuum gauge (6) at both the upper and lower positions, and the rear end of the neutral beam vacuum chamber (11) is provided with a rear vacuum gauge (7) at both the upper and lower positions.

5. A multi-stage isolation high vacuum acquisition system for neutral beam injection according to claim 3, characterized in that, It also includes a control unit (1) and a logic control action unit (2). The control unit (1) is used to receive vacuum degree signals from several vacuum gauges and output control signals to the logic control action unit (2) according to the vacuum degree signals. The logic control action unit (2) is used to control the operation of the cryogenic pump unit, the Roots pump unit and the molecular pump unit, as well as the opening and closing of all pre-extraction valves, gate valves and fore-stage valves.

6. A multi-stage isolation high vacuum acquisition system for neutral beam injection according to claim 5, characterized in that, The control unit (1) can also determine the magnitude of the vacuum signal and the preset vacuum limit, and send a protection signal to the logic control action unit (2). The logic control action unit (2) can control the opening and closing of all valves of the cryogenic pump pre-stage pumping unit (3) and the opening and closing of its switch control contactor or relay according to the protection signal.

7. A multi-stage isolation high vacuum acquisition system for neutral beam injection according to claim 1, characterized in that, An injection valve (4) is provided on one side of the neutral beam vacuum chamber (11), which is used to inject a neutral beam into other devices.

8. A control method for a multi-stage isolated high vacuum acquisition system for a neutral beam injection device according to any one of claims 1 to 7, characterized in that, This includes a step-by-step start-up control method and a step-by-step stop-up control method after the experiment is completed. The step-by-step start-up control method includes the following steps: Start the mechanical pump unit, open the fore-stage valve and the pre-evacuation valve in sequence, and the mechanical pump unit evacuates the neutral beam vacuum chamber (11) through the pre-evacuation pipeline of the Roots pump unit to make the vacuum level reach below 10000Pa and gradually decrease to 1000Pa. This is the first stage of vacuum. When the vacuum level reaches 1000Pa, start the Roots pump group to evacuate the neutral beam vacuum chamber (11) to make the vacuum level below 1000Pa, and gradually reduce it to 10Pa. This is the second stage of vacuum. When the vacuum level reaches 10 Pa, close the pre-evacuation valve and open the fore-stage valve of the molecular pump group. Start the molecular pump group and open the molecular pump group gate valve to evacuate the neutral beam vacuum chamber (11) through the molecular pump group, so that the vacuum level reaches below 10 Pa and is gradually reduced to 10 Pa. -3 Pa level, reaching the third level vacuum; When the vacuum degree reaches 10 -3 At the Pa level, the temperature is gradually lowered by introducing cryogenic liquid nitrogen and liquid helium, and the insertion cryogenic pump (10) is activated to evacuate the neutral beam vacuum chamber (11) to achieve a vacuum level of 10. -5 To achieve an ultra-high vacuum state, the Pa level and below are used.

9. The control method for a multi-stage isolation high vacuum acquisition system for a neutral beam injection device according to claim 8, characterized in that, The step-by-step stop control method includes the following steps: First, the insertion cryogenic pump (10) is stopped by gradually stopping the supply of liquid helium and liquid nitrogen. The gas vacuum level deteriorates, and the gas inside the neutral beam vacuum chamber (11) is continuously discharged through the molecular pump group. When the vacuum level reaches the limit of 10Pa, the limit is triggered to automatically shut down the molecular pump group and the slide valve connecting the molecular pump group to the neutral beam vacuum chamber, open the pre-evacuation valve, and continuously discharge the gas inside the neutral beam vacuum chamber (11) through the Roots pump group. When the molecular pump group stops and the speed drops to 0, the front valve is closed. When the vacuum level reaches 1000Pa, the Roots pump group is turned off, and the gas inside the neutral beam vacuum chamber (11) is continuously discharged through the mechanical pump group until the initial standard is reached. Then the mechanical pump group, the fore-stage valve, and the pre-evacuation valve can be turned off.

10. The control method for a multi-stage isolated high vacuum acquisition system for a neutral beam injection device according to claim 8, characterized in that, It also includes a control unit (1) and a logic control action unit (2), wherein the control unit (1) is used to issue a protection control strategy based on the vacuum level detected in real time inside the neutral beam vacuum chamber (11), the protection control strategy including: When the vacuum level inside the neutral beam vacuum chamber (11) is greater than the preset vacuum level limit, the control unit (1) sends a protection control signal to the logic control action unit (2), causing the logic control action unit (2) to control all valves in the front-stage pumping unit (3) to close, and all switch control contactors or relays to open. Subsequently, the cryogenic system on the cryogenic pump unit was controlled to cool down and the water cooling system on the neutral beam vacuum chamber (11) was controlled to maintain water pressure. The relevant abnormal repairs made the vacuum degree inside the neutral beam vacuum chamber (11) less than the preset vacuum degree limit, and the abnormality diagnosis and repair of the components in the cryogenic pump front-stage pumping unit (3) were performed. After diagnosis and repair, the operation of the cryogenic pump pre-stage air extraction unit (3) can be restored.

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