A plasma thruster plume parameter multi-point measurement device and measurement method

Abstract

The present invention relates to a plasma thruster plume parameter multi-point measurement device and a measurement method, the multi-point measurement device comprises: a vacuum chamber; a vacuum pump unit connected to the vacuum chamber; an industrial control unit connected to the vacuum pump unit, used to provide and maintain the vacuum environment of the vacuum chamber; and a measurement unit; the measurement unit comprises: at least two three-dimensional mobile platforms arranged in the vacuum chamber; a detection structure arranged on the three-dimensional mobile platform; a collection unit connected to the detection structure and used to collect data; the detection structure adopts a Langmuir probe, an RPA probe or a Faraday probe. The present invention can improve the plasma measurement efficiency, can continuously measure the multi-point symmetry of the plume, break the limitation of the use of the Langmuir probe, and shield the error interference in the probe circuit. At the same time, the multi-point measurement device of the present invention has a simple structure, is stable and reliable, and has strong practicality.

Description

Technical Field

[0001] The invention relates to the field of aerospace, and in particular to a plasma thruster plume parameter multi-point measurement device and a measurement method. Background Art

[0002] In recent years, the calibration technology of plasma generators under vacuum environment has gradually become a research hotspot in the field of plasma diagnosis. Researchers from home and abroad have tried to establish a set of standard devices for plasma generators covering two types of microwave plasma and radio frequency plasma along different technical routes, in order to effectively solve the value traceability problem of various types of plasma generators such as inductively coupled plasma generators for etching of micro-electromechanical systems of micro-nano satellites, microwave ECR plasma generators for orbital space plasma environment simulation, and arc thrusters and Hall thrusters for space electric propulsion. In the calibration technology research conducted in this process, Langmuir probe measurement devices with different applicable ranges are used as standard measurement equipment. Its working principle is: by applying a high-precision scanning voltage to the probe, collecting the probe collection current under the scanning voltage, and using the IV curve to obtain the electron density and electron temperature of the plasma, at the same time, high-precision radio frequency compensation is introduced for radio frequency plasma measurement. The standard measurement device also has a high spatial resolution, which minimizes the source of measurement uncertainty of the system.

[0003] In the prior art, the Langmuir probe is fixed on the inner wall of the vacuum chamber. If the plasma parameters at multiple points in the plasma thruster plume area need to be measured, the vacuum chamber needs to be opened repeatedly and the position of the probe needs to be manually adjusted to obtain the plasma parameters at multiple points. This traditional measurement method makes the test cycle very long and increases the test cost.

[0004] In addition, in the prior art, when measuring the symmetry of a plasma thruster plume, the method used is to set up multiple sets of symmetrical Langmuir probes in the plume area. However, this method can only measure the symmetry of the position of the Langmuir probes, and cannot obtain the symmetry of the spatial connection, and the test effect is very unsatisfactory.

[0005] Meanwhile, in the prior art, when the Langmuir probe is used, the existence of interference noise and discharge current will also cause the IV curve to be distorted, and the measurement accuracy will be seriously affected. Summary of the invention

[0006] The object of the present invention is to provide a plasma thruster plume parameter multi-point measurement device and a measurement method.

[0007] To achieve the above-mentioned purpose, the present invention provides a plasma thruster plume parameter multi-point measurement device, comprising: a vacuum chamber; a vacuum pump unit connected to the vacuum chamber; an industrial control unit connected to the vacuum pump unit, used to provide and maintain a vacuum environment of the vacuum chamber; and a measurement unit;

[0008] The measuring unit comprises: at least two three-dimensional mobile platforms arranged in the vacuum chamber; a detection structure arranged on the three-dimensional mobile platform; and a collection unit connected to the detection structure and used for collecting data;

[0009] The detection structure adopts a Langmuir probe, an RPA probe or a Faraday probe.

