A sawtooth multi-anode based plasma z-pinch optimization control device and method

Abstract

A sawtooth multi-anode based plasma Z-pinch optimization control device and method, the device comprising a cathode, a first anode and a second anode, wherein the second anode is a ring structure, arranged on the side of the first anode away from the cathode, and has a periodic distribution of sawtooth protrusions towards the inner edge of the cathode. The sawtooth protrusions generate local electric field distortion and field strength amplification effect in the pre-discharge stage, guiding the directional drift of electrons to the multiple sawtooth tips; after the discharge is conducted, the sawtooth tips serve as arc anchoring points, guiding the formation of multiple symmetrical discharge filaments, constructing a circumferentially uniform distributed current layer, and realizing the Z-pinch constraint of the plasma plume. The present application does not require an external magnetic field, and can improve the Z-pinch uniformity, optimize the breakdown dynamic process, and improve the impulse and thrust-power ratio of the thruster element by improving the electrode topography, and has a simple structure and no additional power consumption.

Description

Technical Field

[0001] This invention relates to plasma physics and electric propulsion technology, and in particular to a plasma Z-pinch optimization control device and method based on serrated multi-anode. Background Technology

[0002] In the field of electric propulsion for micro and nano satellites, vacuum arc thrusters (VATs) offer significant advantages such as simple structure, small size, and non-toxicity because they directly use solid metal cathodes as the propellant source, eliminating the need for additional propellant storage and supply systems. However, during operation, the ejected plasma plume of traditional vacuum arc thrusters lacks physical and magnetic confinement, making it prone to severe radial divergence, which leads to a decrease in thrust directionality and specific impulse.

[0003] In existing technologies, optimizing plasma plume distribution typically involves applying a confinement magnetic field using an external permanent magnet or electromagnetic coil. However, this inevitably leads to an increase in the thruster's mass and volume, as well as a more complex system structure. To address this, a multi-anode electrode structure (comprising a fully insulated first anode and an exposed annular second anode) has been proposed. This structure aims to achieve long-gap vacuum breakdown and utilize the large discharge current flowing through the current sheet formed by the plasma plume to generate a self-generated angular magnetic field. This, in turn, achieves inward Z-pinch magnetic confinement of the plasma plume, reducing radial diffusion of the plasma.

[0004] However, in actual multi-anode discharge processes, there are still shortcomings in the underlying physical mechanisms: during the pre-conduction and arc establishment stages of the discharge, due to the microscopic inhomogeneity of the initial metallic plasma diffusing towards the anode surface in the vacuum, when the distant second anode adopts a smooth annular structure, the attachment point of the arc on the inner surface of the annular anode often exhibits great randomness. This randomness causes the discharge current to easily concentrate in a few local arc channels, making it impossible to form a uniform angular (circumferential) current distribution across the cross-section of the second anode. The asymmetry of the current distribution directly leads to weak magnetic field confinement regions in the space current layer; under the influence of the thermodynamic pressure inside the plasma, some charged particles will escape radially from these weak magnetic confinement regions, resulting in local failure of the Z-pinch confinement effect, severely restricting further improvement of the thruster's axial thrust impulse. Currently, there is no passive control method in the industry that can control the uniformity of multi-anode current distribution and solve the problem of local failure of Z-pinch by changing the electrode microstructure.

[0005] It should be noted that the information disclosed in the background section above is only for understanding the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The main objective of this invention is to overcome the deficiencies in the aforementioned background technology and provide a plasma Z-pinch optimization control device and method based on serrated multi-anodes.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A plasma Z-pinch optimization control device based on a sawtooth multi-anode configuration includes: The cathode is used to generate metallic plasma during the discharge process; The first anode, whose surface is completely covered by an insulating medium, is disposed on the plasma jet path of the cathode to maintain a strong electric field near the cathode to promote plasma generation. The second anode has a ring-shaped structure and is disposed on the side of the first anode away from the cathode, and is spaced at a predetermined distance from the cathode. The inner edge of the second anode facing the cathode has periodically distributed serrated protrusions. The serrated protrusions of the second anode are used to generate local spatial electric field distortion and field strength amplification effect during the discharge breakdown pre-conduction stage, guide the electrons at the front end of the plasma to drift directionally to multiple serrated tips, and serve as multiple arc anchoring points after discharge breakdown conduction, guiding the formation of multiple symmetrical discharge filaments to construct a circumferentially uniformly distributed current layer, thereby achieving Z-pinch confinement of the plasma plume.

