HK1204198B - X-ray device and ct device having said x-ray device - Google Patents

Description

X-ray device and CT apparatus having the same

Technical Field

The present invention relates to an apparatus for generating distributed X-rays, and more particularly, to a two-dimensional array distributed X-ray apparatus for generating X-rays whose focal positions are changed in a predetermined order by two-dimensionally arranging a plurality of independent electron emission units and a plurality of corresponding targets on an anode and by cathode control or grid control in one X-ray light source device, and a CT device having the same.

Background

Generally, an X-ray source is a device that generates X-rays, and is generally composed of an X-ray tube, a power supply and control system, auxiliary devices such as a cooling device and a shielding device, and the core of the X-ray source is the X-ray tube. X-ray tubes are typically constructed with a cathode, anode, glass or ceramic envelope. The cathode is a directly-heated spiral tungsten wire, and is heated to a high-temperature state through current to generate a heat-emitted electron beam current when working, the cathode is surrounded by a metal cover with a slot at the front end, and the metal cover enables electrons to be focused. The anode is a tungsten target embedded on the end face of the copper block, when the cathode works, high voltage is applied between the anode and the cathode, electrons generated by the cathode fly to the anode in an accelerated motion under the action of an electric field and impact the target surface, and therefore X rays are generated.

X-rays have wide applications in the fields of industrial nondestructive testing, safety inspection, medical diagnosis and treatment, etc. In particular, a fluoroscopic X-ray imaging apparatus which is made by utilizing a high transmission capability of X-rays plays an important role in the aspect of daily life of people. The device is a film type planar perspective imaging device in the early days, and the current advanced technology is a digital, multi-view and high-resolution stereo imaging device, such as ct (computed tomography), which can obtain high-definition three-dimensional stereo images or slice images, and is an advanced high-end application.

In the existing CT apparatus, the X-ray source and the detector need to move on the slip ring, and in order to increase the inspection speed, the movement speed of the X-ray source and the detector is usually very high, which results in the decrease of the reliability and stability of the whole apparatus, and in addition, the inspection speed of the CT is also limited due to the limitation of the movement speed. Therefore, there is a need for an X-ray source in a CT apparatus that is capable of producing multiple views without moving position.

In order to solve the reliability, stability and inspection speed problems caused by the slip ring in the existing CT apparatus and the heat resistance of the anode target, some methods are provided in the existing patent documents. Such as a rotating target X-ray source, can solve the problem of overheating of the anode target to some extent, but its structure is complex and the target point for generating X-rays is still a defined target point position relative to the X-ray source as a whole. For example, in some techniques, in order to realize multiple views of a stationary X-ray source, a plurality of independent conventional X-ray sources are arranged closely on a circle to replace the movement of the X-ray source, which can also realize multiple views, but the cost is high, and the target spot spacing between different views is large, and the imaging quality (stereo resolution) is poor. Further, in patent document 1 (US 4926452), a light source and a method of generating distributed X-rays are proposed, an anode target has a large area, the problem of overheating of the target is alleviated, and the target point position varies along the circumference, and a plurality of viewing angles can be generated. Although patent document 1 is a scanning deflection method for obtaining an accelerated high-energy electron beam, which has the problems of great control difficulty, no separation of target positions, and poor repeatability, it is still an effective method for generating a distributed light source. In addition, for example, patent document 2 (US 20110075802) and patent document 3 (WO 2011/119629) propose a light source and a method for generating distributed X-rays, the anode target has a large area, the problem of overheating of the target is alleviated, and the target points are distributed and fixed and arranged in an array, so that a plurality of viewing angles can be generated. In addition, carbon nanotubes are used as cold cathodes, the cold cathodes are arrayed, and field emission is controlled by using voltage between cathode grids, so that each cathode is controlled to emit electrons in sequence, targets are bombarded on anodes in corresponding sequence positions, and the distributed X-ray source is formed. However, the method has the disadvantages of complex production process and low emission capability and service life of the carbon nano tube.

Disclosure of Invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide a two-dimensional array distributed X-ray apparatus and a CT apparatus having the same, which can generate a plurality of viewing angles without moving a light source, and which is advantageous in simplifying a structure, improving system stability, reliability, and improving inspection efficiency.

The present invention provides a two-dimensional array distributed X-ray device, comprising:

the periphery of the vacuum box is sealed, and the inside of the vacuum box is in high vacuum; a plurality of electron emission units arranged in a two-dimensional arrangement on one plane on a cell wall of the vacuum cell; an anode disposed in the vacuum chamber in parallel to a plane on which the plurality of electron emission units are located; a power supply and control system having a high voltage power supply connected to the anode, a filament power supply connected to each of the plurality of electron emission units, a grid control device connected to each of the plurality of electron emission units, and a control system for controlling each power supply, the anode comprising: an anode plate made of a metal material and parallel to an upper surface of the electron emission unit; a plurality of targets mounted on the anode plate and arranged in a manner to correspond to positions of the electron emission units, respectively, bottom surfaces of the targets being connected to the anode plate and top surfaces thereof forming a predetermined angle with the anode plate.

In the two-dimensional array distributed X-ray device of the present invention, the target is a circular frustum structure, a square frustum structure, a polygonal frustum structure or other polygonal protrusions, or other irregular protrusions.

In the two-dimensional array distributed X-ray device of the present invention, the target is a circular pillar stand structure, a square pillar stand structure, or other polygonal pillar stand structure.

