A probe structure

Abstract

The application provides a probe structure, which comprises an electrically insulating mounting assembly and a signal collecting module arranged at one end of the electrically insulating mounting assembly; the signal collecting module comprises two probe probes which are mutually insulated and arranged along the same extension direction, one of the probe probes has a first collecting surface, and the other probe probe has a second collecting surface; the first collecting surface and the second collecting surface are jointly located at an end region of the signal collecting module; the first collecting surface and the second collecting surface are arranged in mutual perpendicularity; the normal of the first collecting surface is perpendicular to the direction of a plasma flow field; and the normal of the second collecting surface is parallel to the direction of the plasma flow field. According to the application, the technical problem that parallel collecting surfaces and perpendicular collecting surfaces are usually distributed at different positions, resulting in local measurement accuracy, can be solved.

Description

Technical Field

[0001] This invention relates to the field of plasma diagnostics and electric propulsion plume testing technology, specifically to a probe structure. Background Technology

[0002] When an electric propulsion device is in operation, it ejects a supersonic, high-speed, directional plasma plume. The flow Mach number and flow velocity are key parameters characterizing the plume's properties, and their accurate measurement is an important basis for evaluating and optimizing electric propulsion performance.

[0003] A Mach probe is an interventional plasma diagnostic device, developed from the Langmuir probe, used to measure local plasma velocity or Mach number. It offers advantages such as simple structure, fast response, and high spatial resolution. A traditional Mach probe typically consists of two Langmuir probes arranged back-to-back and separated by an insulating partition. One probe faces the incoming flow direction, while the other faces away. The plasma flow Mach number is calculated by comparing the ion saturation currents collected by the two probes. This type of probe is mainly suitable for subsonic or near-sonic plasma flow fields. In supersonic directional plume environments, the upstream probe significantly obstructs and disturbs the flow field near the downstream probe, leading to increased measurement errors and limiting its applicability.

[0004] To address the shortcomings of traditional back-to-back Mach probes in supersonic plume environments, existing technologies have further proposed a Mach probe structure combining parallel and perpendicular collection surfaces. This structure collects ion saturation currents parallel and perpendicular to the flow field direction separately, and uses the relationship between the two to invert the Mach number and flow velocity parameters. This avoids the flow field obstruction effect between traditional back-to-back probes and improves the measurement capability under supersonic directional plume conditions.

[0005] However, with the increasing demand for near-field diagnostics of electrically propelled plumes, existing technologies have proposed a parallel-vertical Mach probe. This probe employs two independent collection modules to measure ion saturation current in the parallel and vertical directions, respectively. The two collection surfaces are installed in support structures or mounting channels in two different directions, with a fixed spatial interval between their measurement positions. However, the existing parallel-vertical Mach probe structure still has the following shortcomings:

[0006] Because the parallel and vertical collecting surfaces of existing Mach probes are typically located in different spatial positions, and there is a certain spatial interval between their corresponding measurement areas, it is difficult to achieve approximately synchronous sampling of the same local plasma state, i.e., it is difficult to establish a quasi-co-located measurement relationship. In the near-field region of electrically propelled plumes, parameters such as electron density, ion density, and flow velocity often have large spatial gradients. The ion saturation currents collected by the two collecting surfaces may correspond to different local plasma states, thus introducing local mismatch errors and affecting the accuracy and spatial consistency of Mach number and flow velocity diagnostic results.

[0007] Since the parallel and vertical collection surfaces in existing technologies are usually distributed in different locations, leading to technical problems such as local measurement accuracy, this invention studies and designs a probe structure. Summary of the Invention

[0008] Therefore, the present invention provides a probe structure that can solve the technical problem in the prior art where the parallel collection surface and the vertical collection surface are usually distributed in different positions, resulting in local measurement accuracy.

[0009] To address the above problems, the present invention provides a probe structure, comprising: an electrically insulating mounting assembly and a signal collection module disposed at one end of the electrically insulating mounting assembly;

[0010] The signal collection module includes two mutually insulated probes arranged along the same extension direction. One probe has a first collection surface and the other probe has a second collection surface. The first and second collection surfaces are located in the end region of the signal collection module. The first and second collection surfaces are arranged orthogonally to each other. The normal of the first collection surface is perpendicular to the plasma flow field direction, and the normal of the second collection surface is parallel to the plasma flow field direction.

[0011] In some embodiments, the signal collection module further includes two probe connectors, which are arranged one-to-one with the probe probes. The probe connectors have probe connection holes at the ends facing the probe probes for detachably inserting the probe probes, and lead wire connection holes at the ends facing away from the probe probes for connecting signal leads.

[0012] In some embodiments, the electrical insulation mounting assembly includes an insulating base module, the insulating base module including a third base, one end of the third base having a first inclined surface and a second inclined surface, the normals of the first inclined surface and the second inclined surface being perpendicular to each other, a first probe embedding hole being provided on both the first inclined surface and the second inclined surface, the probe being inserted into the first probe embedding hole, and the first collecting surface being located in the same plane as the first inclined surface, and the second collecting surface being located in the same plane as the second inclined surface.

[0013] In some embodiments, the third base is provided with two second probe embedding holes, which are arranged in a one-to-one correspondence with the two first probe embedding holes. The second probe embedding holes are connected to the first probe embedding holes to form a through-hole structure. The through-hole structure penetrates the third base. Along the extension direction of the probe, the probe has a first segment and a second segment. The first segment is embedded in the first probe embedding hole, and the second segment passes through the second probe embedding hole and is connected to the probe connector.

[0014] In some embodiments, the insulating base module further includes a second base with two second recessed holes, which are arranged in a one-to-one correspondence with the two probe connectors. Along the axial direction of the probe, the second base abuts against the third base, and the probe connector can be partially inserted into the second recessed holes. The probe passes through the through-hole structure and is then inserted into the probe connector.

[0015] In some embodiments, the insulating base module further includes a first base, which abuts against the second base along the axial direction of the probe. The second base is provided with two first recessed holes, which are arranged in a one-to-one correspondence with the two probe connectors. The remaining part of the probe connector can be inserted into the second recessed hole.

[0016] In some embodiments, the outer peripheral wall of the probe connector has a connector limiting structure, and the first base is also provided with two connector limiting holes. The two connector limiting holes are arranged in a one-to-one correspondence with the two first embedded holes. The connector limiting holes are connected to the first embedded holes. The diameter of the connector limiting holes is larger than the diameter of the first embedded holes. The probe connector passes through the connector limiting holes and is inserted into the first embedded holes, and the connector limiting structure is embedded in the connector limiting holes.

[0017] In some embodiments, the electrical insulation mounting assembly further includes an insulating sleeve having, along the axial direction of the insulating sleeve, a third base limiting hole and an insulating base recessed hole that are interconnected. The diameter of the third base limiting hole is larger than the diameter of the insulating base recessed hole. A limiting step is provided on the third base. The third base, the second base, and the first base are fitted into the insulating base recessed hole. One end of the third base extends out of the insulating sleeve after passing through the third base limiting hole, so that a portion of the probe protrudes out of the insulating sleeve. The outer diameter of the limiting step matches the inner diameter of the insulating base recessed hole.

[0018] In some embodiments, the probe structure further includes a support base, one end of which is provided with a base limiting hole. Along the axial direction of the first embedded hole, the outer peripheral wall of the first base has a fifth segment and a sixth segment. The outer diameter of the fifth segment is larger than the outer peripheral dimension of the sixth segment in the corresponding direction. The sixth segment is inserted into the base limiting hole. The outer diameter of the fifth segment is larger than the inner diameter of the base limiting hole. The axial portion of the support base is inserted into the insulating sleeve and detachably connected to the insulating sleeve.

