A magnetic deflection array cathode

Abstract

The present invention discloses a magnetic deflection array cathode, comprising: a housing, a grid structure, and a deflection member; the grid structure and the deflection member are installed inside the housing; the grid structure is used to generate electrons; and the deflection member is used to deflect and accelerate the electrons. The present invention, by using a chip selection electrode, can avoid failure of the entire device due to a short circuit between part of the cathode body and the anode, thereby improving the reliability and life of the cathode. At the same time, the use of a magnetic deflection method to lead out the electron beam can also reduce the cathode body from being bombarded by environmental pollution and external ions, etc., which can cause product failure, thereby increasing product reliability. By adding a grid assembly to the lead-out end, the electron beam can be focused and the energy enhanced, so that the electron source can be used in situations where current is required.

Description

Technical Field

[0001] The invention belongs to the field of vacuum electronics and aerospace propulsion technology, and in particular relates to a magnetic deflection array cathode. Background Art

[0002] Cathode electron sources (hereinafter referred to as cathodes) are widely used in fields such as vacuum and space propulsion. They are also core components in traveling wave tubes, plasma generators, Hall effect propulsion, and ion propulsion. Depending on the specifications of the supporting products, cathode emission currents range from a few milliamperes to several hundred amperes. The magnetically deflected array cathode is designed to address the problems of existing cathodes, such as their susceptibility to contamination, short lifespan, and inability to operate in environments with high plasma density or high levels of contamination or impurities.

[0003] Currently, typical cathodes include hollow cathodes, hot cathodes, and field emission cathodes. However, hollow cathodes are not an option when size and power requirements are high, as they require an additional gas supply. Therefore, hot cathodes or field emission cathodes are often used in low-power or micro-propulsion systems. However, hot cathodes or field emission cathodes can become contaminated by space impurities when exposed to the space environment, and there is a risk of short-circuiting or damage from ion bombardment from the propulsion system's beam. Once a short circuit or localized damage occurs, the entire cathode becomes obsolete. This significantly limits the lifespan of micro-propulsion systems. Summary of the Invention

[0004] The present invention aims to address the existing challenges of electric propulsion applications and electron sources for micro-thrusters, where exposure to contamination and sputtering damage to tiny cathodes can lead to device failure. This invention proposes an array-type, magnetically deflected cathode array with adjustable emission areas. This array protects against external contamination and sputtering from hot cathodes, carbon nanotube cathodes, and other cathodes, providing a favorable operating environment and thus improving product lifespan and reliability. Furthermore, a single cathode array can be constructed based on actual usage requirements, with the positive and negative power supply terminals connected to row and column control circuits, allowing for single-point control of the individual cathodes. This ensures that partial damage does not affect overall cathode performance and lifespan.

[0005] To achieve the above-mentioned object, the present invention provides the following solution: a magnetic deflection array cathode, comprising: a housing, a grid structure, and a deflection member;

[0006] The grid structure and the deflection member are mounted inside the housing;

[0007] The grid structure is used to generate electrons;

[0008] The deflection component is used to deflect and accelerate the electrons.

[0009] Optionally, the grid structure includes: a chip selection electrode, a cathode array and an anode array;

[0010] The chip selection electrode is located below the cathode array, and the anode array is located above the cathode array;

[0011] The cathode array is used to generate the electrons;

[0012] The chip selection electrodes and the anode array are used for chip selection.

[0013] Optionally, the chip selection electrodes are arranged in rows and columns.

[0014] Optionally, the chip selection method includes:

[0015] Turning on the cathode chip selection circuit and the anode array, and determining whether there is a short-circuited cathode body based on the feedback current;

[0016] If a short-circuited cathode body exists, the short-circuited cathode body is shielded by controlling the potential difference between the anode voltage above the short-circuited cathode body and the cathode chip selection circuit below the short-circuited cathode body.

[0017] Optionally, the deflection member comprises: a deflection region and an acceleration region;

[0018] The deflection region is used to realize the deflection of the electrons;

[0019] The acceleration zone is used to accelerate and focus the electrons.