In the two-dimensional array distributed X-ray device of the present invention, the target is a spherical structure.

In the two-dimensional array distributed X-ray device of the present invention, the top surface of the target is a plane, a slope, a sphere, or other irregular surface.

In the two-dimensional array distributed X-ray device of the present invention, the electron emission unit has: a filament; a cathode connected to the filament; an insulating support having an opening and surrounding the filament and the cathode; filament leads led out from two ends of the filament; a gate electrode arranged above the cathode so as to face the cathode; a connection fixture connected to the insulating support to mount the electron emission unit on a wall of the vacuum box to form a vacuum tight connection, the grid having: a gate frame made of metal and having an opening formed in the middle; a grid mesh made of metal and fixed at the position of the opening of the grid frame; and the grid lead is led out from the grid frame, the filament lead and the grid lead are led out to the outside of the electron emission unit through the insulating support part, the filament lead is connected with the filament power supply, and the grid lead is connected with the grid control device.

In the two-dimensional array distributed X-ray device, the connecting and fixing piece is connected to the outer edge of the lower end of the insulating support piece, the cathode end of the electron emission unit is positioned in the vacuum box, and the lead end of the electron emission unit is positioned outside the vacuum box.

In the two-dimensional array distributed X-ray device, the connecting and fixing piece is connected to the upper end of the insulating support piece, and the whole electron emission unit is positioned outside the vacuum box.

In the two-dimensional array distributed X-ray device of the present invention, the electron emission unit includes: the flat grid consists of an insulating framework plate, a grid mesh and a grid lead; the cathode array is formed by closely arranging a plurality of cathode structures, each cathode structure consists of a filament, a cathode connected with the filament, filament leads led out from two ends of the filament, and an insulating support surrounding the filament and the cathode, the grid plate is arranged on the insulating framework plate, the grid mesh is arranged at the position of an opening formed on the grid plate, the grid lead is led out from the grid plate, the flat grid is positioned above the cathode array, in the vertical direction, the circle centers of the grid meshes are respectively overlapped with the circle centers of the cathodes of the cathode array two by two, the flat grid and the cathode array are located in the vacuum box, and the filament lead and the grid lead are led out of the vacuum box through a filament lead transition terminal and a grid lead transition terminal which are arranged on the box wall of the vacuum box respectively.

In the two-dimensional array distributed X-ray device of the present invention, the vacuum box is made of glass or ceramic.

In the two-dimensional array distributed X-ray device of the present invention, the vacuum box is made of a metal material.

The two-dimensional array distributed X-ray device of the present invention further includes: the high-voltage power supply connecting device is used for connecting the anode with a cable of the high-voltage power supply and is arranged on the side wall of one end, close to the anode, of the vacuum box; the filament power supply connecting device is used for connecting the filament and the filament power supply; a gate control means connecting means for connecting the gate of the electron emission unit and the gate control means. A vacuum power supply included within the power and control system; and the vacuum device is arranged on the side wall of the vacuum box and works by utilizing the vacuum power supply to maintain high vacuum in the vacuum box.

In the two-dimensional array distributed X-ray device of the present invention, the two-dimensional array arrangement of the plurality of electron emission units extends in a straight line in both directions.

In the two-dimensional array distributed X-ray device of the present invention, the two-dimensional array arrangement of the plurality of electron emission units extends in a straight line in one direction and in an arc line in the other direction.

In the two-dimensional array distributed X-ray device of the invention, the grid control device comprises a controller, a negative high voltage module, a positive high voltage module and a plurality of high voltage switch elements, each of the plurality of high-voltage switch elements at least comprises a control end, two input ends and an output end, the withstand voltage between the end points is at least larger than the maximum voltage formed by the negative high-voltage module and the positive high-voltage module, the negative high voltage module supplies a stable negative high voltage to one input terminal of each of the plurality of high voltage switching elements, the positive high voltage module provides a stable positive high voltage to the other input terminal of each of the plurality of high voltage switching elements, the controller controls each of the plurality of high-voltage switching elements independently, the gate control device further has a plurality of control signal output channels, and an output terminal of one of the high-voltage switching elements is connected to one of the control signal output channels.

The invention provides a CT apparatus characterized in that the X-ray source used is a two-dimensional array distributed X-ray device as described above.

According to the present invention, there is provided a two-dimensional array distributed X-ray apparatus which generates X-rays in a light source device with focal point positions periodically changed in a certain order. The electron emission unit adopts a hot cathode, and has the advantages of large emission current and long service life; the working state of each electron emission unit is controlled through grid control or cathode control, and convenience and flexibility are achieved; the design of the large anode plate and the target is adopted, so that the problem of anode overheating is relieved, a target focusing effect is formed, and the cost is reduced; the electron emission units and the corresponding targets are arranged in a two-dimensional array, X rays are led out in parallel to the array plane, and when viewed from the ray emitting direction, the target distribution distance is reduced, and the target density is improved; the electron emission units can be arranged in a planar two-dimensional mode or in a cambered two-dimensional mode, the whole body is a linear type distributed X-ray device or a ring type distributed X-ray device, and the application is flexible.

The distributed X-ray light source is applied to CT equipment, and a plurality of visual angles can be generated without moving the light source, so that the movement of a slip ring can be omitted, the structure is simplified, the stability and the reliability of a system are improved, and the inspection efficiency is improved.

