A high-vacuum high-density plasma combined measurement system under ultrahigh power MPDT

Abstract

A combined measurement system for high-vacuum, high-density plasma under ultra-high-power MPDT (Multi-Pump Deployment Device) comprises a thermal shock resistant high-pump-speed molecular pump system, an integrated thermal management system, a superconducting system, a power control and measurement system, a suspended target thrust measurement system, and a plasma diagnostic and integrated measurement and control system. The thermal shock resistant high-pump-speed molecular pump system maintains a high vacuum under high-flow-rate propellant gas; the integrated thermal management system cools the ultra-high-power MPDT during ignition; the superconducting system ensures closed-loop stable magnetic field operation; a probe and optical combined plasma diagnostic system enables real-time monitoring of high-density plasma in the MPDT plume; a special suspended target thrust measurement system tests the MPDT's performance; and the integrated measurement and control system provides comprehensive control and parameter monitoring of the above systems, thus solving the problem of high-density plasma performance testing under high vacuum in ultra-high-power MPDTs.

Description

Technical Field

[0001] This invention relates to a high-vacuum, high-density plasma combined measurement system under ultra-high power MPDT, belonging to the field of plasma measurement technology. Background Technology

[0002] To meet the demands of ultra-large military spacecraft for increased speed, high payload ratio, and rapid maneuverability, space propulsion systems must possess high thrust, high specific impulse, and long lifespan. Chemical propulsion systems offer high thrust but low specific impulse, resulting in excessive propellant consumption for the same missions and failing to meet the high payload ratio requirements of spacecraft. Traditional low-to-medium power electric propulsion systems offer low thrust and high specific impulse, significantly improving the payload ratio, but their thrust is only in the hundreds of mN range, making it difficult to achieve the rapid maneuverability requirements of spacecraft. In contrast, high-power electromagnetic propulsion technology in the hundreds of kilowatts range, characterized by high specific impulse and high thrust, is a powerful tool for enhancing the maneuverability of my country's military spacecraft and is of great significance for improving my country's strategic dominance in the space domain and gaining space superiority in future wars. To this end, with the support of the "Core Technology Reshaping Project" project "High-Power High Specific Impulse Long-Life Electric Propulsion Technology" of the China Academy of Space Technology, the 100kW power-level magneto-plasma thruster (MPDT) was identified as a key technology project. The relevant research and development units were organized to sort out the key technologies and completed key technologies such as high-power electromagnetic propulsion performance test and ground demonstration verification.

[0003] Magnetoplasma-powered thrusters (MPDs), as a type of electric propulsion system, employ a design philosophy drastically different from chemical rockets. Their thrust primarily relies on the combined acceleration of plasma by electromagnetic and aerodynamic forces. Compared to other electric propulsion technologies, MPDs offer advantages in high thrust density and specific impulse, making them highly promising for interplanetary missions. However, performance testing of ultra-high-power MPDs exceeding 100kW requires plasma densities and energies far exceeding those of existing electric propulsion systems. Using current thruster research methods, stable and interference-free testing is difficult. Summary of the Invention

[0004] The technical problem solved by this invention is that, in the current technology, traditional methods are difficult to conduct stable and interference-free plasma testing. Therefore, a high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT is proposed.

[0005] The present invention solves the above-mentioned technical problem through the following technical solution: A high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT includes a thermal shock resistant high-pump-speed molecular pump vacuum subsystem, an integrated thermal management subsystem, a superconducting subsystem, a power control and measurement subsystem, a suspended target thrust measurement subsystem, and a plasma diagnostic and integrated measurement and control subsystem, wherein: The thermal shock resistant high-speed molecular pump assembly vacuum subsystem is used to provide the required vacuum environment for ultra-high power MPDT ignition. The integrated thermal management subsystem provides the cooling circulating water required for the ultra-high power MPDT and other subsystems during the ignition process of the ultra-high power MPDT to ensure the temperature environment; The superconducting subsystem provides a stable operating magnetic field for the ultra-high power MPDT; The power control and measurement subsystem is used to adjust the electrical performance parameters of other subsystems and supply power according to the electrical performance parameters. The suspended target thrust measurement subsystem measures the suspended target thrust parameters, which are the ignition performance parameters during the ignition of the ultra-high power MPDT. The plasma diagnostic and integrated measurement and control system collects and identifies plasma parameters that determine ignition performance parameters during the ignition process of an ultra-high power MPDT.