[0019] In some embodiments, the support base includes a third segment and a fourth segment, the base limiting hole is disposed at the end of the third segment, the third segment is inserted into the insulating sleeve along the axial direction and is detachably connected to the insulating sleeve, and with the axial section of the support base as the projection plane, there is an angle between the central axis of the third segment and the central axis of the fourth segment, the angle satisfying that the central axis of the fourth segment is parallel to the normal of the first collection surface.

[0020] The probe structure provided by this invention has the following beneficial effects:

[0021] Since both the first and second collection surfaces are located in the same end region of the signal collection module, the distance between their corresponding plasma sampling positions is significantly reduced. This results in the signals collected in both directions corresponding to approximately the same local plasma state, creating a quasi-isositu measurement effect. Therefore, in an electrically propelled plume environment with a significant spatial gradient, this reduces diagnostic errors caused by differences in measurement positions and improves the accuracy of flow velocity and Mach number measurements. Attached Figure Description

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the probe structure of the present invention;

[0024] Figure 2 This is an exploded view of the probe structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the signal collection module in the probe structure of the present invention;

[0026] Figure 4 This is a schematic diagram of the third base in the probe structure of the present invention;

[0027] Figure 5This is a schematic diagram of the second base in the probe structure of the present invention;

[0028] Figure 6 This is a schematic diagram of the structure of the first base in the probe structure of the present invention;

[0029] Figure 7 This is a bottom view of the first base in the probe structure of the present invention;

[0030] Figure 8 This is a schematic diagram of the insulating base in the probe structure of the present invention;

[0031] Figure 9 This is a schematic diagram of the support base in the probe structure of the present invention.

[0032] The attached figures are labeled as follows:

[0033] 1. Signal collection module; 11. Probe; 111a. First collection surface; 111b. Second collection surface; 12. Probe connector; 121. Probe connection hole; 122. Connector limiting structure; 123. Lead wire connection hole; 2. Insulating base module; 21. First base; 211. Connector limiting hole; 212. First embedded hole; 213. First base limiting structure; 22. Second base; 221. Second embedded hole; 23. Third base; 231a. First inclined surface; 231b. Second inclined surface; 232. First probe embedded hole; 233. Second probe embedded hole; 234. Limiting step; 3. Insulating sleeve; 31. Third base limiting hole; 32. Insulating base embedded hole; 33. Fixing through hole; 4. Support base; 41. Base limiting hole; 42. Threaded hole; 43. Mounting chassis. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0036] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0037] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0038] See also Figure 1-8 As shown, according to an embodiment of the present invention, a probe structure is provided, including: an electrically insulating mounting assembly and a signal collection module 1 disposed at one end of the electrically insulating mounting assembly;

[0039] The signal collection module 1 includes two mutually insulated probes 11 arranged along the same extension direction. One probe 11 has a first collection surface 111a and the other probe 11 has a second collection surface 111b. The first collection surface 111a and the second collection surface 111b are located in the end region of the signal collection module 1. They are orthogonal to each other and spatially adjacent to each other to form a miniature quasi-isositu measurement structure.

[0040] The normal direction of the first collecting surface 111a is perpendicular to the plasma flow field direction, and the normal direction of the second collecting surface 111b is parallel to the plasma flow field direction.

[0041] In this technical solution, two probes 11 are insulated from each other and arranged along the same extension direction. The ends of the two probes 11 respectively form a first collection surface 111a and a second collection surface 111b. The first collection surface 111a and the second collection surface 111b are located in the end region of the signal collection module 1. They are orthogonal to each other and spatially adjacent to each other to form a miniature quasi-synchronous measurement structure. The normal direction of the first collection surface 111a is perpendicular to the plasma flow field direction, and the normal direction of the second collection surface 111b is parallel to the plasma flow field direction.

[0042] Since the first collection surface 111a and the second collection surface 111b are both located in the end region of the signal collection module and the spatial distance between them is small, the plasma sampling areas corresponding to the two collection surfaces are highly adjacent. They can be considered to be in approximately the same local plasma state, thereby achieving quasi-isositu measurement of the core parameters of plasma Mach number and flow velocity, ensuring the measurement accuracy of ion saturation current in the parallel and perpendicular directions in the local space, reducing the measurement mismatch error caused by spatial gradient, and improving the authenticity and spatial consistency of the flow parameter diagnosis results.

[0043] It should be noted that the probe structure of this invention is an integrated plasma diagnostic probe, adapted to the supersonic, high-speed directional plasma plumes of electric propulsion devices, and can simultaneously acquire the core parameters of the plume plasma Mach number and velocity. The probe body has an electrically insulating encapsulation structure, using insulating materials such as ceramics and high-temperature resistant insulating polymers for integrated encapsulation. This isolates the internal conductive components of the probe from the external plasma environment, avoiding signal interference and short circuits, while also improving the structural stability and corrosion resistance of the probe in vacuum and high-temperature plume environments.

[0044] The two conductive collecting surfaces at the probe tip are the core components for collecting plasma current. The normal of the first collecting surface 111a is perpendicular to the plume flow direction. Its core principle is that when the collecting surface normal is perpendicular to the high-speed directional flow field, the component of the macroscopic flow velocity in the collecting surface normal direction is significantly reduced, thus greatly weakening its influence on the ion saturation current. The collection process of the ion saturation current is mainly constrained by the Bohm criterion. Under the conditions that the electron temperature of the electrically propelled plume is much higher than the ion temperature and that it is unmagnetized or weakly magnetized, the ion saturation current obtained by this collecting surface can be approximately described using a planar Langmuir probe collecting model. The measurement process is as follows: a preset fixed negative bias voltage is applied to the first collecting surface 111a to stably collect the ion saturation current perpendicular to the flow field direction. This current is not sensitive to the macroscopic flow velocity of the plume and is mainly determined by the plasma density, the ion sound velocity corresponding to the electron temperature, and the sheath collection conditions.

[0045] The normal of the second collecting surface 111b is parallel to the plume flow direction. Its core principle is that when the collecting surface normal is parallel to the high-speed directional flow field, the pre-sheath of the collecting surface tends to disappear. This can be approximated as ions being collected by the collecting surface at a macroscopic flow velocity, and the magnitude of the ion saturation current is positively correlated with the flow field velocity. The measurement process involves applying a preset fixed negative bias voltage to the second collecting surface 111b and stably collecting the ion saturation current parallel to the flow field direction. This current is primarily highly correlated with the macroscopic flow velocity of the plume and can be directly used for subsequent Mach number and velocity inversion.

[0046] The probes for the first collecting surface 111a and the second collecting surface 111b are electrically connected to independent bias power supplies to achieve synchronous acquisition of signals from both collecting surfaces within the same time window. Specifically, the first collecting surface 111a is connected to a fixed negative bias power supply, enabling it to operate in the ion current saturation region to collect ion saturation current perpendicular to the plume flow direction. Similarly, the second collecting surface 111b is connected to a fixed negative bias power supply, enabling it to operate in the ion current saturation region to collect ion saturation current parallel to the plume flow direction. The probes for the first collecting surface 111a and the second collecting surface 111b are electrically connected to independent bias power supplies to achieve synchronous acquisition of signals from both collecting surfaces within the same time window. Specifically, the first collecting surface 111a is connected to a fixed negative bias power supply to enter the ion saturation region and collect the vertical ion saturation current; the second collecting surface 111b is connected to a fixed negative bias power supply to enter the ion saturation region and collect the parallel ion saturation current.