Drawings

Fig. 1 is a schematic diagram of the main structure inside the two-dimensional distributed X-ray device of the present invention.

Fig. 2 is a bottom view of an anode structure of a two-dimensional distributed X-ray device in accordance with the present invention.

Fig. 3 is a schematic diagram of the structure of an electron emission unit in the present invention.

Fig. 4 is a schematic view of the structure of another electron emission unit in the present invention.

Fig. 5 is a structural view of a two-dimensional distributed X-ray apparatus in the present invention.

Fig. 6 is a schematic structural diagram of a gate control device in the present invention.

Fig. 7 is a schematic diagram of an electron emission cell array in which gates are separated from cathodes in the present invention, (a) is a side view, (B) is a top view of each gate independent control pattern, and (C) is a top view of each gate interconnection and cathode control pattern.

Fig. 8 is a distributed X-ray device of the present invention with filaments in series.

Fig. 9 is a schematic layout diagram of an internal electron emission unit and an anode of an arc-shaped two-dimensional distributed X-ray device according to the present invention.

Description of reference numerals:

101 filament

102 cathode

103 grid

104 insulating support

105 filament lead

106 grid frame

107 grid

108 gate lead

109 connecting and fixing piece

201 anode plate

202 target

E electron beam current

X X ray

1 Electron emission Unit

2 anode

3 vacuum box

4 high-voltage power supply connecting device

5 filament power supply connecting device

6 grid control device connecting device

7 power supply and control system

8 vacuum device

9 flat grid

901 insulation frame plate

902 grid plate

903 grid mesh

904 gate lead

10 cathode array

1001 filament

1002 cathode

1004 insulating support

1005 filament lead

1006 filament lead transition terminal

1007 gate lead transition terminals.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 6, the two-dimensional array distributed X-ray device of the present invention is composed of a plurality of electron emission units 1 (at least four, hereinafter also referred to as electron emission units 11a, 12a, 13a, 14a, … …, electron emission units 11b, 12b, 13b, 14b, … …), an anode 2, a vacuum box 3, a high-voltage power supply connection device 4, a filament power supply connection device 5, a grid control device connection device 6, a vacuum device 8, and a power supply and control system 7, wherein the electron emission units 1 are composed of a filament 101, a cathode 102, a grid 103, etc., and the anode 2 is composed of an anode plate 201 and a plurality of targets 202 mounted on the anode plate 201 and arranged corresponding to the electron emission units 1. The plurality of electron emission units 1 are arranged in a two-dimensional arrangement on one plane and are parallel to the plane on which the anode plate 201 is placed. The electron emission unit 1, the high-voltage power supply connecting device 4 and the vacuum device 8 are arranged on the box wall of the vacuum box 3 and form an integral sealing structure with the vacuum box 3, and the anode 2 is arranged in the vacuum box.

Fig. 1 shows a schematic structural diagram of a spatial arrangement of electron emission units 1 and anodes 2 within a two-dimensional array distributed X-ray device. The electron emission units 1 are arranged in two rows on one plane, and the electron emission units 1 of the front and rear rows are staggered (see fig. 1), but it is not limited thereto even if the electron emission units of the front and rear rows are not staggered with each other. The anode 2 is arranged above the electron emission unit 1, the targets 202 on the anode 2 correspond to the electron emission units 1 one by one, the top surfaces of the targets 202 point to the electron emission unit 1, and a connecting line between the center of the electron emission unit 1 and the center of the target 202 is perpendicular to the plane of the anode plate 201, and the connecting line is also a motion path of an electron beam current E emitted by the electron emission unit 1. The electrons bombard the target to generate X-rays, the exit direction of the useful X-rays is parallel to the plane of the anode plate 201, and the useful X-rays are parallel to each other.

In fig. 2, a structure of an anode 2 is shown. The anode 2 includes: an anode plate 201; a plurality of targets 202 distributed in a two-dimensional array. The anode plate 201 is a flat plate made of a metal material, and preferably a high temperature resistant metal material, which is completely parallel to the plane formed by the upper surface of the electron emission unit 1, i.e., the surface of the gate electrode 103, and is usually several tens kV to several hundreds kV, typically, for example, 180kV when a positive high voltage is applied to the anode 2, thereby forming a parallel high voltage electric field between the anode plate 201 and the electron emission unit 1. The targets 202 are mounted on the anode plate 201 at positions arranged in a manner to correspond to the positions of the electron emission units 1, respectively, and the surfaces of the targets 202 are usually made of a high-temperature-resistant heavy metal material such as tungsten or a tungsten alloy. The target 202 is a circular frustum structure, the height is usually several mm, for example 3mm, the bottom surface with larger diameter is connected with the anode plate 201, the diameter of the top surface is smaller, usually several mm, for example 2mm, the top surface is not parallel to the anode plate 201, and a small included angle of several degrees to ten and several degrees is usually formed, so that useful X-rays generated by electron targeting can be conveniently emitted. All targets 202 are arranged in such a manner that the top surface inclination direction is uniform, that is, the emission direction of all useful X-rays is uniform. The structural design of the target is equivalent to a small bulge growing on the anode plate 201, and the local electric field distribution on the surface of the anode plate 201 is changed, so that the electron beam has an automatic focusing effect before bombarding the target, the target spot is reduced, and the image quality is favorably improved. In the design of the anode, the anode plate 201 is made of common metal, and only the surface of the target 202 is made of tungsten or tungsten alloy, thereby reducing the cost.

