Double-layer anode structure for radiation field focusing of high-current diode and method of use

Abstract

A double-layer anode structure high-current diode for radiation field focusing and a use method thereof, comprising a ring-shaped cathode plate, an outer-layer anode ring-shaped plate, an inner-layer anode ring-shaped plate and an anode target surface; the side surface of the inner-layer anode ring-shaped plate is provided with the anode target surface side by side, the ring-shaped cathode plate is sleeved outside the inner-layer anode ring-shaped plate and the anode target surface, and a first cavity is formed between the inner-layer anode ring-shaped plate and the anode target surface; the outer-layer anode ring-shaped plate is sleeved outside the ring-shaped cathode plate, and a second cavity is formed between the outer-layer anode ring-shaped plate and the ring-shaped cathode plate; the first cavity and the second cavity are communicated at the anode target surface. Through the design of the double-layer anode structure (the inner-layer anode ring-shaped plate and the outer-layer anode ring-shaped plate), the flow and focusing of the electron beam can be more effectively controlled. This structure helps to maintain the shape stability of the ring-shaped electron beam and reduces the diffusion and defocusing of the electron beam in the transmission process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-current diodes, and particularly relates to a double-layer anode structure high-current diode for radiation field focusing and a use method. BACKGROUND

[0002] A high-current electron beam diode mainly comprises a cathode and an anode in a vacuum, is a device capable of generating and accelerating a high-current density electron beam, and has an important role in multiple fields. Generation of strong radiation X (gamma) rays is one of main uses of the high-power high-current electron beam diode. The strong pinch diode usually has a strong electron beam focusing effect, so that the electron beam bombarding the anode can produce a very strong thermodynamic destruction effect, thereby causing serious damage to the anode of the diode. Meanwhile, due to the high energy and large intensity of the electron beam, the pinch effect of the electrons emitted by the cathode to the target center caused by the action of the self-magnetic field can result in a large electron beam incidence angle and uneven radiation field.

[0003] At present, the commonly used single-anode ring-plate configuration or rod pinch diode in a pulse power device has the electron beam falling point on the anode moving over time in the strong pinch mode, and the high-energy radiation can seriously damage the target surface of the diode, thereby affecting the long-term stability and performance of the diode. SUMMARY

[0004] The application aims to provide a double-layer anode structure high-current diode for radiation field focusing and a use method to solve the above problems.

[0005] To achieve the above-mentioned purpose, the application adopts the following technical solutions:

[0006] The double-layer anode structure high-current diode for radiation field focusing comprises a ring-shaped cathode plate, an outer-layer anode ring-shaped plate, an inner-layer anode ring-shaped plate, and an anode target surface. The side surface of the inner-layer anode ring-shaped plate is provided with the anode target surface in parallel, the ring-shaped cathode plate is sleeved outside the inner-layer anode ring-shaped plate and the anode target surface, and a first cavity is formed between the ring-shaped cathode plate and the inner-layer anode ring-shaped plate and the anode target surface. The outer-layer anode ring-shaped plate is sleeved outside the ring-shaped cathode plate, and a second cavity is formed between the outer-layer anode ring-shaped plate and the ring-shaped cathode plate. The first cavity and the second cavity are communicated at the anode target surface.

[0007] Further, the first cavity and the second cavity are respectively provided with an inner-layer high-current pulse input port and an outer-layer high-current pulse input port at the openings away from the anode target surface.

[0008] Further, the ring-shaped cathode plate, the outer-layer anode ring-shaped plate, the inner-layer anode ring-shaped plate, and the anode target surface are all in the form of a cylinder with both ends open.

[0009] Further, the annular cathode plate, the outer layer annular anode plate and the inner layer annular anode plate at the inner layer strong current pulse input port and the outer layer strong current pulse input port are all extended outward and connected to the insulating support.

[0010] Further, the inner layer annular anode plate and the anode target surface have the same diameter and are connected side by side; the anode target surface and one end of the outer layer annular anode plate are fixedly connected through the annular end plate.

[0011] Further, the connection between the inner layer annular anode plate and the anode target surface is separated by the partition plate.

[0012] Further, the axial length of the annular cathode plate is less than the axial length of the outer layer annular anode plate.

