Carbon nanotube gas field ion thruster

Abstract

The application relates to a carbon nanotube gas field ion thruster which comprises a body and an acceleration zone diagnosis mechanism, the body comprises an upper cover, a base connected to the upper cover, and an electrode assembly assembled between the upper cover and the base, the upper cover and the base are made of insulating materials, the electrode assembly comprises a high-voltage lead ring and a low-voltage lead ring arranged in sequence along the arrangement direction of the base and the upper cover, the high-voltage lead ring abuts against the end face of the base, the low-voltage lead ring abuts against the end face of the upper cover, the high-voltage lead ring is used for electrically connecting with the high-voltage end of a high-voltage power supply, the low-voltage lead ring is used for electrically connecting with the low-voltage end of the high-voltage power supply, and the electrode assembly is used for ionizing working gas which enters the electrode assembly through the base; the acceleration zone diagnosis mechanism comprises a first camera and a first electric signal acquisition card, the first camera is used for observing the ionization condition of the electrode assembly, and the first electric signal acquisition card is used for measuring the sampling resistance electric signal on the side of the low-voltage lead ring and then converting the sampling resistance electric signal into an ion current value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of space propulsion technology, in particular to a carbon nanotube gas field ion thruster. BACKGROUND

[0002] Ion thruster, also known as ion thruster and ion engine, its principle is to ionize the gas first, and then use the electric field force to accelerate the charged ions and spray them out, so as to push the rocket with the reaction force. Among them, the ion thruster with carbon nanotube array as high-voltage electrode can produce extremely high field enhancement effect, and the thrust effect is better. However, there is no matching diagnostic system at present, which cannot observe and detect the working state of the thruster. SUMMARY

[0003] Therefore, it is necessary to provide a carbon nanotube gas field ion thruster for detecting the working state of the carbon nanotube gas field ion thruster.

[0004] A carbon nanotube gas field ion thruster, comprising:

[0005] A body comprising an upper cover, a base connected to the upper cover, and an electrode assembly assembled between the upper cover and the base, the upper cover and the base are made of insulating material, the electrode assembly comprises a high-voltage lead ring and a low-voltage lead ring arranged in sequence along the arrangement direction of the base and the upper cover, and the high-voltage lead ring abuts against the end face of the base, and the low-voltage lead ring abuts against the end face of the upper cover, the high-voltage lead ring is used for electrically connecting with the high-voltage end of a high-voltage power supply, the low-voltage lead ring is used for electrically connecting with the low-voltage end of the high-voltage power supply, and the electrode assembly is used for ionizing working gas entering the electrode assembly through the base;

[0006] An acceleration zone diagnostic mechanism comprising a first camera and a first electric signal acquisition card, the first camera is used for observing the ionization condition of the electrode assembly, and the electric signal acquisition card is used for measuring the sampling resistance electric signal on the side of the low-voltage lead ring, and then converting into ion current value.

[0007] In one embodiment, the electrode assembly comprises a carbon nanotube high-voltage electrode, a carbon nanotube array, an insulating isolation ring and a gate, the side of the carbon nanotube high-voltage electrode away from the carbon nanotube array is attached to the high-voltage lead ring, the upper surface of the gate is attached to the low-voltage lead ring, the insulating isolation ring is used for isolating the carbon nanotube high-voltage electrode and the gate, and the carbon nanotube array is located at the through hole of the insulating isolation ring, and the insulating isolation ring is a polished quartz glass ring.

[0008] The acceleration zone diagnosis mechanism further comprises a second electric signal acquisition card and a mask piece, the mask piece is assembled between the insulating isolation ring and the carbon nanotube high-voltage electrode, the mask piece is used for dividing the plurality of carbon nanotube arrays into a plurality of ionization regions, the gate electrode comprises a plurality of fan-shaped sub-gate electrode pieces, the plurality of sub-gate electrode pieces and the plurality of ionization regions are in one-to-one correspondence, each sub-gate electrode piece can be electrically connected with the low-voltage end, and each sub-gate electrode piece can be connected with the second electric signal acquisition card, and the second electric signal acquisition card is used for measuring the current value induced by ion impact on the sub-gate electrode piece.

[0009] In one of the embodiments, the low-resistance silicon substrate of the carbon nanotube high-voltage electrode is provided with the carbon nanotube array, and the carbon nanotube array extends in a direction away from the high-voltage lead ring, the mask piece comprises a bottom disc and a plurality of radial strips extending along the bottom disc, and the mask piece is inserted on the carbon nanotube array so that the strips separate the carbon nanotube array into a plurality of ionization regions.

[0010] In one of the embodiments, the plume zone diagnosis mechanism further comprises an ion probe and a plume outlet pipe, the plume outlet pipe is in communication with the upper cover so that the ionized gas is discharged through the plume outlet pipe, and the probe of the ion probe extends into the pipe of the plume outlet pipe, and the ion probe is used for detecting the ion flux through a preset position of the plume outlet pipe.

[0011] In one of the embodiments, the plume zone diagnosis mechanism further comprises a conductive collection plate, the conductive collection plate is located at one end of the plume outlet pipe away from the upper cover, the conductive collection plate is connected to the plume outlet pipe to block the end of the plume outlet pipe, a plurality of plume outlets for discharging gas are formed on the side wall of the plume outlet pipe, the conductive collection plate is made of conductive material, and the conductive collection plate is used for measuring the ion extraction flux of the body.