A specific structure of an electron emission unit 1 is shown in fig. 3. The electron emission unit 1 includes a filament 101, a cathode 102, a grid 103, an insulating support 104, a filament lead 105, and a connection fixture 109, and the grid 103 is composed of a grid frame 106, a grid 107, and a grid lead 108. In fig. 3, the position where the filament 101, the cathode 102, the grid 103, etc. are located is defined as a cathode terminal of the electron emission unit 1, and the position where the connection fixture 109 is located is defined as a lead terminal of the electron emission unit 1. The cathode 102 is connected to the filament 101, the filament 101 is usually made of tungsten, and the cathode 102 is usually made of a material with strong ability of thermal emission of electrons, such as barium oxide, scandate, lanthanum hexaboride, etc. An insulating support 104 surrounds the filament 101 and the cathode 102, corresponding to the casing of the electron emission unit 1, and is made of an insulating material, typically ceramic. The filament lead 105 and the grid lead 108 are led out from the lead terminals of the electron emission unit 1 through the insulating support 104, and a vacuum-sealed structure is provided between the filament lead 105 and the grid lead 108 and the insulating support 104. The grid 103 is mounted on the upper end of the insulating support 104 (i.e. disposed on the opening of the insulating support 104) and is opposite to the cathode 102, the grid 103 is aligned with the center of the cathode 102, the grid 103 includes a grid frame 106, a grid mesh 107 and a grid lead 108, the grid frame 106, the grid mesh 107 and the grid lead 108 are all made of metal, generally, the grid frame 106 is made of stainless steel, the grid mesh 107 is made of molybdenum, and the grid lead 108 is made of stainless steel or Kovar material.

Further, specifically, regarding the structure of the gate electrode 103, the main body thereof is a metal plate (e.g., stainless material) or a gate frame 106, an opening is formed in the middle of the gate frame 106, the shape of the opening may be square or circular, etc., a wire mesh (e.g., molybdenum material) or a grid 107 is fixed at the position of the opening, and a lead (e.g., stainless material) or a gate lead 108 is led out from a certain position of the metal plate, so that the gate electrode 103 can be connected to a potential. Further, the gate electrode 103 is located directly above the cathode electrode 102, the center of the above-mentioned opening of the gate electrode is aligned with the center of the cathode electrode 102 (i.e., vertically on a vertical line), and the shape of the opening corresponds to the shape of the cathode electrode 102, but the size of the opening is smaller than the area of the cathode electrode 102. However, the structure of the gate electrode 103 is not limited to the above structure as long as an electron beam can pass through the gate electrode 103. In addition, the grid 103 and the cathode 102 are fixed in relative position by an insulating support 104.

Further, specifically, with regard to the structure of the connecting fixture 109, it is recommended that its main body is a circular knife-edge flange, an opening is formed in the middle, the shape of the opening may be square or circular, etc., the position of the opening is connected with the lower outer edge of the insulating support 104 in a sealing manner, such as welding, the outer edge of the knife-edge flange is formed with a screw hole, the electron emission unit 1 can be fixed on the box wall of the vacuum box 3 by bolting, and the knife-edge thereof is connected with the box wall of the vacuum box 3 in a vacuum sealing manner. This is a flexible structure that is easy to disassemble, and when one of the plurality of electron emission units 1 fails, it can be flexibly replaced. It should be noted that the function of the connecting fixture 109 is to achieve a sealed connection between the insulating support 104 and the vacuum box 3, and there may be various flexible ways, such as welding via metal flange transition, or glass high-temperature melting sealing connection, or welding with metal after ceramic metallization.

A specific structure of another electron emission unit 1 is shown in fig. 4. The electron emission unit 1 includes a filament 101, a cathode 102, a grid 103, an insulating support 104, a filament lead 105, a grid lead 108, and a connection fixture 109. The cathode 102 is connected with the filament 101, the grid 103 is located right above the cathode 102, the shape is the same as that of the cathode 102, the cathode 102 is close to the upper surface, the filament 101 and the cathode 102 are surrounded by the insulating support 104, the filament lead 105 led out from the two ends of the filament 101 and the grid lead 108 led out from the grid 103 are led out to the outside of the electron emission unit 1 through the insulating support 104, and the filament lead 105 and the grid lead 108 are in a vacuum sealing structure with the insulating support 104.

The overall structure of a two-dimensional array distributed X-ray device is shown in fig. 5. The vacuum box 3 is a cavity shell with sealed periphery, and the inside is high vacuum; the electron emission unit 1 is used for generating electron beam current according to requirements and is arranged on the box wall of the vacuum box 3; the anode 2 is used for forming a parallel high-voltage accelerating electric field and generating X-rays and is arranged in the vacuum box 3; the high-voltage power supply connecting device 4 is used for connecting the anode 2 and a cable of the high-voltage power supply 702, and is arranged on the side wall of one end of the vacuum box 3 close to the anode 2; the filament power supply connection means 5 is used for connecting the filament lead 105 and the filament power supply 704, and the filament power supply connection means 5 is usually a plurality of multi-core cables with connectors at both ends; the gate control means connection means 6 are for connecting the gate leads 108 of the electron emission unit 1 and the gate control means 703, the gate control means connection means 6 typically being a plurality of coaxial cables with connectors at both ends. In addition, the two-dimensional array distributed X-ray device of the present invention may further include a vacuum device 8, and the vacuum device 8 is operated by a vacuum power source 705 for maintaining a high vacuum in the vacuum box 3 and is installed on a sidewall of the vacuum box 3.

