HK1222474B - Electron source, x-ray source and device using x-ray source - Google Patents

Description

Electron source, X-ray source, and equipment using the same

Technical Field

The present invention relates to an electron source for generating electron beams and an X-ray source for generating X-rays using the electron source, and in particular to an electron source for generating electron beams from different positions in a predetermined manner and an X-ray source for generating X-rays from different positions in a predetermined manner, as well as equipment using the X-ray source.

Background Art

An electron source is a device or component that produces an electron beam. Common terms include electron gun, cathode, and emitter. Electron sources are widely used in display devices, X-ray sources, microwave tubes, and more. An X-ray source is a device that produces X-rays. Its core is the X-ray tube, which consists of an electron source, an anode, and a vacuum-sealed housing. It typically also includes auxiliary devices such as a power supply and control system, cooling, and shielding. X-ray sources are widely used in industrial nondestructive testing, safety inspections, medical diagnosis, and treatment.

Traditional X-ray sources use a directly heated spiral tungsten filament as the cathode. When operating, current passes through it, heating it to an operating temperature of approximately 2000K, generating a thermally emitted electron beam. The electron beam is accelerated by the hundreds of thousands of volts high-voltage electric field between the anode and cathode, flies toward the anode and hits the target surface, generating X-rays.

Field emission allows a variety of materials, such as metal needle tips and carbon nanotubes, to generate electron emission at room temperature, producing an electron beam. Compared to thermal emission, it has significant advantages such as fast startup/shutdown speed, energy saving, and no need for heat dissipation. With the development of nanotechnology, especially carbon nanomaterials, nanomaterial field emission electron sources have experienced rapid development. For example, Keesmann et al. pointed out in patent US5773921A that nanomaterials can be used for field emission. Furthermore, Otto Zhou et al. in patent US6850595B and Tan Dagang in patent CN02133184.7 proposed a specific structure for a carbon nanomaterial field emission electron source to be used as an X-ray source. Patent US8447013B further proposed a technology for arranging multiple electron emission sources within a single X-ray source to form a distributed X-ray source with multiple targets through field emission from nanomaterials.

X-ray sources require electron sources with high emission currents, typically exceeding 1 mA. For example, the electron source emission current of oil-cooled rotating target X-ray sources currently used in medical CT scans can reach up to 1300 mA. Existing X-ray devices using nanomaterial field emission electron sources as cathodes, to achieve high emission currents, use nanomaterials to create a macroscopic cathode emission surface. A mesh grid is then arranged parallel to the surface to control field emission. This structure, due to machining precision, grid deformation, and installation accuracy, requires a significant distance between the grid and the cathode surface. Consequently, a very high voltage, typically exceeding 1000V, is applied to the grid to control field emission. For example, patent CN102870189B discloses that "the voltage applied to the extraction gate (grid) is approximately 1 to 3 kV." Such high control voltages, for distributed X-ray sources with multiple electron emission sources, typically require control voltages in the hundreds of kilovolts. This imposes significant technical challenges and production costs in terms of control systems and vacuum transition devices.

Nanomaterial field emission electron sources are increasingly being used in display devices and are considered a key technology direction for next-generation products, known as FEDs. Numerous patents, such as those filed by Fan Shoushan et al., describe the field emission principle, emission unit structure, spot layout, and production methods. These include patents CN100583353 and CN101499389. The technical characteristics of field emission electron sources for display applications include a small size of each light-emitting point, ranging from tens to hundreds of micrometers, a low emission current of several hundred nanoamperes to a few microamperes, a low gate control voltage, and a large number of electron sources divided into a two-dimensional planar array by uniformly arranged horizontal and vertical conductive strips, allowing each point to be individually controlled. This structure, for example, is described in CN1285067C. Due to differences in application areas and technical requirements, existing electron sources for display devices differ significantly from those used in X-ray sources.

The paper "Transmission-type microfocus x-ray tube using carbon nanotube field emitters," published in APPLIED PHYSICS LETTERS in 2007, disclosed that the tip of a coated carbon nanotube material with a radius of 5 μm had a stable field emission current of 26 μA, which served as the technical basis for the field emission capability of the nanomaterials in the present invention.

Furthermore, electron emission units employing the field emission principle have generally similar structures, as shown in Figures 3(A), 3(B), and 3(C). Figure 3(A) illustrates the technical solution disclosed in US Patent No. 5,773,921, in which nanomaterials (reference numeral 31 in the figure) are attached to a certain structure (reference numeral 13 in the figure) of the base layer (reference numeral 10 in the figure). Figure 3(B) illustrates the technical solution disclosed in US Patent No. 5,973,444, in which nanomaterials (reference numeral 20 in the figure) are directly grown on the flat surface of the base layer (reference numerals 12 and 14 in the figure). Figure 3(C) illustrates the technical solution disclosed in CN100459019, which is used in an electron source for an X-ray source device. The electron source comprises a macroscopic (millimeter to centimeter) nanomaterial plane (reference numeral 330 in the figure), and a macroscopically sized grid layer, the grid plane being parallel to the nanomaterial plane. In the prior art, electron emission units, as exemplified by Figures 3(A) and (B), are typically arranged in a planar array. Each emission unit is individually controlled through a striped base layer and gate layer (or a complex multi-layered gate layer) arranged longitudinally and transversely (also known as longitude and latitude). This results in a very low emission current for each emission unit, and the structural proportions of the various components are not considered in the application, resulting in poor emission current quality. In the structure shown in Figure 3(B), the gate opening is much larger than the distance from the nanomaterial to the gate. This causes the nanomaterial at the edge to experience a larger electric field, causing it to emit current first. However, this emitted current diverges at a large angle toward the edge, resulting in poor forward directionality and being easily blocked and absorbed by the gate. The nanomaterial in the center, which could have generated a more forward-directed emission current, experiences a smaller electric field, resulting in very little or no emission. The electron emission unit specifically designed for X-ray sources, as exemplified by Figure 3(C), features a large-span, small-pitch parallel structure between the grid plane and the nanomaterial plane. Due to limitations in machining and assembly precision, achieving a spacing below 200μm is difficult. Otherwise, the two planes are prone to non-parallelism, leading to an uneven electric field. Deformation of the grid itself, or deformation caused by the electric field force, can severely affect the uniformity of the electric field and even cause a short circuit between the grid and the nanomaterial. The large distance between the grid plane and the nanomaterial plane in this type of electron emission unit results in a high field emission control voltage, increasing control difficulty and production costs.

In addition, patent US20130230146A1 discloses an electron emission device with a linear electron emission source and a linear gate isolation spaced apart from each other, and the gate having an array of openings. The technical feature of the anti-charging film provided on the surface of the gate isolation effectively prevents the electron emission device from sparking. However, the linear, long electron emission source only emits electrons where the gate has an opening, and not where the gate bridge blocks the electron emission. This wastes the electron emission source. Furthermore, the structural dimensions are not optimized. For example, the size of the opening is larger than the distance from the electron emission source to the gate, which affects the emission efficiency and still results in insufficient emission current intensity.

Summary of the Invention

The present invention is proposed to solve the above-mentioned problems. The present invention provides a field emission electron source with a novel structure, which achieves the purposes of simple structure, low cost, low control voltage and high emission current intensity. At the same time, it provides an X-ray source using the electron source, which has high output X-ray intensity and low cost, or has multiple X-ray targets at different positions, with strong target flux and small spacing.

The present invention primarily provides a field emission electron source with low control voltage and high emission current, and an X-ray source using the electron source. The electron source of the present invention has multiple electron emission regions, each of which contains a large number of micro-electron emission units. The structure of the micro-electron emission units in the present invention allows for a very low control voltage for field emission, and the coordinated operation of a large number of micro-electron emission units enables the electron emission region to have a large emission current. An X-ray source using the electron source can be a dual-energy X-ray source through the design of the anode. The design of the electron source can also provide a distributed X-ray source with multiple targets at different locations. Multiple operating modes can be used to increase the X-ray output intensity of each target, reduce the distance between targets, and avoid black spots, thereby expanding the functions and applications of the field emission distributed X-ray source. At the same time, by reducing the control voltage, the control difficulty and production cost are reduced, failures are reduced, and the life of the distributed X-ray source is increased.

In addition, the present invention also provides the application of a distributed X-ray source with the above-mentioned characteristics in fluoroscopic imaging and backscatter imaging. Various technical solutions demonstrate one or more advantages of low cost, high inspection speed, and high image quality brought by the use of this X-ray source.

The present invention also provides a real-time image-guided radiotherapy system. This real-time image-guided radiotherapy is crucial for treating areas with physiological motion, such as the lungs and heart, by reducing radiation dose and minimizing exposure to normal organs. Furthermore, the distributed X-ray source of the present invention has multiple targets, and the resulting guided images, unlike conventional two-dimensional images, are "stereoscopic" diagnostic images with depth information, further improving the accuracy of positional guidance of the therapeutic beam during image-guided therapy.

To achieve the purpose of the present invention, the following technical solutions are adopted.

The present invention provides an electron source having at least one electron emission region, wherein the electron emission region includes a plurality of micro electron emission units, each of the micro electron emission units occupying a space of micrometer order in the array arrangement direction, and the micro electron emission units including a base layer, an insulating layer located on the base layer, a gate layer located on the insulating layer, an opening located on the gate layer, and an electron emitter fixed on the base layer corresponding to the position of the opening, wherein each of the micro electron emission units in the electron emission region emits electrons simultaneously or does not emit electrons simultaneously.

In addition, in the present invention, the base layer is used to provide structural support and electrical connection.

Furthermore, in the present invention, the gate layer is made of a conductive material.

Furthermore, in the present invention, the opening penetrates the gate layer and the insulating layer and reaches the base layer.

Furthermore, in the present invention, the thickness of the insulating layer is less than 200 μm.

Furthermore, in the present invention, the size of the opening is smaller than the thickness of the insulating layer.

Furthermore, in the present invention, the size of the opening is smaller than the distance from the electron emitter to the gate layer.

Furthermore, in the present invention, the height of the electron emitter is less than half the thickness of the insulating layer.