[0012] In one of the embodiments, the acceleration zone diagnosis mechanism further comprises a second camera, the conductive collection plate is made of conductive glass material, and the second camera is arranged at one end of the conductive collection plate away from the plume outlet pipe, and the second camera is used for observing the light emission phenomenon that may occur in the electrode assembly during operation through the conductive collection plate and the plume outlet pipe.

[0013] In one of the embodiments, the conductive collection plate is provided with a conductive film at one end close to the plume outlet pipe, the conductive film is made of tin oxide material, the thickness of the conductive film is less than 1 μm, and the light transmittance of the conductive film is greater than 90%.

[0014] In one of the embodiments, a plurality of the ion probes are provided, and the plurality of the ion probes are arranged along a circumference of the plume outlet pipe.

[0015] In one of the embodiments, the plume region diagnostic mechanism further comprises a plurality of fixing components, each of the ion probes is provided with a set of the fixing components, the fixing components comprise a support pipe, an insulating sleeve and a fixing member, the support pipe is inserted into a side wall of the plume outlet pipe, the insulating sleeve is installed in the support pipe, the ion probe passes through the insulating sleeve and the support pipe, and the fixing member clamps the insulating sleeve and the ion probe.

[0016] In one of the embodiments, the base is convexly provided with a first annular support in a direction of the base approaching the upper cover in a radial direction, the upper cover is convexly provided with a second annular support in a direction of the upper cover approaching the base in a radial direction, the base, the first annular support, the second annular support and the upper cover form a containing cavity for containing the electrode assembly, and a side wall of the first annular support and / or the second annular support is provided with an opening for the high-voltage lead ring and / or the low-voltage lead ring to pass through.

[0017] The present application has the following beneficial effects:

[0018] The carbon nanotube gas field ion thruster comprises a body and an acceleration zone diagnosis mechanism, the body comprises an upper cover, a base and an electrode assembly, the upper cover and the base are connected to clamp the electrode assembly. The high-voltage lead ring of the electrode assembly is connected with the high-voltage end of a high-voltage power supply, the low-voltage lead ring is connected with the low-voltage end of the high-voltage power supply, the high-voltage power supply is turned on, the working gas flows into the electrode assembly through the base and is ionized by the electrode assembly, thereby generating thrust in the direction of the base. The upper cover and the base are made of insulating materials to prevent conduction. A first camera is arranged in the circumferential direction of the electrode assembly, and a worker observes the ionization condition of the electrode assembly through the first camera. When the electrode assembly has phenomena such as carbon tube root falling off, end rising and regional carbon tube collapse, the electrode assembly can be replaced or repaired in time. Moreover, the ignition state and ionization condition of the thruster can be monitored in all directions through the first camera to determine the service life of the carbon nanotube gas field ion thruster. The ignition state of the electrode assembly can also be observed through the first camera to determine whether the current ionization condition meets the preset requirement. The sampling resistance electric signal on the low-voltage lead ring side is measured through the first electric signal acquisition card, and then converted into an ion current value, thereby measuring the ion current on the low-voltage lead ring and determining whether the current ion current meets the preset range. If the current ion current does not meet the preset range, the electrode assembly is detected and repaired to prevent the working efficiency of the carbon nanotube gas field ion thruster from being low due to the ion current value on the low-voltage lead ring side not meeting the preset range. The ignition state and ionization condition of the electrode assembly are detected through the first camera, the ion current on the low-voltage lead ring is measured through the first electric signal acquisition card, thereby detecting the working state of the carbon nanotube gas field ion thruster and improving the working efficiency of the carbon nanotube gas field ion thruster. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A structure schematic view of a first perspective of the carbon nanotube gas field ion thruster provided by the embodiment of the present application is provided.

[0020] Figure 2 A structure schematic view of a second perspective of the carbon nanotube gas field ion thruster provided by the embodiment of the present application is provided.

[0021] Figure 3 A structure schematic view of the body provided by the embodiment of the present application is provided.

[0022] Figure 4 A structure schematic view of the electrode assembly provided by the embodiment of the present application is provided.

[0023] Figure 5 A structure schematic view of the carbon nanotube high-voltage electrode provided by the embodiment of the present application is provided.

[0024] Figure 6 A structure schematic view of the gate provided by the embodiment of the present application is provided.

[0025] Figure 7 Structure diagram of the base provided for the embodiment of the present application;

[0026] Figure 8 Structure diagram of the upper cover provided for the embodiment of the present application;

[0027] Figure 9 Structure diagram of the plume area diagnosis mechanism provided for the embodiment of the present application;

[0028] Figure 10 Structure diagram of the plume area diagnosis mechanism provided for the embodiment of the present application; Figure 9 Cross-sectional view at A-A;

[0029] Figure 11 Structure diagram of the plume area diagnosis mechanism provided for the embodiment of the present application; Figure 9 Cross-sectional view at B-B.

[0030] In the drawings:

[0031] 100, body; 110, upper cover; 111, second annular strut; 120, base; 121, first annular strut; 130, electrode assembly; 131, high-voltage lead ring; 132, carbon nanotube high-voltage electrode; 133, carbon nanotube array; 134, insulating isolation ring; 135, gate; 1351, sub-gate electrode sheet; 1352, connecting piece; 136, low-voltage lead ring; 140, opening;

[0032] 200, acceleration area diagnosis mechanism; 210, first camera; 220, mask sheet; 221, chassis; 222, strut; 230, second camera;

[0033] 300, plume area diagnosis mechanism; 310, ion probe; 320, plume outlet pipe; 321, plume outlet; 330, conductive collection plate; 340, copper sheet; 350, fixing assembly; 351, support pipe; 352, insulating sleeve;

[0034] 400, gas flow interface. DETAILED DESCRIPTION

[0035] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0036] In the description of the application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application.