[0010] According to one aspect of the present invention, the vacuum chamber is a hollow columnar body, and a mounting position for mounting a plasma thruster is provided on at least one axial end face of the vacuum chamber;

[0011] The installation position penetrates through the wall of the vacuum chamber and can be opened and closed;

[0012] An observation window and an electric vacuum flange are arranged on the side wall of the vacuum chamber.

[0013] According to one aspect of the present invention, the vacuum chamber is arranged horizontally;

[0014] There are two three-dimensional mobile platforms, namely a first three-dimensional mobile platform and a second three-dimensional mobile platform;

[0015] The first three-dimensional moving platform and the second three-dimensional moving platform are symmetrically arranged on the horizontal platform inside the vacuum chamber.

[0016] According to one aspect of the present invention, the three-dimensional mobile platform includes: a first linear drive, a second linear drive arranged on the first linear drive, and a rotating platform arranged on the second linear drive;

[0017] The driving direction of the first linear drive is parallel to the axial direction of the vacuum chamber;

[0018] The driving direction of the second linear drive is perpendicular to the axial direction of the vacuum chamber;

[0019] The rotation direction of the rotating platform is perpendicular to the axial direction of the vacuum chamber, and the rotating platform can rotate within a range of plus or minus 30 degrees;

[0020] The detection structure is installed on the outer edge of the rotating platform, and the detection structure is oriented perpendicular to the axial direction of the vacuum chamber.

[0021] According to one aspect of the present invention, each of the detection structures (142) is respectively provided with a power supply for driving the probe to operate;

[0022] If the detection structure adopts a Langmuir probe, each of the detection structures is respectively provided with a power supply, which is used for independent operation in a single-probe mode to perform continuous and rapid measurement of the spatial distribution of the characteristic parameters of the ion body and symmetrical operation to perform symmetry measurement of the spatial distribution of the ion body plume, or each of the detection structures is connected to the same power supply for continuous and rapid measurement of the spatial distribution of the characteristic parameters of the ion body in a dual-probe mode;

[0023] If the detection structure adopts an RPA probe, each of the detection structures is respectively provided with a power supply for independently operating in a single-probe mode to measure the ion energy distribution of the thruster plume and symmetrically operating to measure the symmetry of the ion energy distribution of the thruster plume;

[0024] If the detection structure adopts a Faraday probe, each detection structure is respectively provided with a power supply for independently operating in a single-probe mode to measure the plume divergence angle and symmetrically operating to measure the symmetry of the plume divergence angle.

[0025] According to one aspect of the present invention, a plurality of inductors are arranged in series at one end of the detection structure connected to the collection unit;

[0026] The resonance frequencies of the plurality of inductors are different from each other.

[0027] According to one aspect of the present invention, the inductor includes: a manganese-zinc ferrite core, and a wire wound around the manganese-zinc ferrite core.

[0028] According to one aspect of the present invention, the acquisition unit adopts a current sampling circuit, wherein the current sampling circuit is a sampling circuit with a high input common mode rejection ratio;

[0029] An operational amplifier active filter circuit is provided in the signal input pre-stage amplifier and the current pickup differential amplifier of the current sampling circuit;

[0030] A compensation resistor having the same resistance as the sampling resistor is connected in series to one end of the current pickup differential amplifier close to the probe scanning voltage source.

[0031] To achieve the above-mentioned object of the invention, the present invention provides a measurement method using the aforementioned plasma thruster plume parameter multi-point measurement device, wherein the detection structure uses a Langmuir probe, an RPA probe or a Faraday probe; comprising:

[0032] S1. The plasma thruster to be tested is installed on the mounting position of the vacuum chamber, and the vacuum chamber is evacuated and maintained through the industrial control unit and the vacuum pump unit;

[0033] S2. The plurality of detection structures in the measuring unit are connected to different power supplies and used as two sets of single probes;

[0034] S3. The plurality of three-dimensional mobile platforms in the measuring unit drive the detection structure to move independently or symmetrically in the plume region generated by the plasma thruster according to the planned path;

[0035] S4. Obtaining the IV curves corresponding to the detection structures respectively, and deriving the plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential;

[0036] S5. Repeat steps S3 to S4 to obtain the spatial distribution of plasma characteristic parameters in the plume region, or obtain the spatial distribution of thruster plume ion energy, or obtain the plume divergence angle.

