X-ray tube and X-ray generating device

Abstract

The present invention provides an X-ray tube, comprising a shell, an anode assembly and a cathode assembly; the shell is provided with an X-ray window and an exhaust port; the anode assembly comprises an anode, an anode protection cover and an anode insulation cover, the anode insulation cover and the anode protection cover are located at the periphery of the shell, the anode protection cover is located at the inner side of the anode insulation cover, the anode insulation cover is connected to the shell and the anode protection cover, the anode comprises a first part and a second part, the first part and the second part are not in a straight line, the first part is located in the shell, one end of the second part extends to connect with the first part, and the other end passes through the anode insulation cover and the anode protection cover, the end face of the end of the first part not connected with the second part is the anode target surface, and the center of the anode target surface corresponds to the center of the X-ray window from top to bottom; the cathode assembly comprises a cathode, a cathode core column and a cathode insulation cover. The present invention helps to improve the stability of electron emission of the X-ray tube and the uniformity and consistency of the electric field around the anode target surface.

Description

Technical Field

[0001] The present invention relates to the field of X-ray technology, and in particular to an X-ray tube and an X-ray generating device. Background Art

[0002] X-ray tube is the core device for generating X-rays. The X-rays it generates can be used for non-destructive testing of the inside of an object and are widely used in the fields of medical treatment, security inspection, industrial flaw detection, etc. X-ray tubes generate electrons from the cathode. The electrons are accelerated by a high-voltage electric field and then hit the anode target surface, generating X-rays through the bremsstrahlung mechanism. An external high-voltage power supply provides a high-voltage electric field between the cathode and the anode, and the external shell packaging provides a high vacuum environment, so that the electron impact event can run continuously and stably, thereby obtaining a continuous and stable output of X-rays.

[0003] X-ray tubes are consumable parts, and internal sparking and discharge are the main reasons for the decline in X-ray tube performance. There are many factors that cause sparking problems, which can be summarized as the decline in internal vacuum. For X-ray tubes, as the number of uses increases, the evaporation loss of internal materials such as filaments and anode target surfaces, as well as the release of residual gases and low-melting-point substances inside the materials, will inevitably cause the internal vacuum of the X-ray tube to decrease. When the vacuum drops below the tolerable high-voltage threshold, sparking and discharge will inevitably occur. The trend of sparking and discharge will change from mild to severe, and the number of occurrences will increase, eventually causing the X-ray tube to be unable to operate. For this reason, improving the limit value of X-ray tubes' tolerance to high voltage is a hot topic in the industry, and it is also a difficult point. The existing commonly used means to avoid sparking include adding a getter in the tube to absorb excess internal gas, but the getter has a saturated air intake volume, which can only delay the process of sparking to a certain extent, and increasing the pressure-resistant size margin in the design will result in an overly large shape, which is not conducive to installation and use. In addition, during the electron emission process, there is electron scattering around the target surface. The scattered electrons will fall on the surface of the material around the target surface. If they cannot be dissipated quickly, they will easily accumulate and form a local negative electric field. On the one hand, it will cause the trajectory of the electrons emitted by the cathode to change. On the other hand, as the accumulated number increases, the local electric field increases, and the electric field strength between the cathode and the anode increases, which is prone to cathode spark discharge problems. At the same time, when the electrons are emitted from the cathode and run before hitting the target, they are affected by the surrounding electric field. In addition to affecting the trajectory of the electrons, this electric field will also affect the focusing effect of the electrons, affecting the stability of the size and position of the focus, and ultimately affecting the stability of the X-ray output. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an X-ray tube and an X-ray generating device, which are used to solve the problems in the prior art that the vacuum degree inside the X-ray tube decreases, resulting in spark discharge inside the tube, and the method of using a getter to absorb excess gas inside has limited effect and will cause the device size to increase; at the same time, due to electron scattering and the influence of the surrounding electric field, the output of X-rays is unstable.

