X-ray source assembly and method of controlling the same

Abstract

The application provides an X-ray source assembly and a control method thereof. The X-ray source assembly comprises: an X-ray tube, the X-ray tube comprising M cathodes, a grid and an anode, the X-ray tube being controlled such that electrons emitted from the M cathodes pass through the grid to hit the anode to emit X-rays, wherein M is a positive integer greater than or equal to 2; an anode controller, the anode controller being connected to the anode and the M cathodes respectively, for generating an electric field applied between the anode and the M cathodes; and a cathode controller, the cathode controller being connected to the M cathodes and the grid respectively, for generating cathode-grid control voltages respectively applied between the M cathodes and the grid, wherein the cathode-grid control voltage applied to each cathode comprises N cathode-grid control voltage pulses, the N cathode-grid control voltage pulses being arranged at intervals in time sequence, and the amplitude values of at least two of the N cathode-grid control voltage pulses are not equal, wherein N is a positive integer greater than or equal to 2.

Description

Technical Field

[0001] This application relates to the field of X-ray source and X-ray control technology, specifically to an X-ray source assembly and its control method. Background Technology

[0002] X-ray sources, as the core of radiation imaging technology, are widely used in medical diagnosis (such as CT imaging), industrial non-destructive testing, and public safety inspection. Traditional X-ray sources mostly operate in continuous mode, but they face problems such as high ineffective radiation dose, large anode heat load, and susceptibility to motion artifacts. To reduce heat dissipation and eliminate the need for bulky mechanical rotating devices, pulsed-mode X-ray source technology, represented by distributed multifocal sources (i.e., multiple cathodes arranged in an array within a vacuum chamber), has developed rapidly in recent years. This technology achieves efficient, multi-view, beat-mode exposure imaging by controlling the rapid on / off switching of electrons emitted by each cathode.

[0003] Currently, the research and development of distributed multi-cathode X-ray sources generally focuses on the absolute stability of pulsed operation and the high consistency of beam output from each focal point as core technical goals. However, this conventional approach faces two prominent problems in practical applications: First, due to limitations in material properties and assembly processes, the emission characteristics of each cathode in a multi-cathode array may vary individually. To achieve constant output control across multiple focal points, traditional technologies typically require each cathode in the array to be equipped with a separate complete control circuit, high-voltage generation module, and signal sampling feedback loop. This traditional system architecture leads to a proportional increase in hardware size, wiring complexity, and manufacturing cost with the increase in the number of cathodes, limiting the large-scale application of multi-cathode X-ray sources. Second, in actual inspection scenarios, the material, density, and physical thickness distribution of the same object under inspection may be uneven. When a distributed multi-cathode array performs high-frequency alternating scanning of the object from multiple perspectives, the X-ray penetration path and resistance at different perspectives can change instantaneously. Multi-cathode X-ray sources are irradiated with a preset constant intensity pulse sequence. This results in the following: when the penetration path is short or the density is low, the constant X-ray intensity is relatively too strong, which can easily cause detector signal saturation and loss of structural details at that angle; while when the penetration path is long or the density is high, the constant X-ray intensity is relatively too weak, which causes the weak useful signal after penetration to be submerged by the system's background noise, and thus it is also impossible to extract effective image information. Summary of the Invention

[0004] In view of the above problems, embodiments of this application provide an X-ray source assembly and a control method thereof.

[0005] According to a first aspect of this application, an X-ray source assembly is provided, comprising: an X-ray tube including M cathodes, a grid, and an anode, the X-ray tube being controlled such that electrons emitted from the M cathodes pass through the grid and strike the anode to emit X-rays, wherein M is a positive integer greater than or equal to 2; an anode controller connected to the anode and the M cathodes respectively, for generating an electric field applied between the anode and the M cathodes, or the anode controller connected to the anode and the grid respectively, for generating an electric field applied between the anode and the grid; and a cathode controller connected to the M cathodes and the grid respectively, for generating a cathode grid control voltage applied between the M cathodes and the grid respectively, wherein the cathode grid control voltage applied to each cathode comprises N cathode grid control voltage pulses, the N cathode grid control voltage pulses being time-spaced, and at least two of the N cathode grid control voltage pulses having unequal amplitude values, wherein N is a positive integer greater than or equal to 2.

[0006] According to an embodiment of this application, the cathode controller is configured to include an output port selector, which is connected to the gate and the M cathodes respectively, and is used to select one of the M cathodes at a given time.

[0007] According to an embodiment of this application, the cathode controller is configured to generate the N cathode control voltage pulses based on the pulse operating characteristic parameters of the X-ray tube. The pulse operating characteristic parameters include a time parameter and an amplitude parameter. The time parameter is used to determine the timing sequence of the N cathode control voltage pulses, and the amplitude parameter is used to determine the amplitude value of the N cathode control voltage pulses.

[0008] According to an embodiment of this application, the cathode controller includes a timing generator and a cathode-gate voltage generator. The timing generator is used to generate a cathode trigger signal sequence according to the time parameter. The cathode-gate voltage generator is connected to the timing generator and is used to generate the N cathode-gate control voltage pulses according to the cathode trigger signal sequence and the amplitude parameter.

[0009] According to an embodiment of this application, the amplitude parameter is data that has a mapping relationship with at least one of the cathode control voltage, cathode emission current, anode operating current, and radiation intensity.

[0010] According to an embodiment of this application, the cathode controller is further configured to adjust the amplitude value of at least one of the N cathode control voltage pulses based on at least one of the cathode emission current, the anode operating current, and the radiation intensity.