[0008] Furthermore, the geometry of the serrated protrusions of the second anode includes one or more of the following: triangular teeth, rectangular teeth, semi-circular teeth, wavy teeth, or trapezoidal teeth; the number, depth, and arrangement period of the serrated protrusions are set according to the rated power of the thruster and the pipe diameter.

[0009] Furthermore, the serrated protrusions of the second anode are formed into a periodically continuously distributed micro-protrusion structure by processing the inner edge of the second anode, and the tips of the serrated protrusions generate a periodically amplified local electric field intensity during the discharge process.

[0010] Furthermore, the axial physical distance between the second anode and the cathode is an adjustable parameter used to change the discharge current amplitude, so as to coordinate the density of the sawtooth protrusions to regulate the compactness of the current layer and the amplitude of the Z-pinch magnetic pressure.

[0011] Furthermore, the serrated protrusions of the second anode are any one or more micro-protrusion array structures capable of inducing periodic distortion of the local spatial electric field on the inner edge of the second anode facing the cathode; the number, depth, apex angle and arrangement period of the micro-protrusion array structure are proportionally scaled and adjusted according to the rated power of the thruster and the pipe diameter; the axial physical distance between the second anode and the cathode is continuously adjustable in the range of 50 mm to 110 mm or a wider range.

[0012] Furthermore, the device is applied in vacuum arc thrusters, metal vapor vacuum arc ion sources, or high-voltage vacuum trigger switches to utilize the magnetic field of the discharge current for plasma self-contraction confinement.

[0013] A plasma Z-pinch optimization control method based on sawtooth multi-anodes, using the aforementioned plasma Z-pinch optimization control device based on sawtooth multi-anodes, includes the following steps: Pre-conduction stage: Utilizing the local spatial electric field distortion and field strength amplification effect generated by the periodic sawtooth protrusions of the second anode toward the inner edge of the cathode side, the electrons at the plasma front end are guided to drift directionally toward the tips of multiple sawtooth protrusions, thus optimizing the dynamic process of long vacuum gap breakdown. Arc establishment stage: After discharge breakdown and conduction, multiple sawtooth protrusions are used as anodic arc anchoring points to guide the formation of multiple symmetrical discharge filaments, constructing a circumferentially uniformly distributed current layer, realizing all-round angular envelope magnetic confinement of the plasma plume, i.e., Z-pinch confinement.

[0014] Furthermore, in the pre-conduction stage, the tips of the serrated protrusions form a periodic high field strength region on the surface of the second anode. When the plasma front end propagates to this region, the tips extract electrons from the plasma front end and guide the electron group to drift directionally along the electric field lines of multiple serrated tips, thus suppressing the randomness of electron diffusion.

[0015] Furthermore, during the arc establishment stage, the multiple sawtooth protrusions serve as the current channel entrances with the lowest impedance, while simultaneously guiding and maintaining multiple symmetrical discharge filaments. These multiple discharge filaments develop in parallel in space, jointly constructing a ring-shaped current layer that is uniformly distributed in the circumferential direction.

[0016] Furthermore, it also includes a two-dimensional synergistic control step: by changing the density of the sawtooth protrusions on the second anode, the density and spatial uniformity of the annular current layer are adjusted; at the same time, the axial physical distance between the second anode and the cathode is synergistically changed to change the discharge current amplitude, so as to control the amplitude of the Z-pinch inward magnetic pressure and realize plasma control at different power levels.