[0037] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0038] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or it can only mean that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or it can only mean that the horizontal height of the first feature is less than that of the second feature.

[0040] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0041] This invention provides a carbon nanotube gas field ionization thruster, such as... Figures 1 to 4 As shown, it includes a body 100 and an acceleration zone diagnostic mechanism 200. The body 100 includes an upper cover 110, a base 120 connected to the upper cover 110, and an electrode assembly 130 assembled between the upper cover 110 and the base 120. The upper cover 110 and the base 120 are made of insulating material. The electrode assembly 130 includes a high-voltage lead ring 131 and a low-voltage lead ring 136 arranged sequentially along the arrangement direction of the base 120 and the upper cover 110. The high-voltage lead ring 131 abuts against the end face of the base 120, and the low-voltage lead ring 136 abuts against the upper cover 120. The end face of the cover 110 has a high-voltage lead ring 131 for electrical connection to the high-voltage end of the high-voltage power supply, a low-voltage lead ring 136 for electrical connection to the low-voltage end of the high-voltage power supply, and an electrode assembly 130 for ionizing the working gas that enters the electrode assembly 130 through the base 120. The acceleration zone diagnostic mechanism 200 includes a first camera 210 and a first electrical signal acquisition card. The first camera 210 is used to observe the ionization of the electrode assembly 130, and the electrical signal acquisition card is used to measure the sampling resistance electrical signal measured by the low-voltage lead ring 136, and then convert it into an ion current value.

[0042] The carbon nanotube gas field ion thruster comprises a body 100 and an acceleration zone diagnostic mechanism 200, the body 100 comprises an upper cover 110, a base 120 and an electrode assembly 130, the upper cover 110 and the base 120 are connected to clamp the electrode assembly 130. The high-voltage lead ring 131 of the electrode assembly 130 is connected with the high-voltage end of a high-voltage power supply, the low-voltage lead ring 136 is connected with the low-voltage end of the high-voltage power supply, the high-voltage power supply is turned on, the working medium gas flows into the electrode assembly 130 through the base 120 and is ionized by the electrode assembly 130, so that the thrust in the direction of the base 120 is generated. The upper cover 110 and the base 120 are made of insulating materials to prevent conduction. The first camera 210 is arranged in the circumferential direction of the electrode assembly 130, and the staff can observe the ionization condition of the electrode assembly 130 through the first camera 210, so that the electrode assembly 130 can be replaced or repaired in time when the electrode assembly 130 has phenomena such as carbon tube root falling off, end rising and regional carbon tube collapse. Moreover, the ionization condition of the body 100 can be monitored in all directions through the first camera 210 to judge the service life of the carbon nanotube gas field ion thruster. At the same time, the ignition condition of the electrode assembly 130 can also be observed through the first camera 210 to judge whether the current ionization condition meets the preset requirement. The sampling resistance electric signal on the side of the low-voltage lead ring 136 is measured through the first electric signal acquisition card, and then converted into an ion current value, so that the ion current on the low-voltage lead ring 136 is measured to judge whether the current ion current meets the preset range. If not, the electrode assembly 130 is detected and repaired to prevent the problem of low working efficiency of the carbon nanotube gas field ion thruster caused by the ion current value on the side of the low-voltage lead ring 136 not meeting the preset range. The ignition state of the electrode assembly 130 and the ionization condition of the electrode assembly 130 are detected through the first camera 210, and the ion current on the low-voltage lead ring 136 is measured through the first electric signal acquisition card, so that the working state of the carbon nanotube gas field ion thruster is detected to improve the working efficiency of the carbon nanotube gas field ion thruster.

[0043] Specifically, the high-voltage end of the positive direct-current high-voltage power supply is connected with the high-voltage lead ring 131, the low-voltage end is connected with the low-voltage lead ring 136, and a sampling resistance is connected in series in the loop current formed by the high-voltage lead ring 131 and the low-voltage lead ring 136 close to the side of the low-voltage lead ring 136. The first electric signal acquisition card is connected with the sampling resistance on the side of the low-voltage lead ring 136, the electric signal of the sampling resistance is acquired through the first electric signal acquisition card, and then the electric signal is converted into an ion current value, so that the ion current on the low-voltage lead ring 136 can be measured.

[0044] Specifically, as shown in Figure 1 and Figure 2As shown, the first camera 210 is provided in plurality, and the plurality of first cameras 210 are uniformly arranged around the circumference of the electrode assembly 130, and the plurality of visual angles observe the ionization condition of the electrode assembly 130.