[0013] Further, the annular cathode plate, the outer layer annular anode plate and the inner layer annular anode plate are made of stainless steel; and the anode target is made of tungsten or tantalum.

[0014] Further, the thickness of the annular cathode plate is 10-20 mm, and the thickness of the outer layer annular anode plate and the inner layer annular anode plate is 10-15 mm.

[0015] Further, the method for using the double-layer anode structure strong current diode for radiation field focusing comprises the following steps:

[0016] In the initial stage of the outer layer voltage pulse, the current at the outer layer strong current pulse input port is small, during which the electron beam flows from the cathode to the anode perpendicularly, and no pinch effect is generated;

[0017] The voltage and the current of the outer layer strong current pulse input port are increased, the outer layer electron orbit is bent due to the self magnetic field, and thus a weak pinch is gradually formed; at this time, the voltage pulse at the inner layer strong current pulse input port is in the initial stage, and no pinch is generated at the inner layer strong current pulse input port.

[0018] The outer layer strong current pulse input port is increased to the voltage peak value, the impedance is stable, the electron beam flow of the outer layer is obviously pinched, and a strong pinch electron flow is formed; at the same time, with the increase of the voltage pulse at the inner layer strong current pulse input port, the inner layer electron orbit is bent due to the influence of the self magnetic field, and a weak pinch is generated.

[0019] The inner and outer layer electron beams are in the strong pinch state, and the electron beams of the two layers are stably focused on the anode target surface under the influence of the strong self magnetic field and the interaction, so that the electron beam stably bombarding the anode target surface interacts with the anode target surface to generate X-ray or gamma ray.

[0020] Compared with the prior art, the present application has the following technical effects:

[0021] The present application can more effectively control the flow and focusing of the electron beam through the design of the double-layer anode structure (inner anode ring plate and outer anode ring plate). This structure helps to maintain the stability of the annular electron beam shape, reduces the diffusion and defocusing of the electron beam during transmission.

[0022] The double-layer anode structure helps to reduce the electron beam current density on a single path by dispersing the electron beam flow path. This not only reduces the direct damage of the electron beam to the target surface, but also improves the uniformity of the radiation field.

[0023] The design of the double-layer anode structure allows the electron beam to be more uniformly distributed before hitting the anode target surface, thereby forming a larger radiation field. This is beneficial for the interaction between the electron beam and the target surface, improving the generation efficiency and focusing effect of X-rays or γ-rays.

[0024] In the strong pinch mode of traditional single-anode ring-plate configuration or rod-pinch diode, the electron beam often focuses on the center of the target surface, resulting in uneven distribution of the radiation field. The double-layer anode structure can effectively avoid this problem by dispersing the electron beam flow and focusing point.

[0025] Due to the reduction of electron beam current density and the uniform distribution of the radiation field, the double-layer anode structure can significantly reduce the direct damage of the electron beam to the target surface, prolonging the service life of the target surface.

[0026] The material selection mentioned in the technical solution (such as stainless steel and tungsten or tantalum) has good electrical conductivity and corrosion resistance, which is suitable for the manufacture of high-current diodes. This technical solution is suitable for various application scenarios that require the generation and focusing of X-rays or γ-rays, such as medical, scientific research, industrial detection, etc.

[0027] Optimization of the use method of the present application: By controlling the voltage and current of the outer layer high-current pulse input port and the inner layer high-current pulse input port in stages, the pinch and focusing process of the electron beam can be accurately controlled, improving the stability and focusing effect of the radiation field. When the inner and outer layer electron beams are in a strong pinch state, the two layers of electron beams are stably focused on the anode target surface under the influence of the strong self-magnetic field and interaction, thereby improving the interaction efficiency between the electron beam and the target surface and the generation efficiency of X-rays or γ-rays.

[0028] In summary, this technical solution effectively solves the problems of uneven radiation field and severe target surface damage in the strong pinch mode of traditional single-anode structure through the design of double-layer anode structure and optimization of use method, improves the stability and focusing effect of the electron beam, and has wide applicability and promotional value. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The figure is a structural schematic diagram of the present application.

[0030] Figure 2 Flowchart of the present invention.