[0017] The present invention has the following beneficial effects: This invention proposes a plasma Z-pinch optimization control device and method based on a sawtooth multi-anode structure. Its core physical mechanism lies in improving the microstructure of the inner edge geometry of the distal second anode in the multi-anode structure. Utilizing the local electric field distortion and tip effect during the discharge process, it guides the directional drift of electrons and forcibly anchors the multi-channel arc, thereby constructing a circumferentially uniformly distributed current layer in space, significantly optimizing the Z-pinch confinement effect of the plasma plume. Addressing the problems of random and localized current distribution caused by smooth circular anodes in existing multi-anode structures, and the resulting weak magnetic field confinement areas, this invention utilizes a sawtooth multi-anode structure to achieve active and uniform control of plasma Z-pinch, achieving several outstanding technical effects.

[0018] During the pre-conduction phase of the discharge, the periodically distributed serrated protrusions on the inner edge of the second anode generate significant local spatial electric field distortion and field strength amplification effects, with the local electric field strength at the serrated tips exhibiting periodic peak amplification. When the plasma front propagates to this high-field region, the serrated tips can more efficiently extract electrons from the plasma front, guiding the electron group to drift regularly and directionally along the dense electric field lines of multiple serrated tips. This effectively suppresses the randomness of electron diffusion and stabilizes the dynamic evolution process in the initial stage of long vacuum gap breakdown. This mechanism significantly improves the thruster's breakdown reliability and discharge stability at low voltages and optimizes the dynamic process of long gap vacuum breakdown.

[0019] During the arc establishment phase, after the vacuum gap is completely broken down, the multiple uniformly distributed serrated tips on the second anode, due to their highest local electric field and lowest impedance path, physically become the preferred entry points for the current channel (i.e., anode spot anchoring points). These dense tips simultaneously guide and maintain multiple symmetrical discharge filaments, which develop in parallel in space, jointly constructing a highly uniform annular current layer in the circumferential direction. The angular self-generated magnetic field excited by this current layer achieves an all-round angular envelope of the internal metallic plasma plume, fundamentally eliminating the weak magnetic field confinement area caused by the current concentration on one side under a smooth anode, maximizing and homogenizing the Z-pinch magnetic pressure, and effectively suppressing the radial escape of charged particles from the weak confinement area.

[0020] Furthermore, this invention provides an optimization method for two-dimensional synergistic control: on the one hand, changing the number, spacing, and depth of the serrated protrusions of the second anode can directly adjust the density and spatial uniformity of the annular current layer (lateral distribution parameter); on the other hand, synergistically changing the axial physical distance between the second anode and the cathode can change the energy ratio released by the energy storage capacitor before discharge and the amplitude of the discharge current, thereby controlling the absolute magnitude of the Z-pinch inward magnetic pressure (longitudinal amplitude parameter). Through the synergy of two-dimensional parameters, this invention can meet the plasma control requirements of the thruster at different power levels, further reduce the diffusion angle of the metal plasma plume, and improve the directional propagation density of ions in the central axis, thereby effectively improving the single-pulse impulse and thrust-power ratio of the vacuum arc thruster.

[0021] Furthermore, this invention eliminates the need for complex external excitation coils, does not increase the overall mass of the thruster, and does not increase the power supply load. It optimizes the underlying physical mechanism solely through passive improvements to the geometry of the electrode edges, offering significant advantages such as simple structure and no additional power consumption. In summary, this invention significantly improves the uniformity and effectiveness of plasma Z-pinch confinement while also ensuring the lightweight and high efficiency of the thruster system, providing a practical optimization solution for micro / nano satellite electric propulsion technology.

[0022] Other beneficial effects of the embodiments of the present invention will be further described below. Attached Figure Description

[0023] Figure 1 This is a diagram of the electrode structure in an embodiment of the present invention, where the second anode is serrated.

[0024] Figure 2 This is a comparison diagram of the electric field intensity of the second anode with and without serrations in an embodiment of the present invention, including: a comparison of the overall axial section electric field intensity distribution when the second anode has serrations and without serrations, and a comparison of the electric field intensity of the radial section at the edge of the second anode.