[0006] The vacuum subsystem of the thermal shock resistant high-speed molecular pump group includes a vacuum chamber, a rough pump group, a molecular pump group, a vacuum gauge, vacuum pipelines and valves. The rough pump group is connected to the vacuum chamber flange and the molecular pump group interface through the vacuum pipeline, and a gate valve is set at a preset pipeline position for valve switching. The valves include a gate valve and a baffle valve. Vacuum gauges are installed at designated interfaces in the vacuum chamber. Molecular pumps are installed on the outside of the main chamber via expansion chambers as needed for the measurement task. Each molecular pump is equipped with a baffle valve between its connection point to the corresponding expansion chamber and a gate valve between its connection point to the roughing pump.

[0007] The integrated thermal management subsystem includes two water tanks, an outdoor chiller unit, an indoor chiller unit, a flow meter, pressure and temperature sensors, a water pump, a water-cooled shield inside the vacuum chamber, a splash-proof water-cooled plate for the vacuum chamber door, and a water supply pipeline. The outdoor chiller unit is connected to the indoor chiller unit via a water supply pipeline, exchanging heat through coolant. The indoor chiller unit is connected to the two water tanks respectively to cool the water in the tanks. The water tanks are connected to the corresponding test components, roughing pump group, and molecular pump group for each water tank via water pumps and water supply pipelines, and a flow meter and pressure and temperature sensors are installed at the return water end. The test components include an ultra-high power MPDT, a power supply, a water-cooled shield, and measuring equipment. The water-cooled shield inside the vacuum chamber and the splash-proof water-cooled plate for the vacuum chamber door are both installed inside the vacuum chamber and connected to the water supply pipeline via a through-chamber water flange.

[0008] When the ultra-high power MPDT is running at a preset power steady state, the integrated thermal management subsystem controls the actual temperature of the inner wall of the cold shield and the temperature of the inner wall of the door splash guard to be stable within the corresponding preset range. The cooling circulating water and the outer surface temperature of the vacuum chamber required during the ignition process of the ultra-high power MPDT are controlled according to the preset power of steady state operation.

[0009] The superconducting subsystem includes a superconducting coil body, a cooling module, and a power supply module. The superconducting coil body is made of superconducting wire. The cooling module uses a cold plate heat exchange to achieve stable operation within a preset temperature range. The power supply module uses a superconducting power supply connected to the power supply end of the superconducting coil to achieve the through-cabin cable connection. The maximum magnetic field strength at the center of the superconducting coil body is 0.5-1.5T.

[0010] The power control and measurement subsystem includes an anode power supply, an arc-starting power supply, a measurement and control module, a cabinet, and an industrial computer. The anode power supply, arc-starting power supply, and measurement and control module are integrated inside the cabinet and connected via internal control circuitry. Communication with the industrial computer is achieved through optical fiber on the measurement and control module. The power cabinet output cable is connected to an ultra-high power MPDT via a through-cabin flange.

[0011] The suspended target thrust measurement subsystem includes an elastic beam, a rigid target, a calibration device, a displacement sensor, a support frame, a vacuum displacement mechanism, a measurement and control signal line, and an industrial control computer. The support frame is mounted on the vacuum displacement mechanism and installed inside the vacuum chamber, aligned with the ultra-high power MPDT. The elastic beam is connected and installed within the support frame, and the rigid target is fixed at the lower end of the elastic beam, transmitting the force of the beam on the target surface to the beam to generate deformation. The displacement sensor is used to measure the deformation of the beam and obtain the thrust according to the thrust frame calibration curve. The suspended target thrust measurement subsystem achieves linear correlation coefficient, repeatability, and thrust measurement range by adjusting the target size and calibration device weight parameters. Meanwhile, the elastic beam uses water cooling and thermal protection to control measurement error fluctuations during 30-minute continuous testing and responds to thrust changes caused by changes in thruster operating conditions.

[0012] The plasma diagnostic and integrated measurement and control system includes an optical diagnostic module and a plasma probe diagnostic module. The optical diagnostic module is equipped with an optical camera to take real-time online photos from outside the vacuum chamber. The plasma probe diagnostic module measures the performance of the high-density plasma inside the plume inside the vacuum chamber using a plasma probe, collects plasma parameters of the ignition performance parameters during the ultra-high power MPDT ignition process, and makes judgments.