Furthermore, in the present invention, the gate layer is parallel to the base layer.

Furthermore, in the present invention, the space size occupied by the micro electron emission units in the array arrangement direction is in the micron order, and preferably the space size occupied by the micro electron emission units in the array arrangement direction ranges from 1 μm to 200 μm.

Furthermore, in the present invention, a ratio of the length to the width of the electron emission region is greater than 2.

Furthermore, in the present invention, the base layer is composed of a base layer and a conductive layer located on the base layer, and the electron emitter is fixed on the conductive layer.

Furthermore, in the present invention, the emission current of the electron emission region is not less than 0.8 mA.

In addition, the present invention provides an electron source having at least two electron emission regions, each of the electron emission regions containing multiple micro electron emission units, the micro electron emission units including a base layer for providing structural support and electrical connection, an insulating layer located on the base layer, a gate layer located on the insulating layer and composed of a conductive material, an opening penetrating the gate layer and the insulating layer and reaching the base layer, and an electron emitter located in the opening and fixed to the base layer, wherein the micro electron emission units in the same electron emission region are electrically connected and emit electrons at the same time or do not emit electrons at the same time, and different electron emission regions are electrically isolated.

Furthermore, in the present invention, the thickness of the insulating layer is less than 200 μm.

Furthermore, in the present invention, the gate layer is parallel to the base layer.

In addition, in the present invention, electrical isolation between different electron emission regions means that the base layer of each electron emission region is separate and independent, or the gate layer of each electron emission region is separate and independent, or the base layer and the gate layer of each electron emission region are separate and independent.

Furthermore, in the present invention, different electron emission regions can be controlled to emit electrons in a predetermined order, including sequential, intermittent, alternating, partially simultaneous, and grouped combinations.

In addition, in the present invention, the base layer of each micro electron emission unit in the same electron emission region is the same physical layer, the gate layer of each micro electron emission unit is the same physical layer, and the insulating layer of each micro electron emission unit can also be the same physical layer.

Furthermore, in the present invention, the size of the micro electron emission units in the array arrangement direction within the electron emission region is in the micrometer order.

Furthermore, in the present invention, the size of the space occupied by the micro electron emission units in the array arrangement direction ranges from 1 μm to 200 μm.

Furthermore, in the present invention, the size of the opening is smaller than the thickness of the insulating layer.

Furthermore, in the present invention, the size of the opening is smaller than the distance from the electron emitter to the gate layer.

Furthermore, in the present invention, the height of the electron emitter is less than half the thickness of the insulating layer.

Furthermore, in the present invention, a linear length of the electron emitter is perpendicular to a surface of the base layer.

Furthermore, in the present invention, the electron emitter is composed of nanomaterials.

In addition, in the present invention, the nanomaterial is single-walled carbon nanotube, double-walled carbon nanotube, multi-walled carbon nanotube, or a combination thereof.

In addition, in the present invention, the base layer is composed of a substrate layer and a conductive layer located on the substrate layer, the substrate layer is used to provide structural support, and the conductive layer is used to form an electrical connection with the base (fixed pole of nanomaterial) of each of the micro electron emission units in the same electron emission area.

Furthermore, in the present invention, a ratio of the length to the width of the electron emission region is greater than 2.

Furthermore, in the present invention, the electron emission regions are of equal size and are arranged parallel, neatly, and evenly along the narrow sides.

Furthermore, in the present invention, the emission current of each of the electron emission regions is greater than 0.8 mA.

In addition, the present invention provides an X-ray source, comprising: a vacuum box; an electron source, disposed in the vacuum box; an anode disposed in the vacuum box opposite to the electron source; an electron source control device for applying a voltage between the base layer and the gate layer of the electron emission region of the electron source; and a high-voltage power supply connected to the anode for providing a high voltage to the anode, characterized in that: the electron source has at least one electron emission region, the electron emission region includes a plurality of micro electron emission units, the space size occupied by each micro electron emission unit in the array arrangement direction is in the micron order, the micro electron emission unit includes a base layer for providing structural support and electrical connection, an insulating layer located on the base layer, a gate layer located on the insulating layer and composed of a conductive material, an opening penetrating the gate layer and the insulating layer and reaching the base layer, and an electron emitter located in the opening and fixed to the base layer, wherein each of the micro electron emission units in the electron emission region emits electrons simultaneously or does not emit electrons simultaneously.

Furthermore, in the present invention, the thickness of the insulating layer is less than 200 μm.

Furthermore, in the present invention, the field emission control voltage applied by the electron source control device to the electron source is less than 500V.

Furthermore, the present invention provides a distributed X-ray source comprising: a vacuum box; an electron source disposed within the vacuum box; an anode disposed within the vacuum box opposite the electron source; an electron source control device for applying a voltage between the base layer and the gate layer of the electron emission region of the electron source; and a high-voltage power supply connected to the anode for providing a high voltage to the anode, characterized in that:

The electron source includes at least two (referred to as N) electron emission regions, each of which includes multiple micro electron emission units. The micro electron emission units include a base layer, an insulating layer located on the base layer, a gate layer located on the insulating layer, an opening located on the gate layer, and an electron emitter fixed on the base layer corresponding to the position of the opening. The micro electron emission units in the same electron emission region are electrically connected to each other and emit electrons at the same time or not at the same time, and different electron emission regions are electrically isolated from each other.

Furthermore, in the present invention, the base layers between different electron emission regions of the electron source are electrically isolated, and each base layer is connected to an electron source control device via an independent lead.

Furthermore, in the present invention, the gate layers are electrically isolated between different electron emission regions of the electron source, and each gate layer is connected to an electron source control device via an independent lead.

Furthermore, in the present invention, the surface of the anode and the surface of the electron source are opposite to each other, have similar shapes and sizes, and maintain a parallel or substantially parallel relationship, thereby generating at least two target points at different positions.

Furthermore, in the present invention, the anode comprises at least two different target materials, and generates X-rays with different comprehensive energies at different target points.

Furthermore, in the present invention, the N electron emission regions have a strip shape and are linearly arranged along the narrow side in the same plane.

Furthermore, in the present invention, the N electron emission regions each independently emit electrons, and generate X-rays at corresponding N positions on the anode, forming N target points.

Furthermore, in the present invention, the N electron emission regions are combined into adjacent non-overlapping groups to emit electrons, and X-rays can be generated at corresponding N/n positions on the anode, forming N/n target points.

Furthermore, in the present invention, the N electron emission regions are combined with n adjacent regions having a overlap to emit electrons as a group, and X-rays are generated at corresponding positions on the anode to form target points.

Furthermore, in the present invention, the surface of the electron emission region is arc-shaped in the width direction, and the electrons emitted by each of the micro electron emission units in the electron emission region are focused toward one point in the width direction.

In addition, in the present invention, the distributed X-ray source further includes a focusing device, which corresponds to the electron emission regions, has the same number as the electron emission regions, and is arranged between the electron source and the anode.

In addition, in the present invention, the distributed X-ray source also includes a collimating device configured inside or outside the vacuum box, and the collimating device is arranged on the output path of the X-rays, and is used to output X-rays in the form of cone, plane fan, pencil or multi-point parallel.

In addition, in the present invention, the target points of the distributed X-ray source are arranged in a circular or arc shape.

In addition, in the present invention, the target points of the distributed X-ray source are arranged in a shape of a square, a broken line segment or a straight line that is adjacent end to end.

Furthermore, in the present invention, the anode target is a transmission target, and the output X-rays are in the same direction as the electron beam from the electron source.

Furthermore, in the present invention, the anode target is a reflective target, and the output X-rays form an angle of 90 degrees with the electron beam from the electron source.

In addition, the present invention provides a fluoroscopic imaging system using the X-ray source of the present invention, comprising: at least one X-ray source of the present invention, for generating X-rays covering a detection area; at least one detector, located on the other side of the detection area different from the X-ray source, for receiving X-rays; and a conveying device, located between the X-ray source and the detector, for carrying the object to be detected through the detection area.

In addition, the present invention provides a backscatter imaging system using the distributed X-ray source of the present invention, comprising: at least one distributed X-ray source of the present invention, used to generate multiple pencil-shaped X-ray beams covering a detection area; and at least one detector located on the same side of the detection area as the X-ray source, used to receive X-rays reflected from the object being detected.

Furthermore, in the backscatter imaging system of the present invention, there are at least two sets of combinations of the X-ray source and the detector, which are arranged on different sides of the object to be inspected.

In addition, the backscatter imaging system of the present invention is further provided with a conveying device for carrying the detected object through the detection area.

In addition, the backscatter imaging system of the present invention is further provided with a moving device for moving the X-ray source and the detector so that the X-ray source and the detector pass through the area where the object to be detected is located.

Furthermore, the present invention provides an X-ray detection system comprising: at least two distributed X-ray sources of the present invention; at least two sets of detectors corresponding to the X-ray sources; and an image integration processing system. At least one set of the distributed X-ray sources and detectors performs fluoroscopic imaging of the detection object, and at least one set of the distributed X-ray sources and detectors performs backscatter imaging of the detection object. The image integration processing system integrates the fluoroscopic and backscatter images to obtain more characteristic information about the detection object.

In addition, the present invention provides a real-time image-guided radiotherapy device comprising: a radiotherapy radiation source for generating a radiation beam for radiotherapy of a patient; a multi-leaf collimator for adjusting the shape of the radiotherapy radiation beam to match the lesion; a movable bed for moving and positioning the patient so that the position of the radiotherapy radiation beam is aligned with the position of the lesion; at least one distributed X-ray source, i.e., a diagnostic radiation source, for generating a radiation beam for diagnostic imaging of the patient; a flat-panel detector for receiving the diagnostic imaging radiation beam; and a control system for forming a diagnostic image based on the radiation beam received by the flat-panel detector, locating the position of the lesion in the diagnostic image, guiding the center of the radiotherapy radiation beam to align with the center of the lesion, and guiding the shape of the radiotherapy radiation beam of the multi-leaf collimator to match the shape of the lesion. The distributed X-ray source is a circular or square-shaped distributed X-ray source that outputs X-rays from the side, and the axis or centerline of the distributed X-ray source is aligned with the beam axis of the radiotherapy radiation source, i.e., the diagnostic radiation source and the radiotherapy radiation source are positioned in the same direction relative to the patient.