[0025] Figure 3 A comparative analysis diagram showing the electric field intensity near the electrodes with and without serrations at the second anode.

[0026] Figure 4 This is a comparison diagram of the uniformity of current density distribution on the plasma surface and radial cross-section when the second anode has serrations or not. Detailed Implementation

[0027] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0028] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for fixing, coupling, or communication.

[0029] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on the present invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] See Figures 1 to 4 This invention provides a plasma Z-pinch optimization control device based on a sawtooth multi-anode, comprising a cathode 1, a first anode 2, and a second anode 3. The cathode 1 is used to generate metallic plasma during discharge. The first anode 2, whose surface is completely covered by an insulating medium, is disposed on the plasma jet path of the cathode 1 to maintain a strong electric field near the cathode 1 to promote plasma generation. The second anode 3 is a ring structure disposed on the side of the first anode 2 away from the cathode 1 and spaced at a predetermined distance from the cathode 1. The inner edge of the second anode 3 facing the cathode 1 has periodically distributed sawtooth protrusions 4. The sawtooth protrusions 4 of the second anode 3 are used to generate local spatial electric field distortion and field strength amplification effect during the discharge breakdown pre-conduction stage, guiding electrons at the plasma front end to drift directionally towards multiple sawtooth tips, and serving as multiple arc anchoring points after discharge breakdown conduction, guiding the formation of multiple symmetrical discharge filaments to construct a circumferentially uniformly distributed current layer, thereby achieving Z-pinch constraint on the plasma plume.

[0032] The core technical principle of the above embodiments of the present invention lies in the following: Utilizing the periodically distributed serrated protrusions on the inner edge of the second anode, local spatial electric field distortion and tip field strength amplification effects are generated during the pre-conduction stage of discharge breakdown, thereby forming periodic high-field-strength regions at multiple serrated tips. When the metallic plasma generated at the cathode propagates towards the front end, these high-field-strength regions can efficiently extract electrons from the plasma, guiding the electron group to drift regularly and directionally along the electric field lines at the serrated tips, effectively suppressing the randomness of electron diffusion and stabilizing the dynamic process of long vacuum gap breakdown. After discharge breakdown and conduction, the multiple serrated tips, due to their lowest impedance paths, become preferred anode spot anchoring points, simultaneously guiding and maintaining multiple symmetrical discharge filaments. These filaments develop in parallel in space, jointly constructing a circumferentially distributed, highly uniform annular current layer. The angularly generated self-generated magnetic field excited by this current layer achieves an all-around angular envelope (i.e., Z-pinch) of the plasma plume, fundamentally eliminating the weak magnetic field confinement region caused by the current concentration in local channels under traditional smooth anodes. Compared with the prior art, the present invention does not require an external permanent magnet or electromagnetic coil. It can maximize and homogenize the Z-pinch magnetic pressure by simply improving the geometry of the electrode edge. This significantly suppresses the radial escape of charged particles and increases the axial directional propagation density of plasma, thereby effectively improving the thrust impulse and thrust-power ratio of the thruster.

[0033] In some embodiments, the geometry of the serrated protrusions 4 of the second anode 3 includes one or more of triangular teeth, rectangular teeth, semi-circular teeth, wavy teeth, or trapezoidal teeth; the number, depth, and arrangement period of the serrated protrusions 4 are set according to the rated power of the thruster and the pipe diameter.

[0034] In some embodiments, the serrated protrusions 4 of the second anode 3 are formed by processing the inner edge of the second anode 3 to form a periodically continuously distributed micro-protrusion structure, and the tips of the serrated protrusions 4 generate a periodically amplified local electric field intensity during the discharge process.

[0035] In some embodiments, the axial physical distance between the second anode 3 and the cathode 1 is an adjustable parameter used to change the discharge current amplitude, so as to coordinate the density of the sawtooth protrusions 4 to regulate the compactness of the current layer and the amplitude of the Z-pinch magnetic pressure.