[0013] The plasma probe diagnostic module makes judgments based on plasma parameters using the following method: Once the ultra-high power MPDT reaches steady-state operation, the plasma probe diagnostic module switches to plasma probe detection mode and performs a two-dimensional moving scan within the plasma plume of the ultra-high power MPDT. This acquires feedback signals at different locations, which are then processed and calculated using MATlab software to obtain distribution cloud maps of the plasma plume's electron density, ion density, electron temperature, and potential. After post-processing and integration, the thrust is calculated and compared with the results of the suspended target thrust measurement to determine accuracy.

[0014] In the plasma diagnostic and integrated measurement and control system, the plasma probe diagnostic module uses Langmuir probes and Faraday probes to achieve the temperature resistance performance of the probe tip and control the measurement range of electron temperature and density.

[0015] The advantages of this invention compared to the prior art are: (1) The present invention provides a high-vacuum high-density plasma joint measurement system under ultra-high power MPDT, which can be used for the performance measurement of ultra-high power MPDT under high vacuum. Under the condition of ensuring the high accuracy and stability of the test system, it can realize the continuous test of anti-disturbance and high temperature resistance, solve the problem of high-density plasma performance test under high vacuum of ultra-high power MPDT, and provide key data for thruster development and ground performance analysis. (2) In the research and experiment of MPD thruster, the present invention completes the calibration of the rated working performance and the plotting of the performance spectrum of the high-precision target thrust measurement device of the thruster. Through the probe and optical combined plasma diagnostic scheme, the high-density plasma in the MPDT plume is monitored in real time, laying the foundation for the research on internal discharge of MPD thruster cavity and long life test technology. Attached Figure Description

[0016] Figure 1 A schematic diagram of the plasma joint measurement system provided by the present invention; Figure 2 This is a schematic diagram of the plasma joint measurement provided by the present invention; Figure 3 A schematic diagram of the vacuum system principle of the thermal shock resistant high-speed molecular pump group provided by the present invention; Figure 4 A schematic diagram of the integrated thermal management system, cold shield, and splash-proof water-cooled plate provided by the present invention; Figure 5 This invention provides a schematic diagram of the suspended target thrust measurement system and typical calibration and measurement curves. Figure 6 This invention provides a schematic diagram of an optical diagnostic measurement system and typical optical imaging results. Figure 7 A schematic diagram of the probe diagnostic measurement system provided by the present invention and a typical ion current density distribution cloud map. Detailed Implementation

[0017] A combined high-vacuum, high-density plasma measurement system for ultra-high-power MPDTs is developed for performance measurement of ultra-high-power MPDTs under high vacuum. This system enables continuous testing with high-temperature resistance and high-precision operation while maintaining high accuracy and stability. Currently, there are no mature technologies or equipment available for MPDs and other electric thrusters that can solve the problem of high-density plasma performance testing under high vacuum for ultra-high-power MPDs. This system can provide crucial data for thruster development and ground performance analysis.

[0018] The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT includes a thermal shock resistant high-pump-speed molecular pump assembly vacuum subsystem, an integrated thermal management subsystem, a superconducting subsystem, a power control and measurement subsystem, a suspended target thrust measurement subsystem, and a plasma diagnostic and integrated measurement and control subsystem. The thermal shock resistant high-pump-speed molecular pump assembly system maintains a high vacuum under high-flow-rate propellant gas conditions; the integrated thermal management subsystem cools the ultra-high power MPDT during ignition and operation; the superconducting subsystem ensures closed-loop stable magnetic field operation; a probe and optical combined plasma diagnostic system enables real-time monitoring of high-density plasma in the MPDT plume; a special suspended target thrust measurement system tests the MPDT's performance; and the integrated measurement and control system provides comprehensive control and parameter monitoring of the above systems.