[0011] According to an embodiment of this application, the cathode controller further includes a first memory and a first processor. The first processor is connected to the first memory, the timing generator, and the cathode-gate voltage generator, respectively. The first memory is used to store the pulse operating characteristic parameters. The first processor is configured to: read the pulse operating characteristic parameters stored in the first memory; instruct the timing generator to generate the cathode trigger signal sequence according to the time parameter in the pulse operating characteristic parameters; generate a serialized voltage amplitude command signal according to the amplitude parameter in the pulse operating characteristic parameters; and send the serialized voltage amplitude command signal to the cathode-gate voltage generator according to the time nodes in the cathode trigger signal sequence, so that the cathode-gate voltage generator generates the N cathode-gate control voltage pulses.

[0012] According to embodiments of this application, the time parameters include pulse width, pulse interval, and repetition period.

[0013] According to an embodiment of this application, the cathode trigger signal sequence has a pulse width that is the same as the pulse width in the time parameter, the rising edge of the pulse in the cathode trigger signal sequence is used to trigger the turn-on, and the falling edge of the pulse in the cathode trigger signal sequence is used to trigger the turn-off; or, the cathode trigger signal sequence has a pulse width that is different from the pulse width in the time parameter, the odd-numbered pulse signals in the cathode trigger signal sequence are used to trigger the turn-on, and the even-numbered pulse signals in the cathode trigger signal sequence are used to trigger the turn-off.

[0014] According to an embodiment of this application, the anode controller is connected to the timing generator, the timing generator is further configured to generate an anode trigger signal according to the time parameters, and the anode controller is configured to control the opening and closing of the high voltage output applied to the anode according to the anode trigger signal.

[0015] According to an embodiment of this application, the anode trigger signal is a wide pulse that includes the cathode trigger signal sequence in timing, and the anode controller is configured to: turn on the high voltage output applied to the anode at the rising edge of the wide pulse, and turn off the high voltage output applied to the anode at the falling edge of the wide pulse.

[0016] According to an embodiment of this application, the first processor is configured to read the pulse operating characteristic parameters stored in the first memory according to a preset clock cycle, and send the serialized voltage amplitude command signal to the cathode gate voltage generator according to the time node used to trigger the turn-on in the cathode trigger signal sequence.

[0017] According to an embodiment of this application, the first processor is configured to: when the pulse width of the cathode trigger signal sequence is the same as the pulse width in the time parameters, read the pulse operating characteristic parameters stored in the first memory in response to the falling edge of the pulse in the cathode trigger signal sequence, and send the serialized voltage amplitude command signal to the cathode-gate voltage generator in response to the rising edge of the next pulse in the cathode trigger signal sequence; or, the first processor is configured to: when the pulse width of the cathode trigger signal sequence is different from the pulse width in the time parameters, read the pulse operating characteristic parameters stored in the first memory in response to the even-numbered pulse signals in the cathode trigger signal sequence, and send the serialized voltage amplitude command signal to the cathode-gate voltage generator in response to the subsequent odd-numbered pulse signals in the cathode trigger signal sequence.

[0018] According to an embodiment of this application, the cathode controller further includes an input module for acquiring pulse operating characteristic parameters of the X-ray tube.

[0019] According to an embodiment of this application, the cathode-gate voltage generator includes a cathode-gate voltage sub-generator and a voltage regulator. The cathode-gate voltage sub-generator is used to generate the N cathode-gate control voltage pulses. The voltage regulator is connected to the timing generator, the first processor, and the cathode-gate voltage sub-generator, respectively. The voltage regulator is used to control the cathode-gate voltage sub-generator to output the N cathode-gate control voltage pulses according to the cathode trigger signal sequence and the voltage amplitude command signal.

[0020] According to an embodiment of this application, the X-ray source assembly further includes: an acquisition component for acquiring the actual operating parameters of the X-ray tube and generating measured values; and a feedback controller, the feedback controller being connected to the acquisition component and the first processor respectively, the feedback controller being configured to: convert the measured values ​​according to the mapping relationship between the measured values ​​and the amplitude parameters; compare the converted measured values ​​with the amplitude parameters; output a difference signal according to the comparison result; and output the difference signal to the first processor.

[0021] According to an embodiment of this application, the first processor is further configured to adjust the amplitude value of at least one voltage amplitude command in the serialized voltage amplitude command signal according to the difference signal.

[0022] According to an embodiment of this application, the acquisition component includes: a cathode current acquisition device disposed in the cathode controller for acquiring the emission current of the M cathodes; and / or an anode current acquisition device disposed in the anode controller for acquiring the operating current of the anode of the X-ray tube; and / or a sampling detector disposed outside the X-ray tube for acquiring the intensity of the radiation output by the X-ray tube.

[0023] According to embodiments of this application, the first memory pre-stores a parameter-voltage mapping relationship, which is used to map the amplitude parameter to the cathode-gate control voltage; the first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter and the parameter-voltage mapping relationship; or, the first memory pre-stores a parameter-cathode current mapping relationship and a cathode current-voltage mapping relationship, whereby the parameter-cathode current mapping relationship is used to map the amplitude parameter to the emission current of the M cathodes, and the cathode current-voltage mapping relationship is used to map the emission current of the M cathodes to the cathode-gate control voltage; the first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-cathode current mapping relationship, and the cathode current-voltage mapping relationship; or, the first memory pre-stores a parameter-anode current mapping relationship and an anode current-... The voltage mapping relationship, wherein the parameter-anode current mapping relationship is used to map the amplitude parameter to the operating current of the anode, and the anode current-voltage mapping relationship is used to map the operating current of the anode to the cathode control voltage; the first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-anode current mapping relationship, and the anode current-voltage mapping relationship; or, the first memory pre-stores a parameter-ray intensity mapping relationship and a ray intensity-voltage mapping relationship, wherein the parameter-ray intensity mapping relationship is used to map the amplitude parameter to the ray intensity output by the X-ray tube, and the ray intensity-voltage mapping relationship is used to map the ray intensity output by the X-ray tube to the cathode control voltage; the first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-ray intensity mapping relationship, and the ray intensity-voltage mapping relationship.