[0036] In some embodiments, the serrated protrusions 4 of the second anode 3 are any one or more micro-protrusion array structures capable of inducing periodic distortion of the local spatial electric field at the inner edge of the second anode 3 facing the cathode 1; the number, depth, apex angle and arrangement period of the micro-protrusion array structure are proportionally scaled and adjusted according to the rated power of the thruster and the pipe diameter; the axial physical distance between the second anode 3 and the cathode is continuously adjustable in the range of 50 mm to 110 mm or a wider range.

[0037] In some specific embodiments, the diameter of the second anode is related to the diameter of the cathode. The parameters of the serrated protrusions on the inner edge of the second anode are determined according to the following range: preferably, the number of teeth is 12 to 18, and the tooth tip angle is 45° to 60°; the tooth spacing is determined by both the diameter of the second anode and the number of teeth, and increases accordingly with the increase of the diameter of the second anode. The discharge voltage is related to the distance between the cathode and the first anode, and can usually be set at around 10kV. The discharge current amplitude ranges from 100A to 200A, the pulse width is about 10μs, and the working vacuum is maintained at 10kV. -4 Pa level.

[0038] In some embodiments, the device is applied in a vacuum arc thruster, a metal vapor vacuum arc ion source, or a high-voltage vacuum trigger switch to utilize the magnetic field of the discharge current for plasma self-contraction confinement.

[0039] It should be noted that the serrated protrusions on the second anode in this invention are not limited to the specific shapes listed above. Any structure that induces a uniform distribution of multi-channel current by setting periodic micro-protrusions on the inner edge of the anode is included within the protection scope of this invention. Furthermore, the device of this invention is not only applicable to the specific applications described above, but can also be applied to any system that utilizes the magnetic field of the discharge current for plasma self-contraction confinement, all of which are within the protection scope of this invention.

[0040] This invention also provides a plasma Z-pinch optimization control method based on sawtooth multi-anodes, using the plasma Z-pinch optimization control device based on sawtooth multi-anodes described in any of the foregoing embodiments, see reference. Figures 1 to 4 The method includes the following steps: Pre-conduction stage: Utilizing the local spatial electric field distortion and field strength amplification effect generated by the periodic sawtooth protrusions of the second anode 3 toward the inner edge of the cathode side, the electrons at the front end of the plasma are guided to drift directionally toward the tips of multiple sawtooth protrusions, thus optimizing the dynamic process of long vacuum gap breakdown. Arc establishment stage: After discharge breakdown and conduction, multiple sawtooth protrusions are used as anodic arc anchoring points to guide the formation of multiple symmetrical discharge filaments, constructing a circumferentially uniformly distributed current layer, realizing all-round angular envelope magnetic confinement of the plasma plume, i.e., Z-pinch confinement.

[0041] In some embodiments, during the pre-conduction phase, the tip of the serrated protrusion 4 forms a periodic high field strength region on the surface of the second anode 3. When the plasma front end propagates to this region, the tip extracts electrons from the plasma front end and guides the electron group to drift directionally along the electric field lines of multiple serrated tips, thereby suppressing the randomness of electron diffusion.

[0042] In some embodiments, during the arc establishment phase, the plurality of sawtooth protrusions 4 serve as the current channel entrances with the lowest impedance, while simultaneously guiding and maintaining multiple symmetrical discharge filaments. These multiple discharge filaments develop in parallel in space, jointly constructing a ring-shaped current layer that is uniformly distributed in the circumferential direction.

[0043] In some embodiments, a two-dimensional synergistic control step is also included: by changing the density of the sawtooth protrusions 4 on the second anode 3, the density and spatial uniformity of the annular current layer are adjusted; at the same time, the axial physical distance between the second anode 3 and the cathode 1 is synergistically changed to change the discharge current amplitude, so as to control the amplitude of the Z-pinch inward magnetic pressure and realize plasma control at different power levels.