[0019] Specifically: The thermal shock resistant high-speed molecular pump assembly vacuum subsystem is used to provide the required vacuum environment for ultra-high power MPDT ignition. The integrated thermal management subsystem provides the cooling circulating water required for the ultra-high power MPDT and other subsystems during the ignition process of the ultra-high power MPDT to ensure the temperature environment; The superconducting subsystem provides a stable operating magnetic field for the ultra-high power MPDT; The power control and measurement subsystem is used to adjust the electrical performance parameters of other subsystems and supply power according to the electrical performance parameters. The suspended target thrust measurement subsystem measures the suspended target thrust parameters, which are the ignition performance parameters during the ignition of the ultra-high power MPDT. The plasma diagnostic and integrated measurement and control system collects and identifies plasma parameters that determine ignition performance parameters during the ignition process of an ultra-high power MPDT.

[0020] The high-speed, thermal shock-resistant molecular pump vacuum subsystem includes a vacuum chamber, a roughing pump assembly, molecular pump assemblies, a vacuum gauge, piping, and valves. The roughing pump assembly connects to the vacuum chamber flanges and molecular pump assembly interfaces via vacuum piping, with gate valves installed at corresponding piping locations for switching. The vacuum gauge is installed at the KF40 interface of the vacuum chamber. Molecular pumps can be installed as needed, totaling 20-30 units, located on the left, right, and top sides of the main chamber. Due to the size limitations of the main vacuum chamber, four expansion chambers are installed on the left and right sides via four DN1000 flanges, with 4-6 molecular pumps evenly distributed around each expansion chamber. An expansion chamber is installed on the top of the main chamber via DN1250 flanges, with 8 molecular pumps evenly distributed around its perimeter. Additionally, four DN400 flanges are located on the top for installing individual molecular pumps. Each molecular pump has a baffle valve between its connection to a chamber and a gate valve between its connection to the pre-stage (roughing pump).

[0021] The integrated thermal management subsystem includes two water tanks (an 8-ton tank provides water cooling for the ultra-high power MPDT, power supply, cold shield, and measuring equipment; a 2-ton tank provides water cooling for the coarse pump group and molecular pump group), an outdoor chiller unit, an indoor chiller unit, flow meters, pressure and temperature sensors, water pumps, a water-cooled cold shield inside the vacuum chamber, a splash-proof water-cooled plate for the vacuum chamber door, and water supply pipes. The outdoor chiller unit is connected to the indoor chiller unit via piping, exchanging heat through coolant; the indoor chiller unit is connected to the two water tanks respectively, cooling the water in the tanks; the water tanks are connected to the ultra-high power MPDT, power supply, cold shield, measuring equipment, coarse pump group, and molecular pump group via water pumps and pipes, and a flow meter and pressure and temperature sensors are installed at the return water end; the water-cooled cold shield inside the vacuum chamber and the splash-proof water-cooled plate for the vacuum chamber door are installed inside the vacuum chamber and connected to the water circuit via a through-chamber water flange.

[0022] When the ultra-high power MPDT is running at a preset power steady state, the integrated thermal management subsystem controls the actual temperature of the inner wall of the cold shield and the inner wall temperature of the door splash guard to remain stable within the corresponding preset range. The cooling circulating water and the outer surface temperature of the vacuum chamber required during the ignition process of the ultra-high power MPDT are controlled according to the preset power of steady state operation.

[0023] The superconducting subsystem includes a superconducting coil body, a cooling module, and a power supply module. The superconducting coil body is made of superconducting wire. The cooling module uses a cold plate heat exchanger to achieve stable operation within a preset temperature range. The power supply module uses a superconducting power supply and is connected to the power supply end of the superconducting coil through a through-cabin cable. The maximum magnetic field strength at the center of the superconducting coil body is 0.5-1.5T.

[0024] The power control and measurement subsystem includes an anode power supply, an arc-starting power supply, a measurement and control module, a cabinet, and an industrial computer. The anode power supply, arc-starting power supply, and measurement and control module are integrated inside the cabinet and connected via internal control circuitry. Communication with the industrial computer is achieved through fiber optic cables on the measurement and control module. The power cabinet output cables are connected to an ultra-high power MPDT via a through-cabin flange.

[0025] The suspended target thrust measurement subsystem includes an elastic beam, a rigid target, a calibration device, a displacement sensor, a support frame, a vacuum displacement mechanism, measurement and control signal lines, and an industrial control computer. The support frame is located on the vacuum displacement mechanism and installed inside the vacuum chamber, aligned with the ultra-high power MPDT. The elastic beam is structurally connected and installed within the support frame. The rigid target is fixed to the lower end of the elastic beam, transferring the force of the beam on the target surface to the beam, causing deformation. The displacement sensor measures the beam's deformation, and the thrust is calculated by combining this with the thrust frame calibration curve.