[0024] According to an embodiment of this application, the X-ray tube includes M gates, each of which corresponds to one of the M cathodes to form M cathode-gate pairs; wherein, the output port selector is connected to each of the M gates, and the output port selector is configured to select one of the cathode-gate pairs corresponding to the cathode and the gate at a given time; or, the M gates are connected in series to the output port selector, and the output port selector is configured to select one of the M gates and the M cathodes at a given time.

[0025] According to an embodiment of this application, the X-ray tube includes M anode targets, the anode is connected to the anode controller, the M anode targets are disposed on the anode and correspond one-to-one with the M cathodes to form M cathode-anode target pairs, and the anode controller is used to generate an electric field applied between the M cathode-anode target pairs.

[0026] According to a second aspect of this application, a method for controlling an X-ray source assembly is provided, the X-ray source assembly including an X-ray tube, the X-ray tube including M cathodes, a grid, and an anode, the method comprising: generating N cathode-grid control voltage pulses according to pulse operating characteristic parameters of the X-ray tube to generate a cathode-grid control voltage, wherein the N cathode-grid control voltage pulses are time-sequentially arranged, at least two of the N cathode-grid control voltage pulses have unequal amplitude values, N is a positive integer greater than or equal to 2, and M is a positive integer greater than or equal to 2; applying the cathode-grid control voltage between the M cathodes and the grid to control the M cathodes to emit electrons; and applying an electric field between the anode and the M cathodes to control the electrons to pass through the grid and strike the anode to emit X-rays.

[0027] According to an embodiment of this application, the method further includes: acquiring at least one of a cathode control voltage, a cathode emission current, an anode operating current, and a radiation intensity; and adjusting the amplitude value of at least one of the N cathode control voltage pulses based on at least one of the cathode emission current, the anode operating current, and the radiation intensity.

[0028] According to an embodiment of this application, the X-ray source assembly further includes an output port selector, which is connected to the gate and the M cathodes respectively, and the method further includes: selecting one of the M cathodes at a certain time. Attached Figure Description

[0029] The above-mentioned contents, other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0030] Figure 1 The schematic diagram illustrates the structure of a radiographic inspection system according to some exemplary embodiments of this application;

[0031] Figure 2A This is a schematic diagram of an X-ray source assembly according to some exemplary embodiments of this application;

[0032] Figure 2B This is a schematic diagram of an X-ray source assembly according to other exemplary embodiments of this application;

[0033] Figure 3 This is a schematic diagram of an X-ray source assembly according to some other exemplary embodiments of this application;

[0034] Figure 4 This is a schematic diagram of an X-ray source assembly according to some further exemplary embodiments of this application;

[0035] Figure 5 This is a schematic diagram of an X-ray source assembly according to some further exemplary embodiments of this application;

[0036] Figure 6 This is a schematic diagram of an X-ray source assembly according to some other exemplary embodiments of this application;

[0037] Figure 7 This is a schematic diagram of an X-ray source assembly according to other exemplary embodiments of this application;

[0038] Figure 8 This is a timing diagram of the cathode trigger signal sequence generated by the timing generator in some embodiments of this application;

[0039] Figure 9 This is a timing diagram of the cathode control voltage output by the cathode voltage generator in some embodiments of this application;

[0040] Figure 10 This is a timing diagram of the electron beam output from the cathode in some embodiments according to this application;

[0041] Figure 11 This is a timing diagram of the X-ray output dose rate associated with the anode in some embodiments according to this application;

[0042] Figure 12 This is a timing diagram of the cathode trigger signal according to some embodiments of this application;

[0043] Figure 13 This is a timing diagram of the cathode trigger signal according to some other embodiments of this application;

[0044] Figure 14This is a timing diagram illustrating the X-ray output dose rate generation process according to some embodiments of this application. Figure 14 (a) in the diagram is the timing diagram of the anode voltage trigger signal. Figure 14 (b) in the diagram is the timing diagram of the anode voltage. Figure 14 (c) in the diagram is the timing diagram of the cathode trigger signal. Figure 14 (d) in the diagram is the timing diagram of the cathode gate control voltage. Figure 14 (e) Cathode current timing diagram, Figure 14 In the diagram, (f) represents the time series plot of ray intensity; and

[0045] Figure 15 This is a flowchart of a control method for an X-ray source assembly according to some exemplary embodiments of this application;

[0046] Figure 16 This is a flowchart illustrating an X-ray source assembly and a control method for the X-ray source assembly between two adjacent pulse timings, according to some exemplary embodiments of this application; and

[0047] Figure 17 This is a supplementary flowchart of a control method for an X-ray source assembly according to some exemplary embodiments of this application. Detailed Implementation