[0044] The serrated multi-anode structure provided by this invention guides the directional drift of electrons through local electric field distortion during the discharge pre-conduction stage, and forcibly anchors the multi-channel arc and constructs a circumferentially uniform current layer during the arc establishment stage, thereby achieving Z-pinch confinement. The Z-pinch effect can be adjusted by modifying the number, density, geometry of the serrated protrusions, and the axial distance between the second anode and the cathode. Its confinement effect is limited by the balance between the uniformity of the current layer and the thermodynamic pressure inside the plasma. Based on this, this invention utilizes a specific control method for improving the propulsion effect of a vacuum arc thruster using Z-pinch. By processing the inner edge of the second anode into periodic serrated protrusions and coordinating the adjustment of the serrated parameters and axial distance, two-dimensional dynamic control of the current layer density and Z-pinch magnetic pressure is achieved, thereby obtaining a concentrated and uniform plasma jet at different power levels. Experimental results (which will be further detailed below) show that the present invention can effectively reduce the plasma plume diffusion angle, increase the axial ion directional propagation density, and significantly improve the single-pulse element impulse and thrust-power ratio, while not increasing the thruster mass, volume, or additional power consumption. This provides a simple, efficient, and reliable technical path for the performance optimization of micro- and nano-satellite electric propulsion systems.

[0045] The working principle and experimental verification of specific embodiments of the present invention are further described below.

[0046] This invention proposes a plasma Z-pinch optimization control device and method based on a sawtooth multi-anode. The device mainly includes a cathode 1, a first anode 2 (whose surface is completely covered by an insulating medium), and a second anode 3 (the exposed distal anode). Based on this structure, the inner edge of the annular second anode 3 near the cathode 1 is processed into periodically continuously distributed sawtooth protrusions 4 (e.g., Figure 1(As shown). Its core physical mechanism is: by microstructuring the inner edge geometry of the second anode at the far end in the multi-anode structure, a sawtooth-shaped protrusion is constructed. By utilizing the local electric field distortion and tip effect during the discharge process, electrons are guided to drift in a specific direction and are forcibly anchored to the multi-channel arc, thereby constructing a circumferentially uniformly distributed current layer in space and optimizing the Z-pinch constraint effect.

[0047] The specific working principle and experimental verification are described below: In the pre-conduction phase of the discharge (electron-guided orientation): when initial metallic plasma is generated between the cathode and the first anode and propagates towards the second anode, there exists a region with opposite electric field vector directions between the first and second anodes (referred to as the X region). Figure 2 As shown, this figure comprehensively illustrates the comparison of the overall axial sectional electric field intensity distribution with and without serrations on the second anode, as well as the comparison of the radial sectional electric field intensity at the edge of the second anode. Compared to a smooth ring, the introduction of serrated protrusions causes a significant local electrostatic field distortion in region X near the boundary of the second anode. According to... Figure 2 The comparison of radial cross-sectional electric field intensity, and Figure 3 Analysis of the diagram (comparative analysis of electric field strength near the electrode with and without serrations at the second anode) shows that the local electric field strength at the serrated tips exhibits periodic peak amplification. When the plasma front propagates to this high-field region, the serrated tips can more efficiently extract electrons from the plasma front, guiding the electron group to drift regularly along the dense electric field lines of multiple serrated tips. This process effectively suppresses the randomness of electron diffusion and stabilizes the dynamic evolution process in the initial stage of long vacuum gap breakdown.

[0048] During the arc establishment phase (multi-channel anchoring and current layer envelope): After the vacuum gap is completely broken down, the multiple uniformly distributed serrated tips on the second anode, due to their highest local electric field and lowest impedance path, physically tend to become the preferred entry points for the current channels (i.e., anode spot anchoring points). These dense tips simultaneously guide and maintain multiple symmetrical discharge filaments, which develop in parallel in space, jointly constructing a highly uniform annular current layer in the circumferential direction. The angular self-generated magnetic field excited by this current layer achieves an all-round angular envelope of the internal metallic plasma plume, fundamentally eliminating the weak magnetic field confinement area caused by the current concentration on one side under a smooth anode, and maximizing and homogenizing the Z-pinch magnetic pressure.