According to the present invention, an electron source with low control voltage and high emission current intensity, an X-ray source using the electron source, an imaging system using the X-ray source, an X-ray detection system, and a real-time image-guided radiotherapy device can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of an electron source of the present invention.

FIG2 is a schematic structural diagram of a micro electron emission unit in the present invention.

FIG. 3 is a schematic diagram of several structures of a field emission unit in the prior art.

FIG. 4 is a diagram schematically showing a cross-sectional view of the front end of the electron source of the present invention.

FIG. 5 is a schematic diagram of several electron sources with different region separations according to the present invention.

FIG6 is a schematic diagram of the specific structure of the micro electron emission unit in the present invention.

FIG. 7 is a schematic diagram of a micro electron emission unit in which nanomaterials are fixed in different ways.

FIG8 is a schematic diagram showing the structure of an X-ray source using the electron source of the present invention.

FIG9 is a schematic diagram of a distributed X-ray source having an anode with multiple target materials according to the present invention.

FIG10 is a schematic diagram of three working modes of the distributed X-ray source in the present invention.

FIG11 is a schematic diagram of a distributed X-ray source having a specific structure as the electron source of the present invention.

FIG12 is a schematic diagram of a distributed X-ray source with a focusing device.

FIG13 is a schematic diagram of several collimation effects of a distributed X-ray source.

FIG14 is a schematic diagram of a ring-shaped distributed X-ray source.

FIG15 is a schematic diagram of a box-shaped distributed X-ray source.

FIG16 is a schematic diagram of several cross-sectional structures of a distributed X-ray source.

FIG17 is a schematic diagram of a transmission imaging system using the distributed X-ray source of the present invention.

FIG18 is a schematic diagram of a backscatter imaging system using the distributed X-ray source of the present invention.

Description of reference numerals:

1 electron source; 11, 12, 13, ... electron emission regions on the electron source;

100 micro electron emission unit; 101 base layer; 102 insulating layer; 103 gate layer; 104 electron emitter; 105 opening; 106 substrate layer; 107 conductive layer;

2 anode; 21, 22, 23, ... X-ray target on the anode;

3 Vacuum box; 4 Electron source control device; 41 First connecting device; 5 High voltage power supply; 51 Second connecting device; 6 Focusing device; 7 Collimating device;

81 X-ray source; 82 detector; 83 object to be detected; 84 transmission device;

S is the size of the micro electron emission unit; D is the size of the opening; H is the distance from the electron emitter to the gate layer; h is the height of the electron emitter; d is the spacing between the electron emission regions;

V field emission voltage; E electron beam current; X X-ray; O X-ray source center, center line or axis.

DETAILED DESCRIPTION

The present invention is described in detail below with reference to the accompanying drawings. Figure 1 is a schematic diagram of one structure of an electron source according to the present invention. As shown in Figure 1 , the electron source 1 according to the present invention includes multiple electron emission regions, such as an electron emission region 11 and an electron emission region 12. Although not shown, the electron source 1 may also include only one electron emission region. As shown in Figure 1 , each electron emission region includes multiple micro electron emission units 100. Furthermore, the micro electron emission units 100 within the same electron emission region are physically (electrically) connected, while different electron emission regions are physically separated (i.e., electrically isolated). In Figure 1 , the multiple electron emission regions 11, 12, ... are arranged in a row along the width of the electron emission region (shown as the left-right direction in Figure 1 ). However, the present invention is not limited to this arrangement. The electron emission regions may also be arranged in other arrangements, such as multiple rows, or multiple rows with the electron emission regions in each row arranged in a staggered manner. Furthermore, the size, shape, and distance between the electron emission regions can be customized as needed.

All micro electron emission units 100 in the same electron emission region emit electrons simultaneously or do not emit electrons at the same time. Different electron emission regions can be controlled to emit electrons in a predetermined order, such as sequential emission, intermittent emission, alternating emission, partial simultaneous emission, or grouped combined emission.

FIG2 is a schematic diagram of the structure of a micro electron emission unit 100 according to the present invention. As shown in FIG2 , micro electron emission unit 100 includes a base layer 101, an insulating layer 102 located on base layer 101, a gate layer 103 located on insulating layer 102, an opening 105 penetrating gate layer 103 and insulating layer 102 and reaching base layer 101, and an electron emitter 104 located within opening 105 and fixed to base layer 101. Among them, the base layer 101 is the structural foundation of the micro electron emission unit 100, providing structural support and electrical connectivity (electrical connection); the insulating layer 102 is located above the base layer 101 and is made of insulating material. It insulates the gate layer 103 from the base layer 101. At the same time, due to the supporting effect of the insulating layer 102, the distance between the gate layer and the base layer is equal at all points in the same electron emission region (that is, the planes on which the two layers are located are parallel), thereby ensuring a uniform electric field distribution between the gate layer 103 and the base layer 101; the gate layer 103 is located above the insulating layer 102 and is made of a metallic conductive material; the opening 105 penetrates the gate layer 103 and the insulating layer 102; the electron emitter 104 is located in the opening 105 and is connected to the base layer 101. Furthermore, the opening 105 can be any machinable shape, such as circular, square, polygonal, or elliptical, but is preferably circular. The size (dimensions) of the opening 105 in the gate layer 103 and the insulating layer 102 can be the same or different. For example, as shown in FIG2 , the opening in the insulating layer 102 is slightly larger than the opening in the gate layer 103. Furthermore, an electron emitter 104 is located in the opening 105 and connected to the base layer 101. Preferably, the electron emitter 104 is located at the center of the opening, with the linear length of the electron emitter 104 perpendicular to the surface of the base layer 101. When a voltage difference (i.e., a field emission voltage) is applied between the gate layer 103 and the base layer 101 via an external power supply V, an electric field is generated between the gate layer 103 and the base layer 101. When the electric field strength reaches a certain level, for example, exceeding 2 V/μm, the electron emitter 104 generates field emission, and the emitted electron beam E passes through the insulating layer 102 and the gate layer 103 and is emitted from the opening 105.

In addition, the electron emitter 104 is a structure containing "nanomaterials". "Nanomaterials" refer to materials whose at least one dimension in the three-dimensional space is in the nanoscale range (1 to 100 nm) or are composed of them as basic units, including metal and non-metal nanopowders, nanofibers, nanofilms, nanoblocks, etc., typically such as carbon nanotubes, zinc oxide nanowires, etc. In the present invention, the preferred nanomaterials are single-walled carbon nanotubes and double-walled carbon nanotubes, whose diameters are less than 10 nanometers.

Compared with the structures of the prior art shown in Figures 3(A), 3(B), and 3(C), in the present invention, better electron emission characteristics and a larger electron emission current E are achieved through the specific structure, proportion, and electron emission area of the components of the micro electron emission unit 100, while reducing the control voltage V required for field emission.

Figure 4 is a schematic diagram of a front-end cross-sectional view of the electron source 1 of the present invention. As shown in Figure 4, each micro-electron emission unit 100 within the same electron emission region is physically (electrically) connected. For example, the base layer 101 of each micro-electron emission unit 100 is the same physical layer, the gate layer 103 of each micro-electron emission unit 100 is the same physical layer, and the insulating layer 102 of each micro-electron emission unit 100 can be the same physical layer. "The same physical layer" means that they are at the same spatial level, electrically connected, and structurally connected as a single entity. The insulating layer 102 of each micro-electron emission unit 100 can also be composed of multiple insulating pillars, insulating blocks, insulating strips, etc., located at the same spatial level, as long as the gate layer 103 and base layer 101 are insulated and the distance between them is equal (i.e., the gate layer 103 and base layer 101 are parallel). Furthermore, different electron emission regions are physically separated. For example, the gate layer 103 of each electron emission region is separate and independent, the base layer 101 of each electron emission region is separate and independent, or both the gate layer 103 and the base layer 101 of each electron emission region are separate and independent. This allows all micro electron emission units within the same electron emission region to emit electrons simultaneously or simultaneously. Different electron emission regions can be controlled to emit electrons in a predetermined independent or combined control sequence. The simultaneous operation of multiple micro electron emission units 100 can achieve an emission current greater than 0.8 mA for a single electron emission region.

Figure 5 is a schematic diagram of several electron sources with different region separations according to the present invention. As shown in Figures (A), (B), and (C) of Figure 5, the physical separation between different electron emission regions can be implemented in a variety of specific ways. For example, Figure 5 (A) shows that electron emission region 11 and electron emission region 12 share a common base layer and insulating layer, but have separate gate layers separated by a distance d; Figure 5 (B) shows that electron emission region 11 and electron emission region 12 share a common gate layer and insulating layer, but have separate base layers separated by a distance d; and Figure 5 (C) shows that the gate layer, insulating layer, and base layer of emission region 11 and emission region 12 are all separated by a distance d.

Furthermore, the shape of each electron emission region can be square, circular, elongated, oblong, polygonal, or other combinations thereof; square refers to a square or rectangle, and elongated refers to a shape where the ratio of length to width is much greater than 1 (e.g., 10). The shapes of the electron emission regions of an electron source can be the same or different; the sizes of the electron emission regions can be equal or unequal; and the electron emission regions have macroscopic dimensions on the millimeter scale, for example, 0.2 mm to 40 mm. The spacing d between the electron emission regions can be on the micrometer scale or on the macroscopic scale of millimeters to centimeters, and the spacing d between different electron emission regions can be the same or different. In a typical structure, the electron emission regions are elongated, measuring 1 mm x 20 mm, of equal size, and arranged parallel, neatly, and evenly along their narrow sides (1 mm), with the spacing d between adjacent electron emission regions being 1 mm.