[0037] To achieve the above-mentioned object of the invention, the present invention provides a measurement method using the aforementioned plasma thruster plume parameter multi-point measurement device, wherein the detection structure uses a Langmuir probe; comprising:

[0038] S1. The plasma thruster to be tested is installed on the mounting position of the vacuum chamber, and the vacuum chamber is evacuated and maintained through the industrial control unit and the vacuum pump unit;

[0039] S2. The plurality of detection structures in the measurement unit are connected to the same power supply and used as a set of dual probes;

[0040] S3. The plurality of three-dimensional mobile platforms in the measuring unit drive the detection structure to move symmetrically in the plume region generated by the plasma thruster according to the planned symmetrical paths;

[0041] S4. Obtaining the IV curves corresponding to the detection structures respectively, and deriving the plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential;

[0042] S5. Repeat steps S3 to S4 to obtain the spatial distribution of plasma characteristic parameters in the plume region.

[0043] According to one solution of the present invention, the present invention can improve the plasma measurement efficiency, can continuously measure the multi-point symmetry of the plume, break the limitations of the use of Langmuir probes, and shield the error interference in the probe circuit. At the same time, the multi-point measurement device of the present invention has a simple structure, is stable and reliable, and has strong practicality.

[0044] According to one solution of the present invention, the present invention can realize the combined use of a single probe and a double probe, can reduce the probe signal noise, and is an efficient plasma diagnostic device with a simple structure and a stable and reliable system.

[0045] According to one solution of the present invention, the present invention can realize the combined use of multiple measurement sensors, replace the Langmuir probe with an RPA probe or a Faraday probe, and realize the measurement of the electric thruster plume ion energy distribution and the plume divergence angle. It is a modular multifunctional plume plasma diagnostic device.

[0046] According to one solution of the present invention, the multi-point measurement device of the present invention can be implemented for accurate simulation of space plasma environment, spacecraft life test and failure verification, and serving space flight missions in different fields. Especially in the field of plasma thruster plume area parameter measurement and symmetry verification, the present invention can achieve rapid, high-precision and continuous measurement of plasma thruster plume area parameters by relying on its excellent performance; at the same time, it also has the advantages of verifying the symmetry of the plume and obtaining the startup performance of the plasma thruster.

[0047] According to one solution of the present invention, the solution of the present invention utilizes two upper and lower three-dimensional moving platforms to move the probe to different positions, thereby enabling rapid and continuous measurement without opening the vacuum chamber.

[0048] According to one solution of the present invention, the solution of the present invention can be flexibly adjusted according to different test environments and conditions by adopting a single-probe and dual-probe combination technology, thereby being able to minimize discharge interference and avoid distortion of the IV characteristic curve.

[0049] According to one solution of the present invention, a high-impedance isolation filter is installed at the rear end of the probe tip to isolate the interference noise received by the tip; and an operational amplifier active filter circuit and a high input common-mode rejection ratio sampling circuit are set in the current sampling circuit to further improve the measurement accuracy and ensure the excellent use effect of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic front view of a plasma thruster plume parameter multi-point measurement device according to an embodiment of the present invention is shown;

[0051] Figure 2 A cross-sectional top view schematically showing a plasma thruster plume parameter multi-point measurement device according to an embodiment of the present invention;

[0052] Figure 3 The diagram schematically shows the variation of the impedance of the isolation resonant inductor with frequency according to one embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0054] When describing the embodiments of the present invention, the orientation or positional relationship expressed by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the relevant drawings and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0055] Combination Figure 1 and Figure 2 As shown, according to one embodiment of the present invention, a plasma thruster plume parameter multi-point measurement device of the present invention comprises: a vacuum chamber 11; a vacuum pump unit 12 connected to the vacuum chamber 11; an industrial control unit 13 connected to the vacuum pump unit 12, used to provide and maintain the vacuum environment of the vacuum chamber 11; and a measurement unit 14. In this embodiment, the vacuum chamber is a hollow columnar body, and its opposite ends are respectively sealed by a cover body with an arc-shaped cross section, so that its internal space can be evacuated to be hollow, ensuring the normal conduct of the experiment.