[0049] Figure 4 The experimental results shown in the comparison diagram of current density distribution uniformity on the plasma surface and radial cross-section with and without serrations at the second anode further verify the improvement effect of this invention on current layer uniformity. Figure 4It can be seen that when the second anode is without serrations, the current density distribution near the second anode on the plasma plume surface exhibits a large, highly non-uniform region, with a similar trend of non-uniform current distribution on the radial cross-section. This region easily becomes a local weak point in Z-pinch. However, with serrated protrusions, the current density near the second anode is precisely anchored by the serrated protrusions, resulting in a relatively regular distribution without large, highly non-uniform regions. It should be noted that the electrode parameters are relatively ideal under simulation conditions. However, under actual discharge conditions, insufficient processing precision can easily lead to various asymmetries, making it more likely that local Z-pinch deficiencies will occur due to non-uniform current density distribution. Therefore, this invention uses serrated protrusions to forcibly anchor the multi-channel arc, which plays an important role in compensating for and stabilizing non-ideal factors in practical applications.

[0050] Furthermore, this invention provides a two-dimensional synergistic control of the Z-pinch confinement effect. This method not only provides a uniform current layer but also achieves dynamic synergistic control of the Z-pinch confinement effect by adjusting electrode structure parameters. On one hand, changing the number, spacing, and depth of the serrated protrusions on the second anode directly adjusts the density and spatial uniformity of the annular current layer (lateral distribution parameter). On the other hand, synergistically changing the axial physical distance (D) between the second anode and cathode alters the energy ratio released by the energy storage capacitor before discharge and the discharge current amplitude, thereby controlling the absolute magnitude of the inward magnetic pressure of the Z-pinch (longitudinal amplitude parameter). This synergistic control of two-dimensional parameters can meet the plasma control requirements of the thruster at different power levels.

[0051] Compared with existing technologies, this invention utilizes a sawtooth multi-anode structure to achieve optimized control of plasma Z-pinch, and has the following significant advantages: 1. Improved uniformity of Z-pinch current layer and magnetic pressure: The electric field distortion at the tip of the sawtooth is used to forcefully guide the multi-channel arc anchoring, overcoming the problem of random and localized current distribution under the traditional smooth anode, so that the current layer achieves uniform envelope in the circumferential direction, effectively suppressing the radial escape of charged particles from the weak constraint area.

[0052] 2. The dynamic process of long-gap vacuum breakdown has been optimized: the periodic high field strength generated by the sawtooth tip helps to accelerate the extraction and spatial directional drift of electrons in the pre-conduction stage, thereby improving the breakdown reliability and discharge stability of the thruster under low voltage.

[0053] 3. Improved overall thrust performance: By eliminating the weak area of ​​Z-pinch constraint and adjusting the axial pole spacing, the diffusion angle of the metal plasma plume was further reduced, and the directional propagation density of ions in the central axis was increased, thereby effectively improving the single-pulse impulse and thrust-power ratio of the vacuum arc thruster.

[0054] 4. Simple structure and no additional power consumption: It does not require the introduction of complex external excitation coils, does not increase the overall mass of the thruster, and does not increase the power supply load. The underlying physical mechanism can be optimized simply by passively improving the geometry of the electrode edges.

[0055] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A plasma Z-pinch optimization control device based on sawtooth multi-anodes, characterized in that, include: The cathode is used to generate metallic plasma during the discharge process; The first anode, whose surface is completely covered by an insulating medium, is disposed on the plasma jet path of the cathode to maintain a strong electric field near the cathode to promote plasma generation. The second anode has a ring-shaped structure and is disposed on the side of the first anode away from the cathode, and is spaced at a predetermined distance from the cathode. The inner edge of the second anode facing the cathode has periodically distributed serrated protrusions. The serrated protrusions of the second anode are used to generate local spatial electric field distortion and field strength amplification effect during the discharge breakdown pre-conduction stage, guide the electrons at the front end of the plasma to drift directionally to multiple serrated tips, and serve as multiple arc anchoring points after discharge breakdown conduction, guiding the formation of multiple symmetrical discharge filaments to construct a circumferentially uniformly distributed current layer, thereby achieving Z-pinch confinement of the plasma plume.