[0047] The probe structure of this invention has two probes mounted on the same end of the electrically insulating mounting assembly. The two probes 11 are parallel to each other and extend in the same direction. The first collection surface 111a and the second collection surface 111b formed by the end faces of the two probes 11 are located in the end region of the signal collection module 1. They are orthogonal to each other and spatially adjacent to each other to form a miniature quasi-synchronous measurement structure. This solves the technical problems of spatiotemporal inconsistency between traditional separate Langmuir probes and Mach probes, and the unsuitability of traditional Mach probes for supersonic plumes. At the same time, this miniature structure significantly reduces the disturbance of the plume field caused by probe insertion, improves measurement accuracy and result consistency, and is suitable for high-speed directional, non-thermal equilibrium, non-magnetized or weakly magnetized plasma environments of electrically propelled plumes, thus possessing higher measurement reliability and engineering applicability.

[0048] In some embodiments, the two probe probes 11 are arranged in a spaced and insulated manner along the radial direction of the probe body, and an insulating element may be provided between the two probe probes 11 to ensure that the two probe probes 11 are insulated from each other.

[0049] In some embodiments, the main bodies of the two probe probes 11 extend in the same direction, and the orthogonal spatial relationship between the first collecting surface 111a and the second collecting surface 111b is determined by the oblique cutting structure at the end of the probe probe 11, without changing the extension direction of the main bodies of the two probe probes 11. The normals of the first collecting surface 111a and the second collecting surface 111b are perpendicular. By ensuring that the normals of the first collecting surface 111a and the second collecting surface 111b are perpendicular, the collection of ion saturation currents perpendicular to and parallel to the plume flow field direction is achieved, respectively.

[0050] In some embodiments, the probe 11 includes a first collecting surface 111a and a second collecting surface 111b. The end of the probe 11 is provided with a collecting surface for collecting plasma current, which is formed by an end beveling. The probe 11 typically has a variable diameter structure with one end having a larger diameter and the other end having a smaller diameter. The larger diameter end is formed by a 45° beveling to create the collecting surface, and the smaller diameter end is used for insertion into the probe connector 12. Alternatively, the probe 11 may also have a columnar structure, with the collecting surface formed by a beveling at one end, and the non-beveling end inserted into the probe connector 12. It should be noted that the beveling angle of the probe 11 does not necessarily have to be 45°; it is sufficient that the normals of the first collecting surface 111a and the second collecting surface 111b are perpendicular. For example, if the first collecting surface 111a is beveling at 30°, then the second collecting surface 111b needs to be beveling at 60°. It should also be noted that this angle change will require the two top bevel angles of the third base 23 to change accordingly, becoming one bevel angle of 30° and the other bevel angle of 60°; it will also cause the tilt angle of the support base 4 to change, with the tilt angle becoming 60°. It is necessary to ensure that when the support base 4 is placed vertically, the first collecting surface 111a can be presented in a completely horizontal state. It should also be noted that if the bevel angles of the first collecting surface 111a and the second collecting surface 111b are different, the collecting surface areas of the two will be different, and the inversion formulas for the ion saturation current of the two need to include the collecting electrode area information.

[0051] The probe structure of this invention is particularly suitable for high-speed directional plasma flow fields with obvious spatial gradient characteristics, such as electrically propelled plumes. Unlike the existing Mach probes with separate parallel and vertical collection surfaces, this invention integrates the two collection surfaces into the same micro probe tip region, significantly reducing the distance between the corresponding measurement positions of the two collection surfaces. This enables quasi-isositu measurement of ion saturation currents in the parallel and vertical directions within a local area, reducing measurement mismatch errors caused by spatial gradients and improving the accuracy and spatial consistency of flow parameter diagnostic results.

[0052] Meanwhile, the miniaturized design of the probe head can significantly reduce the shielding effect, wake disturbance, and local flow field reconstruction phenomenon generated when the probe is inserted into a high-speed plume, thereby improving the probe's ability to measure the local flow state of the electrically propelled plume. Furthermore, the pluggable probe structure enables rapid replacement and maintenance of the probe head components, improving the probe's reusability and engineering maintenance convenience in complex plasma environments.

[0053] In some embodiments, the signal collection module 1 includes a probe 11 and a probe connector 12. The probe 11 is disposed in the front end region of the signal collection module 1 and is used to directly contact the plasma and collect current signals; the probe connector 12 is used to realize the electrical and mechanical connection between the probe 11 and the external leads.

[0054] See also Figure 3 As shown, the probe 11 includes a first collecting surface 111a and a second collecting surface 111b. The first collecting surface 111a is used to collect the ion saturation current perpendicular to the flow field direction; the second collecting surface 111b is used to collect the ion saturation current parallel to the flow field direction. Both the first collecting surface 111a and the second collecting surface 111b are located in the front end region of the probe head. The two collecting surfaces are isolated from each other by an insulating structure and are connected to independent signal paths to ensure the independence of the measurement signals.

[0055] In some embodiments, the first collecting surface 111a and the second collecting surface 111b form different collecting normals, wherein the normal of the first collecting surface 111a is perpendicular to the plasma flow field direction, and the normal of the second collecting surface 111b is parallel to the plasma flow field direction, thereby realizing the collection of ion saturation current in the vertical and parallel directions respectively.

[0056] In some embodiments, the signal collection module 1 further includes two probe connectors 12, which are arranged one-to-one with the probe probes 11. The probe connector 12 has a probe connection hole 121 at the end facing the probe probe 11 for detachably inserting the probe probe 11. The probe connector 12 has a lead wire connection hole 123 at the end facing away from the probe probe 11 for connecting signal leads.

[0057] In this technical solution, the probe connection hole 121 is used for detachable insertion and mating with the probe probe 11. When the probe head's performance deteriorates due to plasma sputtering deposition, corrosion wear, or mechanical damage, only the probe probe 11 needs to be disassembled and replaced to restore the probe's working performance, without having to disassemble the entire probe body, thereby reducing maintenance costs and shortening experimental downtime. The lead connection hole 123 is used to connect signal leads and lead out measurement signals.

[0058] In some implementations, both the probe connection hole 121 and the lead wire connection hole 123 are blind holes, meaning that the probe connection hole 121 and the lead wire connection hole 123 are not connected.

[0059] In some embodiments, the probe connection hole 121 and the lead wire connection hole 123 only need to satisfy the requirement that the size of the probe connection hole 121 matches the size of the connection end of the probe 11, so as to ensure reliable positioning and electrical connection after the probe 11 is inserted. The depth of the probe connection hole 121 can be set according to the insertion length of the probe 11 to meet the installation stability requirements of the probe 11.

[0060] In some embodiments, the probe 11 is made of tungsten, molybdenum, graphite or other metals or carbon-based materials with high melting points and good electrical conductivity.

[0061] In some embodiments, the probe connector 12 is provided with a plug-in conductive structure. The probe 11 and the probe connector 12 are detachably connected via this plug-in conductive structure. (See also...) Figure 3 As shown, the probe connector 12 is a variable diameter structure, including a probe connection hole 121, a connector limiting structure 122, and a lead wire connection hole 123. The probe connection hole 121 is used for insertion and mating with the probe 11; the connector limiting structure 122 is used for axial positioning with the insulating base module 2; and the lead wire connection hole 123 is used for connecting signal leads and leading out measurement signals.

[0062] In some embodiments, a claw spring, crown spring, or other elastic conductive connection structure may be provided inside the probe connection hole 121 to achieve reliable electrical connection and mechanical fixation between the probe 11 and the probe connector 12, and to enable the probe 11 to be pluggably replaceable. In some embodiments, the elastic conductive structure is disposed on the inner peripheral wall of the probe connection hole 121, which can generate a radial clamping force on the probe 11. The elastic conductive structure is preferably disposed on the inner peripheral wall of the probe connection hole 121 and extends axially along the probe connection hole 121, and the radial clamping force is generated by the elastic conductive structure after the probe 11 is inserted.