[0005] To achieve the above-mentioned object and other related objects, the present invention provides an X-ray tube, comprising a shell, an anode assembly and a cathode assembly; X-ray windows and exhaust ports are arranged on different sides of the shell; the anode assembly comprises an anode, an anode protection cover and an anode insulation cover, the anode insulation cover and the anode protection cover are located at the periphery of the shell, the anode protection cover is located at the inner side of the anode insulation cover, the anode insulation cover is connected to the shell and the anode protection cover, the anode comprises a first part and a second part, the first part and the second part are not in a straight line, the first part is located in the shell, and one end of the second part extends to the shell The cathode assembly comprises a cathode, a cathode core column and a cathode insulation cover, the cathode insulation cover is connected to the shell, the cathode is located in the cathode insulation cover, the cathode faces the anode target surface, and the cathode and the exhaust port are located on opposite sides of the anode target surface, the cathode core column is electrically connected to the cathode, and the cathode core column extends outward from the cathode insulation cover.

[0006] Optionally, the first part is in a horizontal state, and the second part is in a vertical state.

[0007] More optionally, the angle between the anode target surface and the horizontal plane is greater than 0 degrees and less than 90 degrees, and the center point of the anode target surface and the center point of the X-ray window are on the same vertical line.

[0008] Optionally, the X-ray window includes a beryllium sheet, the anode protection cover includes any one of a stainless steel cover, an oxygen-free copper cover and a monel alloy cover, and the anode insulation cover and the cathode insulation cover include any one of a glass cover and a ceramic cover.

[0009] In an optional solution, the first part and the second part are integrally connected.

[0010] In another optional solution, the first part and the second part are each a separate structure, and are connected by any one of welding, riveting and threaded connection.

[0011] Optionally, a focusing window is formed at one end of the cathode corresponding to the anode target surface, and the center point of the focusing window, the center point of the anode target surface and the center point of the exhaust port are on the same horizontal line.

[0012] Optionally, the shell is an integrally formed structure, and the shell includes any one of a stainless steel shell, an oxygen-free copper shell and a monel alloy shell.

[0013] Optionally, the cathode core column includes a plurality of electrodes, and the electrodes are connected by metal wires, or by welding metal sheets, or by riveting.

[0014] The present invention also provides an X-ray generating device, which includes a high-voltage power supply and an X-ray tube as described in the above-mentioned personnel scheme, and the high-voltage power supply is electrically connected to the cathode and the anode respectively.

[0015] As described above, the X-ray tube and X-ray generating device of the present invention have the following beneficial effects: the improved structural design of the present invention can avoid the influence of the peripheral structure of the anode target surface on the uniformity of the electric field of the anode target surface to the greatest extent, can significantly improve the uniformity of the electric field around the anode target surface, improve the high voltage resistance of the X-ray tube, and reduce the sparking problem; can improve the stability of the electron emission of the X-ray tube and the uniformity and consistency of the electric field around the anode target surface, improve the stability of the cathode electron focusing performance, and facilitate the output of various focal rays; help to improve the consistency of mass production of the X-ray tube and X-ray source. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown is a schematic diagram of the cross-sectional structure of the X-ray tube provided by the present invention.

[0017] Figure 2 Shown is a schematic diagram of the cross-sectional structure of the X-ray generating device provided by the present invention.

[0018] Component number description

[0019] 1 Housing

[0020] 1a Exhaust port

[0021] 2 Anode target surface

[0022] 3 X-ray window

[0023] 4 Exhaust pipe

[0024] 5 Anode insulation cover

[0025] 6 Anode protection cover

[0026] 7 Anode

[0027] 71 Part 1

[0028] 72 Part 2

[0029] 8 Cathode

[0030] 81 Focus Window

[0031] 9 Cathode core

[0032] 10 Cathode insulation cover

[0033] 11. High voltage power supply DETAILED DESCRIPTION

[0034] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0035] For ease of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0036] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0037] It should be noted that the diagrams provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the diagrams only show the components related to the present invention rather than the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed arbitrarily, and the layout of the components may also be more complicated. In order to make the diagrams as concise as possible, not all structures are marked in the drawings.

[0038] The anode target surface of the X-ray tube is the part that collides with electrons. It bears the heat energy converted from the kinetic energy of the electrons and is the high-temperature part in the tube. High temperature will induce evaporation of the target surface and surrounding materials, resulting in a decrease in vacuum, and sparks are likely to occur between the target surface and surrounding materials. When the design of the structure around the target surface is not ideal, with gaps or obvious tip fluctuations, the uniformity of the high-voltage electric field is affected, and sparks are likely to occur at the distorted electric field. In this regard, the inventor of the present application has proposed an improvement plan after long-term research.

[0039] See also Figure 1 to Figure 2 .