[0048] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0049] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0050] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0051] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0052] X-ray sources, as non-destructive penetrating radiation sources, have a wide range of applications, particularly in transmission imaging technologies in fields such as medical diagnostics (e.g., X-ray scanning, CT imaging), industrial non-destructive testing, and public safety inspections. From a basic physical perspective, an X-ray source typically consists of a cathode, a grid, and an anode located within a vacuum chamber. In some imaging systems designed to eliminate mechanical movement and achieve rapid multi-view imaging, multiple cathodes can be arrayed within the vacuum chamber to form a distributed multifocal X-ray source. The basic working principle of an X-ray source is as follows: the cathode emits electrons under controlled conditions. These electrons gain extremely high kinetic energy under the acceleration of the high-voltage electric field between the cathode and anode, and then collide at high speed with the anode target, generating X-rays through bremsstrahlung and characteristic radiation. In transmission imaging applications, X-rays with a certain initial intensity are attenuated to varying degrees when penetrating the object being inspected, due to the combined effects of the material, density, physical configuration, and thickness of different regions within the object. The detector at the back end collects the attenuated signals after penetration and, based on the signal strength distribution, can reconstruct image information reflecting the internal structural characteristics of the object being inspected.

[0053] In traditional X-ray imaging applications, to meet high-throughput requirements such as acquiring thousands of images from different angles in medical CT scans, conducting continuous inspections of large batches of products on industrial production lines, or continuously scanning packages on security conveyor belts, X-ray sources typically operate in continuous mode. In continuous mode, the X-ray source maintains a continuous X-ray output after a single voltage application, while the detector repeatedly performs the "signal acquisition-signal output" operation at a fixed operating frequency to form a continuous image sequence. However, with the upgrading of application requirements, the drawbacks of continuous mode have become increasingly apparent: First, continuous output means that the X-ray source is still emitting rays during the intervals between detector output signals (i.e., non-sampling time), which not only increases unnecessary radiation dose but also puts enormous thermal load pressure on the anode of the X-ray tube, limiting the peak power and lifespan of the equipment; second, to obtain projections from different angles, traditional single-cathode equipment relies on bulky devices such as mechanical slip rings for high-speed rotation, and continuous exposure is prone to producing motion artifacts in the imaging of moving objects, reducing spatial resolution. Therefore, in order to reduce ineffective radiation dose, control heat dissipation, and achieve precise dynamic exposure from multiple perspectives to freeze motion, the development of X-ray source technology that operates in pulse mode and has multiple cathode arrays has become a trend.

[0054] Pulsed X-ray source technologies include various pulsed X-ray source technologies such as grid-controlled hot cathodes, grid-controlled cold cathodes (e.g., carbon nanotube cold cathodes), and distributed multifocal systems. These technologies enable a new, highly efficient, time-lapse imaging mode where X-ray source pulse exposure and detector signal acquisition are synchronized, and the X-ray source stops exposure and detector output signals are synchronized. Currently, the main control method for traditional pulsed X-ray source technologies is to apply a specific control voltage between the grid and the cathode, utilizing the electric field to suppress or extract electron emission from the cathode surface to achieve rapid switching on and off of the electron beam, thereby generating pulsed X-rays. Especially in distributed multifocal systems, due to the slight differences in the material properties and assembly dimensions of each cathode, uneven beam intensity at each focus can easily occur. Therefore, to ensure imaging reliability, traditional technological development focuses on pursuing absolute stability of pulsed operation and consistency of beam output at each focus. Traditional X-ray sources typically incorporate cathode or anode current sampling mechanisms and construct negative feedback regulation loops. Their core technical objective and control logic are to compensate in real-time for the effects of cathode aging, temperature drift, or individual differences among multiple cathodes. This ensures that the operating current and X-ray intensity of each output pulse remain constant, striving for high consistency between multiple pulses and among the individual cathodes in the array. More challenging is that achieving this multi-focus constant current control may necessitate equipping each cathode with a separate complete control, voltage generation, and sampling loop, causing the hardware size and cost of multi-cathode systems to increase proportionally with the number of cathodes.

[0055] However, this traditional pulsed X-ray source technology, which aims for constant pulse intensity, reveals insurmountable technical contradictions and limitations when faced with complex and ever-changing real-world detection scenarios. Specifically, during continuous detection on the same device, the density, material, and thickness of the object being inspected may vary. For example, in medical CT scans, due to the elliptical cross-section of the human body and the uneven distribution of internal bones and soft tissues, the penetration resistance of X-rays differs at different rotation angles (i.e., when the beam exits from different cathode focal points in a multi-cathode array in turn). In security inspection scenarios, a single package may contain both extremely thin clothing and extremely dense metal components, causing instantaneous changes in the transmitted thickness from different perspectives. When an X-ray source (especially a distributed multi-cathode X-ray source performing high-frequency alternating beam scanning) irradiates with a constant-intensity pulse sequence, it faces a dilemma: for regions with low density and thinness or short penetration paths, the constant X-ray intensity is too strong, resulting in the amount of residual X-rays after penetration far exceeding the detector's range limit, causing detector signal saturation and loss of detailed features in that region; on the other hand, for regions with high density and thickness or extremely long penetration paths, the constant X-ray intensity is too weak, resulting in very little residual X-rays after penetration, causing useful weak signals to be drowned out by the system's background noise, making it impossible to extract effective structural information.

[0056] To address at least one aspect of the above-mentioned problems, embodiments of this application provide an X-ray source assembly and a control method thereof.

[0057] Figure 1 The schematic diagram illustrates the structure of a radiographic inspection system according to some exemplary embodiments of this application.