[0045] Specifically, as shown, the base 120 is connected to the upper cover 110 by means of bolts. The base 120 and the upper cover 110 are made of quartz glass material, and the side surface is polished to prevent the base 120 and the upper cover 110 from blocking the observation line of sight of the first camera 210. Figure 1

[0046] In some embodiments, as shown, the carbon nanotube gas field ion thruster further comprises a gas flow interface 400 in communication with the base 120, and the gas flow interface 400 is used to communicate with a gas supply source to transport working gas. By providing the gas flow interface 400, the communication between the base 120 and the gas supply source is facilitated, and the transportation of working gas is facilitated, and more specifically, the working gas is argon or xenon. Figure 1

[0047] In some embodiments, as shown, the electrode assembly 130 comprises a carbon nanotube high-voltage electrode 132, a carbon nanotube array 133, an insulating isolation ring 134, and a gate 135, the carbon nanotube high-voltage electrode 132 is attached to the high-voltage lead ring 131 on the side away from the carbon nanotube array 133, the upper surface of the gate 135 is attached to the low-voltage lead ring 136, the insulating isolation ring 134 is used to isolate the carbon nanotube high-voltage electrode 132 and the gate 135, and the carbon nanotube array 133 is located at the through hole of the insulating isolation ring 134, and the insulating isolation ring 134 is a polished quartz glass ring; the acceleration region diagnostic mechanism 200 further comprises a second electric signal acquisition card and a mask sheet 220, the mask sheet 220 is assembled between the insulating isolation ring 134 and the carbon nanotube high-voltage electrode 132, the mask sheet 220 is used to divide the plurality of carbon nanotube arrays 133 into a plurality of ionization regions, the gate 135 comprises a plurality of fan-shaped sub-gate electrode sheets 1351, the plurality of sub-gate electrode sheets 1351 and the plurality of ionization regions are one-to-one corresponding, each sub-gate electrode sheet 135 can be electrically connected to the low-voltage end, and each sub-gate electrode sheet 1351 can be connected to the second electric signal acquisition card, and the second electric signal acquisition card is used to measure the current value induced by the ion impact on the sub-gate electrode sheet 1351. Figure 3 Figure 4

[0048] ​​​​When the high-voltage power supply is turned on, the working gas flows into the electrode assembly 130 through the base 120, and flows to the region near the carbon nanotube array 133 of the electrode assembly 130. The tip of the carbon nanotube array 133 discharges to ionize the working gas to generate positive ions and electrons. The electrons are attracted by the carbon nanotube array 133, and the positive ions are attracted by the grid 135. The positive ions move to the grid 135 and continuously accelerate to generate a thrust in the direction of the base 120. The insulating isolation ring 134 prevents the grid 135 and the carbon nanotube high-voltage electrode 132 from being conductive. The mask 220 is arranged between the carbon nanotube high-voltage electrode 132 and the insulating isolation ring 134. The mask 220 divides the carbon nanotube array 133 into multiple ionization regions. The grid 135 corresponds to the multiple ionization regions and includes multiple sub-grid electrode pieces 1351 corresponding to the multiple ionization regions one by one. Each sub-grid electrode piece 135 is electrically connected to the low-voltage end of the high-voltage power supply. Each sub-grid electrode piece 1351 can be connected to the second electric signal acquisition card, so as to measure the current value induced by the ion impact on each sub-grid electrode piece 1351 through the second electric signal acquisition card.

[0049] It should be noted that the low-voltage lead ring 136 is in contact with the grid 135. In the diagnosis of the current of the sub-grid electrode piece 1351, the low-voltage lead ring 136 only has the function of fixing each sub-grid electrode piece 1351. In the measurement of the current of the whole grid 135, the low-voltage lead ring 136 is connected to the low-voltage end of the high-voltage power supply and is connected in series with the high-precision first ammeter in the first loop to measure the total current value of the grid 135.

[0050] Specifically, as shown in Figure 4 and Figure 5 The low-resistance silicon substrate of the carbon nanotube high-voltage electrode 132 is provided with multiple carbon nanotube arrays 133, and the carbon nanotube arrays 133 extend in the direction away from the high-voltage lead ring 131. The mask 220 includes a bottom disc 221 and multiple bars 222 extending radially therefrom. The mask 220 is inserted on the carbon nanotube array 133, so that the bars 222 separate the carbon nanotube array 133 into multiple ionization regions. The multiple bars 222 are connected to each other through the bottom disc 221. The bottom disc 221 and the multiple bars 222 of the mask 220 are inserted on the carbon nanotube array 133, so as to divide the multiple carbon nanotube arrays 133 into multiple ionization regions.

[0051] More specifically, as shown in Figure 5 and Figure 6As shown, the eight struts 222 are connected to the base 221 at one end and extend in the radial direction of the base 221 at the other end, thereby separating the plurality of carbon nanotube arrays 133 into eight ionization regions. The gate 135 includes eight sub-gate electrode pieces 1351 corresponding to the eight ionization regions.

[0052] In particular, as shown in Figure 6 The gate 135 is composed of a plurality of fan-shaped sub-gate electrode pieces 1351 and corresponds to the ionization regions. The sub-gate electrode pieces 1351 are made of molybdenum, the fan-shaped angle of the sub-gate electrode pieces 1351 is 45°, the fan-shaped tips are inserted into an insulating substrate made of polytetrafluoroethylene, and finally cooperate to form a complete gate 135. The distributed sub-gate electrode pieces 1351 can measure the current of each sub-gate electrode piece 1351.