Further, the power supply and control system 7 includes a control system 701, a high voltage power supply 702, a grid control device 703, a filament power supply 704, a vacuum power supply 705, and the like. The high voltage power supply 702 is connected to the anode 2 via a high voltage power supply connection 4 on the wall of the vacuum box 3. The gate control device 703 is connected to each gate lead 108 via the gate control device connecting device 6, and generally has the same number of independent gate leads 108 as the number of electron emission units 1, and the number of output paths of the gate control device 703 is the same as the number of gate leads 108. The filament power supply 704 is connected to each filament leg 105 through the filament power supply connection means 5, and typically has the same number of groups of independent filament legs 105 as the number of electron emission units 1 (i.e., each electron emission unit has one group of filament legs, 2, connected to both ends of the filament, as described above), and the filament power supply 704 has the same number of output circuits as the filament legs 105. The vacuum power source 705 is connected to the vacuum apparatus 8. The control system 701 controls and comprehensively manages the operating states of the high-voltage power supply 702, the grid control device 703, the filament power supply 704, the vacuum power supply 705, and the like.

As shown in fig. 6, the gate control device 703 includes a controller 70301, a negative high voltage module 70302, a positive high voltage module 70303, a plurality of high voltage switching elements switch1, switch2, switch3, switch4, and switch …. Each of the plurality of high voltage switching elements includes at least one control terminal (C), two input terminals (In 1 and In 2), and an output terminal (Out), and the withstand voltage between the terminals is at least greater than the maximum voltage formed by the negative high voltage module 70302 and the positive high voltage module 70303 (i.e., if the negative high voltage outputs-500V and the positive high voltage outputs +2000V, the withstand voltage between the terminals is at least greater than 2500V). The controller 70301 has multiple independent outputs, each connected to the control terminal of one of the high voltage switching elements. The negative high voltage module 70302 provides a stable negative high voltage, typically negative hundreds of volts, ranging from 0V to-10 kV, preferably-500V, which is connected to one input of each high voltage switching element, and the positive high voltage module 70303 provides a stable positive high voltage, typically positive thousands of volts, ranging from 0V to +10kV, preferably +2000V, which is connected to the other input of each high voltage switching element. The output terminals of the high-voltage switching elements are connected to control signal output channels channel1a, channel1b, channel2a, channel2b, channel3a, channel3b, and …, respectively, and are merged into a plurality of control signals to be output. The controller 70301 controls the operating state of each high-voltage switching element so that the control signal of each output channel is a negative high voltage or a positive high voltage.

In addition, the power supply and control system 7 can adjust the current of each output loop of the filament power supply 704 under different use conditions, so as to adjust the heating temperature of each filament 101 to the cathode 102, so as to change the emission current of each electron emission unit 1 and finally adjust the intensity of each X-ray emission. In addition, the intensity of the positive high voltage control signal of each output channel of the gate control device 703 may also be adjusted, so as to change the magnitude of the emission current of each electron emission unit 1, and finally adjust the intensity of each X-ray emission. In addition, the operation timing and the combination operation mode of each electron emission unit 1 can be programmed and flexibly controlled.

It is to be noted in particular that in the two-dimensional distributed X-ray device of the invention the electron emitting unit may be a structure in which the grid and the cathode are separated. An array of electron emitting cells with separate gates and cathodes is shown in fig. 7. In fig. 7, the flat grid 9 is composed of an insulating skeleton plate 901, a grid plate 902, a grid 903 and a grid lead 904. As shown in the figure, a grid plate 902 is disposed on an insulating skeleton plate 901, a grid 903 is disposed at a position of an opening formed on the grid plate 902, and a gate lead 904 is led out from the grid plate 902. The cathode array 10 is composed of a plurality of cathode structures closely arranged, each cathode structure is composed of a filament 1001, a cathode 1002, and an insulating support 1004. The flat grid 9 is above the cathode array 10 and the distance between the two is small, typically a few mm, for example 3 mm. The grid structures formed by the grid plate 902, the grids 903, and the grid leads 904 correspond to the cathode structures one to one, and the circle center of each grid 903 and the circle center of each cathode 1002 coincide two by two when viewed in the vertical direction. The flat grid 9 and the cathode array 10 are located inside the vacuum box 3, and the filament lead 1005 and the grid lead 904 are led out to the outside of the vacuum box through a filament lead transition terminal 1006 and a grid lead transition terminal 1007 provided on the box wall of the vacuum box 3.

Further, as shown in fig. 7 (B), in the present invention, the gate structure may be a structure in which each gate lead is independently drawn and state control is independently performed by the gate control device. Each cathode 1002 of the cathode array 10 may be at the same potential, for example, grounded, and each gate is switched between two states of minus several hundred volts and plus several thousand volts, for example, between-500V and +2000V, so as to control the operation state of each electron emission unit, for example, when a certain gate is-500V at a certain time, the electric field between the gate and the corresponding cathode is a negative electric field, electrons emitted from the cathode are confined on the surface of the cathode, when the gate voltage becomes +2000V at the next time, the electric field between the gate and the corresponding cathode becomes a positive electric field, electrons emitted from the cathode move toward the gate and pass through the grid, are emitted into the accelerating electric field between the gate and the anode, are accelerated and finally bombard the anode, and generate X-rays at the corresponding target position.