[0056] In this embodiment, a mounting position 111 for mounting a plasma thruster is provided on at least one axial end face of the vacuum chamber 11, that is, a mounting position 111 penetrating the cover body is provided on the cover body at at least one end of the vacuum chamber. In this embodiment, the mounting position 111 is located in the middle position of the cover body, so that the mounting position is in a protruding position on the cover body, which is very conducive to the installation and removal of the device to be tested. In this embodiment, the mounting position 111 penetrates the wall of the vacuum chamber 11 and can be opened and closed. When the device to be tested needs to be installed, it is an opening and is sealed after being installed and connected with the device to be tested. When the device to be tested is not installed, it is sealed by a structural member and is removed only when the device to be tested needs to be installed. In this embodiment, an observation window 112 and an electric vacuum flange for connecting the electrical circuits of the equipment inside the vacuum chamber and the equipment outside the chamber are provided on the side wall of the vacuum chamber 11. In this embodiment, a plurality of observation windows 112 can be arranged in sequence along the axial direction on the side wall of the vacuum chamber 11, and each observation window 112 is sealed with a transparent structural member to achieve observation of the operation process in the chamber.

[0057] Combination Figure 1 and Figure 2 As shown, in this embodiment, the measuring unit 14 includes: at least two three-dimensional mobile platforms 141 disposed in the vacuum chamber 11; a detection structure 142 disposed on the three-dimensional mobile platform 141; and a collection unit connected to the detection structure 142 for collecting data. In this embodiment, the detection structure 142 adopts a Langmuir probe, an RPA probe or a Faraday probe.

[0058] like Figure 1 As shown, according to one embodiment of the present invention, the vacuum chamber 11 is horizontally arranged. In this embodiment, there are two three-dimensional mobile platforms 141, namely, a first three-dimensional mobile platform 141a and a second three-dimensional mobile platform 141b; wherein, the first three-dimensional mobile platform 141a and the second three-dimensional mobile platform 141b are relatively arranged on the horizontal platform inside the vacuum chamber 11, and the first three-dimensional mobile platform 141a and the second three-dimensional mobile platform 141b are arranged symmetrically to each other. In this embodiment, the first three-dimensional mobile platform 141a and the second three-dimensional mobile platform 141b are symmetrically arranged on the left and right sides of the plume area.

[0059] like Figure 1 As shown, according to one embodiment of the present invention, the three-dimensional mobile platform 141 includes: a first linear drive 1411, a second linear drive 1412 arranged on the first linear drive 1411, and a rotating platform 1413 arranged on the second linear drive 1412. In this embodiment, the driving direction of the first linear drive 1411 is parallel to the axial direction of the vacuum chamber 11; the driving direction of the second linear drive 1412 is perpendicular to the axial direction of the vacuum chamber 11; the rotation direction of the rotating platform 1413 is perpendicular to the axial direction of the vacuum chamber 11 (that is, the rotation axis of the rotating platform 1413 is perpendicular to the axial direction of the vacuum chamber 11), and the rotating platform 1413 can rotate within a range of plus or minus 30 degrees. In this embodiment, the detection structure 142 is installed on the outer edge of the rotating platform 1413, and the probe direction is perpendicular to the axial direction of the vacuum chamber 11.

[0060] According to an embodiment of the present invention, each detection structure 142 is respectively provided with a power supply for driving the probe to operate.