[0053] In particular, the electrode assembly 130 is in a ring structure, the low-resistance silicon substrate of the carbon nanotube high-voltage electrode 132 grows the carbon nanotube array 133 away from the high-voltage lead ring 131, the length of the carbon nanotube array 133 ranges between 100mm-500mm, and the silicon substrate is uniformly arrayed with gas-permeable holes for the working gas to pass through, with a diameter of 0.2mm; the mask 220 is made of stainless steel with a thickness of 0.1mm. The working gas passes through the gas inlet, the base 120, and the carbon nanotube high-voltage electrode 132 in sequence, and is finally ionized by the tips of the carbon nanotube array 133. The tips of the carbon nanotube array 133 refer to the end of the carbon nanotube array 133 away from the carbon nanotube high-voltage electrode 132. The carbon nanotube array 133 provided on the carbon nanotube high-voltage electrode 132 is a conventional technical means in the art, which will not be described here.

[0054] More specifically, referring back to Figure 4 An insulating isolation ring 134 is arranged between the gate 135 and the carbon nanotube high-voltage electrode 132. The insulating isolation ring 134 not only prevents the gate 135 and the carbon nanotube high-voltage electrode 132 from being conductive, but also adjusts the distance between the gate 135 and the carbon nanotube high-voltage electrode 132 by clamping insulating isolation rings 134 of different thicknesses. More specifically, the end faces of the insulating isolation ring 134 are attached to the gate 135 and the carbon nanotube high-voltage electrode 132, respectively, and the through holes of the insulating isolation ring 134 are surrounded by a plurality of carbon nanotube arrays 133. The insulating isolation ring 134 is made of polished quartz glass to prevent the insulating isolation ring 134 from obstructing the viewing angle of the first camera 210.

[0055] In some embodiments, as shown in Figure 7 and Figure 8As shown, the base 120 is provided with a first annular support 121 protruding in a direction along the radial direction of the base 120 towards the cover 110, and the cover 110 is provided with a second annular support 111 protruding in a direction along the radial direction of the cover 110 towards the base 120, and the base 120, the first annular support 121, the second annular support 111 and the cover 110 form a receiving cavity for receiving the electrode assembly 130, and the side wall of the first annular support 121 and / or the second annular support 111 is provided with an opening 140 for the high-voltage lead ring 131 and / or the low-voltage lead ring 136 to pass through. By providing the first annular support 121 on the base 120 and the second annular support 111 on the cover 110, and the end surface of the base 120, the side wall of the first annular support 121, the side wall of the second annular support 111 and the end surface of the cover 110 form the receiving cavity for receiving the electrode assembly 130, and the opening 140 provided on the side wall of the first annular support 121 and / or the side wall of the second annular support 111 facilitates the passage of the high-voltage lead ring 131 and the low-voltage lead ring 136.

[0056] Specifically, the base 120 and the cover 110 are made of quartz glass material, and are transparent as a whole, which is insulating and does not hinder the observation line of sight of the first camera 210.

[0057] In some embodiments, the high-voltage lead ring 131 and the low-voltage lead ring 136 have the same structure, and the high-voltage lead ring 131 / low-voltage lead ring 136 includes an annular main body portion and a lead connection portion, and the lead connection portion is in a strip shape, and when the electrode assembly 130 is installed, the annular main body portion is arranged in the receiving cavity, and the lead connection portion passes through the opening 140 to be electrically connected with the high-voltage power supply. More specifically, the lead connection portion and the high-voltage power supply are electrically connected by a wire clamp. In some embodiments, only four openings 140 are provided on the base 120 for the lead connection portions of the high-voltage lead ring 131 and the low-voltage lead ring 136 to pass through.

[0058] Preferably, as shown in Figure 7 and Figure 8 The base 120 is provided with a first through hole, the gas flow interface 400 communicates with the first through hole, the electrode assembly 130 is provided with a second through hole corresponding to the first through hole and communicating with the first through hole, and the cover 110 is provided with a third through hole corresponding to the second through hole and communicating with the second through hole, and the working gas enters the first through hole through the gas flow interface 400, flows into the carbon nanotube high-voltage electrode 132 of the electrode assembly 130 through the first through hole, and then flows to the region near the carbon nanotube array 133 through the carbon nanotube high-voltage electrode 132.

[0059] In some embodiments, please refer to Figure 1 and Figure 2The carbon nanotube gas field ion thruster further comprises a plume region diagnostic mechanism 300, the plume region diagnostic mechanism 300 comprises an ion probe 310 and a plume outlet pipe 320, the plume outlet pipe 320 is communicated with the upper cover 110 to discharge the ionized gas through the plume outlet pipe 320, the probe of the ion probe 310 extends into the pipe of the plume outlet pipe 320, and the ion probe 310 is used to detect the ion flux through the preset position of the plume outlet pipe 320. By setting the plume outlet pipe 320 to be communicated with the upper cover 110, when the working medium gas is ionized, the positive ions are attracted to the grid electrode 135 to move to the grid electrode 135, and finally the positive ions are transmitted to the plume outlet pipe 320 and measured by the ion probe 310 installed at the preset position of the plume outlet pipe 320, so that the number of ions is measured. It should be noted that the preset position refers to the position where the probe extends into the plume outlet pipe 320, and the preset position can be adjusted according to actual conditions.

[0060] Specifically, as shown in Figure 1 and Figure 9 , the ion probe 310 is provided in plurality, and the plurality of ion probes 310 are arranged along the circumference of the plume outlet pipe 320. More specifically, the number of ion probes 310 is equal to the number of ionization regions and sub-grid electrode pieces 1351, and the ion probe 310 is provided in eight, and the eight ion probes are used to measure the number of ions at the eight preset positions of the plume outlet pipe 320. It should be noted that the number of ions measured by the ion probe 310 can be converted into a current value through a formula, that is, the current value at the preset position of the plume outlet pipe 320 can be obtained.