[0063] In some embodiments, the elastic conductive structure is mainly used to apply a continuous clamping force to the probe 11 in the radial direction, and it is not used as the main positioning reference for the axial position of the probe 11. The probe 11 achieves its axial positioning through the cooperation with the probe connection hole 121; the probe connector 12 achieves its axial positioning through the cooperation between the connector limiting structure 122 and the insulating base module 2; the above-mentioned positioning relationship between the probe 11 and the probe connector 12 jointly determines the axial installation position of the signal collection module 1. Therefore, the measurement position of the probe 11 is mainly guaranteed by the probe connection hole 121 and the connector limiting structure 122, rather than by the elastic conductive structure. The elastic conductive structure only undertakes the functions of clamping and conducting electricity, and will not cause significant axial displacement of the probe 11, thus not affecting the repeatability and accuracy of the measurement position. Compared with the interference fit, the elastic conductive structure can achieve quick disassembly and repeated replacement of the probe 11 while ensuring reliable mechanical and electrical connections. In addition, the flexible conductive structure can automatically compensate for manufacturing tolerances and dimensional changes caused by long-term use between the probe 11 and the probe connection hole 121. It can maintain stable contact pressure and contact resistance after multiple insertions, thereby improving the reliability of electrical connection and consistency of repeated assembly.

[0064] When the probe's performance deteriorates due to plasma sputtering deposition, corrosion wear, or mechanical damage, the probe's working performance can be restored simply by disassembling and replacing the probe 11, without having to disassemble the entire probe body. This reduces maintenance costs and shortens experimental downtime.

[0065] In some embodiments, the electrical insulation mounting assembly includes an insulating base module 2, which includes a third base 23. One end of the third base 23 has a first inclined surface 231a and a second inclined surface 231b. The normals of the first inclined surface 231a and the second inclined surface 231b are perpendicular to each other. A first probe probe embedded hole 233 is provided on both the first inclined surface 231a and the second inclined surface 231b. The probe probe 11 is inserted into the first probe probe embedded hole 233. Furthermore, the first collecting surface 111a is located in the same plane as the first inclined surface 231a, and the second collecting surface 111b is located in the same plane as the second inclined surface 231b.

[0066] In this technical solution, the two probe probes 11 are insulated and separated by the third base 23. The probe probe 11 is inserted into the embedded hole 233 of the first probe probe. The first collecting surface 111a and the first inclined surface 231a are located on the same plane, and the second collecting surface 111b and the second inclined surface 231b are located on the same plane, thereby installing, positioning and constraining the two probe probes 11.

[0067] In some embodiments, the top of the third base 23 is provided with two directional ramps 231a and 231b. Preferably, the two directional ramps are arranged at a 45° angle relative to the axis of the probe body, and the spatial orientations of the two directional ramps are perpendicular to each other. The two probes 11 are respectively installed in the corresponding first probe embedding hole 232 and second probe embedding hole 233, and the installation positioning and attitude constraint are achieved by the directional ramps 231a and 231b.

[0068] Since the two probes 11 are installed with corresponding oriented inclined planes as their mounting references, the first collecting surface 111a and the second collecting surface 111b each obtain a predetermined spatial orientation. Specifically, the normal direction of the first collecting surface 111a is perpendicular to the normal direction of the second collecting surface 111b, thus ensuring that after the probes are installed, they can meet the measurement requirements that the normal direction of the first collecting surface 111a is perpendicular to the plasma flow field direction and the normal direction of the second collecting surface 111b is parallel to the plasma flow field direction.

[0069] Furthermore, through the geometric constraint of the two 45° oriented inclined planes at the top of the third base 23, the orthogonal spatial relationship between the two collection surfaces can be automatically established during the probe assembly process, avoiding the attitude deviation of the collection surfaces due to manual assembly errors, and improving the consistency and repeatability of the probe measurement attitude.

[0070] Furthermore, both collection surfaces are arranged in the same probe tip region, and their center-to-center distance is determined by the front-end structure size of the third base 23, which can be controlled within the millimeter range or even smaller. This enables local quasi-isositu measurement of ion saturation current in the parallel and vertical directions, thereby improving the local measurement accuracy in a strong gradient electric propulsion plume environment.

[0071] Compared to the existing structure of Mach probes with parallel and vertical collection surfaces arranged separately, this invention significantly reduces the spatial distance between the two measurement positions, enabling the two collection surfaces to more accurately reflect the same local plasma state, thereby improving the accuracy of local measurements in strong gradient plume environments.

[0072] In some embodiments, the third base 23 is provided with two second probe embedded holes 233, the two second probe embedded holes 233 are arranged in a one-to-one correspondence with the two first probe embedded holes 232, and the second probe embedded holes 233 are connected to the first probe embedded holes 232 to form a through hole structure, the through hole structure penetrates the third base 23 and extends along the extension direction of the probe 11.

[0073] In some embodiments, the probe 11 has a first segment and a second segment, the diameter of the first segment is larger than the diameter of the second segment, the inner diameter of the first probe inner hole 232 is larger than the inner diameter of the second probe inner hole 233, the first segment is embedded in the first probe inner hole 232, and the second segment passes through the second probe inner hole 233 and is connected to the probe connector 12.

[0074] In some embodiments, the diameter of the first segment is equal to the diameter of the second segment, and the inner diameter of the first probe inner hole 232 is equal to the inner diameter of the second probe inner hole 233.

[0075] In this technical solution, the probe 11 has a first segment and a second segment. The diameter of the first segment is larger than the diameter of the second segment. The probe 11 has a stepped structure, with the collecting surface located at the end of the first segment. Alternatively, the diameter of the first segment is equal to the diameter of the second segment, and the probe 11 has a beveled columnar structure, with the collecting surface located at the end of the first segment. The first segment is embedded in the inner hole 232 of the first probe, and the second segment passes through the inner hole 233 of the second probe and connects to the probe connector 12, thereby axially limiting the probe 11, ensuring the stability of the probe 11 installation, and facilitating the disassembly and installation of the probe 11.

[0076] In other embodiments, the probe 11 may also be a cylindrical structure with equal diameter. In this case, the inner hole 232 of the first probe and the inner hole 233 of the second probe can be set to the same diameter. After the probe 11 passes through the through hole structure, it is connected to the probe connector 12 and axially fixed by the probe connector 12 or other limiting structures.

[0077] In some embodiments, the insulating base module 2 further includes a second base 22, which has two second recessed holes 221. The two second recessed holes 221 are arranged in a one-to-one correspondence with the two probe connectors 12. Along the axial direction of the probe 11, the second base 22 abuts against the third base 23. The probe connector 12 is partially insertable into the second recessed hole 221. The probe 11 passes through the through hole structure and is then inserted into the probe connector 12.

[0078] In this technical solution, the second base 22 has a second embedded hole 221 for the connector, which is used to further accommodate the front end area of ​​the probe connector 12 and together with the first base 21, forms a coaxial support structure for the probe connector 12, thereby ensuring that the probe connector 12 is consistent with the axis of the probe body and avoiding the probe 11 posture deviation due to assembly deviation.

[0079] In some embodiments, the insulating base module 2 further includes a first base 21. Along the axial direction of the probe 11, the first base 21 abuts against the second base 22. The second base 22 is provided with two first recessed holes 212. The two first recessed holes 212 are arranged in a one-to-one correspondence with the two probe connectors 12. The remaining part of the probe connector 12 can be inserted into the second recessed hole 221.

[0080] In some embodiments, the outer peripheral wall of the probe connector 12 has a connector limiting structure 122, and the first base 21 is also provided with two connector limiting holes 211. The two connector limiting holes 211 are arranged in a one-to-one correspondence with the two first embedded holes 212. The connector limiting holes 211 are connected to the first embedded holes 212. The diameter of the connector limiting hole 211 is larger than the diameter of the first embedded hole 212. The probe connector 12 passes through the connector limiting hole 211 and is inserted into the first embedded hole 212, and the connector limiting structure 122 is embedded in the connector limiting hole 211.