[0061] If the detection structure 142 uses a Langmuir probe, when each detection structure 142 is respectively provided with a power supply, each detection structure 142 is respectively in a different circuit. Then, when the multi-point measurement device of the present invention is in use, the detection structure 142 can be moved to the starting position by the corresponding three-dimensional mobile platform 141. The two detection structures 142 are located in two circuits (single probe mode), and the IV curves are drawn independently to derive important parameters such as the electron temperature, density, energy distribution and plasma potential of the plasma. Then, the important parameters such as the electron temperature, density, energy distribution and plasma potential of the plasma at different positions are measured in turn according to the planned route. Continuous and rapid measurement of the spatial distribution of plasma characteristic parameters is achieved. Alternatively, when the multi-point measurement device of the present invention is in use, the two detection structures 142 can be moved to symmetrical positions by the corresponding three-dimensional mobile platform 141, so that the symmetry of the spatial distribution of the plasma plume can be measured, and the plasma thruster can be started. If the plasma parameters detected by the two Langmuir probes are the same, it means that the plume of the plasma thruster is symmetrically distributed in space; if the plasma parameters detected by the two Langmuir probes are different, or the parameter difference between the two measurement points exceeds the permitted range, the plume of the plasma thruster is asymmetrically distributed in space. Further, when measuring the starting performance of the plasma thruster, the time from when the thruster receives the ignition command to when the parameters of the two Langmuir probes (position symmetry) are the same can be recorded to characterize the starting performance of the plasma thruster.

[0062] When each detection structure 142 is connected to the same power supply, the two detection structures 142 are in the same circuit. At this time, the detection structure 142 realizes a dual-probe mode when there is no suitable reference point at the use site or the discharge current is too large. The two detection structures 142 are respectively connected to the positive and negative poles of the same power supply, and the two detection structures 142 are moved to the same position by the three-dimensional mobile platform 141. Since the net current collected by the two Langmuir probes is zero, their potentials are lower than the plasma potential; if the potential difference between the two Langmuir probes is not equal to zero, the current will flow between the two Langmuir probes. When the voltage is very large, the probe with a lower potential is basically equal to the ion saturation current, which is equal to the electron saturation current collected by the other probe, so it can minimize the interference of the discharge current and avoid distortion of the IV characteristic curve.

[0063] If the detection structure 142 uses an RPA probe (ion energy analyzer), each detection structure 142 is respectively provided with a power supply for independent operation in single-probe mode to measure the ion energy distribution of the thruster plume and symmetrical operation to measure the symmetry of the ion energy distribution of the thruster plume. In this embodiment, there is no dual-probe mode.

[0064] If the detection structure 142 uses a Faraday probe (Faraday ring), each detection structure 142 is respectively provided with a power supply for independent operation in single-probe mode to measure the plume divergence angle and symmetrical operation to measure the symmetry of the plume divergence angle. In this embodiment, there is no dual-probe mode.

[0065] According to the present invention, the multi-point measurement device of the present invention can realize the single-probe and double-probe combination modes, can maximize the measurement efficiency, and can effectively avoid the distortion of the IV characteristic curve.

[0066] According to an embodiment of the present invention, a plurality of inductors are arranged in series at one end of the detection structure 142 connected to the collection unit. In this embodiment, the resonance frequencies of the plurality of inductors are different from each other.

[0067] Through the above arrangement, multiple inductors connected in series can form a large impedance, which can achieve the purpose of isolating the noise received by the tip of the detection structure 142, which is beneficial to improving the detection accuracy of the present solution. In addition, since the impedance of the inductor reaches the maximum at the resonant frequency, the multiple inductors arranged in series can form a very high impedance to noise within a wide frequency range, which is beneficial to further effectively isolating the interference noise received on the tip. The effect of the change of the isolation impedance with frequency can be seen in Figure 3 shown.

[0068] In this implementation, the inductor includes: a manganese-zinc ferrite core, and a wire wound around the manganese-zinc ferrite core, which can significantly reduce radio frequency interference.