[0058] Embodiments of this application also provide a radiographic inspection system 1000, which may include a radiation source assembly and a detector. For example, the radiation source assembly of the radiographic inspection system 1000 may include a carbon nanotube cold cathode. The carbon nanotube cold cathode may be located on a substrate 19 and form a triode electron gun structure with a gate 12 and an anode 13. For example, the distance between the gate 12 and the activated carbon nanotube cold cathode is 150-300 μm. A certain voltage value is applied to the gate 12 to form a first electric field E1, the magnitude of which is 1-20 V / μm. When the voltage of the gate 12 generates an electric field threshold greater than the field emission threshold, the activated carbon nanotube cold cathode emits electrons 17. A certain voltage value is applied to the anode 13 to form a second electric field E2. The emitted electrons 17 are accelerated under the action of the second electric field E2 and bombard the anode target 14 to generate X-rays 18. After passing through the beryllium window 15, the X-ray 18 is received by the detector 16, and then processed and analyzed by devices such as the amplifier 7, oscilloscope 8, and computer 9 to achieve imaging or detection of the object.

[0059] Combined with reference Figure 2A , Figures 3 to 7 As shown, the X-ray source assembly includes: an X-ray tube 1, which includes M cathodes 11, a grid 12, and an anode 13. The X-ray tube 1 is controlled such that electrons emitted from the M cathodes 11 pass through the grid 12 and strike the anode 13 to emit X-rays, where M is a positive integer greater than or equal to 2; an anode controller 2, which is connected to the anode 13 and the M cathodes 11 respectively, for generating an electric field applied between the anode 13 and the M cathodes 11, or the anode controller 2 is connected to the anode 13 and the grid 12 respectively, for generating an electric field applied between the anode 13 and the grid 12; and a cathode controller 3, which is connected to the M cathodes 11 and the grid 12 respectively, for generating a cathode control voltage applied between the M cathodes 11 and the grid 12 respectively, wherein the cathode control voltage applied to each cathode 11 includes N cathode control voltage pulses, the N cathode control voltage pulses are time-spaced, and at least two of the N cathode control voltage pulses have unequal amplitude values, where N is a positive integer greater than or equal to 2.

[0060] In some specific embodiments, the M cathodes 11 can be arranged in an array within the vacuum cavity of the X-ray tube 1, for example, arranged along the electron beam emission direction or in a transverse array, and each of the M cathodes 11 can independently and controllably emit electrons. To ensure that at least two of the N cathode control voltage pulses have unequal amplitude values, the cathode controller 3 can include a programmable pulse generation circuit. This pulse generation circuit can generate a series of sequential voltage pulses according to a preset amplitude sequence. In some exemplary embodiments, such as... Figure 9As shown, in this pulse sequence, the amplitude of each cathode control voltage pulse can be individually set and adjusted according to the actual imaging requirements, thereby generating a sequence of N cathode control voltage pulses with different amplitudes. The amplitude values ​​of the first to the Nth cathode control voltage pulses can be characterized by the voltage amplitude of each cathode control voltage pulse. For example, assuming that three cathode control voltage pulses (i.e., N=3) need to be output in one local scanning cycle, and the amplitudes of these three cathode control voltage pulses correspond to low, medium, and high X-ray beam intensities, respectively, the cathode controller 3 will generate three cathode control voltage pulses corresponding to low, medium, and high amplitudes in sequence according to the amplitude sequence setting, and apply them as cathode control voltages between the cathode 11 and the grid 12 of the X-ray tube 1. By dynamically changing the electric field strength between the cathode 11 and the grid 12, the electron emission intensity of the corresponding cathode 11 can be controlled, thereby achieving pulse-by-pulse modulation of the X-ray beam intensity. During this operation, the anode controller 2 can be connected to the anode 13 and the M cathodes 11 via cables, thereby establishing a stable electrostatic field between the anode 13 and the M cathodes 11. The anode controller 2 consistently provides a stable electrostatic field between the anode 13 and the M cathodes 11. The magnitude of this stable electrostatic field is unaffected by the presence or variation of electron beam current between the cathodes 11 and the anode 13, thus ensuring the stability of the electron acceleration process within the vacuum chamber and preventing interference from pulse amplitude modulation. In other embodiments, please refer to [reference needed]. Figure 2B As shown, the anode controller 2 can be connected to the gate 12 and the anode 13 via a cable, thereby establishing a stable electrostatic field between the gate 12 and the anode 13. The magnitude of this stable electrostatic field is not affected by the presence or variation of the electron beam between the gate 12 and the anode 13. At the same time, it is understood that in some embodiments, the amplitude values ​​of multiple cathode control voltage pulses in these N cathode control voltage pulses may be equal.

[0061] According to the X-ray source assembly provided in this embodiment, by introducing a cathode controller 3 in the multi-cathode array structure that can output pulses of different amplitudes sequentially according to a preset sequence, independent control of the intensity of each output pulse of the X-ray source is achieved. This ability to modulate the amplitude of each pulse allows the X-ray source assembly to output the X-ray intensity that meets the current transmission detection requirements in real time, based on the thickness and density changes of different objects under inspection, or the same object under inspection at different scanning angles (i.e., when the cathode focal points at different positions in the multi-cathode array emit X-rays in turn). For example, when encountering a high-density, thick area under inspection or a scanning angle with a long penetration path, a high-intensity X-ray pulse can be output to ensure that the X-ray has sufficient penetrating power and avoid the useful signal after penetration being too weak and drowned out by background noise; conversely, when encountering a low-density, thin area under inspection or a scanning angle with a short penetration path, a low-intensity X-ray pulse is output to avoid excessive residual X-rays causing the received signal to become too strong and saturate, thereby losing detailed features. Therefore, by addressing the imaging quality issues of traditional pulsed X-ray sources, which suffer from local oversaturation or weak signals due to constant output intensity, the overall clarity and contrast of the target image can be improved.