[0031] Figure 3 Schematic diagram of the present invention connected with insulation support.

[0032] Wherein:

[0033] 1, annular cathode plate; 2, outer layer anode annular plate; 3, inner layer anode annular plate; 4, outer layer high-current pulse input port; 5, inner layer high-current pulse input port; 6, anode target surface; 7, annular end plate; 8, partition plate; 9, insulation support. DETAILED DESCRIPTION

[0034] The present invention is further illustrated below in conjunction with the accompanying drawings:

[0035] Example 1, please refer to Figure 1 The present invention provides a double-layer anode structure high-current diode for radiation field focusing, which includes: an annular cathode plate 1, an outer layer anode annular plate 2, an inner layer anode annular plate 3, and an anode target surface 6. The inner layer anode annular plate 3 has anode target surfaces 6 arranged side by side on its sides. The annular cathode plate 1 is sleeved outside the inner layer anode annular plate 3 and the anode target surface 6, forming a first cavity between them. The outer layer anode annular plate 2 is sleeved outside the annular cathode plate 1, forming a second cavity between them. The first cavity and the second cavity are connected at the anode target surface 6.

[0036] The combination of the double-layer anode structure (inner layer anode annular plate and outer layer anode annular plate) and the annular cathode plate forms a complex but highly controllable electron beam transmission path. This structure allows for more precise control of the electron beam during transmission, which helps to achieve more accurate focusing.

[0037] Through the design of the double-layer anode structure, the electron beam can be more evenly distributed before reaching the anode target surface. This helps to reduce the unevenness of the radiation field and improve the overall quality and consistency of the radiation field.

[0038] The design of the connection of the first cavity and the second cavity at the anode target surface allows the electron beam to form a more concentrated and uniform radiation field when bombarding the target surface, which is crucial for improving the generation efficiency and focusing effect of X-rays or γ-rays.

[0039] The double-layer anode structure effectively reduces the electron beam current density on a single path by dispersing the electron beam flow path. This not only helps to reduce the direct damage of the electron beam to the target surface, but also prolongs the service life of the target surface. At the same time, due to the reduction of electron beam current density, the risk of target surface heating and damage is also reduced, thereby improving the stability and reliability of the entire diode.

[0040] The design of the double-layer anode structure enables the electron beam to interact more fully with the target material when bombarding the anode target surface, thereby improving the generation efficiency of X-rays or gamma rays. In addition, due to the optimization of the radiation field and the reduction of the electron beam current density, the radiation efficiency of the entire diode is significantly improved.

[0041] The double-layer anode structure provides more flexibility for voltage and current control. By adjusting the voltage and current of the outer and inner high-current pulse input ports respectively, the pinch and focusing process of the electron beam can be precisely controlled. This flexibility enables the diode to adapt to different application scenarios and requirements, improving its practicality and versatility.

[0042] In summary, the double-layer anode structure high-current diode for radiation field focusing provided by the present application, through its unique design and optimization, achieves more precise control of the electron beam, optimizes the radiation field distribution, reduces the electron beam current density and target damage, improves the radiation efficiency, provides flexible voltage and current control, and maintains a compact structure and ease of manufacture. These technical effects make the diode have wide application prospects and great potential in the fields of radiation field focusing and X-ray or gamma ray generation.

[0043] In embodiment 2, the double-layer anode structure high-current diode for radiation field focusing provided by the present application specifically includes:

[0044] The double-layer anode structure high-current diode for radiation field focusing mainly includes a ring-shaped cathode plate 1, an outer-layer anode ring-shaped plate 2, an inner-layer anode ring-shaped plate 3, and an anode target surface 6. The side of the inner-layer anode ring-shaped plate 3 is closely arranged with the anode target surface 6 side by side, and the ring-shaped cathode plate 1 is sleeved outside the inner-layer anode ring-shaped plate 3 and the anode target surface 6 to form a first cavity together. The outer-layer anode ring-shaped plate 2 is further sleeved outside the ring-shaped cathode plate 1 to form a second cavity with the ring-shaped cathode plate 1. The first cavity and the second cavity are connected to each other at the position of the anode target surface 6, which helps the transmission and focusing of the electron beam.