Figure 6 is a schematic diagram of the specific structure of a micro electron emission unit according to the present invention. As shown in Figure 6, in the structure of a micro electron emission unit 100, the base layer 101 provides structural support and electrical connectivity. It can be a metal layer or comprise a substrate layer 106 and a conductive layer 107. The substrate layer 106 provides structural support, such as a smooth surface for the conductive layer to adhere to. It serves as the structural foundation of the electron emission region. That is, the conductive layer 107, insulating layer 102, gate layer 103, and electron emitter 104 are all attached, bonded, grown, or fixed to the substrate layer 106. The substrate layer 106 can be a metal material, such as stainless steel, or a non-metallic material, such as ceramic. The conductive layer 107 provides base electrical connections for each micro electron emission unit 100 within the same electron emission region. Conductive layer 107 is made of a material with good electrical conductivity and can be a metal or a non-metallic material, such as gold, silver, copper, molybdenum, or carbon nanofilm.

Furthermore, the dimension S of the micro electron emission units 100 in the array direction within the electron emission region is micron-scale. That is, the space occupied by each micro electron emission unit 100 in the array direction ranges from 1 μm to 200 μm, typically 50 μm. The direction perpendicular to the array plane is defined as depth, or thickness. The thickness of the base layer 106 is macroscopically millimeter-scale, for example, 1 mm to 10 mm, typically 4 mm. Figure 6 only shows a portion of the base layer 106 in the thickness direction. The thickness of the conductive layer 107 can be in the millimeter or micron range, depending on the material used. For ease of processing and cost reduction, a micron-scale is recommended, such as a 20 μm thick carbon nanofilm. The thickness of the insulating layer 102 is micron-scale, for example, 5 μm to 400 μm, typically 100 μm. The thickness of the gate layer 103 is also micron-scale, and a thickness similar to, but slightly less than, the insulating layer 102 is recommended, for example, 5 μm to 400 μm, typically 30 μm. The dimension D of the opening 105 is on the micron scale and is smaller than the thickness of the insulating layer 102, for example, 5 μm to 100 μm, typically 30 μm. The height h of the electron emitter 104 is on the micron scale and is smaller than ½ the thickness of the insulating layer 102, for example, 1 μm to 100 μm, typically 20 μm. The distance H between the electron emitter 104 and the gate layer 103, i.e., the distance from the top of the electron emitter 104 to the bottom edge of the gate layer 103, is on the micron scale and smaller than the thickness of the insulating layer 102, more specifically, less than 200 μm, typically 80 μm.

The size S of the micro electron emission unit 100 is on the micron scale, and the size D of the opening 105 is also on the micron scale. This allows a large number of single-walled or double-walled carbon nanotubes, multi-walled carbon nanotubes, or combinations thereof, with a diameter of less than 10 nanometers, to be arranged within the opening 105, ensuring a certain current emission capability. The size of the opening 105 is smaller than the thickness of the insulating layer 102, that is, the shape of the opening 105 is a "deep well". The electric field distribution felt by the top of the electron emitter 104 is relatively uniform, ensuring that the current emitted by the electron emitter 104 has good forward characteristics. The thickness of the gate layer 103 is close to but smaller than the thickness of the insulating layer 102. On the one hand, this ensures a relatively uniform electric field on the top of the electron emitter 104, and on the other hand, it does not significantly block the electron beam E emitted by the electron emitter 104. The structural and dimensional relationship of the above-mentioned parts improves the quality of the electron beam E emitted by the micro electron emission unit 100, increases the emission current intensity, and enhances the forward characteristics. In addition, by adjusting the control voltage, the emission capacity of each micro electron emission unit 100 is greater than 100nA, for example, 100nA to 25μA.

At the same time, the distance H between the electron emitter 104 and the gate layer 103 is less than 200 μm, so that the control voltage of the gate is less than 500 V (this is because when the ratio of the voltage between the gate layer and the electron emitter to the distance between the gate layer and the electron emitter exceeds 2V/μm, the electron emitter will produce field emission. In fact, the nanomaterial tip of the electron emitter has a strong field intensity enhancement effect, that is, the electric field felt by the tip of the nanomaterial can be much greater than V/H, where V is the control voltage of the gate and H is the distance between the gate layer and the electron emitter). Typically, H = 80 μm and the control voltage V = 300 V, which makes the electron source of the present invention simple to control and low in control cost.

In addition, the size S of the micro electron emission unit 100 is in the micron level. According to the typical size parameters recommended above, the size S of the micro electron emission unit 100 is 50 μm. There are 8,000 micro electron emission units 100 in an electron emission area of 1 mm × 20 mm. The emission capacity of each micro electron emission unit 100 is 100 nA to 25 μA, and the current emission capacity of the electron emission area is greater than 0.8 mA, for example, 0.8 mA to 200 mA.

Furthermore, the electron emitter 104 can be directly fixed to the conductive layer through growth, printing, bonding, sintering, or other means, or fixed to certain specially designed protrusions on the conductive layer, as shown, for example, in Figures 7(A), (B), and (C). Figure 7(A) is a schematic diagram of a structure in which a nanomaterial is fixed to a conical boss. The boss can also be square, cylindrical, or other shapes, which is a common structure in the prior art. Figure 7(B) shows a structure in which micro-metal rods (or metal tips) are arranged on the conductive layer, and nanomaterials are fixed to the metal rods to form a nanomaterial tree-like structure. Figure 7(C) shows a structure in which the conductive layer itself is a film made of nanomaterial, and subsequent processing causes a portion of the nanomaterial in the nanofilm at the opening to stand upright.

FIG8 is a schematic diagram of the structure of an X-ray source using the electron source of the present invention. The X-ray source shown in FIG8 includes: an electron source 1; an anode 2 disposed opposite the electron source 1; a vacuum box 3 surrounding the electron source 1 and the anode 2; an electron source control device 4 connected to the electron source 1; a high-voltage power supply 5 connected to the anode 2; a first connection device 41 extending through the wall of the vacuum box 3 to connect the electron source 1 to the electron source control device 4; and a second connection device 51 extending through the wall of the vacuum box 3 to connect the anode 2 to the high-voltage power supply 5.

As described above, the electron source 1 includes at least one electron emission region, which includes a plurality of micro electron emission units 100. The spatial size of each micro electron emission unit 100 in the array arrangement direction is in the micron range. The micro electron emission unit 100 includes a base layer 101, an insulating layer 102 located on the base layer 101, a gate layer 103 located on the insulating layer 103, an opening 105 that penetrates the gate layer 102 and the insulating layer 102 and reaches the base layer 101, and an electron emitter 104 located in the opening 105 and fixed to the base layer 101. The plurality of micro electron emission units 100 emit electrons simultaneously or do not emit electrons simultaneously.

Furthermore, the operating state of the electron emission region is controlled by an electron source control device 4 connected to the electron source 1. The electron source control device 4 applies two different voltages to the base layer 101 and gate layer 103 of the electron emission region of the electron source 1 via a first connection device 41. This establishes a field emission electric field with a voltage difference of V between the base layer 101 and the gate layer 103. The electric field strength is V/H (H is the distance between the electron emitter 104 and the gate layer 103). V is positive when the voltage of the gate layer 103 is higher than the voltage of the base layer 101, and negative when it is lower. When the electric field voltage V is positive, the nanomaterial of the electron emitter 104 is carbon nanotubes, and the strength V/H is greater than 2V/μm (due to the field enhancement effect at the nanomaterial's tip, the actual electric field felt by the nanomaterial may be much greater than the value of V/H), the electron emission region generates electron emission. When the electric field voltage is zero or negative, the electron emission region does not generate electron emission. When the voltage V is higher and the ratio V/H is greater, the current intensity of the electron emission increases. Therefore, the current intensity of the electron source 1 can be adjusted by adjusting the output voltage V of the electron source control device 4. For example, the electron source control device 4 can output a voltage with an adjustable range of 0V to 500V. When the output voltage is 0V, the electron source 1 does not emit electrons. When the output voltage reaches a certain amplitude, such as 200V, the electron source 1 begins to emit electrons. When the output voltage increases by a certain amplitude, such as 300V, the current intensity of the electrons emitted by the electron source 1 reaches the target value. If the current intensity of the electron source 1 is lower or higher than the target value, the output voltage of the electron source control device 4 can be increased or decreased to return the current intensity of the electron source 1 to the target value. Modern control systems can easily implement this automatic feedback adjustment. Generally, for ease of use, the base layer 101 of the electron emission region of the electron source 1 is connected to the ground potential and a positive voltage is applied to the gate layer 103; or the gate layer 103 is connected to the ground potential and a negative voltage is applied to the base layer 101.

Anode 2 is also used to establish a high-voltage electric field between itself and electron source 1, while simultaneously receiving electron beam E emitted from electron source 1 and accelerated by the high-voltage electric field, thereby generating X-rays. Anode 2, also commonly referred to as a target, is typically made of a high-Z metal material, known as the target material. Commonly used materials include tungsten, molybdenum, palladium, gold, and copper. This can be a single metal or an alloy. To reduce costs, a common metal substrate is typically used, to which one or more high-Z target materials are affixed via electroplating, sputtering, high-temperature pressing, welding, or bonding.

The anode 2 is connected to the anode high-voltage power supply 5 via a second connection device 51. The high-voltage power supply 5 generates a high voltage ranging from tens to hundreds of kV (e.g., 40 kV to 500 kV) and applies it between the anode 2 and the electron source 1. The anode 2 has a positive voltage relative to the electron source 1. For example, a typical embodiment is to connect the main body of the electron source 1 to ground potential, while applying a positive voltage of 160 kV to the anode 2 via the high-voltage power supply 5. A high-voltage electric field is formed between the anode 2 and the electron source 1. The electron beam E emitted by the electron source 1 is accelerated by the high-voltage electric field, traveling along the direction of the electric field (against the electric lines of force), and ultimately bombarding the target material at the anode 2, generating X-rays.