[0026] The suspended target thrust measurement subsystem achieves linear correlation coefficient, repeatability, and thrust measurement range by adjusting the target size and calibration device weight parameters. Meanwhile, the elastic beam uses water cooling and thermal protection to control measurement error fluctuations during 30-minute continuous testing and responds to thrust changes caused by changes in thruster operating conditions.

[0027] The plasma diagnostic and integrated measurement and control system includes an optical diagnostic module and a plasma probe diagnostic module. The optical diagnostic module is equipped with an optical camera to take real-time online pictures from outside the vacuum chamber. The plasma probe diagnostic module measures the performance of the high-density plasma inside the plume inside the vacuum chamber using a plasma probe, collects plasma parameters of ignition performance parameters during the ultra-high power MPDT ignition process, and makes judgments.

[0028] The plasma probe diagnostic module makes judgments based on plasma parameters as follows: The ultra-high power MPDT employs an optical diagnostic module, plasma probe diagnostics, and a suspended target thrust measurement subsystem for integrated measurement. The optical diagnostic module uses an ultra-high-speed camera to capture the MPDT ignition and startup process, and a filter with a fixed center wavelength is used to eliminate interference from plume arc light. During the MPDT's transition from ignition to steady state, the suspended target thrust measurement subsystem collects the feedback voltage from the displacement sensor in real time, converts it into real-time thrust based on calibration coefficients, and records the curve. After the MPDT reaches steady-state operation, it switches to plasma probe mode, performing a two-dimensional moving scan within the plasma plume to acquire feedback signals at different locations. These signals are then processed and calculated using software such as MATLAB to obtain distribution cloud maps of the plasma plume's electron density, ion density, electron temperature, and potential. Post-processing and integration are then used to calculate the thrust, which is compared with the results of the suspended target thrust measurement to determine their accuracy.

[0029] Among them, the optical diagnostic module uses an ultra-high-speed camera to capture the MPDT ignition and startup process, and uses a filter with a fixed center wavelength to eliminate interference from plume arc light.

[0030] In the plasma diagnostic and integrated measurement and control system, the plasma probe diagnostic module uses Langmuir probes and Faraday probes to achieve the temperature resistance performance of the probe tip and control the measurement range of electron temperature and density.

[0031] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details: In the current embodiment, the high-vacuum high-density plasma performance joint diagnostic measurement system for ultra-high power MPDT solves the problem of difficulty in detecting the performance and plasma state of ultra-high power MPDT, and can provide key data for thruster development and ground performance analysis.

[0032] A high-vacuum, high-density plasma performance joint diagnostic measurement system, such as... Figure 1 As shown, it consists of a high-speed molecular pump group vacuum subsystem 1 with thermal shock resistance, an integrated thermal management subsystem 2, a superconducting subsystem 3, a power control and measurement subsystem 4, a suspended target thrust measurement subsystem 5, and a plasma diagnostic and integrated measurement and control subsystem 6. The thermal shock resistant high-speed molecular pump vacuum subsystem provides a vacuum environment for MPDT testing, housing the MPDT, internal cooling shield and splash-proof water-cooled plate, superconducting subsystem, suspended target measurement system, plasma diagnostic system, and through-chamber cabling. This thermal shock resistant high-speed molecular pump vacuum subsystem comprises a vacuum chamber, a roughing pump unit (such as Shenke Instrument JLG-4200A), a molecular pump unit (such as Hefei Yuchi FFD-400), vacuum gauges, piping, and valves, achieving an ultimate vacuum of 10⁻⁶. -4 Below Pa, the thruster can maintain 0.06~0.2Pa when supplying gas at 40~120mg / s; the vacuum chamber consists of a main chamber and a secondary chamber, the main chamber has a diameter of 3m and a length of 6m, and the secondary chamber has a diameter of 1.2m and a length of 1.6m, which meets the plume length requirements for ultra-high power MPDT ignition testing.