As shown in fig. 7 (C), the grid may be formed by connecting grid leads in parallel, and the grid leads may be at the same potential, and the filament power supply may control the operating state of each electron emission unit. For example, all grids are at-500V, each cathode filament is led out independently, the voltage difference between two end points of each cathode filament is constant, and the overall voltage of each cathode is switched between two states of 0V and-2500V. At a certain moment, the cathode is at 0V potential, a negative field is between the grid and the cathode, the electrons emitted from the cathode are confined on the surface of the cathode, at the next moment, the voltage of the cathode becomes-2500V, the electric field between the grid and the corresponding cathode becomes a positive field, the electrons emitted from the cathode move towards the grid and pass through the grid, are emitted into the accelerating electric field between the grid and the anode, obtain acceleration and finally bombard the target, generating X-rays at the corresponding target position.

It should be noted that in the two-dimensional distributed X-ray device of the present invention, the filament leads of the electron emission units may be individually connected to the respective output terminals of the filament power supply, or may be connected in series and then integrally connected to one output terminal of the filament power supply. In fig. 8 a schematic diagram is shown in which the filament legs of an electron emitting unit are connected in series to a filament power supply. In a system in which filament leads of an electron emission unit are connected in series, the cathodes are usually at the same potential, and each grid lead needs to be led out independently, so that the working state of the electron emission unit is controlled by a grid control device.

It should be noted that in the two-dimensional distributed X-ray device of the present invention, the electron emission units may be arranged in a linear manner or in an arc manner, so as to meet different application requirements. Fig. 9 is a view showing an effect of arrangement of an electron emission unit and an anode of a circular arc type two-dimensional distributed X-ray device. The electron emission units 1 are arranged on a plane according to the inner circle and the outer circle of the circumference, the radian of the arrangement can be the whole circumference or a section of arc length, and the electron emission units can be flexibly arranged according to requirements. The anode 2 is arranged above the electron emission unit 1, the plane where the anode 2 is located is parallel to the arrangement plane of the electron emission unit 1, the positions of the targets 202 on the anode 2 correspond to the positions of the electron emission unit 1 one by one, and the top surface inclination angles of the targets 202 are all uniformly directed to the circle center of the circular array. The electron beam is emitted from the upper surface of the electron emission unit 1, and is accelerated by a high-voltage electric field between the anode 2 and the electron emission unit 1 to bombard the target 202 on the anode 2, so that arc-shaped array X-ray target spots are formed on the anode 2, and the emitting direction of useful X-rays points to the center of the arc. Regarding the vacuum box of the arc-shaped two-dimensional distributed X-ray device, the vacuum box is also a ring-shaped structure corresponding to the arrangement of the electron emission units 1 and the shape of the anode 2 inside the vacuum box, and the length of the vacuum box can be one circle or one section. Emergent X rays of the arc-shaped distributed X-ray device all point to the circle center of the arc, and the device can be applied to occasions needing circular arrangement of the ray sources.

It should be noted that, in the two-dimensional distributed X-ray device of the present invention, the array of electron emission units may be two rows or a plurality of rows.

In addition, it should be noted that, in the two-dimensional distributed X-ray device of the present invention, the target of the anode may have a circular frustum structure, a cylindrical structure, a square frustum structure, a polygonal frustum structure, or other polygonal protrusions, or other irregular protrusions.

In addition, it should be noted that, in the two-dimensional distributed X-ray device of the present invention, the top surface of the target of the anode may be a plane, a slope, a sphere, or other irregular surface.

In addition, it should be particularly noted that, in the two-dimensional distributed X-ray device of the present invention, the two-dimensional array arrangement of the electron emission units may be in various combinations such that both directions are linearly extended, one direction is linearly extended and the other direction is an arc line extended, one direction is linearly extended and the other direction is piecewise linearly extended, or one direction is linearly extended and the other direction is piecewise arc extended.

In addition, it should be noted that, in the two-dimensional distributed X-ray device of the present invention, the two-dimensional array arrangement of the electron emission units may be uniform in interval between two directions, may be uniform in interval between each direction and nonuniform in interval between two directions, may be uniform in interval between one direction and nonuniform in interval between the other direction, or may be nonuniform in interval between two directions.

Examples

(System composition)