Furthermore, the vacuum box 3 is a sealed, hollow shell that surrounds the electron source 1 and anode 2. The shell is primarily made of an insulating material, such as glass or ceramic. The shell of the vacuum box 3 can also be made of a metal material, such as stainless steel. When the shell of the vacuum box 3 is made of a metal material, it maintains a sufficient distance from the electron source 1 and anode 2 within it. This prevents sparking between the electron source 1 and anode 2, while also preventing any impact on the electric field distribution between the electron source 1 and anode 2. A first connecting device 41 is also mounted on the wall of the vacuum box 3. This allows electrical leads to pass through the wall of the vacuum box 3 and maintain the sealing properties of the vacuum box 3. These leads are typically ceramic lead terminals. A second connecting device 51 is also mounted on the wall of the vacuum box 3. This allows electrical leads to pass through the wall of the vacuum box 3 and maintain the sealing properties of the vacuum box. These leads are typically ceramic high-voltage lead terminals. The interior of the vacuum box 3 is a high vacuum, which is achieved by baking and exhausting in a high-temperature exhaust furnace. The vacuum degree is usually not less than 10 ^-3 Pa, and the recommended vacuum degree is not less than 10 ^-5 Pa. The vacuum box 3 itself may also be equipped with a vacuum maintaining device such as an ion pump.

In addition, the electron source 1 includes at least two electron emission regions, for example, N electron emission regions, each of which includes multiple micro electron emission units 100. As mentioned above, the micro electron emission unit 100 includes a base layer 101, an insulating layer 102 located on the base layer 101, a gate layer 103 located on the insulating layer 102, an opening 105 that penetrates the gate layer 103 and the insulating layer 102 and reaches the base layer 101, and an electron emitter 104 located in the opening 105 and fixed to the base layer 101. The micro electron emission units 100 in the same electron emission region are physically connected, and there is physical separation between different electron emission regions.

As mentioned above, the micro-electron emission units 100 within the same electron emission region are physically connected, meaning their base layers 101, gate layers 103, and insulating layers 102 are the same layer. Physical separation between different electron emission regions can be: (A) The base layers 101 and insulating layers 102 of different electron emission regions are the same layer, and the gate layers 103 are located on the same plane but are separated. For example, the gate layers 103 of adjacent electron emission regions are separated by a distance d. In this case, the base layer 101 of the electron source 1 has a common lead connected to the electron source control device 4 via the first connection device 41. The gate layer 103 of each electron emission region has an independent lead connected to the electron source control device 4 via the first connection device 41. For N electron emission regions, the first connection device 41 has at least N+1 independent leads. Furthermore, the base layer 101 of the electron source 1 is connected to the ground potential of the electron source control device 4 via a common lead. The multiple outputs of the electron source control device 4 (all outputting positive voltages) are connected to the gate layer 103 of each electron emission region via a first connection device 41, thereby enabling independent control of each electron emission region. (B) The gate layers 103 and insulating layer 102 of different electron emission regions are co-existing, while the base layers 101 are co-planar but separated. For example, the base layers 101 of adjacent electron emission regions are separated by a distance d. When the base layers 101 are composed of a non-conductive base layer 106 and a conductive layer 107, the separation can be solely the separation of the conductive layer 107. In this case, the gate layer 103 of the electron source 1 has a common lead connected to the electron source control device 4 via the first connection device 41, while the base layer 101 of each electron emission region has an independent lead connected to the electron source control device 4 via the first connection device 41. For N electron emission regions, the first connection device 41 has at least N+1 independent leads. Furthermore, the gate layer 103 of the electron source 1 is connected to the ground potential of the electron source control device 4 via a common lead. The multiple outputs of the electron source control device 4 (all outputting negative voltages) are connected to the base layer 101 of each electron emission region via a first connection device 41, thereby enabling independent control of each electron emission region. (C) Different electron emission regions are located on the same plane, but their gate layers 103, insulating layers 102, and base layers 101 are separated, for example, with a spacing d between adjacent electron emission regions. In this case, each electron emission region has a lead extending from the base layer 101 and gate layer 103, respectively, and connected to the electron source control device 4 via the first connection device 41. For N electron emission regions, the first connection device 41 has at least 2N independent leads. The multiple outputs of the electron source control device 4 (consisting of two leads in a group, with a voltage difference between them) are connected to the base layer 101 and gate layer 103 of each electron emission region via the first connection device 41, thereby enabling independent control of each electron emission region.

As shown in FIG8 , electron source 1 has N electron emission regions 11, 12, 13, etc. at different locations arranged linearly, capable of emitting electron beams at different locations on electron source 1. Anode 2 is arranged corresponding to electron source 1. That is, as shown in FIG8 , anode 2 is located above electron source 1 and has the same or similar shape and size as electron source 1. The surface of the target material of anode 2 is opposite to the surface of gate layer 103 of electron source 1, maintaining a parallel or approximately parallel relationship. The electron beams E generated by electron emission regions 11, 12, 13, etc. generate N X-ray target points 21, 22, 23, etc. at different locations on anode 2. In the present invention, an X-ray source that generates multiple X-ray target points at different locations on the anode is referred to as a distributed X-ray source.

FIG9 is a schematic diagram of a distributed X-ray source in the present invention, wherein the anode has a plurality of target materials. As shown in FIG9 , the anode 2 of the distributed X-ray source contains at least two different target materials, which can generate X-rays with different comprehensive energies at different target locations. X-rays are a continuous energy spectrum, and the concept of "comprehensive energy" is used here to illustrate the comprehensive effect reflected by the change in the proportion of X-rays of various energies. The electron source 1 includes at least two electron emission regions, and the electron beam emitted by each electron emission region forms an X-ray target at a different position of the anode 2. By setting different target materials at different target positions of the anode 2, since different materials have different identification spectra, X-rays with different comprehensive energies can be obtained. For example, the anode 2 is based on molybdenum material, and on the surface of the anode 2 (the surface opposite to the electron source 1), a tungsten target material with a thickness of 200 μm is sputtered and deposited at target positions 21, 23, 25... opposite to the electron emission regions 11, 13, 15..., and a copper target material with a thickness of 200 μm is sputtered and deposited at target positions 22, 24, 26... opposite to the electron emission regions 12, 14, 16... When the X-ray source operates at the same anode voltage, the intensity and energy of the electron beam E generated by each electron emission region are the same, but the comprehensive energy of the X-ray X1 generated by the target positions 21, 23, 25... (tungsten target material) is higher than the comprehensive energy of the X-ray X2 generated by the target positions 22, 24, 26... (copper target material).

In addition, Figure 10 is a schematic diagram illustrating the three operating modes of the distributed X-ray source of the present invention. As shown in Figure 10, the distributed X-ray source using the electron source 1 of the present invention has multiple operating modes and produces a variety of beneficial effects. A typical internal structure of a distributed X-ray source is as follows: the multiple electron emission regions 11, 12, 13, etc. of the electron source 1 have the same elongated rectangular shape and are neatly and evenly arranged linearly along their narrow sides within the same plane. When the number of electron emission regions is large (for example, dozens to thousands), the electron source 1 also has an elongated rectangular shape, with its long sides perpendicular to those of the electron emission regions. The corresponding anode 2 is also elongated and aligned vertically with the electron source 1, parallel to it. This distributed X-ray source can have multiple operating modes and exhibit a variety of beneficial effects.

The first type of operating mode is Mode A. N electron emission regions 11, 12, 13, etc., each independently emit electrons, generating X-rays at N corresponding positions on the anode 2, forming N target points. For example, in the first mode, each electron emission region sequentially generates electron beam emissions for a certain duration T according to its arrangement position. That is, under the control of the electron source control device 4: ① Electron emission region 11 emits an electron beam, generating X-rays at position 21 of the anode 2, and after a period of time T, the emission stops; ② Electron emission region 12 emits an electron beam, generating X-rays at position 22 of the anode 2, and after a period of time T, the emission stops; ③ Electron emission region 13 emits an electron beam, generating X-rays at position 23 of the anode 2, and after a period of time T, the emission stops; and so on. After all electron emission regions have completed a single electron emission, the cycle starts again from ① and continues. The second method: partially spaced electron emission areas generate electron beam emissions of a certain duration T in sequence, that is, under the control of the electron source control device 4: ① the electron emission area 11 emits an electron beam, generates X-ray emission at position 21 of the anode 2, and stops emitting after a period of time T; ② the electron emission area 13 emits an electron beam, generates X-ray emission at position 23 of the anode 2, and stops emitting after a period of time T; ③ the electron emission area 15 emits an electron beam, generates X-ray emission at position 25 of the anode 2, and stops emitting after a period of time T; ..., and so on, until the end of the electron source, and then this part of the electron emission area can emit again, or another part (12, 14, 16, ...) can emit, and form a cycle. The third method: some electron emission areas form a combination, and each combination generates electron beam emission for a certain duration T in turn, that is, under the control of the electron source control device 4: ① The electron emission areas 11, 14, and 17 emit electron beams, and generate X-ray emissions at positions 21, 24, and 27 of the anode 2 respectively. After a period of time T, the emission stops; ② The electron emission areas 12, 15, and 18 emit electron beams, and generate X-ray emissions at positions 22, 25, and 28 of the anode 2 respectively. After a period of time T, the emission stops; ③ The electron emission areas 13, 16, and 19 emit electron beams, and generate X-ray emissions at positions 23, 26, and 29 of the anode 2 respectively. After a period of time T, the emission stops; ..., and so on, until all combinations complete electron emission and form a cycle. In mode A, each electron emission region is independently controlled and generates an independent target corresponding to the electron emission region. Each electron emission region has a larger width, for example, 2 mm, and a larger emission current, for example, greater than 1.6 mA. The spacing between adjacent electron emission regions is larger, for example, d = 2 mm, and the corresponding targets are larger in spacing (for example, the center distance is 2 + 2 = 4 mm) and clearly positioned, which are easy to control and use.