[0081] In some embodiments, the end of the connector limiting structure 122 facing the second base 22 abuts against the second base 22.

[0082] In some implementations, see reference Figures 4 to 7 As shown, the insulating base module 2 supports the signal collection module 1 and provides electrical insulation between the first collection surface 111a and the second collection surface 111b, while also providing a unified geometric positioning reference for the spatial orientation of the two collection surfaces. The insulating base module 2 includes a first base 21, a second base 22, and a third base 23 arranged coaxially. The three are stacked sequentially along the axis of the probe body, together forming the support and positioning structure of the signal collection module 1.

[0083] In some embodiments, the first base 21 is provided with a connector limiting hole 211 and a connector first embedded hole 212 inside, for accommodating the probe connector 12 and axially positioning and radially constraining it; a first base limiting structure 213 may be provided on the outside of the first base 21, for cooperating with the support base 4 to realize the angular positioning of the overall anti-rotation of the insulating base module 2.

[0084] The second base 22 has a second embedded hole 221 for connectors, which is used to further accommodate the front end area of ​​the probe connector 12 and together with the first base 21, form a radial constraint structure for the probe connector 12, thereby ensuring that the probe connector 12 is aligned with the axis of the probe body and avoiding the probe 11 from shifting its posture due to assembly deviation.

[0085] The third base 23 is disposed in the probe tip region, and two directional inclined surfaces 231a and 231b are formed on its top. Preferably, the two directional inclined surfaces are arranged at a 45° angle relative to the probe body axis, and the spatial orientations of the two directional inclined surfaces are perpendicular to each other. The two directional inclined surfaces serve as the mounting and positioning references for the probe probe 11 corresponding to the first collection surface 111a and the second collection surface 111b, respectively.

[0086] The third base 23 has a first probe embedding hole 232 and a second probe embedding hole 233 inside, which are used to accommodate the mounting ends of the corresponding probes 11. The axial directions of the two embedding holes maintain a fixed geometric relationship with the corresponding directional inclined surfaces 231a and 231b, respectively, so that the two probes 11 automatically obtain a preset spatial posture after installation.

[0087] Because the two probes 11 are subject to the dual geometric constraints of the corresponding directional inclined surfaces 231a and 231b, as well as the embedded holes 232 and 233 of the first and second probes respectively, the normals of the first and second collecting surfaces 111a and 111b can always remain perpendicular to each other, thus establishing a stable 90° spatial layout relationship. This structure can achieve precise positioning of the two collecting surfaces without relying on manual adjustment, effectively reducing assembly errors and improving the consistency and repeatability of probe posture.

[0088] The third base 23 may also be provided with a limiting step 234 for axial positioning with the insulating sleeve 3. The limiting step 234 cooperates with the corresponding internal structure of the insulating sleeve 3, and combined with the coaxial dimensional cooperation between the first base 21, the second base 22 and the third base 23, a multi-level positioning structure of the insulating base module 2 is formed. Furthermore, the first base limiting structure 213 of the first base 21 cooperates with the support base 4 to achieve angular positioning, and the insulating sleeve 3 is locked and fixed to the support base 4 through the fixing through hole 33, thereby constructing the signal collection module 1, the insulating base module 2, the insulating sleeve 3 and the support base 4 into an integrated assembly configuration. This structure can ensure the stable and reliable relative positional relationship between the components and ensure that the spatial attitude of the first collection surface 111a and the second collection surface 111b remains consistent over a long period of time, providing a stable structural foundation for local quasi-coordinate measurement.

[0089] Meanwhile, the first base 21, the second base 22, and the third base 23 are all made of high-temperature resistant insulating materials such as alumina and boron nitride, so that reliable electrical insulation isolation is formed between the first collecting surface 111a and the second collecting surface 111b, avoiding signal crosstalk and leakage, and improving the independence and measurement accuracy of the two current signal acquisitions.

[0090] In some implementations, the insulating base module 2 not only supports, positions, and insulates the signal collection module 1, but also ensures that the two collection surfaces maintain a preset 90° spatial relationship for a long time, thereby providing a stable and reliable structural foundation for local quasi-co-location measurement and ensuring that the probe has good structural stability and measurement repeatability in a high-speed electric propulsion plume environment.

[0091] It should be noted that the specific modular form of the insulating base module 2 is not limited to the above-described embodiments. Depending on the processing technology and structural size requirements, some base structures can be integrally formed to reduce assembly errors and improve overall structural stability. In some embodiments, the first base 21 and the second base 22 can be configured as independently connected structures or integrally formed structures, depending on the probe structure size, processing technology, and assembly requirements. When the integrated design of the first base 21 and the second base 22 meets the requirements for structural strength, insulation performance, and dimensional processing, the insulating base module 2 can also be composed of an integral structure of the interconnected first base 21 / second base 22 and a third base 23.

[0092] In some embodiments, the electrical insulation mounting assembly further includes an insulating sleeve 3. Along the axial direction of the insulating sleeve 3, the insulating sleeve 3 has a third base limiting hole 31 and an insulating base embedded hole 32 that are interconnected. The diameter of the third base limiting hole 31 is smaller than the diameter of the insulating base embedded hole 32. A limiting step 234 is provided on the third base 23. The third base 23, the second base 22, and the first base 21 are sequentially stacked and fitted into the insulating base embedded hole 32. The third base 23 is axially positioned and installed by the limiting step 234 cooperating with the third base limiting hole 31. One end of the third base 23 passes through the third base limiting hole 31 and extends out of the insulating sleeve 3, so that the measuring end of the probe 11 extends out of the insulating sleeve 3. The outer diameter of the limiting step 234 matches the inner diameter of the insulating base embedded hole 32 to ensure a stable assembly relationship between the insulating base module 2 and the insulating sleeve 3.

[0093] In some embodiments, the sidewall of the insulating sleeve 3 may be provided with a fixing through hole 33 for connection and fixation with the support base 4. When the insulating sleeve 3 is assembled with the support base 4, the limiting step 234 of the third base 23, the internal positioning structure of the insulating sleeve 3, and the limiting structure 213 of the first base 21 together form a multi-level limiting system, thereby realizing the overall positioning and locking between the insulating sleeve 3, the insulating base module 2, the signal collection module 1, and the support base 4.

[0094] In some embodiments, the insulating sleeve 3 is mainly used for insulating and mechanically protecting the internal structure of the probe, and can cooperate with the main probe structure to achieve axial positioning and overall assembly and fixation of internal components, thereby improving the stability of the probe structure. The preset spatial orientation between the first collecting surface 111a and the second collecting surface 111b is mainly determined and maintained by the insulating base module 2 and the support base 4. The insulating base module 2 is used to position and install the two probe probes 11, and the support base 4 is used to circumferentially limit the insulating base module 2 and provide an overall installation reference.

[0095] In some embodiments, the insulating sheath 3 can be made of high-temperature resistant insulating materials such as alumina and boron nitride to meet the requirements of high-temperature insulation, resistance to plasma corrosion, and long-term stable operation in a vacuum environment.

[0096] In some embodiments, the inner diameter of the embedded hole 32 in the insulating base matches the outer diameter of the limiting step 234. Furthermore, the outer diameter of the limiting step 234, the outer diameter of the second base 22, and the outer diameter of the first base 21 are the same.

[0097] In some implementations, see reference Figure 8 As shown, the insulating sleeve 3 has a third base limiting hole 31 and an insulating base embedded hole 32 inside.

[0098] The third base limiting hole 31 is used to accommodate the third base limiting step 234. The limiting step 234 abuts against the step surface formed between the third base limiting hole 31 and the insulating base embedded hole 32, which is used to realize the axial positioning and installation of the third base 23. The insulating base embedded hole 32 is used to accommodate the insulating base module 2 composed of the first base 21, the second base 22 and the third base 23, and to provide axial support and assembly positioning for the insulating base module 2.