[0061] In some embodiments, as shown in Figure 1 and Figure 10 , the plume region diagnostic mechanism 300 further comprises a fixing assembly 350, each ion probe 310 is provided with a set of fixing assemblies 350, the fixing assembly 350 comprises a support pipe 351, an insulating sleeve 352 and a fixing piece, the support pipe 351 is inserted on the side wall of the plume outlet pipe 320, the insulating sleeve 352 is installed in the support pipe 351, the ion probe 310 passes through the insulating sleeve 352 and the support pipe 351, and the fixing piece clamps the insulating sleeve 352 and the ion probe 310. By setting the fixing assembly 350, the ion probe 310 is fixed at the preset position. A mounting hole is formed on the side wall of the plume outlet pipe 320, the support pipe 351 is installed in the mounting hole, the insulating sleeve 352 is installed in the support pipe 351, the ion probe 310 passes through the insulating sleeve 352, and the probe of the ion probe 310 protrudes out of the insulating sleeve 352 and the support pipe 351 and is located in the plume outlet pipe 320, and finally the fixing piece clamps the insulating sleeve 352 and the ion probe 310 to limit the movement of the ion probe 310. The fixing piece is a clamp, the support pipe 351 and the mounting hole are in interference fit, and the insulating sleeve 352 and the support pipe 351 are in interference fit.

[0062] In some embodiments, as shown in Figure 1 , Figure 9 and Figure 11 , the plume area diagnosis mechanism 300 further comprises a conductive collection plate 330, which is located at the end of the plume outlet pipe 320 away from the upper cover 110, and is connected to the plume outlet pipe 320 to block the end of the plume outlet pipe 320. A plurality of plume outlets 321 for exhausting gas are formed on the side wall of the plume outlet pipe 320. The conductive collection plate 330 is made of conductive material and is used to measure the ion extraction flux of the body 100. By arranging the conductive collection plate 330 at the end of the plume outlet pipe 320 away from the upper cover 110, the ions passing through the plume outlet pipe 320 are uniformly collected, and the ion extraction flux of the body 100 can be measured. Moreover, because the conductive collection plate 330 blocks the end of the plume outlet pipe 320, and a plurality of plume outlets 321 are formed on the side wall of the plume outlet pipe 320, it is convenient to exhaust gas.

[0063] It should be noted that the ion flux can be measured by the following method: the conductive collection plate 330 is connected in series with an ammeter, the current value on the conductive collection plate 330 is measured, and the corresponding ion quantity can be obtained by converting the current value. The corresponding ion quantity is the ion flux extracted by the body 100.

[0064] Specifically, as shown in Figure 1 and Figure 9 , the plurality of plume outlets 321 are uniformly arranged at the same height and have dual functions. One function is to balance the external air pressure and the internal air pressure of the body 100 as a plume outlet. The other function is to connect the lead wires passing through the plume outlets 321 as lead wire through holes. The plurality of plume outlets 321 correspond one-to-one to the plurality of sub-grid electrode pieces 1351.

[0065] Preferably, as shown in Figure 1 and Figure 9 , the plume area diagnosis mechanism 300 further comprises a copper sheet 340, which is clamped between the conductive collection plate 330 and the plume outlet pipe 320 to increase the connection area between the plume outlet pipe 320 and the conductive collection plate 330, facilitate connection, and has a certain performance of collecting ions, thereby improving the accuracy of detecting the ion flux extracted by the body 100.

[0066] In some embodiments, as shown in Figure 1 and Figure 9As shown, the acceleration zone diagnostic mechanism 200 further comprises a second camera 230, the conductive collection plate 330 is made of conductive glass material, and the second camera 230 is arranged at one end of the conductive collection plate 330 away from the plume outlet pipe 320, and the second camera 230 is used to observe the light emission phenomenon that may occur during the operation of the electrode assembly 130 through the conductive collection plate 330 and the plume outlet pipe 320. The second camera 230 is arranged above the conductive collection plate 330, and the conductive collection plate 330 is made of quartz glass material, which can not only collect ions, but also not hinder the viewing angle of the second camera 230. The second camera 230 observes the ionization of the electrode assembly 130 through the conductive collection plate 330 and the plume outlet pipe 320, and the first camera 210 and the second camera 230 cooperate with each other, the first camera 210 observes from the side, and the second camera 230 observes from the top, multiple viewing angles are used to observe the ionization of the electrode assembly 130 and the light emission phenomenon.

[0067] Specifically, the first camera 210 is provided with four, and the second camera 230 is provided with one, which can detect the ionization of the electrode assembly 130 in five directions, accurately locate the position of the carbon nanotube field ionization light emission and sparking, and monitor the possible carbon nanotube morphology change phenomenon of the body 100 during operation.

[0068] In some embodiments, the conductive collection plate 330 is provided with a conductive film at one end close to the plume outlet pipe 320, the conductive film is made of tin oxide material, the thickness of the conductive film is less than 1 μm, and the light transmittance of the conductive film is greater than 90%. By setting the conductive film, the conductivity of the conductive collection plate 330 is improved, and the accuracy of detecting the ion extraction flux of the body 100 is improved, and the light transmittance of the conductive film is greater than 90%, which does not affect the viewing angle of the second camera 230.