2. The apparatus according to claim 1, characterized in that, The geometric shape of the serrated protrusions of the second anode includes one or more of the following: triangular teeth, rectangular teeth, semi-circular teeth, wavy teeth, or trapezoidal teeth; the number, depth, and arrangement period of the serrated protrusions are set according to the rated power of the thruster and the pipe diameter.

3. The apparatus according to claim 1, characterized in that, The serrated protrusions of the second anode are formed into a periodically continuously distributed micro-protrusion structure by processing the inner edge of the second anode. The tips of the serrated protrusions generate a periodically amplified local electric field intensity during the discharge process.

4. The apparatus according to claim 1, characterized in that, The axial physical distance between the second anode and the cathode is an adjustable parameter used to change the discharge current amplitude, so as to coordinate the density of the sawtooth protrusions to regulate the compactness of the current layer and the amplitude of the Z-pinch magnetic pressure.

5. The apparatus according to claim 1, characterized in that, The serrated protrusions of the second anode are any one or more micro-protrusion array structures that can induce periodic distortion of the local spatial electric field on the inner edge of the second anode facing the cathode; the number, depth, apex angle and arrangement period of the micro-protrusion array structure are proportionally scaled and adjusted according to the rated power of the thruster and the pipe diameter; the axial physical distance between the second anode and the cathode is continuously adjustable in the range of 50 mm to 110 mm or a wider range.

6. The apparatus according to claim 1, characterized in that, The device is applied in vacuum arc thrusters, metal vapor vacuum arc ion sources, or high-voltage vacuum trigger switches to utilize the magnetic field of the discharge current for plasma self-contraction confinement.

7. A plasma Z-pinch optimization control method based on sawtooth multi-anodes, characterized in that, Using the apparatus as described in any one of claims 1 to 6 includes the following steps: Pre-conduction stage: Utilizing the local spatial electric field distortion and field strength amplification effect generated by the periodic sawtooth protrusions of the second anode toward the inner edge of the cathode side, the electrons at the plasma front end are guided to drift directionally toward the tips of multiple sawtooth protrusions, thus optimizing the dynamic process of long vacuum gap breakdown. Arc establishment stage: After discharge breakdown and conduction, multiple sawtooth protrusions are used as anodic arc anchoring points to guide the formation of multiple symmetrical discharge filaments, constructing a circumferentially uniformly distributed current layer, realizing all-round angular envelope magnetic confinement of the plasma plume, i.e., Z-pinch confinement.

8. The method according to claim 7, characterized in that, During the pre-conduction phase, the tips of the serrated protrusions form a periodic high field strength region on the surface of the second anode. When the plasma front end propagates to this region, the tips extract electrons from the plasma front end and guide the electron group to drift directionally along the electric field lines of multiple serrated tips, thus suppressing the randomness of electron diffusion.

9. The method according to claim 7, characterized in that, During the arc establishment phase, multiple sawtooth protrusions serve as the current channel entrances with the lowest impedance, while simultaneously guiding and maintaining multiple symmetrical discharge filaments. These multiple discharge filaments develop in parallel in space, jointly constructing a ring-shaped current layer that is uniformly distributed circumferentially.

10. The method according to claim 7, characterized in that, It also includes a two-dimensional synergistic control step: by changing the density of the sawtooth protrusions on the second anode, the density and spatial uniformity of the annular current layer are adjusted; at the same time, the axial physical distance between the second anode and the cathode is synergistically changed to change the discharge current amplitude, so as to control the amplitude of the Z-pinch inward magnetic pressure and realize plasma control at different power levels.

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