[0099] In some embodiments, the limiting step 234 of the third base 23 and the limiting hole 31 of the third base form a matching structure, thereby establishing the positioning relationship between the third base 23 and the insulating sleeve 3; at the same time, the first base 21, the second base 22 and the third base 23 form a continuous stacked coaxial positioning structure through corresponding size matching, so that the components inside the insulating base module 2 always maintain the preset assembly position.

[0100] In some embodiments, the probe structure further includes a support base 4, one end of which is provided with a base limiting hole 41. Along the axial direction of the first embedded hole 212, the outer peripheral wall of the first base 21 has a fifth segment and a sixth segment. The outer diameter of the fifth segment is larger than the outer peripheral dimension of the sixth segment in the corresponding direction. The sixth segment is inserted into the base limiting hole 41. The outer diameter of the fifth segment is larger than the inner diameter of the base limiting hole 41. The support base 4 is partially inserted into the insulating sleeve 3 along the axial direction and is detachably connected to the insulating sleeve 3.

[0101] In some embodiments, the outer peripheral wall of the first base 21 has a fifth segment and a sixth segment along the axial direction. The fifth segment is a circumferential structure with an outer diameter equal to the outer diameter of the second base 22. The sixth segment is a rectangular columnar positioning segment, and the outer contour dimension of the fifth segment is larger than the dimension of the sixth segment in the corresponding direction. The sixth segment is inserted into the base limiting hole 41 to restrict the circumferential rotation and radial offset of the first base 21 relative to the support base 4.

[0102] In some implementations, the support base 4 is used to mount and fix the probe, maintain its posture, and support the overall structure.

[0103] In some implementations, see reference Figure 9 As shown, the support base 4 includes a base limiting hole 41, a threaded hole 42, and a mounting base 43.

[0104] The base limiting hole 41 matches the first base limiting structure 213 set on the first base 21, which is used to realize the angular positioning of the insulating base module 2 and prevent the insulating base module 2 from rotating or shifting in the angular direction during assembly or use, thereby ensuring that the spatial orientation of the first collecting surface 111a and the second collecting surface 111b relative to the flow direction of the plume remains consistent.

[0105] The threaded hole 42 is used to mate with the fixing through hole 33 provided on the side wall of the insulating sleeve 3, and the insulating sleeve 3 and the support base 4 are reliably locked together by screw connection. After the support base 4 and the insulating sleeve 3 are fixed, the first base 21, the second base 22, the third base 23, the insulating sleeve 3 and the signal collection module 1 form an integral assembly structure, thereby ensuring the relative spatial attitude stability of the two collection surfaces at the end of the probe head.

[0106] The mounting chassis 43 is used to connect with an external displacement mechanism, probe scanning platform, or mounting bracket to achieve the positioning and installation of the probe in the electric propulsion plume.

[0107] In some embodiments, the insulating sleeve 3 is disposed outside the insulating base module 2 to form an integral encapsulation of the insulating base module 2, and together with the insulating base module 2 and the support base 4, constitutes an integrated positioning structure for the probe body.

[0108] In some embodiments, the insulating sleeve 3 is detachably connected to the outer peripheral wall of the support base 4. Specifically, the insulating sleeve 3 and the outer peripheral wall of the support base 4 can be connected by thread or other means.

[0109] In some embodiments, the support base 4 includes a third segment and a fourth segment. The base limiting hole 41 is disposed at the end of the third segment. The third segment is inserted into the insulating sleeve 3 along its axial direction and is detachably connected to the insulating sleeve 3. Taking the axial section of the support base 4 as the projection plane, a preset angle is formed between the central axis of the third segment and the central axis of the fourth segment. The angle satisfies the condition that the central axis of the fourth segment is parallel to the normal direction of the first collecting surface 111a.

[0110] In some embodiments, the support base 4 adopts a two-section preset tilt structure, including a fourth section connected to the mounting chassis 43 and a third section set at a preset angle relative to the fourth section. Preferably, the third section is tilted at 45° relative to the fourth section. Through this two-section tilt structure, when the mounting chassis 43 is horizontally installed with the external displacement mechanism, the insulating base module 2 and the signal collection module 1 at the probe tip can automatically obtain a preset measurement posture, so that the first collection surface 111a and the second collection surface 111b form a horizontal orientation and a vertical orientation, respectively, thereby facilitating the measurement requirement that the normal of the first collection surface 111a is perpendicular to the plasma flow field direction and the normal of the second collection surface 111b is parallel to the plasma flow field direction.

[0111] The probe structure of this invention mainly includes a signal collection module 1, an insulating base module 2, an insulating sleeve 3, and a support base 4. The signal collection module 1 is used to collect plasma current signals; the insulating base module 2 is used to support and position the signal collection module 1 and form electrical insulation isolation; the insulating sleeve 3 is used to encapsulate and protect the internal structure; the support base 4 is used to realize the mechanical connection between the entire probe and the external displacement mechanism or mounting platform, and is used to determine the spatial installation posture of the probe relative to the plume flow field, so that the first collection surface 111a and the second collection surface 111b on the signal collection module 1 maintain the preset measurement direction.

[0112] In some implementations, the installation posture of the probe can be automatically determined by the structural geometry through the preset tilt structure of the support base 4, the angular positioning cooperation between the first base limiting structure 213 and the base limiting hole 41, and the locking and fixing between the insulating sleeve 3 and the support base 4. This reduces the angle error caused by manual posture adjustment and improves the posture consistency and repeatability of measurement results when the probe is repeatedly installed.

[0113] In some implementations, an integrated configuration of the probe body can be constructed through the hierarchical positioning and locking structure between the support base 4, the insulating sleeve 3, and the insulating base module 2. This ensures the stability of the spatial relationship between the two collection surfaces during assembly, disassembly, and reuse, providing a reliable structural foundation for local quasi-isositu measurements and high-precision Mach number diagnosis. Simultaneously, the coordinated design of the directional inclined plane and the preset tilt angle support structure enables the automatic establishment and repeated maintenance of the spatial attitude of the two collection surfaces.

[0114] In an electrically propelled supersonic plasma flow field, the first collecting surface 111a and the second collecting surface 111b collect ion saturation currents perpendicular to and parallel to the flow field direction, respectively. Taking advantage of the characteristic that the velocity of the electrically propelled supersonic flow field has a weak influence on the ion saturation current perpendicular to the flow field direction but a significant influence on the ion saturation current parallel to the flow field direction, a ratio model of the ion saturation current in the parallel and perpendicular directions is constructed to achieve stable inversion of the flow field Mach number and plasma velocity.

[0115] Since the two collection surfaces are integrated into the same micro probe tip region, quasi-isositu measurements can be achieved within a local area, improving the accuracy and spatial consistency of flow parameter diagnosis in strong gradient electric propulsion plume environments.

[0116] The acquired current signal is transmitted to an external measurement system via probe 11, probe connector 12 and signal lead, and is further used for inversion calculation of parameters such as Mach number and plasma velocity.

[0117] The probe structure of this invention enables local quasi-isositu measurement of ion saturation current in both parallel and perpendicular directions. This effectively reduces the influence of the spatial gradient of the electrically propelled plume on the measurement results, improving the accuracy and spatial consistency of local flow parameter diagnosis. Simultaneously, the miniaturized probe head design significantly reduces the obstruction effect, wake disturbance, and local flow field reconstruction phenomena generated when the probe is inserted into the plume, thereby improving measurement accuracy and spatial resolution. Furthermore, the pluggable probe head structure further enhances the probe's maintenance convenience and reusability.