[0033] The integrated thermal management subsystem provides deionized circulating water for cooling the MPDT, superconducting subsystem, thermal shock resistant high-speed molecular pump vacuum subsystem, and suspended target measurement system, ensuring that the equipment or system temperature meets operating requirements during the ultra-high power MPDT ignition test. The thermal management system consists of an outdoor cooling unit, an indoor chiller unit, a water tank, a centrifugal pump, an internal cooling shield and splash-proof water-cooled plate, sensors, and piping. The outdoor chiller exchanges refrigerant with the indoor chiller unit to cool the water tank, dissipating heat outdoors while reducing indoor noise. The total cooling capacity is [not specified]. The power is 350-450kW; the water tank adopts a 2-4 tank structure, which can hold a total of 6-10t of deionized water. Water is supplied to each piece of equipment by 15-20 centrifugal pumps (such as Nanfang Pump Industry, with a head of 70-120m and a flow rate of 3-6 cubic meters / hour); the internal cooling screen and anti-splash water-cooled plate are respectively placed on the inner wall of the main chamber of the vacuum chamber and at the door. The cooling screen adopts a stainless steel expansion plate type cooling screen with an inner diameter of 2550-2700mm. The inner wall is installed with titanium plates. The anti-splash water-cooled plate is made of titanium alloy strips in the form of louvers. The back is connected to water-cooling pipes to ensure that the temperature of the chamber wall is at room temperature.

[0034] The superconducting subsystem provides a matched and stable magnetic field configuration for the MPDT, including the superconducting coil body, cooling system, and power supply system. The superconducting coil is wound with low-temperature or high-temperature superconducting wire and uses a cold plate heat exchanger to achieve stable low-temperature operation, with a maximum central magnetic field strength of 0.5-1.5T. The cooling system is used to maintain the stable closed-loop operation inside the superconducting coil and removes heat through an external refrigerator. The power supply system is used to control the start-up and shutdown of the coil, current loading, and stable closed-loop operation. The power control and measurement subsystem provides the electrical parameters such as current and voltage required for MPDT ignition. The total power output is 750kW, including an anode power supply, an arc-starting power supply, a measurement and control module, a cabinet, and an industrial computer (such as ADLINK RK-610). The anode power supply supplies power to the MPDT output terminal, with an open-circuit voltage of 500-750V and a rated current of 100-2000A. The arc-starting power supply provides a pulse voltage for the MPDT ignition start-up, with an instantaneous voltage of 8000-20000V. The suspended target thrust measurement subsystem employs a multi-layer target structure, a laser displacement sensor, and a temperature drift suppression device to achieve high-precision thrust measurement. The linear correlation coefficient of the thrust measurement system is above 0.99999, the repeatability is above 99.9%, the thrust measurement range covers 0-10N, the measurement error fluctuation is within ±2% during a 30-minute continuous test, and it has a rapid response characteristic to thrust changes caused by changes in thruster operating conditions.

[0035] The plasma diagnostic system consists of a high-temperature probe, an optical camera, an industrial control computer (such as ADLINK RK-610), a data acquisition card (such as NI PCIe-6111), and a data processor. The industrial control computer is connected to the high-speed camera or probe signal acquisition unit via a network cable, acquiring images captured by the high-speed camera or electrical signals fed back by the probe and sending them to the data processor. The data acquisition card is used to output control signals to drive the rotation of the filter wheel. The high-temperature probe mainly adopts Langmuir probes, Faraday probes, etc. The high-temperature probe probe feeds back the plasma characteristics in the thruster plume in the form of its own current. The positioning system completes the characteristic acquisition at the corresponding position, and noise filtering and output signal gain are achieved through the signal compensation path. The signal is then transmitted to the data acquisition system and analyzed and processed by the post-processing system.

[0036] The thermal shock resistant high-speed molecular pump vacuum subsystem 1 provides the required vacuum environment for the ignition of the ultra-high power MPDT. The power control and measurement subsystem 4 provides electrical performance parameters. The superconducting subsystem 3 provides a stable magnetic field. The suspended target thrust measurement subsystem 5 and the plasma diagnostic and integrated measurement and control subsystem 6 are installed inside the thermal shock resistant high-speed molecular pump vacuum subsystem 1 to measure the ignition performance of the ultra-high power MPDT. The integrated thermal management subsystem 2 is located outside the vacuum system 1 and provides the required cooling circulating water for the ultra-high power MPDT, vacuum system 1, power control and measurement subsystem 4, and superconducting subsystem 3 to ensure that the temperature meets the requirements.