[0069] like Figure 1 As shown, according to one embodiment of the present invention, the acquisition unit adopts a current sampling circuit, wherein the current sampling circuit is a sampling circuit with a high input common mode rejection ratio. In this embodiment, an operational amplifier active filter circuit is set in the signal input preamplifier and the current pickup differential amplifier of the current sampling circuit; in the current sampling circuit, the interference signal in the process of collecting the signal is further effectively filtered out by the setting of the signal input preamplifier and the active filter circuit, and the electromagnetic interference received by the cables inside and outside the vacuum environment can be effectively filtered out, so that the detection accuracy of the present invention is better. In this embodiment, the current sampling circuit is a sampling circuit with a high input common mode rejection ratio, and then because the bias voltage and the interference signal are common mode signals for the differential amplifier circuit, and the Langmuir probe current is a differential mode signal, then the current sampling circuit of this scheme can effectively ensure that the differential amplifier circuit only measures the differential mode signal. At the same time, in this embodiment, a compensation resistor with the same resistance as the sampling resistor is connected in series at one end of the current pickup differential amplifier close to the probe scanning voltage source, so as to effectively compensate for the voltage imbalance between the two input ends of the differential amplifier circuit caused by the sampling resistor, and further ensure the measurement accuracy of the present invention.

[0070] like Figure 1 As shown, according to an embodiment of the present invention, a measurement method of the present invention using the aforementioned plasma thruster plume parameter multi-point measurement device, the detection structure 142 uses a Langmuir probe, including:

[0071] S1. The plasma thruster to be tested is installed on the mounting position 111 of the vacuum chamber 11, and the vacuum chamber 11 is evacuated and maintained through the industrial control unit 13 and the vacuum pump unit 12;

[0072] S2. The plurality of detection structures 142 in the measuring unit 14 are connected to different power supplies and used as two sets of single probes;

[0073] S3. The multiple three-dimensional mobile platforms 141 in the measuring unit 14 drive the detection structure 142 to move independently or symmetrically in the plume area generated by the plasma thruster according to the planned path;

[0074] S4. Obtaining the IV curves corresponding to the detection structures 142 respectively, and deriving the plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential;

[0075] S5. Repeat steps S3 to S4 to obtain the spatial distribution of plasma characteristic parameters in the plume region.

[0076] According to one embodiment of the present invention, another embodiment of the present invention adopts the measurement method of the plasma thruster plume parameter multi-point measurement device described above, and the detection structure 142 adopts an RPA probe, including:

[0077] S1. The plasma thruster to be tested is installed on the mounting position 111 of the vacuum chamber 11, and the vacuum chamber 11 is evacuated and maintained through the industrial control unit 13 and the vacuum pump unit 12;

[0078] S2. The plurality of detection structures 142 in the measuring unit 14 are connected to different power supplies and used as two sets of single probes;

[0079] S3. The multiple three-dimensional mobile platforms 141 in the measuring unit 14 drive the detection structure 142 to move independently or symmetrically in the plume area generated by the plasma thruster according to the planned path;

[0080] S4. Obtaining the IV curves corresponding to the detection structures 142 respectively, and deriving the plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential;

[0081] S5. Repeat steps S3 to S4 to obtain the spatial distribution of thruster plume ion energy.

[0082] According to one embodiment of the present invention, another embodiment of the present invention adopts the measurement method of the plasma thruster plume parameter multi-point measurement device described above, and the detection structure 142 adopts a Faraday probe, including:

[0083] S1. The plasma thruster to be tested is installed on the mounting position 111 of the vacuum chamber 11, and the vacuum chamber 11 is evacuated and maintained through the industrial control unit 13 and the vacuum pump unit 12;

[0084] S2. The plurality of detection structures 142 in the measuring unit 14 are connected to different power supplies and used as two sets of single probes;

[0085] S3. The multiple three-dimensional mobile platforms 141 in the measuring unit 14 drive the detection structure 142 to move independently or symmetrically in the plume area generated by the plasma thruster according to the planned path;

[0086] S4. Obtaining the IV curves corresponding to the detection structures 142 respectively, and deriving the plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential;

[0087] S5. Repeat steps S3 to S4 to obtain the plume divergence angle.