[0062] In some exemplary embodiments, such as Figure 2A As shown, the cathode controller 3 includes an output port selector 39, which is connected to the grid 12 and the M cathodes 11. The output port selector 39 is used to select one of the M cathodes 11 at any given time. Specifically, the output port selector 39 can be regarded as a multiplexer switch, whose input terminal receives the cathode control voltage output from the cathode grid voltage generator 34 of the cathode controller 3, and whose output terminal is connected to the M cathodes 11 in the X-ray tube 1 through physical leads.

[0063] In some specific embodiments, a timing control signal generated internally by the cathode controller 3 instructs the output port selector 39 to perform channel switching in real time. Before or at the same time as each cathode control voltage pulse arrives, the output port selector 39 switches the voltage transmission channel to the target cathode 11 for the currently predetermined beam output. For example, during the first pulse cycle, the first cathode is selected; after the cathode control voltage pulse ends and enters the pulse interval (off-time), the channel is switched to the second cathode to prepare for receiving and transmitting the next cathode control voltage pulse; and so on, until the Mth cathode is connected, after which the cycle can be repeated according to scanning requirements.

[0064] In some specific embodiments, for example, using an X-ray tube 1 with M=3, if three cathode control voltage pulses of different amplitudes need to be applied sequentially to the three cathodes, the output port selector 39 will turn on the first cathode when the first cathode control voltage pulse is output, turn on the second cathode when the second cathode control voltage pulse is output, and turn on the third cathode when the third cathode control voltage pulse is output, thereby realizing time-division driving of the array focus. This gating mechanism allows a single cathode control voltage source to serve multiple cathodes 11 in a time-division manner, fundamentally avoiding the complexity and high cost of equipping each cathode 11 in a multi-cathode array with an independent voltage source, laying the foundation for subsequent large-scale expansion of multi-cathode arrays.

[0065] In some exemplary embodiments, such as Figure 2A , Figures 3 to 9 As shown, the cathode controller 3 is configured to generate N cathode control voltage pulses based on the pulse operating characteristic parameters of the X-ray tube 1. These pulse operating characteristic parameters include time parameters and amplitude parameters. The time parameters determine the timing sequence of the N cathode control voltage pulses, and the amplitude parameters determine the amplitude values ​​of the N cathode control voltage pulses. The pulse operating characteristic parameters are a set of preset control commands for the entire X-ray tube 1 containing M cathodes 11. These parameters control not only the number N of beam pulses emitted from each cathode 11, but also coordinate the activation sequence of each cathode 11 in the array and the specific operating intensity of each beam emission.

[0066] In some embodiments, the time parameters may include pulse width (on-time), pulse interval (off-time), the number of cathodes 11 involved in operation M, and the complete repetition period N; while the amplitude parameters refer to the amplitude setting matrix for generating a total of MN cathode control voltage pulses for N repetitions of M cathodes 11. For example, the amplitude parameter sequence for the first round is u11, u21, …, uM1; and the amplitude parameter sequence for the Nth round is u1N, u2N, …, uMN. The time parameters and amplitude parameters are coupled and jointly determine the start and stop timing of the beam output of each cathode 11 in the multi-cathode X-ray source array in a time-sharing manner. For example, in establishing the pulse timing, assuming that the pulse width on-time = 5 μs and the pulse interval off-time = 10 μs are set, then a pulse window will be generated every 15 μs on the time axis, and the effective beam output width of the cathode control voltage pulse is 5 μs. In a specific embodiment, refer to the following... Figure 8 The timing diagram of the cathode trigger signal sequence generated by the timing generator is shown below. Figure 8 The horizontal axis represents the time axis, with units in milliseconds (ms), and the vertical axis represents the pulse signal axis of the cathode voltage trigger signal. Figure 8The diagram schematically illustrates the pulses of the cathode trigger signals for three cathodes 11, where the time interval t=(1,3) represents the pulse width (on-time) of the first cathode trigger signal pulse, and the time interval t=(3,4) represents the pulse interval (off-time) between the pulses of the first cathode trigger signals of the first cathode 11 and the first cathode trigger signals of the second cathode. Within this timeframe, the amplitude parameter further determines the actual voltage height of the cathode control voltage pulse falling within each window: for example, a setting value u11=1000 for the first cathode represents an output amplitude value of 1000V within the first pulse window; immediately following, a setting value u21=1500 for the second cathode represents an output amplitude value jump to 1500V within the second pulse window, and so on. After sequentially traversing the parameter settings of M cathodes 11, the next repetition cycle begins, executing the next round of parameter calls. For example, refer to [reference needed]. Figure 9 As shown, Figure 9 The horizontal axis represents the time axis, and the vertical axis represents the amplitude of the cathode control voltage pulse, in volts (V). Figure 9 There are 3 cathode control voltage pulses in each round.

[0067] In some exemplary embodiments, such as Figure 2A , Figures 3 to 7 As shown, the cathode controller 3 includes a timing generator 33 and a cathode-gate voltage generator 34, which can be referred to in conjunction with the above. Figure 6 and Figure 7 As shown, timing generator 33 generates a cathode trigger signal sequence and an anode trigger signal based on time parameters. Cathode-gate voltage generator 34 is connected to timing generator 33 and generates cathode-gate control voltage pulses based on the cathode trigger signal sequence and amplitude parameters. Timing generator 33 and cathode-gate voltage generator 34 work together in hardware to reconstruct the pulse waveform. Specifically, timing generator 33 is responsible for generating a series of cathode trigger signals with time boundaries based on the received time parameters (e.g., on-time, off-time, and the number of cathodes 11, M). These trigger signals not only define when the future cathode-gate control voltage pulse should start and end on the time axis, but also implicitly contain timing synchronization information in the control logic regarding which specific cathode 11 the currently triggered cathode-gate control voltage pulse should be assigned to.