[0069] The carbon nanotube gas field ionization thruster provided by the embodiment of the application can achieve the following effects:

[0070] 1. The acceleration zone and the plume zone of the carbon nanotube gas field ionization thruster can be diagnosed in multiple ways and synchronously;

[0071] (1) The carbon nanotube array 133 is divided into different ionization regions by the mask 220 covering the carbon nanotube array 133, and the same sub-grid electrode sheet 1351 is arranged corresponding to the grid 135, and by measuring the current of the sub-grid electrode sheet 1351 in different regions, the internal field ionization performance, ion extraction condition, and the motion trajectory of the charged particles in the electric field of the carbon nanotube gas field ionization thruster can be diagnosed;

[0072] (2) The plume region is arranged with a plume outlet pipe 320, the cross-sectional size of which is slightly larger than that of the working region surrounded by the plurality of carbon nanotube arrays 133, and a plurality of distributed ion probes 310 are arranged at the height of the side wall of the plume outlet pipe 320, so that the distribution characteristics of the number of ions in different spatial ranges of the plume region can be obtained, and the ion distribution angle of the plume region can be calculated, thereby optimizing the carbon nanotube gas field ion thruster;

[0073] (3) While the distributed ion probes 310 are arranged, a conductive collection plate 330 is arranged at the top end of the plume region to synchronously measure the total ion extraction flux. At the same time, the total ion extraction efficiency can be calculated in combination with the total grid 135 current, which is the sum of the currents of the plurality of sub-grid electrode pieces 1351, and the total ion extraction efficiency is equal to the plume current divided by the emission current, wherein the plume current is the current value measured by the conductive collection plate 330, and the emission current is the current value of the first circuit;

[0074] (4) The plurality of ionization regions of the carbon nanotube array 133 not only correspond one-to-one to the plurality of sub-grid electrode pieces 1351, but also correspond one-to-one to the plurality of probes on the plume outlet pipe 320, so that the particle ionization, acceleration, ion extraction, etc. of the specific micro-ionization region can be synchronously diagnosed, and the overall distribution can be obtained by comparing the diagnostic parameters in different micro-regions, thereby increasing the plasma space diagnosis accuracy;

[0075] 2. The multi-channel optical / electrical synchronous combined diagnosis can be realized during the operation of the thruster;

[0076] (1) The base 120 and the upper cover 110 of the body 100 are composed of side-polished quartz glass, and a first camera 210 is arranged at a plurality of orientations on the side of the body 100, so that the carbon tube root falling off, end rising, and regional carbon tube collapse, etc. that may occur during the long-term operation of the electrode assembly 130 can be monitored in all directions, thereby evaluating the working life of the carbon nanotube array 133;

[0077] (2) The top end of the plume outlet pipe 320 is covered by a transparent conductive collection plate 330, and a second camera 230 is arranged above the conductive collection plate 330, so that the functions of plume ion flux collection and optical measurement can be compatible. By taking a close-up shot of the discharge region of the carbon nanotube array 133 during the operation of the electrode assembly 130, the position of the carbon tube field ionization light emission and sparking can be accurately located, thereby judging the working performance of the thruster;

[0078] (3) The combination of multi-channel optical observation and distributed electrical diagnosis can quantitatively diagnose the abnormal discharge region of the carbon tube, and the carbon tube morphology change behavior, abnormal discharge data, and induced grid 135 current and plume ion flux, etc. obtained by synchronous measurement are combined, which greatly enhances the accuracy and reliability of the diagnosis, and plays an important role in optimizing the performance of the body 100.

[0079] The application also provides a method for using the carbon nanotube gas field ion thruster.

[0080] 1. Adjust the ambient pressure of the body 100 to 0.01 Pa and keep stable;

[0081] 2. Connect the high-voltage end of the positive direct-current high-voltage power supply with the high-voltage lead ring 131, and connect the low-voltage end with the low-voltage lead ring 136, and at the same time, connect a 1MΩ protective resistor in series in the first loop current;

[0082] 3. Connect a 1MΩ sampling resistor in series for each ion probe 310;

[0083] 4. Turn off the external environment light, and at the same time, turn on the night capture mode of the first camera 210 and the second camera 230;

[0084] 5. Slowly adjust the voltage to a stable value in the range of +300V to +3000V at an interval of 100V, keep for 180s, and then continue to increase the voltage until the limit voltage of +3000V is met;

[0085] 6. Analyze the ion current intensity, discharge stability and threshold discharge intensity of the stable light-emitting environment of different regions by collecting I-t and I-V curves.

[0086] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict, they should be considered as within the scope of the present application.