The second operating mode is Mode B. N electron emission regions 11, 12, 13, etc., are grouped in adjacent, non-overlapping groups to emit electrons. This allows X-rays to be generated at N/n corresponding locations on the anode, forming N/n target points. For example, electron emission regions (11, 12, 13) form Group 1, electron emission regions (14, 15, 16) form Group 2, and electron emission regions (17, 18, 19) form Group 3, etc. These new N/n = N/3 groups (1, 2, 3, etc.) can operate in various ways as in Mode A. The advantages of operating mode B are that, on the one hand, the combination of electron emission regions increases the intensity of the emission current, and the X-ray intensity at each target point also increases. n can be set according to the specific application of the distributed X-ray source to achieve the required electron beam emission intensity. On the other hand, the width of each electron emission region can be further reduced, and a larger number of electron emission regions can be combined into a group. If an electron emission region fails (for example, a short circuit occurs in a micro-electron emission unit), the group can be removed from the group, and the group will still function normally, with the emission current decreasing by 1/n. This decrease can be easily compensated by adjusting parameters, so that the entire distributed X-ray source still has N/n targets. This means that "black spots" (similar to black lines on a monitor) will not be generated due to the failure of a single electron emission region. Avoiding "black spots" not only eliminates blind spots in X-ray targets and reduces failures, but also extends the service life of the distributed X-ray source if a few electron emission units prematurely age and fail. Of course, the number of combinations n in this mode can be fixed or non-fixed, such as some are in groups of 3, some are in groups of 5, etc. N/n only indicates that the number of groups and the number of targets is the number of electron emission areas N divided by a certain combination factor n.

The third operating mode is Mode C. N electron emission regions 11, 12, 13, etc. are arranged in groups with n adjacent regions overlapping a times, emitting electrons. X-rays are generated at corresponding positions on the anode, forming target points. Here, represents the integer value of the result. For example, when n = 3 and a = 2, electron emission regions (11, 12, 13) form group ①, electron emission regions (12, 13, 14) form group ②, and electron emission regions (13, 14, 15) form group ③, and so on. This creates N-2 groups ①, ②, ③, etc., which can operate in various ways described in Mode A. The advantages of operating mode C include the increased electron beam intensity and the elimination of target "black spots" caused by failures in individual electron emission areas, as described in mode B. Furthermore, mode C offers a greater number of targets and a smaller target center-to-center spacing compared to mode B (adjacent targets and electron emission areas partially overlap). This is also beneficial for the application of distributed X-ray sources. The increased number of targets increases the number of viewing angles, significantly improving the image quality of imaging systems using these distributed X-ray sources. As with mode B, factors n and a can be non-fixed values and simply refer to a specific calculation method. This indicates that mode C has fewer targets than mode A but more than mode B. The advantage is that the electron emission current is greater than in mode A and "black spots" are avoided.

Wherein, N is a positive integer of , n is a positive integer of , and a is a positive integer of .

In addition, the operating mode of the X-ray source of the present invention is not limited to the above three modes, as long as it can make the electron emission area of the electron source 1 emit electrons in a predetermined order, or make a predetermined number of adjacent electron emission areas of the electron source 1 emit electrons in a predetermined order.

Furthermore, the arrangement of the electron emission regions of the electron source 1 described above is merely an example of a specific structure. The arrangement can also include electron emission regions of different shapes, a non-uniform arrangement, a multi-dimensional arrangement (e.g., a 4×100 array), or an arrangement that is not on the same plane, all of which are possible implementations of the electron source 1 of the present invention. The corresponding anode 2 has a structure and shape that matches the arrangement of the electron emission regions. For example, various arrangements are disclosed in patent documents CN203377194U, CN203563254U, CN203590580U, and CN203537653U. In the present invention, the electron emission regions can also be arranged in the same manner as disclosed in these patent documents.

Figure 11 is a schematic diagram of a distributed X-ray source with a specific structure, according to the present invention. As shown in Figure 11 , when the electron emission region of the electron source 1 has a relatively large macroscopic width, for example, 2 mm to 40 mm, and is of a similar order of magnitude to the distance between the electron source 1 and the anode 2 (for example, when the ratio of the distance between the electron source 1 and the anode 2 to the width of the electron emission region is less than 10), the surface of the electron emission region is curved in the width direction (left-right in Figure 11 ), resulting in better focusing of the electrons emitted by each micro-electron emission unit 100 within the electron emission region. The curvature of the electron emission region's surface can be arranged around the corresponding target point on the anode 2 as the center. For example, when the electron beam E emitted by the electron emission region 11 forms a target point 21 on the anode 2, the surface of the electron emission region 11 in the width direction (or cross-section) lies on an arc centered at the center of point 21.

Figure 12 is a schematic diagram of a distributed X-ray source with a focusing device. As shown in Figure 12, the distributed X-ray source also includes a focusing device 6. Multiple focusing devices 6 are arranged corresponding to the electron emission regions and are located between the electron source 1 and the anode 2. The focusing device 6 can be, for example, an electrode or a coil capable of generating a magnetic field. When the focusing device 6 is an electrode, it can be connected to an external power source (or control system, not shown) via a focusing cable and connection device (not shown) to obtain a pre-applied voltage (potential). This causes the electrons generated by each micro-emitting unit 100 to converge toward the center when passing through the focusing device 6. When the focusing device 6 is an electrode, it can also be an electrode insulated from other components. When each micro-emitting unit 100 emits electrons, a portion of the electrons generated by micro-emitting units 100 located at the edge of the emission region are intercepted by the focusing electrode, forming static electricity. This static electricity field then exerts a force on subsequent electrons passing through the focusing device 6 to converge toward the center. When the focusing device 6 is a coil, it can be connected to an external power source (or control system, not shown) via a focusing cable and connection device (not shown). This allows a predetermined current to flow through the coil, generating a focusing magnetic field of a predetermined strength above the emission region. This allows the electrons generated by each micro-emission unit 100 to be concentrated toward the center when passing through the focusing device 6. In the present invention, the focusing device is characterized by being arranged in a one-to-one correspondence with each electron emission region and surrounding all micro-emission units 100 within that region above the electron emission region. The focusing cable, connection device, and external power source (or control system, not shown) are well-established technologies.

Figure 13 is a schematic diagram of several collimation effects of a distributed X-ray source. As shown in Figure 13, the distributed X-ray source also includes a collimator 7, which is arranged in the X-ray output path and is used to output X-rays in a conical, fan-shaped, pencil-shaped, or multi-point parallel shape. The collimator 7 can be an internal collimator installed inside the distributed X-ray source or an external collimator installed outside the distributed X-ray source. The material of the collimator 7 is typically a high-density metal material, such as one or more of tungsten, molybdenum, depleted uranium, lead, and steel. The shape of the collimator 7 is generally designed according to the purpose of the distributed X-ray source. For ease of description, a coordinate system is defined, with the length direction of the distributed X-ray source (the direction of target arrangement) being the X direction, the width direction being the Y direction, and the X-ray emission direction being the Z direction. As shown in Figure 13(A), the collimator 7 is positioned in front of the distributed X-ray source (in the direction of X-ray output) and has a relatively wide X-ray collimation slit inside. The length of the collimation slit is close to the target distribution length of the distributed X-ray source. The collimator outputs a cone-shaped X-ray beam with a large angle in the X direction and a relatively large angle in the Y direction (Figure 13(A) shows only the cone-shaped X-ray beam generated by a target point in the middle). As shown in Figure 13(B), the collimator 7 is positioned in front of the distributed X-ray source and has a very narrow X-ray collimation slit inside. The length of the collimation slit is close to the target distribution length of the distributed X-ray source. The collimator outputs a fan-shaped X-ray beam in the X-Z plane, that is, with a very small thickness in the Y direction (Figure 13(B) shows only the fan-shaped X-ray beam generated by a target point in the middle). As shown in Figure 13(C), the collimator 7 is positioned in front of the distributed X-ray source. The internal X-ray collimation slits are a series of thin slits with a certain width (in the Y direction) aligned with the target point arrangement. The length of the collimation slits is close to the target point distribution length of the distributed X-ray source. The collimator outputs an X-ray beam array with a certain divergence angle in the Y direction and a certain thickness in the X direction. In the X-Z plane, it is a multi-point parallel X-ray beam. As shown in Figure 13(D), the collimator 7 is positioned in front of the distributed X-ray source. The internal X-ray collimation slits are a series of small holes aligned with the target point arrangement. The length of the collimation slits is close to the target point distribution length of the distributed X-ray source. The collimator outputs an array of X-ray spot beams in the X-Y plane. Each spot beam is a pencil-shaped X-ray beam coaxial with the Z direction. The collimator 7 shown in Figures 13 (A), (B), (C), and (D) is located outside the radiation source, restricting the shape of the X-ray beam along its output path. Alternatively, the collimator 7 can be installed inside the radiation source, that is, between the anode 2 and the vacuum box 3, either near the anode 2 or near the wall of the vacuum box 3. Similarly, it restricts the shape of the X-ray beam along its output path. Installing the collimator inside the radiation source can reduce size and weight, and in some cases, achieve better collimation.

Figure 14 is a schematic diagram of a ring-shaped distributed X-ray source. As shown in Figure 14, a distributed X-ray source has its targets arranged in the shape of a circle or an arc segment. Figure 14 illustrates a distributed X-ray source in the shape of a ring. The multiple electron emission regions of electron source 1 are arranged in a circle, and the corresponding anode 2 is also a circle. The vacuum box 3 is a ring surrounding the electron source 1 and anode 2, with the center of the ring being O. The generated X-rays are directed toward the center O or the axis around O. The shape of a distributed X-ray source can also be an ellipse, a three-quarter circle, a semicircle, a quarter circle, or an arc segment at other angles.

Figure 15 is a schematic diagram of a distributed X-ray source in the form of a square. As shown in Figure 15, a distributed X-ray source has targets arranged in the shape of a square, a broken line segment, or a straight line. Figure 15 illustrates a distributed X-ray source in the form of a square. The multiple electron emission regions of the electron source 1 are arranged in a square, and the corresponding anode 2 is also a square. The vacuum box 3 is a square surrounding the electron source 1 and anode 2, with the generated X-rays directed toward the interior of the square. Distributed X-ray sources can also take the form of a U-shape (3/4 square), an L-shape (half square), a straight line segment (1/4 square), a regular polygon, or other broken line segments connected at non-right angles.

Figure 16 is a schematic diagram of several cross-sectional structures of a distributed X-ray source. As shown in Figure 16, the target on the anode 2 of the distributed X-ray source is a transmission target, and can also be a reflection target.