[0068] In some specific embodiments, the cathode-gate voltage generator 34 receives the aforementioned trigger signal sequence and synchronously acquires the amplitude parameters (e.g., u11, u21, etc.) uniquely corresponding to each cathode-gate control voltage pulse. During the effective period of the trigger signal, the cathode-gate voltage generator 34 dynamically generates cathode-gate control voltage pulses with corresponding amplitudes. When the rising edge of each specific trigger signal arrives, the cathode-gate voltage generator 34 responds and begins to output a cathode-gate control voltage pulse, the amplitude of which is determined by the instruction for the amplitude parameter currently assigned to that cathode-gate control voltage pulse; and when the falling edge of the trigger signal arrives, the cathode-gate voltage generator 34 turns off and stops voltage output. This series of continuously generated cathode-gate control voltage pulses with variable amplitudes will then be directed and applied to the corresponding cathode 11 via subsequent distribution circuitry (e.g., output port selector 39). Through the coordinated action of timing generator 33 and cathode-gate voltage generator 34, a cathode-gate control voltage waveform with controllable timing interval and amplitude that can jump one by one is finally output, that is, N cathode-gate control voltage pulses of each cathode 11 are generated, which are time-interval arranged and have different amplitude values ​​as needed.

[0069] In some exemplary embodiments, such as Figure 2A , Figures 3 to 7 As shown, the cathode controller 3 also includes a first memory 31 and a first processor 32. The first processor 32 is connected to the first memory 31, the timing generator 33, and the cathode-gate voltage generator 34, respectively. The first memory 31 is used to store pulse operating characteristic parameters. The first processor 32 is configured to: read the pulse operating characteristic parameters stored in the first memory 31; instruct the timing generator 33 to generate a cathode trigger signal sequence according to the time parameter in the pulse operating characteristic parameters; generate a serialized voltage amplitude command signal according to the amplitude parameter in the pulse operating characteristic parameters; and send the serialized voltage amplitude command signal to the cathode-gate voltage generator 34 according to the time nodes in the cathode trigger signal sequence, so that the cathode-gate voltage generator 34 generates N cathode-gate control voltage pulses for each cathode 11. In some specific embodiments, the first memory 31 pre-stores the pulse operating characteristic parameters (i.e., time parameters and amplitude parameters) to construct a parameter data space. In the configuration of a multi-cathode array, the amplitude parameters stored in the first memory 31 are organized into a multi-dimensional array according to the physical number of the cathode 11 and the timing sequence of the cathode gate control voltage pulses. For example, the amplitude parameter sequence can be set as u11, u21, …, uM1, u12, u22, …, uMN, which correspond to the first cathode gate control voltage pulse emitted by the first cathode 11, the first cathode gate control voltage pulse emitted by the second cathode 11, … up to the Nth cathode gate control voltage pulse emitted by the Mth cathode 11.

[0070] In some specific embodiments, the control logic of the first processor 32 includes the following steps: First, the first processor 32 reads the pulse operating characteristic parameters in the first memory 31; second, the first processor 32 instructs the timing generator 33 to generate a cathode trigger signal sequence according to the extracted time parameters. This signal sequence establishes the start and end times of each cathode gate control voltage pulse in the time domain, and logically configures the timing synchronization relationship between the current trigger signal and the corresponding target cathode 11 in the multi-cathode array; finally, the first processor 32 generates a serialized voltage amplitude command signal according to the extracted amplitude parameters, and sends the command signal to the cathode gate voltage generator 34 according to the time nodes in the cathode trigger signal sequence. The execution method, which sends commands according to time nodes, is as follows: Before the rising edge of the trigger signal corresponding to the activation of a specific cathode 11 arrives, the first processor 32 pre-sends the voltage amplitude command corresponding to the target cathode 11 and the current cathode gate control voltage pulse to the cathode gate voltage generator 34. The cathode gate voltage generator 34 adjusts the output voltage accordingly, and then, in conjunction with the channel switching of the output port selector 39, conducts the cathode gate control voltage pulse of the set amplitude to the selected target cathode 11. Through the timing synchronization of the pre-stored parameters, trigger signals, and amplitude commands, independent amplitude modulation of each cathode 11 in the multi-cathode array within a single pulse period is achieved.

[0071] In some exemplary embodiments, the amplitude parameter is data that is mapped to at least one of the cathode control voltage, the emission current of the cathode 11, the operating current of the anode 13, and the radiation intensity.

[0072] In some specific embodiments, when mapped to the cathode-gate control voltage, the amplitude parameter can directly represent the desired absolute cathode-gate control voltage value. For example, setting the amplitude parameter to "1200" directly indicates that a cathode-gate control voltage of 1200V is expected to be output to the specific cathode 11 currently in the selected state. In some optional specific embodiments, the first memory 31 pre-stores a parameter-voltage mapping relationship, which is used to map the amplitude parameter to the cathode-gate control voltage; the first processor 32 is configured to determine the voltage amplitude command signal based on the amplitude parameter and the parameter-voltage mapping relationship; that is, the first memory 31 pre-stores a one-dimensional lookup table recording "amplitude parameter value to cathode-gate control voltage value". The first processor 32 directly uses the externally input amplitude parameter as a search index to extract the corresponding voltage amplitude command value from the lookup table.