As shown in fig. 1 to 6, the two-dimensional distributed X-ray device is composed of a plurality of electron emission units 1, an anode 2, a vacuum box 3, a high-voltage power supply connection device 4, a filament power supply connection device 5, a grid control device connection device 6, a vacuum device 8, and a power supply and control system 7. A plurality of electron emission units 1 are arranged in a two-dimensional array on a plane and are mounted on a wall of a vacuum chamber 3, each electron emission unit 1 is independent of the other, and an anode 2 having a bar shape is disposed above the electron emission unit 1 and is mounted at an upper end in the vacuum chamber 3 in parallel with the plane on which the electron emission unit 1 is disposed. The electron emission unit 1 includes a filament 101, a cathode 102, a grid 103, an insulating support 104, a filament lead 105, and a connection fixture 109, and the grid 103 is composed of a grid frame 106, a grid 107, and a grid lead 108. Further, the anode 2 is composed of an anode plate 201 and a target 202. The targets 202 are mounted on the anode plate 201 at positions arranged in a manner corresponding to the positions of the electron emission units 1, respectively, and the inclination directions of the top surfaces of all the targets 202 coincide and are useful X-ray emission directions. A high voltage power supply connection means 4 is installed at one end of the vacuum box 3 near the anode 2, the inside is connected to the anode 2, the outside is connected to the high voltage power supply 702, and a filament power supply connection means 5 connects the filament lead 105 of each electron emission unit 1 to the filament power supply 704. The filament power supply connecting device 5 is a plurality of two-core cables with connectors at two ends. The gate control device connecting means 6 connects the gate lead 108 of each electron-emitting unit 1 to the gate control device 703. The grid control device connecting device 6 is a plurality of high-voltage coaxial cables with connectors at two ends. The vacuum device 8 is mounted on a side wall of the vacuum box 3. The power supply and control system 7 includes a plurality of modules such as a control system 701, a high voltage power supply 702, a grid control device 703, a filament power supply 704, and a vacuum power supply 705, and is connected to the filament 101, the grid 103, the anode 2, the vacuum device 8, and the like of the plurality of electron emission units 1 of the system through power cables and control cables.

(working principle)

In the two-dimensional distributed X-ray device of the present invention, the power supply and control system 7 controls the filament power supply 704, the grid control device 703, and the high voltage power supply 702. Under the action of the filament power supply 704, the filament 101 heats the cathode 102 to 1000-2000 ℃, the cathode 102 generates a large amount of electrons on the surface, the grid control device 703 makes each grid 103 at a negative voltage, for example-500V, a negative electric field is formed between the grid 103 of each electron emission unit 1 and the cathode 102, the electrons are confined on the surface of the cathode 102, the high voltage power supply 702 makes the anode 2 at a very high positive high voltage, for example +180kV, and a positive accelerating electric field is formed between the electron emission unit 1 and the anode 2. When the X-ray is required to be generated, the power supply and control system 7 switches a certain output of the gate control device 703 from negative voltage to positive voltage according to an instruction or a set program, and changes each output signal in time sequence, for example, at time 1, the output channel1a of the gate control device 703 is changed from-500V to +2000V, the electric field between the gate 103 and the cathode 102 in the corresponding electron emission unit 11a is changed to a positive electric field, electrons move from the surface of the cathode 102 to the gate 103, enter the positive electric field between the electron emission unit 11a and the anode 2 through the grid 107, obtain acceleration, change to high energy, and finally bombard the target 21a, thereby generating X-ray emission at the position of the target 21 a; at the time 2, the output channel1b of the gate control device 703 is changed from-500V to +2000V, the corresponding electron emission unit 11b emits electrons, bombards the target 21b, and generates X-ray emission at the position of the target 21 b; at the time 3, the output channel2a of the gate control device 703 is changed from-500V to +2000V, the corresponding electron emission unit 12a emits electrons, bombards the target 22a, and generates X-ray emission at the position of the target 22 a; at the time 4, the output channel2b of the gate control device 703 changes from-500V to +2000V, the corresponding electron emission unit 12b emits electrons, bombards the target 22b, and generates X-ray emission at the position of the target 22 b; by analogy, the target 23a then generates X-rays, and the target 23b then generates X-rays … …, cycling back and forth. Therefore, the power supply and control system 7 causes the respective electron emission units 1 to alternately operate at a predetermined timing by the gate control device 703 to emit electron beams, and alternately generates X-rays at different target positions, thereby forming a distributed X-ray source.

The gas released when the target 202 is bombarded by the electron beam is pumped away by the vacuum device 8 in real time, and high vacuum is maintained in the vacuum box 3, which is beneficial to long-time stable operation. The power supply and control system 7 controls each power supply to drive each component to work coordinately according to a set program, and can receive external commands through a communication interface and a human-computer interface, modify and set key parameters of the system, update the program and perform automatic control and adjustment.

In addition, the two-dimensional array distributed X-ray light source is applied to the CT equipment, so that the CT equipment with good system stability and reliability and high inspection efficiency can be obtained.

(advantageous effects)

The invention mainly provides a two-dimensional array distributed X-ray device, which generates X-rays with focus positions periodically changed according to a certain sequence in a light source device. The electron emission unit adopts a hot cathode, and has the advantages of large emission current and long service life; the working state of each electron emission unit is controlled through grid control or cathode control, and convenience and flexibility are achieved; the design of the large anode plate and the target is adopted, so that the problem of anode overheating is relieved, a target focusing effect is formed, and the cost is reduced; the electron emission units and the corresponding targets are arranged in a two-dimensional array, X rays are led out in parallel to the array plane, and when viewed from the ray emitting direction, the target distribution distance is reduced, and the target density is improved; the electron emission units can be arranged in a planar two-dimensional mode or in a cambered two-dimensional mode, the whole body is a linear type distributed X-ray device or a ring type distributed X-ray device, and the application is flexible.

In addition, the two-dimensional array distributed X-ray light source is applied to CT equipment, and a plurality of visual angles can be generated without moving the light source, so that the movement of a slip ring can be omitted, the structure is simplified, the stability and the reliability of a system are improved, and the inspection efficiency is improved.