Figure 16(A) illustrates a distributed X-ray source in which the anode target is a transmission target, meaning that the direction of the output X-rays is substantially the same as the direction of the incident electron beam E. In conjunction with Figure 14 , Figure 16(A) can be understood as follows: the multiple electron emission regions of electron source 1 are arranged on an outer circle, with the surfaces of the electron emission regions parallel to the axis of the ring; the multiple target points of anode 2 are arranged on an inner circle, with the two circles concentric; the vacuum box 3 is a hollow ring surrounding the electron source 1 and anode 2; the target points of anode 2 are very thin, for example, less than 1 mm; and the electron beam E and X-rays are both directed toward the center O of the ring. Combined with Figure 15, Figure 16 (A) can be understood as that the multiple electron emission regions of the electron source 1 are arranged on the outer square, and the surface of the electron emission region is parallel to the center line of the square, and the multiple target points of the anode 2 are arranged on the inner square, and the centers of the two squares coincide. The vacuum box 3 is a hollow annular square surrounding the electron source 1 and the anode 2. The target position of the anode 2 has a very thin thickness, for example, less than 1 mm, and the directions of the electron beam E and the X-rays are both pointing to the inside of the square.

Figure 16(B) illustrates a distributed X-ray source with a reflective anode target. Specifically, the direction of the output X-rays forms a 90-degree angle (approximately 90 degrees) with the direction of the incident electron beam E. This angle can range from 70 to 120 degrees, preferably from 80 to 100 degrees. In conjunction with Figure 14, Figure 16(B) can be understood as the arrangement of the multiple electron emission regions of electron source 1 on a circle, with the surface of the electron emission regions perpendicular to the axis O of the circle. The multiple target points of anode 2 are arranged on another circle, with both circles of equal size, their centers on the axis of the circle, and their planes parallel. Alternatively, anode 2 can be tilted at a certain angle (e.g., 10 degrees) relative to electron source 1, such that the surface on which the multiple target points of anode 2 are arranged forms a conical surface, with the axis of the cone coinciding with the axis of the circle. The vacuum box 3 is a hollow ring surrounding the electron source 1 and anode 2. The direction of the electron beam E is parallel to the axis, and the X-rays are directed toward the center O of the ring. Combined with Figure 15 , Figure 16 (B) can be understood as the arrangement of multiple electron emission regions of electron source 1 in a square, with the surface of the electron emission regions perpendicular to the centerline O of the box. Multiple targets of anode 2 are arranged in another square, with the two squares being equal in size and their planes parallel. Alternatively, anode 2 can be tilted at a certain angle (e.g., 10 degrees) relative to electron source 1, such that the surface on which the multiple targets of anode 2 are arranged forms a square cone, with the centerline of the cone coinciding with the centerline of the box. Vacuum box 3 is a hollow, annular box surrounding electron source 1 and anode 3. The electron beam E is arranged in a square parallel to the centerline of the box, with the X-rays directed toward the interior of the box.

In addition, the light source shown in FIG16 (C) is also a transmission target. Compared with FIG16 (A), the only difference is that the arrangement of the electron source 1 and the anode 2 inside the ring (or frame) is different, from the inner and outer circles (or the inner and outer squares) to the front and back circles (or the front and back squares). The directions of the electron beam E and the X-rays are parallel to the axis of the ring (or the center line of the frame), that is, the distributed X-rays are emitted toward the side of the ring (or the side of the frame).

In addition, the light source shown in FIG16 (D) is also a reflection target. Compared with FIG16 (B), the only difference is that the arrangement of the electron source 1 and the anode 2 inside the ring (or frame) is different, from the front and back circles (or the front and back squares) to the inner and outer circles (or the inner and outer squares). The direction of the electron beam E is perpendicular to the axis of the ring (or the center line of the frame), and the direction of the X-ray is parallel to the axis of the ring (or the center line of the frame), that is, the distributed X-rays are emitted toward the side of the ring (or the side of the frame).

Strictly speaking, only FIG16(A) corresponds to FIG14 and FIG15 , and FIG16(B) is a combined illustration of FIG14 and FIG15 only for the convenience of better describing FIG16(B) .

In addition, the shape of the distributed X-ray source can also be a combination of the above-mentioned arc segments and straight line segments, a spiral line, etc., which are all processable with modern processing technology.

Figure 17 is a schematic diagram of a transmission imaging system using a distributed X-ray source according to the present invention. The transmission imaging system shown in Figure 17 includes: at least one X-ray source 81 according to the present invention, configured to generate X-rays covering an inspection area; at least one detector 82, located on the other side of the inspection area relative to the X-ray source 81, configured to receive the X-rays; and a conveyor 84, located between the X-ray source 81 and the detector 82, configured to carry an inspection object 83 through the inspection area.

Specific solution 1: A single X-ray source with an electron-emitting region forming an X-ray target is used, and multiple detectors are provided, forming a linear array or a planar array (or planar detectors). This structure is similar to existing X-ray fluoroscopic imaging systems. This solution is simple, compact, and low-cost. Furthermore, the field emission X-ray source of the present invention offers the advantages of low control voltage and fast startup.

Specific solution 2: A single X-ray source with two electron-emitting regions, each made of different target materials, alternately produces X-ray beams of varying energies. Multiple detectors are provided, forming a linear array or a planar array (or planar detectors), or even dual-energy detectors. This solution offers a simple structure, compact size, and low cost. Furthermore, dual-energy imaging enhances the ability to identify the material of the object being inspected.

Specific solution three: The X-ray source is a distributed X-ray source with multiple X-ray targets and multiple detectors, forming a linear array or a planar array (or a planar array of detectors). These multiple targets perform fluoroscopic imaging of the object at different angles (positions), ultimately producing a fluoroscopic image with multi-layered information in the depth direction. This solution offers a simpler structure, smaller size, and lower cost than a multi-view system using multiple conventional X-ray sources.

Specific solution 4: The X-ray source is a distributed X-ray source with multiple X-ray targets and one or a few detectors. Fluoroscopic images are obtained using the "reverse" imaging principle. This solution features a reduced number of detectors and lower costs.

Specific solution five: The X-ray source is one or more distributed X-ray sources, and the detectors are one or more corresponding arrays. All X-ray targets surround the object under inspection, with an angle exceeding 180 degrees. This solution, through the large-angle arrangement of static X-ray sources, can obtain a complete 3D perspective image of the inspection object, while also providing fast and efficient inspections.

Specific solution six: Multiple distributed X-ray sources and corresponding arrays of detectors are arranged on multiple planes along the direction of travel of the object being inspected. This approach can exponentially increase inspection speed, generate multi-energy 3D perspective images using X-rays of varying energies in different planes, or improve image quality in a progressive manner. For example, a rough inspection in the first plane can identify suspicious areas, while a second plane uses different parameters to perform a detailed inspection of these areas, resulting in high-resolution and clear images.

Figure 18 is a schematic diagram of a backscatter imaging system using a distributed X-ray source according to the present invention. The backscatter imaging system shown in Figure 18 includes: at least one distributed X-ray source 81 according to the present invention, configured to generate multiple pencil-shaped X-ray beams covering an inspection area; and at least one detector 82, located on the same side of the inspection area as the X-ray source 81, configured to receive X-rays reflected from an object under inspection.

Specific solution 1: It also includes a conveying device 84 for carrying the object to be detected 83 through the detection area to complete the overall imaging of the object to be detected.

Specific solution 2: It also includes a motion device for moving the distributed X-ray source 81 and the detector 82 so that the detection area sweeps across the object to be detected, completing the overall imaging of the object to be detected.

Specific solution three: There are at least two groups of distributed X-ray sources 81 and detectors 82, which are distributed on different sides of the object to be inspected. The object to be inspected is moved by a conveying device or the X-ray source is moved by a motion device to achieve "no blind spot" imaging of the object to be inspected.

Furthermore, an X-ray detection system is provided, comprising: at least two distributed X-ray sources of the present invention; at least two sets of detectors corresponding to the X-ray sources; and an image integration processing system. At least one set of the distributed X-ray sources and detectors performs fluoroscopic imaging of the detection object, and at least one set of the distributed X-ray sources and detectors performs backscatter imaging of the detection object. The image integration processing system integrates the fluoroscopic and backscatter images to obtain more characteristic information of the detection object.

In addition, it should be pointed out that the above-mentioned perspective imaging and backscatter imaging systems can be arranged in a common ground form, or can be integrated into mobile devices, such as vehicles, to become mobile perspective imaging systems and mobile backscatter imaging systems.

In addition, it should be pointed out that the detection objects of the above-mentioned perspective imaging and backscatter imaging systems have a broad meaning. With or without adding auxiliary components, they can be used to inspect small vehicles, cargo, luggage, parcels, mechanical parts, industrial products, personnel, body parts, etc.

In addition, a real-time image-guided radiotherapy device is provided, comprising: a radiotherapy radiation source for generating a radiation beam for radiotherapy of a patient; a multi-leaf collimator for adjusting the shape of the radiotherapy radiation beam to match the lesion; a movable bed for moving and positioning the patient so that the position of the radiotherapy radiation beam is aligned with the position of the lesion; at least one distributed X-ray source according to the present invention for generating a radiation beam for diagnostic imaging of the patient; a flat-panel detector for receiving the diagnostic imaging radiation beam; and a control system for forming a diagnostic image based on the radiation beam received by the flat-panel detector, locating the lesion in the diagnostic image, guiding the center of the radiotherapy radiation beam to align with the center of the lesion, and guiding the shape of the multi-leaf collimator radiation beam to match the shape of the lesion. The distributed X-ray source is an annular or square-shaped distributed X-ray source that outputs X-rays from the side (as shown in Figures 16(C) and (D)). The axis or centerline of the distributed X-ray source is collinear with the beam axis of the therapeutic radiation source, i.e., the diagnostic radiation source and the therapeutic radiation source are positioned in the same direction relative to the patient. The flat-panel detector is located on the opposite side of the patient from the diagnostic radiation source. This allows for simultaneous image acquisition and image-guided radiotherapy (IGRT) without rotating the radiotherapy arm. This provides real-time IGRT, significantly reducing radiation dose and exposure to normal organs in areas with physiological motion, such as the lungs and heart. Furthermore, the distributed X-ray source of the present invention has multiple targets, and the resulting images, unlike conventional two-dimensional images, are "stereoscopic" diagnostic images with depth information. This further improves the accuracy of the guidance and positioning of the therapeutic beam during IGRT.