[0040] like Figure 1As shown, the present invention provides an X-ray tube, comprising a shell 1, an anode assembly and a cathode assembly; an X-ray window 3 and an exhaust port 1a are arranged on different sides of the shell 1, the exhaust port 1a is connected to an exhaust pipe 4, the X-ray window 3 is preferably located on a horizontal plane, and the surface where the exhaust port 1a is located is a surface perpendicular to the surface where the exhaust port 1a is located; the anode assembly comprises an anode 7, an anode protection cover 6 and an anode insulation cover 5, the anode insulation cover 5 and the anode protection cover 6 are located on the periphery of the shell 1, the anode protection cover 6 is located on the inner side of the anode insulation cover 5, that is, the anode insulation cover 5 is arranged on the anode The anode insulating cover 5 is connected to the shell 1 and the anode protective cover 6 in the circumference of the protective cover 6; more specifically, the anode insulating cover 5 is connected to the shell 1 in the circumference to partially cover the shell 1 in the anode insulating cover 5, and the anode 7 includes a first part 71 and a second part 72, the first part 71 and the second part 72 are not in a straight line, or there is an angle of non-180 degrees between the two, the first part 71 is located in the shell 1, one end of the second part 72 extends into the shell 1 and is connected to the first part 71, and the other end passes through the anode insulating cover 5 and the anode protective cover 6 and extends outward, to be connected to an external power source; the end surface of one end of the first part 71 not connected to the second part 72 is an anode target surface 2, the center of the anode target surface 2 corresponds to the center of the X-ray window 3 up and down, and the anode target surface 2 is inclined at a certain angle toward the X-ray window 3; the cathode assembly includes a cathode 8, a cathode core column 9 and a cathode insulating cover 10, the cathode insulating cover 10 is connected to the shell 1, the cathode insulating cover 10 and the anode insulating cover 5 are located on two mutually perpendicular sides of the shell 1, the cathode 8 is located in the cathode insulating cover 10, and the cathode 8 faces the anode target The cathode 8 and the exhaust port 1a are located on opposite sides of the anode target surface 2. If the end of the anode target surface 2 facing the cathode 8 is defined as the front end, the exhaust port 1a is located at the rear end of the anode target surface 2, or the exhaust port 1a is located at the end of the anode target surface 2 away from the cathode 8, so the straight-line distance between the exhaust port 1a and the anode target surface 2 is increased. The cathode core column 9 is electrically connected to the cathode 8, and the cathode core column 9 extends outward from the cathode insulation cover 10 to be electrically connected to an external high-voltage power supply. For example, in this example, it is a single-ended anode high voltage, and the cathode only outputs a lower voltage required for the generation of electrons and grid-controlled focusing. After the cathode 8 is connected to the high voltage, the generated electrons hit the anode target surface 2 at a high speed, and part of the kinetic energy of the electrons is converted into heat energy to generate X-rays, which are emitted through the X-ray window 3.The X-ray tube provided in this embodiment has an improved structural design, in which the anode target surface 2 is turned to extend toward the cathode, and the cathode 8 is moved backward in the same direction (in the prior art, the anode is usually in a straight line as a whole, and the cathode is also arranged inside the shell), so that the electric field lines around the anode target surface 2 are relatively uniform, which can improve the withstand voltage performance of the anode target surface; the design of the anode target surface extending in the lateral direction can extend the anode target surface as much as possible under the premise of ensuring the anode installation processability and a certain device size, thereby improving the influence of the electric field distortion caused by the hole and the surrounding uneven structure on the anode target surface; the exhaust port 1a is located at the end of the anode target surface 2 away from the cathode 8, so that the distance between the tip of the exhaust port 1a and the anode target surface 2 is increased, and the distortion effect of the tip of the exhaust port on the electric field around the anode target surface can be reduced to a minimum, thereby improving the withstand voltage performance of the anode target surface; the X-ray window 3 is extended to a position corresponding to the anode target surface 2 to a position aligned with the anode target surface 2, which can ensure the normal emission of X-rays without causing adverse effects on the overall structure. Through the above design, the influence of the peripheral structure of the anode target surface on the uniformity of the electric field on the anode target surface can be avoided to the greatest extent, the uniformity of the electric field around the anode target surface can be significantly improved, the high voltage resistance of the X-ray tube can be improved, and the sparking problem can be reduced; the stability of the electron emission of the X-ray tube and the uniformity and consistency of the electric field around the anode target surface can be improved, the stability of the cathode electron focusing performance can be improved, and the output of various focal rays can be facilitated; it is helpful to improve the consistency of mass production of the X-ray tube and the X-ray generating device.