[0045] The first cavity and the second cavity are respectively provided with an inner layer high current pulse input port 5 and an outer layer high current pulse input port 4 at a position away from the anode target surface 6. These ports provide convenience for injection and regulation of the electron beam. In addition, the annular cathode plate 1, the outer layer annular anode plate 2, the inner layer annular anode plate 3 and the anode target surface 6 are designed as open-ended cylinder structures, which not only ensure smooth transmission of the electron beam, but also facilitate processing and assembly. The inner layer annular anode plate 3 and the anode target surface 6 have the same diameter and are connected side by side, and they are fixedly connected with one end of the outer layer annular anode plate 2 through the annular end plate 7, which ensures the stability and reliability of the entire structure. The annular cathode plate 1, the outer layer annular anode plate 2 and the inner layer annular anode plate 3 at the inner layer high current pulse input port 5 and the outer layer high current pulse input port 4 are all extended outwardly and connected to the insulating support 9.

[0046] At the same time, the connection between the inner layer annular anode plate 3 and the anode target surface 6 is also separated by the partition plate 8 to avoid unnecessary interference of the electron beam during transmission.

[0047] In terms of material selection, the annular cathode plate 1, the outer layer annular anode plate 2 and the inner layer annular anode plate 3 all use stainless steel material, which has good electrical conductivity and corrosion resistance and is suitable for manufacturing high current diodes. The anode target surface 6 is made of tungsten or tantalum target material, which can generate strong X-ray or gamma-ray when bombarded by an electron beam. In terms of size parameters, the axial length of the annular cathode plate 1 is designed to be smaller than the axial length of the outer layer annular anode plate 2, which helps to optimize the transmission path and focusing effect of the electron beam. At the same time, the thickness of the annular cathode plate 1 is controlled to be between 10-20mm, while the thickness of the outer layer annular anode plate 2 and the inner layer annular anode plate 3 is controlled to be between 10-15mm. The selection of these size parameters not only ensures the strength of the structure, but also avoids unnecessary waste of materials.

[0048] The high current diode with a double-layer anode structure designed and selected in the application can make the annular electron beam stable, reduce the electron beam current density while maintaining a large radiation field, and facilitate the focusing of the rays generated after the anode is bombarded. The double-layer anode structure solves the problems of uneven radiation field and serious damage to the target surface in the strong pinch mode of the commonly used single-anode ring-plate configuration or rod-pinch diode, and is suitable for wide application.

[0049] Working principle: relatively large voltage pulses are injected from the outer layer high-current pulse input port 4 and the inner layer high-current pulse input port 5, so that the cathode emits electrons to form an electron beam under the action of a strong electric field, and the position of the electron beam focus can be adjusted by adjusting the delay time of the inner and outer layer voltage pulses. In this process, the current of the two layers of diodes is significantly increased, and then the electrons of the two layers are axially offset under the action of the self-magnetic field, and begin to enter the pinch state. The electron beams of the two layers can be stably focused on the corresponding positions of the anode target surface under the combined influence of the electric field and the self-magnetic field, so that the electron beams can stably bombard the anode target surface to interact with it to generate X-rays or γ-rays.

[0050] When the voltage pulse input by the inner layer is delayed for a certain time from the voltage pulse input by the outer layer, the basic working process is schematically shown as Figure 2 , which is divided into the following four stages:

[0051] 1) Outer electron beam non-pinch stage: In the initial stage of the outer layer voltage pulse, the current is very small, and the self-magnetic field can be ignored. During this period, the electron beam basically flows vertically from the cathode to the anode, and the electron beam current is weak and no pinch effect is generated.

[0052] 2) Weak pinch of outer electron beam and non-pinch of inner layer: With the continuous rise of the outer layer input voltage and current, the influence of the self-magnetic field begins to expand, resulting in the bending of the outer electron orbit and the gradual formation of weak pinch. At this time, the inner layer voltage pulse is in the initial stage, and the self-magnetic field generated by it can be ignored, and the inner layer electron beam does not pinch.