[0088] like Figure 1 As shown, according to another embodiment of the present invention, a measurement method of the plasma thruster plume parameter multi-point measurement device according to the present invention, the detection structure 142 adopts a Langmuir probe and includes:

[0089] S1. The plasma thruster to be tested is installed on the mounting position 111 of the vacuum chamber 11, and the vacuum chamber 11 is evacuated and maintained through the industrial control unit 13 and the vacuum pump unit 12;

[0090] S2. The plurality of detection structures 142 in the measuring unit 14 are connected to the same power supply and used as a set of dual probes;

[0091] S3. The multiple three-dimensional mobile platforms 141 in the measuring unit 14 drive the detection structure 142 to move symmetrically in the plume area generated by the plasma thruster according to the planned symmetrical path;

[0092] S4. Obtaining the IV curves corresponding to the detection structures 142 respectively, and deriving the plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential;

[0093] S5. Repeat steps S3 to S4 to obtain the spatial distribution of plasma characteristic parameters in the plume region.

[0094] The above contents are merely examples of specific solutions of the present invention. For devices and structures not described in detail therein, it should be understood that they can be implemented by adopting general devices and general methods available in the art.

[0095] The above is only one solution of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A plasma thruster plume parameter multi-point measurement device, characterized in that: include: A vacuum chamber (11); a vacuum pump unit (12) connected to the vacuum chamber (11); an industrial control unit (13) connected to the vacuum pump unit (12), used for providing and maintaining a vacuum environment of the vacuum chamber (11); and a measuring unit (14); The measuring unit (14) comprises: at least two three-dimensional moving platforms (141) arranged in the vacuum chamber (11); A detection structure (142) disposed on the three-dimensional mobile platform (141) is connected to different power supplies and used as two groups of single probes, or is connected to the same power supply and used as a group of double probes; a collection unit connected to the detection structure (142) and used to collect data; the vacuum chamber (11) is a hollow columnar body, and a mounting position (111) for mounting a plasma thruster is provided on at least one axial end face of the vacuum chamber (11); The installation position (111) penetrates the wall of the vacuum chamber (11) and is openable and closable; The vacuum chamber (11) is arranged horizontally; There are two three-dimensional mobile platforms (141), namely a first three-dimensional mobile platform (141a) and a second three-dimensional mobile platform (141b); The first three-dimensional mobile platform (141a) and the second three-dimensional mobile platform (141b) are symmetrically arranged on a horizontal platform inside the vacuum chamber (11); the three-dimensional mobile platform (141) comprises a first linear drive (1411), and the driving direction of the first linear drive (1411) is parallel to the axial direction of the vacuum chamber (11); The detection structure (142) adopts a Langmuir probe, an RPA probe or a Faraday probe.

2. The plasma thruster plume parameter multi-point measurement device according to claim 1, characterized in that: An observation window (112) and an electric vacuum flange are provided on the side wall of the vacuum chamber (11).

3. The plasma thruster plume parameter multi-point measurement device according to claim 1, characterized in that: The three-dimensional moving platform (141) further comprises: a second linear drive (1412) arranged on the first linear drive (1411), and a rotating platform (1413) arranged on the second linear drive (1412); The driving direction of the second linear drive (1412) is perpendicular to the axial direction of the vacuum chamber (11); The rotation direction of the rotating platform (1413) is perpendicular to the axial direction of the vacuum chamber (11), and the rotating platform (1413) can rotate within a range of plus or minus 30 degrees; The detection structure (142) is mounted on the outer edge of the rotating platform (1413), and the detection structure (142) is oriented perpendicular to the axial direction of the vacuum chamber (11).