[0087] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A carbon nanotube gas field ionization thruster, characterized in that, include: The body (100) includes a top cover (110), a base (120) connected to the top cover (110), and an electrode assembly (130) assembled between the top cover (110) and the base (120). The top cover (110) and the base (120) are made of insulating material. The electrode assembly (130) includes a high-voltage lead ring (131) and a low-voltage lead ring (132) arranged sequentially along the arrangement direction of the base (120) and the top cover (110). 136), and the high voltage lead ring (131) abuts against the end face of the base (120), the low voltage lead ring (136) abuts against the end face of the top cover (110), the high voltage lead ring (131) is used to electrically connect to the high voltage end of the high voltage power supply, the low voltage lead ring (136) is used to electrically connect to the low voltage end of the high voltage power supply, and the electrode assembly (130) is used to ionize the working gas that enters the electrode assembly (130) through the base (120); The accelerated zone diagnostic device (200) includes a first camera (210) and a first electrical signal acquisition card. The first camera (210) is used to observe the ionization of the electrode assembly (130), and the first electrical signal acquisition card is used to measure the sampling resistance electrical signal on the low-voltage lead ring (136) side and then convert it into an ion current value. The electrode assembly (130) includes a carbon nanotube high-voltage electrode (132), a carbon nanotube array (133), an insulating isolation ring (134), and a gate (135). The side of the carbon nanotube high-voltage electrode (132) facing away from the carbon nanotube array (133) is attached to the high-voltage lead ring (131). The upper surface of the gate (135) is attached to the low-voltage lead ring (136). The insulating isolation ring (134) is used to isolate the carbon nanotube high-voltage electrode (132) and the gate (135). The carbon nanotube array (133) is located at the through hole of the insulating isolation ring (134). The insulating isolation ring (134) is a side-polished quartz glass ring. The accelerated zone diagnostic device (200) further includes a second electrical signal acquisition card and a mask (220). The mask (220) is assembled between the insulating isolation ring (134) and the carbon nanotube high-voltage electrode (132). The mask (220) is used to divide the multiple carbon nanotube arrays (133) into multiple ionization regions. The gate (135) includes multiple fan-shaped sub-gate electrode pieces (1351). The multiple sub-gate electrode pieces (1351) correspond one-to-one with the multiple ionization regions. Each sub-gate electrode piece (1351) can be electrically connected to the low-voltage end. Each sub-gate electrode piece (1351) can be connected to the second electrical signal acquisition card. The second electrical signal acquisition card is used to measure the current value induced by ion bombardment of the sub-gate electrode piece (1351).

2. The carbon nanotube gas field ionization thruster according to claim 1, characterized in that, The low-resistivity silicon substrate of the carbon nanotube high-voltage electrode (132) is provided with a carbon nanotube array (133), and the carbon nanotube array (133) extends in a direction away from the high-voltage lead ring (131). The mask (220) includes a chassis (221) and a plurality of supports (222) extending radially therefrom. The mask (220) is inserted into the carbon nanotube array (133) so that the supports (222) divide the carbon nanotube array (133) into a plurality of ionization regions.

3. The carbon nanotube gas field ionization thruster according to claim 1, characterized in that, It also includes a plume region diagnostic device (300), which includes an ion probe (310) and a plume outlet tube (320). The plume outlet tube (320) is connected to the top cover (110) so that the ionized gas is discharged through the plume outlet tube (320). The probe of the ion probe (310) extends into the tube of the plume outlet tube (320). The ion probe (310) is used to detect the ion flux passing through a preset position of the plume outlet tube (320).

4. The carbon nanotube gas field ionization thruster according to claim 3, characterized in that, The plume zone diagnostic device (300) further includes a conductive collection plate (330), which is located at the end of the plume outlet pipe (320) away from the top cover (110). The conductive collection plate (330) is connected to the plume outlet pipe (320) to block the end of the plume outlet pipe (320). Multiple plume outlets (321) are provided on the side wall of the plume outlet pipe (320). The conductive collection plate (330) is made of conductive material and is used to measure the ion extraction flux of the body (100).

5. The carbon nanotube gas field ionization thruster according to claim 4, characterized in that, The acceleration zone diagnostic device (200) also includes a second camera (230). The conductive collection plate (330) is made of conductive glass. The second camera (230) is configured at the end of the conductive collection plate (330) away from the plume outlet pipe (320). The second camera (230) is used to observe the luminescence phenomenon that may occur in the electrode assembly (130) during operation through the conductive collection plate (330) and the plume outlet pipe (320).

6. The carbon nanotube gas field ionization thruster according to claim 5, characterized in that, A conductive film is provided at one end of the conductive collecting plate (330) near the plume outlet pipe (320). The conductive film is made of tin oxide material, the thickness of the conductive film is less than 1 μm, and the light transmittance is greater than 90%.

7. The carbon nanotube gas field ionization thruster according to claim 3, wherein multiple ion probes (310) are provided, and the multiple ion probes (310) are arranged circumferentially along the plume outlet pipe (320).

8. The carbon nanotube gas field ionization thruster according to claim 7, characterized in that, The plume region diagnostic device (300) further includes a fixing assembly (350), each of the ion probes (310) is equipped with a set of the fixing assemblies (350), the fixing assembly (350) includes a support tube (351), an insulating sleeve (352) and a fixing member, the support tube (351) is inserted into the side wall of the plume outlet pipe (320), the insulating sleeve (352) is installed inside the support tube (351), the ion probe (310) passes through the insulating sleeve (352) and the support tube (351), and the fixing member clamps the insulating sleeve (352) and the ion probe (310).

9. The carbon nanotube gas field ionization thruster according to claim 1, characterized in that, The base (120) has a first annular support column (121) protruding radially toward the upper cover (110), and the upper cover (110) has a second annular support column (111) protruding radially toward the base (120). The base (120), the first annular support column (121), the second annular support column (111), and the upper cover (110) form a receiving cavity for accommodating the electrode assembly (130). An opening (140) is provided on the side wall of the first annular support column (121) and / or the second annular support column (111), and the opening (140) is used for the high voltage lead ring (131) and / or the low voltage lead ring (136) to pass through.

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