As described above, the invention of this application has been described, but the present invention is not limited to this. It should be understood that various combinations, various changes, and devices, equipment, or systems that apply the electron source of the present invention or the X-ray source of the present invention are all within the scope of protection of the present invention as long as they are within the scope of the purpose of the present invention.

Claims (41)

1. An electronic source, characterized in that, It has at least two electron emission regions, each of which contains multiple micro electron emission units. The micro electron emission unit includes: a base layer, an insulating layer on the base layer, a gate layer on the insulating layer, an opening penetrating the gate layer and the insulating layer and reaching the base layer, and an electron emitter fixed on the base layer corresponding to the position of the opening. The micro-electron emitting units within the same electron emitting region are electrically connected, and may emit electrons simultaneously or not emit electrons at the same time. The different electron emission regions are electrically isolated. The electron emitter is composed of nanomaterials. The space occupied by the micro-electron emission unit in the array arrangement direction is on the micrometer scale. The opening in the insulating layer is larger than the opening in the gate layer. The size of the opening is smaller than the thickness of the insulating layer. The height of the electron emitter is less than half the thickness of the insulating layer. 2. The electronic source as described in claim 1, characterized in that, Electrical isolation between different electron emission regions means that the base layer of each electron emission region is separate and independent, or the gate layer of each electron emission region is separate and independent, or both the base layer and the gate layer of each electron emission region are separate and independent. 3. The electronic source as described in claim 1, characterized in that, The thickness of the insulating layer is less than 200 μm. 4. The electronic source as described in claim 1, characterized in that, The gate layer is parallel to the base layer. 5. The electron source according to any one of claims 1 to 4, characterized in that, The size of the opening is smaller than the distance from the electron emitter to the gate layer. 6. The electron source according to any one of claims 1 to 4, characterized in that, The nanomaterial is a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, or a combination thereof. 7. The electron source according to any one of claims 1 to 4, characterized in that, The base layer consists of a base layer and a conductive layer located on the base layer. The electron emitter is fixed on the conductive layer. 8. The electron source as claimed in claim 7, wherein the electron emitter is configured such that the conductive layer is a film made of nanomaterials, such that a portion of the nanomaterials of the nanofilm at the opening is upright and perpendicular to the surface of the conductive layer. 9. The electron source according to any one of claims 1 to 4, characterized in that, The space occupied by the micro electron emission unit in the array arrangement direction ranges from 1μm to 200μm. 10. The electron source according to any one of claims 1 to 4, characterized in that, The ratio of the length to the width of the electron emission region is greater than 2. 11. The electron source according to any one of claims 1 to 4, characterized in that, The emission current of each electron emission region is greater than 0.8 mA. 12. An X-ray source, characterized in that it comprises: Vacuum box; The electron source as described in any one of claims 1 to 11 is disposed within the vacuum chamber; The anode is disposed within the vacuum chamber opposite to the electron source; An electron source control device for applying a voltage between the base layer and the gate layer of the electron emission region of the electron source; and A high-voltage power supply, connected to the anode, is used to provide high voltage to the anode. 13. The X-ray source as described in claim 12, characterized in that it further comprises: A first connecting device, mounted on the wall of the vacuum chamber, is used to connect the electronic source and the electronic source control device; and The second connecting device is installed on the wall of the vacuum box and is used to connect the anode and the high-voltage power supply. 14. The X-ray source as described in claim 12, characterized in that, The target material at the target point position corresponding to each electron emission region of the electron source at the anode is different. 15. The X-ray source as described in claim 12, characterized in that, The electron source control device controls the electron emission region of the electron source to emit electrons in a predetermined sequence. 16. The X-ray source as described in claim 12, characterized in that, The electron source control device controls the electron source so that a predetermined number of adjacent electron emission regions emit electrons in a predetermined order. 17. The X-ray source as claimed in claim 12, characterized in that, The surface of the electron emission region is arc-shaped in the width direction, and the electrons emitted by each of the micro electron emission units in the electron emission region are focused towards a point in the width direction. 18. The X-ray source according to any one of claims 12 to 17, characterized in that, It also includes: multiple focusing devices, each corresponding to one of the multiple electron emission regions, disposed between the electron source and the anode. The focusing device surrounds all the micro-electron emitting units within the electron emission region above the electron emission region. 19. The X-ray source as described in claim 18, characterized in that, The focusing device is an electrode or a coil. 20. The X-ray source according to any one of claims 12 to 17, characterized in that, It also includes a collimation device, disposed inside or outside the X-ray source, located in the output path of the X-ray, for making the output X-rays into a predetermined shape. 21. The X-ray source according to any one of claims 12 to 17, characterized in that, The target points on the anode are arranged in a circular or arc shape. 22. The X-ray source according to any one of claims 12 to 17, characterized in that, The target points on the anode are arranged in a square, a broken line, or a straight line with the first and last points adjacent to each other. 23. The X-ray source according to any one of claims 12 to 17, characterized in that, The anode target is a transmission target, and the X-rays it outputs are in the same direction as the electron beam from the electron source. 24. The X-ray source according to any one of claims 12 to 17, characterized in that, The anode target is a reflective target, and the X-rays it outputs form a 90-degree angle with the electron beam from the electron source. 25. A perspective imaging system, characterized in that it comprises: The X-ray source as described in any one of claims 12 to 24 is located on one side of the detection area and is used to generate X-rays covering the detection area; At least one detector, located on the side of the detection area opposite the X-ray source, is used to receive X-rays from the X-ray source; and A conveying device, located between the X-ray source and the detector, is used to carry the object to be detected through the detection area. 26. A backscatter imaging system, characterized in that it comprises: The X-ray source as described in any one of claims 12 to 24 is located on one side of the detection area and is used to generate X-rays covering the detection area; and A detector, located on the same side of the detection area as the X-ray source, is used to receive X-rays reflected back from the object being detected. 27. The backscatter imaging system as described in claim 26, characterized in that, A combination of at least two sets of the X-ray sources and the detectors is configured on different sides of the object being inspected. 28. The backscatter imaging system as described in claim 26 or 27, characterized in that, It also includes: a conveying device for carrying the object to be detected through the detection area. 29. The backscatter imaging system as described in claim 26 or 27, characterized in that, It also includes: a motion device for moving the X-ray source and the detector so that the X-ray source and the detector pass through the area where the object being detected is located. 30. An X-ray detection system, characterized in that it comprises: At least two X-ray sources as described in any one of claims 12 to 14; and The detector corresponding to the X-ray source At least one set of the X-ray sources and the detector perform transmission imaging on the object under test. At least one set of the X-ray sources and the detector perform backscatter imaging on the object under test. 31. A real-time image-guided radiotherapy device, characterized in that it comprises: A radiation source for radiotherapy, used to generate a beam of radiation to treat a patient. Multi-leaf collimators are used to adjust the shape of the radiotherapy beam to match the lesion; A mobile bed is used to move and position the patient so that the position of the radiotherapy beam is aligned with the position of the lesion. At least one X-ray source as described in any one of claims 12 to 14, i.e., a diagnostic X-ray source, is used to generate a beam of X-rays for diagnostic imaging of a patient. Flat panel detectors for receiving X-ray beams used in diagnostic imaging; and The control system forms a diagnostic image based on the X-ray beam received by the flat panel detector, locates the lesion in the diagnostic image, guides the center of the radiotherapy beam to align with the center of the lesion, and guides the shape of the treatment beam from the multi-leaf collimator to match the shape of the lesion. The X-ray source is a distributed X-ray source with a circular or square shape and side-emitting X-rays. The axis or center line of the distributed X-ray source is the same straight line as the beam axis of the radiotherapy X-ray source, that is, the positions of the diagnostic X-ray source and the radiotherapy X-ray source are in the same direction relative to the patient. 32. An electronic source, characterized in that, It has an electron emission region, which contains multiple micro electron emission units. The micro electron emission unit includes: a base layer; an insulating layer on the base layer; a gate layer on the insulating layer; an opening penetrating the gate layer and the insulating layer and reaching the base layer; and an electron emitter fixed on the base layer corresponding to the position of the opening. The micro-electron emitting units within the electron emitting region are electrically connected, and may emit electrons simultaneously or not emit electrons simultaneously. The electron emitter is composed of nanomaterials. The space occupied by the micro-electron emission unit in the array arrangement direction is on the micrometer scale. The opening in the insulating layer is larger than the opening in the gate layer. The size of the opening is smaller than the thickness of the insulating layer. The height of the electron emitter is less than half the thickness of the insulating layer. 33. The electronic source as described in claim 32, characterized in that, The thickness of the insulating layer is less than 200 μm. 34. The electronic source as described in claim 33, characterized in that, The size of the opening is smaller than the distance from the electron emitter to the gate layer. 35. The electron source according to any one of claims 32 to 34, characterized in that, The gate layer is parallel to the base layer. 36. The electron source according to any one of claims 32 to 34, characterized in that, The space occupied by the micro electron emission unit in the array arrangement direction ranges from 1μm to 200μm. 37. The electron source according to any one of claims 32 to 34, characterized in that, The ratio of the length to the width of the electron emission region is greater than 2. 38. The electron source according to any one of claims 32 to 34, characterized in that, The base layer consists of a base layer and a conductive layer located on the base layer. The electron emitter is fixed on the conductive layer. 39. The electron source according to any one of claims 32 to 34, characterized in that, The emission current in the electron emission region is greater than 0.8mA. 40. An X-ray source, characterized in that it comprises: Vacuum box; The electron source as described in any one of claims 32 to 39 is disposed within the vacuum chamber; The anode is disposed within the vacuum chamber opposite to the electron source; An electron source control device for applying a voltage between the base layer and the gate layer of the electron emission region of the electron source; and A high-voltage power supply, connected to the anode, is used to provide high voltage to the anode. 41. An X-ray imaging system, characterized in that it comprises: The X-ray source as described in claim 40; A detector for receiving X-rays generated by the X-ray source; Control and image display system.