4. The plasma thruster plume parameter multi-point measurement device according to any one of claims 1 to 3, characterized in that: Each of the detection structures (142) is respectively provided with a power supply for driving the probe to operate; If the detection structure (142) adopts a Langmuir probe, each detection structure (142) is respectively provided with a power supply, which is used for independently operating in a single-probe mode to perform continuous and rapid measurement of the spatial distribution of ion characteristic parameters and symmetrically operating to perform symmetry measurement of the spatial distribution of ion plumes, or each detection structure (142) is connected to the same power supply to perform continuous and rapid measurement of the spatial distribution of ion characteristic parameters in a dual-probe mode; If the detection structure (142) adopts an RPA probe, each detection structure (142) is respectively provided with a power supply for independently operating in a single-probe mode to measure the ion energy distribution of the thruster plume and symmetrically operating to measure the symmetry of the ion energy distribution of the thruster plume; If the detection structure (142) adopts a Faraday probe, each detection structure (142) is respectively provided with a power supply for independently operating in a single-probe mode to measure the plume divergence angle and symmetrically operating to measure the symmetry of the plume divergence angle.

5. The plasma thruster plume parameter multi-point measurement device according to claim 4, characterized in that: A plurality of inductors are arranged in series at one end of the detection structure (142) connected to the collection unit; The resonance frequencies of the plurality of inductors are different from each other.

6. The plasma thruster plume parameter multi-point measurement device according to claim 5, characterized in that: The inductor comprises: a manganese-zinc ferrite core and a conducting wire wound around the manganese-zinc ferrite core.

7. The plasma thruster plume parameter multi-point measurement device according to claim 4, characterized in that: The acquisition unit adopts a current sampling circuit, wherein the current sampling circuit is a sampling circuit with a high input common mode rejection ratio; An operational amplifier active filter circuit is provided in the signal input pre-stage amplifier and the current pickup differential amplifier of the current sampling circuit; A compensation resistor having the same resistance as the sampling resistor is connected in series to one end of the current pickup differential amplifier close to the probe scanning voltage source.

8. A measurement method using the plasma thruster plume parameter multi-point measurement device according to any one of claims 1 to 7, characterized in that: The detection structure (142) uses a Langmuir probe, an RPA probe or a Faraday probe; and comprises: S1. The plasma thruster to be tested is mounted on the mounting position (111) of the vacuum chamber (11), and the vacuum chamber (11) is evacuated and maintained through the industrial control unit (13) and the vacuum pump unit (12); S2. The plurality of detection structures (142) in the measuring unit (14) are respectively connected to different power supplies and used as two sets of single probes; S3. The plurality of three-dimensional mobile platforms (141) in the measuring unit (14) drive the detection structure (142) to move independently or symmetrically in the plume region generated by the plasma thruster according to the planned path; S4. Obtaining the IV curves corresponding to each of the detection structures (142) respectively, and deriving plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential; S5. Repeat steps S3 to S4 to obtain the spatial distribution of plasma characteristic parameters in the plume region, or obtain the spatial distribution of thruster plume ion energy, or obtain the plume divergence angle.

9. A measurement method using the plasma thruster plume parameter multi-point measurement device according to any one of claims 1 to 7, characterized in that: The detection structure (142) uses a Langmuir probe; comprising: S1. The plasma thruster to be tested is mounted on the mounting position (111) of the vacuum chamber (11), and the vacuum chamber (11) is evacuated and maintained through the industrial control unit (13) and the vacuum pump unit (12); S2. The plurality of detection structures (142) in the measurement unit (14) are connected to the same power supply and used as a set of dual probes; S3. The plurality of three-dimensional mobile platforms (141) in the measuring unit (14) respectively drive the detection structure (142) to move symmetrically in the plume region generated by the plasma thruster according to the planned symmetrical paths; S4. Obtaining the IV curves corresponding to each of the detection structures (142) respectively, and deriving plasma characteristic parameters; wherein the plasma characteristic parameters include: electron temperature, density, energy distribution and plasma potential; S5. Repeat steps S3 to S4 to obtain the spatial distribution of plasma characteristic parameters in the plume region.

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