[0041] The angle between the first part 71 and the second part 72 can be adjusted according to the inclination angle of the anode target surface 2. However, in a preferred example, the first part 71 is in a horizontal state, and the second part 72 is in a vertical state, that is, the first part 71 and the second part 72 intersect vertically, so that the distance between the anode target surface 2 and the exhaust port 1a can be as large as possible while ensuring the normal emission of X-rays, so as to minimize the distortion of the electric field around the anode target surface 2 caused by the tip of the exhaust port 1a.

[0042] The angle θ between the anode target surface 2 and the horizontal plane is greater than 0 degrees and less than 90 degrees, and the angle can be adjusted accordingly according to the angle between the first part 71 and the second part 72 to ensure that the direction of the emitted X-ray beam remains unchanged. In a preferred example, when the first part 71 and the second part 72 are perpendicular to each other, the angle θ between the anode target surface 2 and the horizontal plane is 30°-60°, preferably 45°, which can ensure that the X-ray beam is vertically incident on the X-ray window 3 to the greatest extent, and preferably, the center point of the anode target surface 2 and the center point of the X-ray window 3 are on the same vertical line. The X-ray window 3 always remains in a horizontal state, and the position can be adjusted corresponding to the center of the anode target surface 2.

[0043] In a preferred example, the X-ray window 3 includes a beryllium sheet, which can minimize the absorption of X-rays and ensure the energy of the emitted X-rays.

[0044] The second part 72 covered by the anode protection cover 6 is a connection between multiple materials (such as a welding point between a metal material and a glass material), which is relatively fragile, so the stability of each connection can be improved by the protection of the anode protection cover 6. The anode protection cover 6 is preferably a metal cover, including but not limited to any one of a stainless steel cover, an oxygen-free copper cover and a monel alloy cover. The anode insulation cover 5 and the cathode insulation cover 10 are made of insulating materials, preferably but not limited to any one of a glass cover and a ceramic cover.

[0045] The first part 71 and the second part 72 may be integrally formed (e.g., integrally formed by mold processing), or they may be separate structures connected by any one of welding, riveting, and threaded connection. The materials of the first part 71 and the second part 72 include, but are not limited to, one or two of tungsten, molybdenum, oxygen-free copper, and heavy metal materials, such as pure molybdenum, or formed by pouring tungsten material in an oxygen-free copper shell.

[0046] In a preferred example, a focusing window 81 is formed at one end of the cathode 8 corresponding to the anode target surface 2, and the center point of the focusing window 81, the center point of the anode target surface 2 and the center point of the exhaust port 1a are on the same horizontal line, which helps to further improve the uniformity of the electric field around the anode target surface 2.

[0047] The shell 1 is preferably an integrally formed structure, and is usually made of vacuum metal materials through integrated processing. For example, the shell 1 is preferably but not limited to any one of a stainless steel shell, an oxygen-free copper shell and a monel alloy shell. During operation, the shell 1 is directly grounded, which can reduce the accumulation of electrons around the anode target surface, further improve the pressure resistance of the X-ray tube, and improve the stability of electron emission and focusing, thereby facilitating the output of stable X-rays.

[0048] The cathode core column 9 generally includes a plurality of electrodes, each of which is connected by a metal wire, or welded by a metal sheet, or riveted. The electrode has both a wiring function and a function of fastening the cathode. The cathode 8 is connected to the cathode high voltage via the electrode on the cathode core column 9.

[0049] like Figure 2As shown, the present invention also provides an X-ray generating device, the X-ray generating device includes a high-voltage power supply 11 and an X-ray tube as described in any of the above schemes, the high-voltage power supply 11 is electrically connected to the cathode 8 and the anode 7 respectively, so as to provide cathode high voltage to the cathode 8 and anode high voltage to the anode 7 respectively, thereby outputting electrons and providing a high-voltage electric field environment. For more information about the X-ray tube, please refer to the above content, which will not be repeated for the purpose of brevity. Due to the use of the above-mentioned X-ray tube, the X-ray generating device provided by the present invention can improve the stability of X-ray output without increasing the size of the device, and is convenient for the output of various focal rays.