[0118] In some embodiments, the larger diameter of the collecting end of the probe 11 is 1.5 mm, and its end is beveled at 45° to form an elliptical collecting surface. Preferably, the major axis of a single collecting surface is approximately 2.1 mm, and the minor axis is approximately 1.5 mm. Both probes 11 are arranged in the same probe tip region, and their center-to-center distance can be no greater than 3 mm, thus maintaining a small spatial interval between the measurement positions corresponding to the two collecting surfaces. Further, the maximum outer diameter of the probe body can be no greater than 9 mm, and the minimum outer diameter can be no greater than 5 mm.

[0119] The probe structure of this invention features a miniaturized design that effectively reduces the shielding effect, wake disturbance, and local flow field reconstruction phenomenon generated when the probe is inserted into a high-speed electrically propelled plume, while ensuring mechanical strength and signal acquisition capability. This improves the spatial resolution and local diagnostic accuracy of the measurement, and is particularly suitable for the near-field region of a plume with a large spatial gradient of plasma parameters.

[0120] In some implementations, the center-to-center distance between the two collection surfaces is no greater than 3 mm. For a typical electrically propelled plume, parameters such as electron density, ion density, and velocity all possess finite spatial gradient characteristic scales. For example, in a typical magnetic plasma electrically propelled plume without an external magnetic field, if the radial electron density gradient characteristic scale is considered... The scale characterizing the spatial variation of plume parameters is defined by Ln, where Ln is the characteristic size of the electron density gradient and ne is the electron density. Let r be the electron density gradient and r be the radial direction, with a magnitude ranging from tens to hundreds of millimeters. The center-to-center distance between the two collecting surfaces in this invention is much smaller than the spatial gradient characteristic scale of the plume's main parameters. Therefore, the measurement regions corresponding to the two collecting surfaces can be approximated as the same local plasma region. Based on this, the ion saturation current signals collected by the first collecting surface 111a and the second collecting surface 111b can more realistically reflect the same local plasma state, thereby achieving local quasi-isositu measurement of ion saturation current in the parallel and perpendicular directions, and effectively reducing the local mismatch error caused by the spatial separation of the collecting surfaces in traditional Mach probes.

[0121] In some embodiments, the probe structure of the present invention, through the directional inclined surface provided on the top of the third base 23, the positioning constraint structure of the embedded holes 232 and 233 of the first and second probes, the angular positioning structure between the first base limiting structure 213 and the support base 4, and the preset tilt angle structure of the support base 4, jointly constructs an automatic attitude establishment mechanism for the probe collecting surface. This mechanism allows the spatial orientation relationship between the first collecting surface 111a and the second collecting surface 111b to be directly determined by the structural geometry, without relying on manual adjustment or repeated calibration.

[0122] During probe installation, as long as the mounting base 43 is connected to the external displacement mechanism or mounting platform in a preset manner, the predetermined measurement posture can be automatically obtained, ensuring that the normal direction of the first collecting surface 111a is perpendicular to the plasma flow field direction and the normal direction of the second collecting surface 111b is parallel to the plasma flow field direction. Compared with probe structures that require angle calibration or posture adjustment during installation to ensure the consistency of the collecting surface direction, the probe structure of the present invention can effectively reduce installation errors and repeated assembly errors, and improve the consistency of measurement conditions and the repeatability of results between different experimental batches.

[0123] Meanwhile, the automatic attitude establishment mechanism combined with the local quasi-isositu measurement structure can ensure that the two collection surfaces maintain a stable spatial relationship during long-term use, disassembly and replacement and repeated assembly, thus providing a reliable structural guarantee for the measurement of local flow parameters in high-speed electric propulsion plume environment.

[0124] Therefore, the probe structure of this invention integrates parallel and vertical ion saturation current collection units into the same micro probe tip region, achieving local quasi-isositu measurement of parallel and vertical ion saturation currents. This effectively reduces diagnostic errors caused by measurement position mismatch in the strong spatial gradient environment of electrically propelled plumes. The miniaturized probe tip design reduces the obstruction effect and flow field disturbance when the probe is inserted into the plume, improving the accuracy and spatial resolution of local flow parameter measurements. The pluggable probe tip structure enables rapid disassembly and convenient replacement, improving probe maintenance efficiency and reusability. The automatic attitude establishment mechanism, constructed collaboratively by the directional inclined plane, limiting structure, and preset tilt angle support base, achieves automatic determination and repeated maintenance of the spatial attitude of the dual collection surfaces, improving the consistency of probe installation and the repeatability of measurement results.

[0125] The probe structure of this invention can achieve high-precision local diagnosis of flow parameters of electrically propelled plumes within a limited space. It has the advantages of local quasi-isositu measurement, low disturbance, high spatial resolution, easy maintenance, reusability, and automatic attitude establishment. It is particularly suitable for the near-field region of electrically propelled plumes, local flow fields with large parameter gradients, and plasma diagnostic scenarios with high requirements for measurement repeatability. It has good engineering application value and promotion prospects.

[0126] This invention provides a miniature pluggable Mach probe for local diagnostics of electric propulsion supersonic plumes, which solves the problems of large spatial spacing between parallel and vertical collection surfaces, difficulty in accurately measuring local flow parameters, large probe structure size leading to significant flow field disturbance, inconvenient probe maintenance and replacement, and poor measurement attitude repeatability in the prior art. This improves the accuracy, spatial consistency, and engineering application convenience of measuring local flow parameters in electric propulsion plumes.

[0127] In some embodiments, the probe 11 forms a first collection surface 111a and a second collection surface 111b, and the two probes 11 are arranged in the same probe tip region with a center-to-center distance of no more than 3 mm, thereby realizing local quasi-isositu measurement of ion saturation current in the parallel and perpendicular directions.

[0128] In some embodiments, the first collecting surface 111a is used to collect ion saturation current perpendicular to the plasma flow field direction, and the second collecting surface 111b is used to collect ion saturation current parallel to the plasma flow field direction. The ion current information is used for the diagnosis of Mach number and plasma velocity of the supersonic electric propulsion plume plasma flow field.

[0129] In some embodiments, the probe 11 and the probe connector 12 are connected by a plug-in conductive connection structure, which enables the probe 11 to be detachably installed, so as to facilitate the quick replacement and reuse of the probe 11.

[0130] In some embodiments, the insulating base module includes a first base 21, a second base 22 and a third base 23; the top of the third base 23 is provided with two directional inclined surfaces, which are respectively used to install the probe probes 11 corresponding to the first collection surface 111a and the second collection surface 111b, and form a preset spatial posture of the two collection surfaces.

[0131] In some embodiments, the two directional ramps are arranged at a 45° angle relative to the axis of the probe body, and their spatial orientations are perpendicular to each other, thereby ensuring that the normal of the first collection surface 111a and the normal of the second collection surface 111b remain perpendicular to each other.

[0132] In some embodiments, the probe body adopts a miniaturized structural design, with the probe tip size and the distance between the two collection surfaces being smaller than the spatial gradient characteristic scale of the main parameters of the electrically propelled plume, so as to reduce the disturbance to the local flow field when the probe is inserted into the plume and improve the spatial resolution of local flow parameter measurement.

[0133] Existing parallel-vertical Mach probe structures have the following shortcomings:

[0134] First, the parallel and vertical collection surfaces are typically located at different positions, with a certain spatial interval between their corresponding measurement areas. In the near-field region of the electrically propelled plume, parameters such as electron density, ion density, and flow velocity often exhibit large spatial gradients. The ion saturation currents collected by the two collection surfaces may correspond to different local plasma states, thus introducing local mismatch errors and affecting the accuracy and spatial consistency of Mach number and flow velocity diagnostic results.

[0135] Secondly, the existing probe front end structure is relatively large, and the probe head and insulating encapsulation structure are prone to blocking effects and wake disturbances on high-speed directional plumes, thereby changing the local flow field distribution, reducing the accuracy of local measurement and spatial resolution, which is not conducive to fine diagnosis in strong gradient plume environments.