As described above, the present invention has been explained, but the present invention is not limited to this, and it should be understood that various modifications can be made within the spirit of the present invention.

Claims (14)

1. An X-ray device is characterized by comprising:

the periphery of the vacuum box is sealed, and the inside of the vacuum box is in high vacuum;

a plurality of electron emission units arranged in a two-dimensional arrangement on one plane on a cell wall of the vacuum cell;

an anode disposed in the vacuum chamber in parallel to a plane on which the plurality of electron emission units are located;

a power supply and control system having a high voltage power supply connected to the anode, a filament power supply connected to each of the plurality of electron emission units, a grid control device connected to each of the plurality of electron emission units, and a control system for controlling each power supply,

the anode includes: an anode plate made of a metal material and parallel to an upper surface of the electron emission unit; a plurality of targets mounted on the anode plate and arranged in a manner to respectively correspond to positions of the electron emission units,

the target has a bottom surface connected to the anode plate and a top surface forming a predetermined angle with the anode plate.

2. The X-ray apparatus according to claim 1,

the target is a circular frustum structure, a square platform structure, a multi-edge platform structure or other polygonal bulges or other irregular bulges.

3. The X-ray apparatus according to claim 1,

the target is a circular pillar stand structure, a square pillar stand structure, or other polygonal pillar stand structures.

4. The X-ray apparatus according to claim 1,

the target is a spherical structure.

5. The X-ray apparatus according to claim 1,

the top surface of the target is a flat, beveled, spherical, or other irregular surface.

6. The X-ray apparatus according to claim 1,

the electron emission unit has: a filament; a cathode connected to the filament; an insulating support having an opening and surrounding the filament and the cathode; filament leads led out from two ends of the filament; a gate electrode arranged above the cathode so as to face the cathode; a connecting fixture connected with the insulating support member to mount the electron emission unit on the wall of the vacuum box to form a vacuum sealing connection,

the gate electrode has: a gate frame made of metal and having an opening formed in the middle; a grid mesh made of metal and fixed at the position of the opening of the grid frame; a gate lead drawn out from the gate frame,

the filament lead and the grid lead penetrate through the insulating support and are led out to the outside of the electron emission unit, the filament lead is connected with the filament power supply, and the grid lead is connected with the grid control device.

7. The X-ray apparatus according to claim 6,

the connecting and fixing piece is connected to the outer edge of the lower end of the insulating support piece, the cathode end of the electron emission unit is located in the vacuum box, and the lead end of the electron emission unit is located outside the vacuum box.

8. The X-ray apparatus according to claim 6,

the connection fixing piece is connected to the upper end of the insulation support piece, and the whole electron emission unit is located outside the vacuum box.

9. The X-ray apparatus according to claim 1,

the electron emission unit includes: the flat grid consists of an insulating framework plate, a grid mesh and a grid lead; a cathode array formed by closely arranging a plurality of cathode structures, each cathode structure is formed by a filament, a cathode connected with the filament, filament leads led out from two ends of the filament, and an insulating support surrounding the filament and the cathode,

the grid plate is arranged on the insulating framework plate, the grid mesh is arranged at the position of an opening formed on the grid plate, the grid lead is led out of the grid plate,

the flat grid is positioned above the cathode array, the center of the grid mesh and the center of the cathode are overlapped in pairs in the vertical direction,

the flat grid and the cathode array are located in the vacuum box, and the filament lead and the grid lead are led out of the vacuum box through a filament lead transition terminal and a grid lead transition terminal which are arranged on the box wall of the vacuum box respectively.

10. The X-ray apparatus according to any one of claims 6 to 9,

further comprising: the high-voltage power supply connecting device is used for connecting the anode with a cable of the high-voltage power supply and is arranged on the side wall of one end, close to the anode, of the vacuum box; the filament power supply connecting device is used for connecting the filament and the filament power supply; a gate control means connecting means for connecting the gate of the electron emission unit and the gate control means; a vacuum power supply included within the power and control system; and the vacuum device is arranged on the side wall of the vacuum box and works by utilizing the vacuum power supply to maintain high vacuum in the vacuum box.

11. The X-ray apparatus according to any one of claims 1 to 9,

the array in which the plurality of electron emission units are arranged is a straight line in both directions, or one direction is a straight line and the other direction is a piecewise straight line.

12. The X-ray apparatus according to any one of claims 1 to 9,

the array of the plurality of electron emission units is a straight line in one direction and an arc or a segmented arc in the other direction.

13. The X-ray apparatus according to any one of claims 1 to 9,

the grid control device comprises a controller, a negative high-voltage module, a positive high-voltage module and a plurality of high-voltage switch elements,

each of the plurality of high-voltage switching elements at least comprises a control end, two input ends and an output end, the withstand voltage between the end points is at least larger than the maximum voltage formed by the negative high-voltage module and the positive high-voltage module,

the negative high voltage module supplies a stable negative high voltage to one input terminal of each of the plurality of high voltage switching elements,

the positive high voltage module provides a stable positive high voltage to the other input terminal of each of the plurality of high voltage switching elements,

the controller independently controls each of the plurality of high voltage switching elements,

the gate control device also has a plurality of control signal output channels,

the output end of one of the high-voltage switch elements is connected with one of the control signal output channels.

14. A CT apparatus is characterized in that a CT scanner is provided,

the X-ray source used is the X-ray device of any one of claims 1 to 13.