[0050] In summary, the present invention provides an X-ray tube, comprising a shell, an anode assembly and a cathode assembly; X-ray windows and exhaust ports are arranged on different sides of the shell; the anode assembly comprises an anode, an anode protection cover and an anode insulation cover, the anode insulation cover and the anode protection cover are located at the periphery of the shell, the anode protection cover is located at the inner side of the anode insulation cover, the anode insulation cover is connected to the shell and the anode protection cover, the anode comprises a first part and a second part, the first part and the second part are not in a straight line, the first part is located in the shell, one end of the second part extends to the shell and connects to the first part The cathode assembly comprises a cathode, a cathode core column and a cathode insulation cover, the cathode insulation cover is connected to the shell, the cathode is located in the cathode insulation cover, the cathode faces the anode target surface, and the cathode and the exhaust port are located on opposite sides of the anode target surface, the cathode core column is electrically connected to the cathode, and the cathode core column extends outward from the cathode insulation cover. The improved structural design of the present invention can avoid the influence of the peripheral structure of the anode target surface on the uniformity of the electric field of the anode target surface to the greatest extent, can significantly improve the uniformity of the electric field around the anode target surface, improve the high voltage resistance of the X-ray tube, and reduce the problem of sparking; it can improve the stability of the electron emission of the X-ray tube and the uniformity and consistency of the electric field around the anode target surface, improve the stability of the cathode electron focusing performance, and facilitate the output of various focal rays; it is helpful to improve the consistency of the mass production of the X-ray tube and the X-ray source. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0051] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An X-ray tube, characterized in that: The invention comprises a shell, an anode assembly and a cathode assembly; X-ray windows and exhaust ports are arranged on different sides of the shell; the anode assembly comprises an anode, an anode protection cover and an anode insulation cover, the anode insulation cover and the anode protection cover are located at the periphery of the shell, the anode protection cover is located at the inner side of the anode insulation cover, and the anode insulation cover is connected to the shell and the anode protection cover; the anode comprises a first part and a second part, the first part and the second part are integrally formed and connected, the first part and the second part are not in a straight line, the first part is located in the shell, one end of the second part extends into the shell and is connected to the first part, and the other end passes through the anode insulation cover and the anode protection cover and extends outward, the end face of the end of the first part that is not connected to the second part is the anode target face, and the anode target The center of the surface corresponds to the center of the X-ray window in the upper and lower parts, the angle between the anode target surface and the horizontal plane is greater than 0 degree and less than 90 degrees, and the center point of the anode target surface and the center point of the X-ray window are on the same vertical line; the cathode assembly includes a cathode, a cathode core column and a cathode insulating cover, the cathode insulating cover is connected to the shell, the cathode is located in the cathode insulating cover, the cathode faces the anode target surface, and the cathode and the exhaust port are located on opposite sides of the anode target surface, the exhaust port is located at an end of the anode target surface away from the cathode, the cathode core column is electrically connected to the cathode, the cathode core column extends outward from the cathode insulating cover, a focusing window is formed at one end of the cathode corresponding to the anode target surface, and the center point of the focusing window, the center point of the anode target surface and the center point of the exhaust port are on the same horizontal line.

2. The X-ray tube according to claim 1, characterized in that The first part is in a horizontal state, and the second part is in a vertical state.

3. The X-ray tube according to claim 1, characterized in that The X-ray window includes a beryllium sheet, the anode protection cover includes any one of a stainless steel cover, an oxygen-free copper cover and a monel alloy cover, and the anode insulation cover and the cathode insulation cover include any one of a glass cover and a ceramic cover.

4. The X-ray tube according to claim 1, characterized in that The shell is an integrally formed structure, and the shell includes any one of a stainless steel shell, an oxygen-free copper shell and a monel alloy shell.

5. The X-ray tube according to claim 1, characterized in that The cathode core column comprises a plurality of electrodes, and the electrodes are connected by metal wires, or by welding of metal sheets, or by riveting.

6. An X-ray generating device, characterized in that: The X-ray generating device comprises a high-voltage power supply and an X-ray tube as claimed in any one of claims 1 to 5, wherein the high-voltage power supply is electrically connected to a cathode and an anode, respectively.

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