[0136] Furthermore, although the existing probe collection modules have a certain disassembly capability, they usually require disassembling the entire probe head or part of the main structure before replacement can be completed. When the collection surface is subject to sputtering deposition, corrosion wear, or damage, the maintenance process is cumbersome, affecting experimental efficiency and reusability.

[0137] In addition, existing Mach probes generally rely on manual adjustment of probe posture and calibration of collection surface direction. Different experimental batches are prone to inconsistencies in measurement posture due to installation errors and repeated assembly errors, which affects the repeatability and reliability of diagnostic results.

[0138] This invention provides a novel Mach probe suitable for local diagnostics of electrically propelled plumes. While ensuring the measurement capability of supersonic plumes, it further realizes local quasi-isositu measurement of ion saturation current in the parallel and perpendicular directions, reduces probe disturbance to the plume, improves spatial resolution, and also takes into account the rapid maintenance and replacement of the probe, as well as the automatic establishment and repeated maintenance of the measurement posture, so as to meet the needs of high-precision local diagnostics in the near-field region of electrically propelled plumes.

[0139] Compared with the prior art, the probe structure of the present invention has the following advantages:

[0140] 1. By integrating the first and second collection surfaces into the same micro probe tip region, local quasi-isositu measurement of ion saturation current in the parallel and perpendicular directions is achieved, reducing the influence of the spatial gradient of the electric propulsion plume on the measurement results and improving the authenticity and spatial consistency of flow parameter diagnosis.

[0141] 2. By miniaturizing the probe head structure design, the shielding effect and wake disturbance generated when the probe is inserted into the high-speed directional plume are reduced, thereby improving the local measurement accuracy and spatial resolution.

[0142] 3. The pluggable probe head structure enables quick disassembly and convenient replacement of the probe, improving probe maintenance efficiency and reusability;

[0143] 4. An automatic attitude establishment mechanism is constructed through the coordinated construction of directional inclined plane, limiting structure and preset tilt angle support base to realize the automatic determination and repeated maintenance of the spatial attitude of the dual collection surface, reduce installation error and improve the consistency and repeatability of measurement results.

[0144] 5. It can achieve high-precision local diagnosis of electric propulsion plume flow parameters in a limited space, and is particularly suitable for measurement scenarios of electric propulsion plume near field region and local flow field with large parameter gradient.

[0145] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0146] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A probe structure, characterized in that: include: Electrically insulating mounting assembly and a signal collection module (1) disposed at one end of the electrically insulating mounting assembly; The signal collection module (1) includes two mutually insulated probes (11) arranged along the same extension direction. One probe (11) has a first collection surface (111a) and the other probe (11) has a second collection surface (111b). The first collection surface (111a) and the second collection surface (111b) are located in the end region of the signal collection module (1). The first collection surface (111a) and the second collection surface (111b) are arranged orthogonally to each other. The normal of the first collection surface (111a) is perpendicular to the plasma flow field direction, and the normal of the second collection surface (111b) is parallel to the plasma flow field direction.

2. The probe structure according to claim 1, characterized in that: The signal collection module (1) further includes two probe connectors (12), which are arranged one-to-one with the probe probes (11). The probe connectors (12) facing the probe probes (11) are provided with probe connection holes (121), which are used to detachably insert the probe probes (11). The probe connectors (12) facing away from the probe probes (11) are provided with lead wire connection holes (123), which are used to connect signal leads.

3. The probe structure according to claim 2, characterized in that: The electrical insulation mounting assembly includes an insulation base module (2), which includes a third base (23). One end of the third base (23) has a first inclined surface (231a) and a second inclined surface (231b). The normals of the first inclined surface (231a) and the second inclined surface (231b) are perpendicular to each other. A first probe embedded hole (233) is provided on both the first inclined surface (231a) and the second inclined surface (231b). The probe (11) is inserted into the first probe embedded hole (233). The first collecting surface (111a) is located on the same plane as the first inclined surface (231a), and the second collecting surface (111b) is located on the same plane as the second inclined surface (231b).

4. The probe structure according to claim 3, characterized in that: The third base (23) is provided with two second probe embedded holes (233). The two second probe embedded holes (233) are arranged in a one-to-one correspondence with the two first probe embedded holes (232). The second probe embedded holes (233) and the first probe embedded holes (232) are connected to form a through hole structure. The through hole structure penetrates the third base (23). Along the extension direction of the probe (11), the probe (11) has a first segment and a second segment. The first segment is embedded in the first probe embedded hole (232), and the second segment passes through the second probe embedded hole (233) and is connected to the probe connector (12).

5. The probe structure according to claim 4, characterized in that: The insulating base module (2) further includes a second base (22), on which two second embedded holes (221) are provided. The two second embedded holes (221) are arranged in a one-to-one correspondence with the two probe connectors (12). Along the axial direction of the probe (11), the second base (22) abuts against the third base (23). The probe connector (12) can be partially inserted into the second embedded hole (221). The probe (11) passes through the through hole structure and is then inserted into the probe connector (12).

6. The probe structure according to claim 5, characterized in that: The insulating base module (2) further includes a first base (21). Along the axial direction of the probe (11), the first base (21) abuts against the second base (22). The second base (22) is provided with two first embedded holes (212). The two first embedded holes (212) are arranged in a one-to-one correspondence with the two probe connectors (12). The remaining part of the probe connector (12) can be inserted into the second embedded hole (221).

7. The probe structure according to claim 6, characterized in that: The outer peripheral wall of the probe connector (12) has a connector limiting structure (122). The first base (21) is also provided with two connector limiting holes (211). The two connector limiting holes (211) are arranged in a one-to-one correspondence with the two first embedded holes (212). The connector limiting holes (211) are connected to the first embedded holes (212). The diameter of the connector limiting hole (211) is larger than the diameter of the first embedded hole (212). The probe connector (12) passes through the connector limiting hole (211) and is inserted into the first embedded hole (212). The connector limiting structure (122) is embedded in the connector limiting hole (211).

8. The probe structure according to claim 6, characterized in that: The electrical insulation mounting assembly also includes an insulating sleeve (3). Along the axial direction of the insulating sleeve (3), the insulating sleeve (3) has a third base limiting hole (31) and an insulating base embedded hole (32) that are interconnected. The diameter of the third base limiting hole (31) is larger than the diameter of the insulating base embedded hole (32). A limiting step (234) is provided on the third base (23). The third base (23), the second base (22), and the first base (22) are fitted in the insulating base embedded hole (32). One end of the third base (23) passes through the third base limiting hole (31) and extends out of the insulating sleeve (3) so that part of the probe (11) extends out of the insulating sleeve (3). The outer diameter of the limiting step (234) matches the inner diameter of the insulating base embedded hole (32).

9. The probe structure according to claim 8, characterized in that: The probe structure also includes a support base (4), one end of which is provided with a base limiting hole (41). Along the axial direction of the first embedded hole (212), the outer peripheral wall of the first base (21) has a fifth segment and a sixth segment. The outer diameter of the fifth segment is larger than the outer peripheral dimension of the sixth segment in the corresponding direction. The sixth segment is inserted into the base limiting hole (41). The outer diameter of the fifth segment is larger than the inner diameter of the base limiting hole (41). The support base (4) is partially inserted into the insulating sleeve (3) along the axial direction and is detachably connected to the insulating sleeve (3).

10. The probe structure according to claim 9, characterized in that: The support base (4) includes a third section and a fourth section. The base limiting hole (41) is provided at the end of the third section. The third section is inserted into the insulating sleeve 3 along the axial direction and is detachably connected to the insulating sleeve 3. Taking the axial section of the support base (4) as the projection plane, there is an angle between the central axis of the third section and the central axis of the fourth section. The angle satisfies that the central axis of the fourth section is parallel to the normal of the first collecting surface (111a).

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