[0053] 3) Strong pinch of outer electron beam and weak pinch of inner layer: In this stage, the outer layer input is near the voltage peak value, and the impedance is stable. The Lorentz force generated by the extremely high current causes the outer electron beam to pinch significantly, thereby forming an extremely strong pinched electron current. At the same time, with the increase of the inner layer voltage pulse, the inner electron orbit is bent under the influence of the self-magnetic field and begins to produce weak pinch.

[0054] 4) Stable focusing stage of inner and outer electron beams: The inner and outer electron beams are in a strong pinch state, and the electron beams of the two layers can be stably focused on a certain position of the anode target surface under the influence of the strong self-magnetic field and interaction, so that the electron beams stably bombard the anode target surface to interact with it to generate X-rays or γ-rays.

[0055] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and any modification or equivalent replacement within the spirit and scope of the present application should be covered by the protection scope of the claims of the present application.

Claims

1. A double-layer anode structure high-current diode for radiation field focusing, characterized in that: include: An annular cathode plate (1), an outer anode annular plate (2), an inner anode annular plate (3) and an anode target surface (6); the anode target surface (6) is arranged side by side on the side of the inner anode annular plate (3); the annular cathode plate (1) is sleeved on the outer side of the inner anode annular plate (3) and the anode target surface (6), and a first cavity is formed between the inner anode annular plate (3) and the anode target surface (6); the outer anode annular plate (2) is sleeved on the outer side of the annular cathode plate (1), and a second cavity is formed between the outer anode annular plate (1); the first cavity and the second cavity are connected at the anode target surface (6); The openings of the first cavity and the second cavity away from the anode target surface (6) are respectively an inner layer high current pulse input port (5) and an outer layer high current pulse input port (4); The annular cathode plate (1), the outer anode annular plate (2), the inner anode annular plate (3) and the anode target surface (6) are all cylindrical structures with openings at both ends; The inner anode annular plate (3) and the anode target surface (6) have the same diameter and are connected side by side; the anode target surface (6) and one end of the outer anode annular plate (2) are fixedly connected via an annular end plate (7); The connection between the inner anode annular plate (3) and the anode target surface (6) is separated by a partition (8); The axial length of the annular cathode plate (1) is smaller than the axial length of the outer anode annular plate (2).

2. The double-layer anode structure high-current diode for radiation field focusing according to claim 1, characterized in that: The annular cathode plate (1), the outer anode annular plate (2) and the inner anode annular plate (3) at the inner high-current pulse input port (5) and the outer high-current pulse input port (4) are all extended outwardly and connected to the insulating support (9).

3. The double-layer anode structure high-current diode for radiation field focusing according to claim 1, characterized in that: The materials used for the annular cathode plate (1), the outer annular anode plate (2) and the inner annular anode plate (3) are stainless steel; the target surface material used for the anode target (6) is tungsten or tantalum.

4. The double-layer anode structure high-current diode for radiation field focusing according to claim 1, characterized in that: The thickness of the annular cathode plate (1) is 10 to 20 mm, and the thickness of the outer annular anode plate (2) and the inner annular anode plate (3) are 10 to 15 mm.

5. A method for using a double-layer anode structure high-current diode for radiation field focusing, characterized in that: The double-layer anode structure high-current diode for radiation field focusing according to any one of claims 1 to 4 comprises the following steps: In the initial stage of the outer voltage pulse, the current at the input port of the outer high current pulse is small. During this period, the electron beam flows vertically from the cathode to the anode, and no pinch effect occurs. By increasing the voltage and current at the outer high-current pulse input port, the self-magnetic field causes the outer electron orbit to bend, gradually forming a weak pinch. At this time, the voltage pulse at the inner high-current pulse input port is in the initial stage, and no pinch occurs at the inner high-current pulse input port. When the voltage of the outer high-current pulse input port is increased to the peak value, the impedance is stable, and the outer electron beam current is obviously pinched, forming a strong pinch electron current. At the same time, as the voltage pulse at the inner high-current pulse input port increases, the inner electron orbit is affected by the self-magnetic field and bends, starting to produce a weak pinch. The inner and outer electron beams are both in a strongly pinched state. The two electron beams are stably focused onto the anode target surface under the influence of the strong self-magnetic field and the interaction, so that the electron beams stably bombarding the anode target surface interact with it to produce X-rays or gamma rays.

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