[0037] like Figure 2 , Figure 3 As shown, this invention employs a vacuum subsystem composed of dozens of molecular pumps, consisting of a thermal shock resistant, high-pumping-speed molecular pump group, to achieve the vacuum level required for ultra-high power MPDT ignition, with an ultimate vacuum level reaching 10. -4 Below Pa, a gas supply of 40~120 mg / s can maintain a Pa level of 0.06~0.2; among which, Figure 3 In Chinese: GG1 - Pre-stage resistance gauge; GG2 - Full range gauge; T - Molecular pump; L - Dry pump unit; G - Pneumatic slide gate valve; G' - Pneumatic baffle valve; DF - Baffle valve; DF' - Pneumatic baffle valve; F1 - DN400 blind flange reserved; F2 - DN40 blind flange reserved; V1 - Baffle valve × 1; C1 - Filter; like Figure 4 As shown, the present invention employs a cold screen and a splash-proof water-cooled plate placed inside the chamber, and a titanium plate installed on the inner wall to reduce plasma sputtering erosion. The chamber is cooled by water through an integrated thermal management subsystem, which can meet the requirements of long-life ignition and performance diagnostic measurement of ultra-high power MPDT. like Figure 5As shown, the present invention employs a thrust measurement system composed of a multi-layer target surface structure, a laser displacement sensor, and a temperature drift suppression device to achieve high-precision thrust measurement, which can meet the thrust measurement requirements of ultra-high power MPDTs.

[0038] This invention takes into account the high-energy, high-density plasma plume characteristics of ultra-high power MPDTs and designs, for example... Figure 6 The optical diagnostics shown and such Figure 7 The plasma probe diagnostic combination shown is a performance joint diagnostic measurement system that can perform online performance testing of ultra-high power MPDTs.

[0039] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0040] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT, characterized in that: This includes a thermal shock resistant high-speed molecular pump vacuum subsystem, an integrated thermal management subsystem, a superconducting subsystem, a power control and measurement subsystem, a suspended target thrust measurement subsystem, and a plasma diagnostic and integrated measurement and control subsystem, among which: The thermal shock resistant high-speed molecular pump assembly vacuum subsystem is used to provide the required vacuum environment for ultra-high power MPDT ignition. The integrated thermal management subsystem provides the cooling circulating water required for the ultra-high power MPDT and other subsystems during the ignition process of the ultra-high power MPDT to ensure the temperature environment. The superconducting subsystem provides a stable operating magnetic field for the ultra-high power MPDT; The power control and measurement subsystem is used to adjust the electrical performance parameters of other subsystems and supply power according to the electrical performance parameters. The suspended target thrust measurement subsystem measures the suspended target thrust parameters, which are the ignition performance parameters during the ignition of the ultra-high power MPDT. The plasma diagnostic and integrated measurement and control system collects and identifies plasma parameters that determine ignition performance parameters during the ignition process of an ultra-high power MPDT.

2. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT as described in claim 1, characterized in that: The vacuum subsystem of the thermal shock resistant high-speed molecular pump group includes a vacuum chamber, a rough pump group, a molecular pump group, a vacuum gauge, vacuum pipelines and valves. The rough pump group is connected to the vacuum chamber flange and the molecular pump group interface through the vacuum pipeline, and a gate valve is set at a preset pipeline position for valve switching. The valves include a gate valve and a baffle valve. Vacuum gauges are installed at designated interfaces in the vacuum chamber. Molecular pumps are installed on the outside of the main chamber via expansion chambers as needed for the measurement task. Each molecular pump is equipped with a baffle valve between its connection point to the corresponding expansion chamber and a gate valve between its connection point to the roughing pump.

3. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT as described in claim 1, characterized in that: The integrated thermal management subsystem includes two water tanks, an outdoor chiller unit, an indoor chiller unit, a flow meter, pressure and temperature sensors, a water pump, a water-cooled shield inside the vacuum chamber, a splash-proof water-cooled plate for the vacuum chamber door, and a water supply pipeline. The outdoor chiller unit is connected to the indoor chiller unit via a water supply pipeline, exchanging heat through coolant. The indoor chiller unit is connected to the two water tanks respectively to cool the water in the tanks. The water tanks are connected to the corresponding test components, roughing pump group, and molecular pump group for each water tank via water pumps and water supply pipelines, and a flow meter and pressure and temperature sensors are installed at the return water end. The test components include an ultra-high power MPDT, a power supply, a water-cooled shield, and measuring equipment. The water-cooled shield inside the vacuum chamber and the splash-proof water-cooled plate for the vacuum chamber door are both installed inside the vacuum chamber and connected to the water supply pipeline via a through-chamber water flange.

4. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT as described in claim 3, characterized in that: When the ultra-high power MPDT is running at a preset power steady state, the integrated thermal management subsystem controls the actual temperature of the inner wall of the cold shield and the temperature of the inner wall of the door splash guard to be stable within the corresponding preset range. The cooling circulating water and the outer surface temperature of the vacuum chamber required during the ignition process of the ultra-high power MPDT are controlled according to the preset power of steady state operation.

5. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT as described in claim 1, characterized in that: The superconducting subsystem includes a superconducting coil body, a cooling module, and a power supply module. The superconducting coil body is made of superconducting wire. The cooling module uses a cold plate heat exchange to achieve stable operation within a preset temperature range. The power supply module uses a superconducting power supply connected to the power supply end of the superconducting coil to achieve the through-cabin cable connection. The maximum magnetic field strength at the center of the superconducting coil body is 0.5-1.5T.

6. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT as described in claim 1, characterized in that: The power control and measurement subsystem includes an anode power supply, an arc-starting power supply, a measurement and control module, a cabinet, and an industrial computer. The anode power supply, arc-starting power supply, and measurement and control module are integrated inside the cabinet and connected through an internal control circuit. They communicate with the industrial computer through an optical fiber on the measurement and control module. The power cabinet output cable is connected to the ultra-high power MPDT via a through-cabin flange.

7. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT as described in claim 1, characterized in that: The suspended target thrust measurement subsystem includes an elastic beam, a rigid target, a calibration device, a displacement sensor, a support frame, a vacuum displacement mechanism, a measurement and control signal line, and an industrial control computer. The support frame is mounted on the vacuum displacement mechanism and installed inside the vacuum chamber, aligned with the ultra-high power MPDT. The elastic beam is connected and installed within the support frame, and the rigid target is fixed at the lower end of the elastic beam, transmitting the force of the beam on the target surface to the beam to generate deformation. The displacement sensor is used to measure the deformation of the beam and obtain the thrust according to the thrust frame calibration curve. The suspended target thrust measurement subsystem achieves linear correlation coefficient, repeatability, and thrust measurement range by adjusting the target size and calibration device weight parameters. Meanwhile, the elastic beam uses water cooling and thermal protection to control measurement error fluctuations during 30-minute continuous testing and responds to thrust changes caused by changes in thruster operating conditions.

8. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT according to claim 1, characterized in that: The plasma diagnostic and integrated measurement and control system includes an optical diagnostic module and a plasma probe diagnostic module. The optical diagnostic module is equipped with an optical camera to take real-time online photos from outside the vacuum chamber. The plasma probe diagnostic module measures the performance of the high-density plasma inside the plume inside the vacuum chamber using a plasma probe, collects plasma parameters of the ignition performance parameters during the ultra-high power MPDT ignition process, and makes judgments.

9. The high-vacuum high-density plasma joint measurement system under ultra-high power MPDT according to claim 8, characterized in that: The plasma probe diagnostic module makes judgments based on plasma parameters using the following method: Once the ultra-high power MPDT reaches steady-state operation, the plasma probe diagnostic module switches to plasma probe detection mode and performs a two-dimensional moving scan within the plasma plume of the ultra-high power MPDT. This acquires feedback signals at different locations, which are then processed and calculated using MATlab software to obtain distribution cloud maps of the plasma plume's electron density, ion density, electron temperature, and potential. After post-processing and integration, the thrust is calculated and compared with the results of the suspended target thrust measurement to determine accuracy.

10. The high-vacuum, high-density plasma joint measurement system under ultra-high power MPDT according to claim 9, characterized in that: In the plasma diagnostic and integrated measurement and control system, the plasma probe diagnostic module uses Langmuir probes and Faraday probes to achieve the temperature resistance performance of the probe tip and control the measurement range of electron temperature and density.

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