[0020] Optionally, the deflection region includes: a magnetic field and an electron channel;

[0021] The magnetic field is used to achieve deflection of the electrons;

[0022] The deflected electrons reach the acceleration region through the electron channel.

[0023] Optionally, the acceleration zone includes: an acceleration grid and a screen grid;

[0024] The emission energy of the electrons is adjusted by adjusting the voltage between the acceleration grid and the screen grid.

[0025] Optionally, the acceleration grid and the screen grid are designed as curved surfaces to achieve focusing of the electrons.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention mainly proposes a magnetic deflection array cathode for aerospace propulsion and vacuum electron sources. By using chip selection electrodes, the present invention can avoid the failure of the entire device due to a short circuit between part of the cathode body and the anode, thereby improving the reliability and life of the cathode. At the same time, the use of magnetic deflection to lead out the electron beam can also reduce the cathode body from being bombarded by environmental pollution and external ions, etc., which may cause product failure, thereby increasing the reliability of the product. By adding a grid component to the lead-out end, the electron beam can be focused and the energy enhanced, so that the electron source can be used in situations where current is required. The present invention has the advantage of being able to achieve large currents without the need for working fluid gas, and is more suitable for situations where high vacuum requirements and large electron beam energy requirements are required. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a schematic diagram of the magnetic deflection array cathode structure of the present invention;

[0030] Figure 2 Schematic diagram of a general single cathode structure; (a) field emission array cathode, (b) hot cathode;

[0031] Figure 3 Schematic diagram of the cathode array structure of the present invention;

[0032] Figure 4 Schematic diagram of the anode array structure.

[0033] Description of reference numerals:

[0034] 1. Chip selection electrode; 2. Cathode array; 3. Anode array; 4. Magnetic field; 5. Acceleration grid; 6. Screen grid; 7. Electron channel; 8. Outer shell. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 1 , which is a schematic diagram of the magnetic deflection array cathode structure of the present invention, comprises: a housing 8 , a grid structure and a deflection component; the grid structure and the deflection component are installed inside the housing 8 .

[0038] The grid structure is used to generate electrons. Specifically, the grid structure includes: chip select electrodes 1, cathode array 2, and anode array 3. The chip select electrodes 1 are generally arranged in rows and columns, and the control of the cathode body at the intersection of rows and columns is achieved through the control of an external chip select circuit. The chip select electrodes 1, cathode array 2, and anode array 3 constitute the core part of the magnetic deflection array cathode. The positional relationship between the three is as follows: Figure 3 As shown, the chip selection electrode 1 is connected to the ground of the cathode array 2 and the anode array 3 respectively. The rows (columns) of the chip selection electrode 1 are set below the cathode array 2, and the columns (rows) of the chip selection electrode 1 are the anode array 3. The structure of the anode array 3 is as shown Figure 4 As shown, each region is insulated by ceramic. The grid formed by the anode array 3 and the cathode array 2 corresponds to the cathode body one by one, and the cathode in the grid emits electrons by controlling the voltage of the anode and cathode in the grid.

[0039] The cathode array 2 is used to provide electrons. It can be generally composed of field emission cathodes, thermal cathodes, carbon nanotube cathodes and other cathodes in an array manner. Different cathode arrays 2 can also be designed according to different currents. Figure 2 Figure 1 shows a schematic diagram of a typical single cathode structure. Anode array 3, when in operation, requires a voltage to be applied, pulling electrons from the cathode body and accelerating them. Anode array 3 and chip select electrode 1 form the cathode body's emission region selection component, enabling chip selection.

[0040] The chip selection method includes: first turning on the chip selection electrode 1 and the anode array 3, determining whether there is a short-circuited cathode body through feedback current, and if there is a short-circuited cathode body, shielding the short-circuited cathode body by individually controlling the potential difference between the anode voltage at the top of the cathode body at the short-circuit point and the chip selection electrode 1 at the bottom of the cathode body.

[0041] After chip selection is completed, the cathode starts working (hot cathodes need to be heated), and the electrons generated by the cathode enter the deflection member under the acceleration of the anode array 3. In this embodiment, the deflection member is used to deflect and accelerate electrons; the deflection member includes: a deflection area and an acceleration area. Among them, the deflection area includes: a magnetic field 4 and an electron channel 7; the acceleration area includes: an acceleration grid 5 and a screen grid 6. After being accelerated by the anode array 3, the electrons fly into the magnetic field 4. Because the directions of the electrons and the magnetic field 4 are perpendicular to each other, under the action of the Lorentz force, the movement path of the electrons in the magnetic field 4 is offset. The offset angle can be implemented according to the size of the device and actual requirements. The electrons reach the vicinity of the screen grid 6 through the electron channel 7, and then achieve secondary acceleration of the electrons through the potential difference between the acceleration grid 5 and the screen grid 6. Adjusting the potential difference can further adjust the emission energy of the electrons. The acceleration grid 5 and the screen grid 6 can be designed as curved surfaces such as flat grids, concave grids, and convex grids. The electron beam can be focused through the curved surface design. It can be a two-grid structure or a multi-grid structure. The specific design can be determined according to the electron beam energy requirement. The structure can be designed with different mesh sizes (number of holes) and different layouts according to different performance requirements.

[0042] The present invention is suitable for improving the performance of field emission cathodes and hot cathodes in harsh environments such as those with high levels of space pollution or the presence of plasma. Typical application scenarios include space electric propulsion systems and vacuum electronics. The magnetic deflection array cathode proposed in the present invention is a secondary design based on carbon nanotube cathodes, hot cathodes, and field emission cathodes. To address pollution and sputtering corrosion issues, the cathode body is placed inside a protective shield so that the beam cannot directly impact the cathode surface. The electron beam is deflected by a magnetic field 4 and extracted along the direction of the magnetic field 4. At the same time, by introducing a chip select electrode 1, the anode voltage of the anode array point at the top of the cathode at this coordinate point is not supplied. Due to the matrix anode design, the voltages of the individual anodes do not affect each other. Therefore, damage to the cathode at a certain coordinate point does not affect the operation of other cathodes. Finally, to address the problem of relatively divergent electron beams from hot cathodes and carbon nanotube cathodes, a gate is designed at the extraction site to achieve focusing and strengthening of the electron beam, which can meet the needs of different emission current levels.

[0043] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A magnetic deflection array cathode, characterized in that: include: shells, lattice structures, and deflection elements; The grid structure and the deflection member are mounted inside the housing; The grid structure is used to generate electrons; The deflection member is used to deflect and accelerate the electrons; The grid structure includes: a chip selection electrode, a cathode array and an anode array; The chip selection electrode is located below the cathode array, and the anode array is located above the cathode array; The cathode array is used to generate the electrons; The chip selection electrode and the anode array are used for chip selection; The chip selection method includes: Turning on the cathode chip selection circuit and the anode array, and determining whether there is a short-circuited cathode body based on the feedback current; If a short-circuited cathode body exists, shielding the short-circuited cathode body by controlling the potential difference between the anode voltage above the short-circuited cathode body and the cathode chip select circuit below the short-circuited cathode body; The deflection member includes: a deflection area and an acceleration area; The deflection region is used to realize the deflection of the electrons; The acceleration zone is used to accelerate and focus the electrons; The deflection region includes: a magnetic field and an electron channel; The magnetic field is used to achieve deflection of the electrons; The deflected electrons arrive at the acceleration region through the electron channel; The acceleration zone includes: an acceleration grid and a screen grid; adjusting the ejection energy of the electrons by adjusting the voltage between the acceleration grid and the screen grid; The acceleration grid and the screen grid are designed as curved surfaces to achieve focusing of the electrons.

2. The magnetic deflection array cathode according to claim 1, characterized in that: The chip selection electrodes are arranged in rows and columns.

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