[0073] In some specific embodiments, when mapped to the cathode emission current, the amplitude parameter can represent the desired cathode emission current value. For example, the amplitude parameter "200" indicates that the currently selected cathode 11 is expected to emit an electron beam of 200mA. In this case, it is necessary to pre-acquire and call the voltage-current characteristic curve (i.e., IV curve) of the cathode 11 itself, and convert the desired current value into the corresponding cathode gate control voltage value in real time through table lookup or interpolation calculation. Since there are M independent cathodes 11 in the multi-cathode array, the physical emission characteristics of each cathode 11 have slight differences due to manufacturing and assembly processes. Therefore, the characteristic data such as the IV curve that are called should be preset and stored independently for each of these M cathodes 11. In some alternative embodiments, the first memory 31 pre-stores parameter-cathode current mapping relationships and cathode current-voltage mapping relationships. The parameter-cathode current mapping relationship is used to map the amplitude parameter to the emission current of M cathodes 11, and the cathode current-voltage mapping relationship is used to map the emission current of M cathodes 11 to the cathode gate control voltage. The first processor 32 is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-cathode current mapping relationship, and the cathode current-voltage mapping relationship. That is, the first memory 31 pre-allocates and stores two types of data table structures: one is a relationship table mapping "amplitude parameter to desired cathode current value", which can be stored in independent blocks for each cathode 11 to accommodate the emission efficiency dispersion of different cathode 11 materials; the other is the "cathode current-cathode gate control voltage" correlation characteristic curve (i.e., IV curve) characterizing the intrinsic physical properties of the X-ray tube 1. The computational logic configuration of the first processor 32 is as follows: First, based on the amplitude parameter, consult the relationship table between the amplitude parameter and the desired cathode current value to obtain the desired cathode current. Then, based on this desired current, perform interpolation calculations in the IV curve model to solve for the instruction of the required final cathode gate control voltage. For multi-cathode arrays, the first memory 31 can independently store M calibration IV curves corresponding to each of the M cathodes 11, or store a single typical reference IV curve supplemented by an M-group characteristic correction coefficient array. For example, refer to... Figure 9 and Figure 10 As shown, Figure 10 The horizontal axis represents time (ms), and the vertical axis represents the cathode current (mA). Figure 10Each round contains three pulses of cathode current. For example, the first pulse of cathode current has a corresponding amplitude parameter, which can determine the corresponding current value I1 based on the parameter-cathode current mapping relationship. The amplitude value of the first cathode control voltage pulse generated is controlled by I1 (i.e., reaching the target voltage value V1 corresponding to I1). The second pulse of cathode current has a corresponding amplitude parameter, which determines its corresponding current value I2. The current value I2 controls the amplitude value of the second cathode control voltage pulse generated (i.e., jumping to the corresponding target voltage value V2).

[0074] In some specific embodiments, when mapped to the anode operating current, the amplitude parameter represents the anode operating current that is expected to be maintained. In this case, data conversion is required through the cathode-gate voltage-anode current operating curve (i.e., the Vg-Ia curve), which can be calculated and calibrated by combining multiple physical factors such as the IV curve corresponding to each cathode 11 in the array, the transmittance of the gate 12 under the current physical structure, and the capture rate of the target surface of the anode 13. In some alternative embodiments, the first memory 31 pre-stores a parameter-anode current mapping relationship and an anode current-voltage mapping relationship. The parameter-anode current mapping relationship is used to map the amplitude parameter to the operating current of the anode 13, and the anode current-voltage mapping relationship is used to map the operating current of the anode 13 to the cathode gate control voltage. The first processor 32 is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-anode current mapping relationship, and the anode current-voltage mapping relationship. That is, the first memory 31 pre-stores a relationship table of "amplitude parameter to desired anode current value" and a comprehensive characteristic curve of "anode current-cathode gate control voltage". This curve model can be obtained by mathematical calculation and conversion of the aforementioned cathode IV curve, combined with the parameters of gate 12 transmittance and anode capture rate obtained by physical field simulation.

[0075] In some specific embodiments, when mapped to radiation intensity, the amplitude parameter directly represents the desired X-ray output dose. This requires conversion using the cathode voltage-output dose working curve (i.e., the Vg-D curve), and the shape of this conversion curve is closely related to external factors such as the anode voltage applied by the current anode controller 2. In some optional specific embodiments, the first memory 31 pre-stores parameter-radiation intensity mapping relationships and radiation intensity-voltage mapping relationships. The parameter-radiation intensity mapping relationship is used to map the amplitude parameter to the radiation intensity output by the X-ray tube 1, and the radiation intensity-voltage mapping relationship is used to map the radiation intensity output by the X-ray tube 1 to the cathode control voltage. The first processor 32 is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-radiation intensity mapping relationship, and the radiation intensity-voltage mapping relationship. That is, the first memory 31 pre-stores a relationship table of "amplitude parameter to desired radiation intensity value" and a conversion characteristic curve of "radiation intensity-cathode control voltage" (i.e., the Vg-D curve). Since the X-ray radiation intensity depends on the anode voltage level, the characteristic curve model is configured as a multi-dimensional lookup table structure. The first processor 32 needs to switch to the corresponding sub-curve table to perform the search calculation based on the currently set anode voltage operating point. For example, refer to... Figure 9 and Figure 11 As shown, Figure 11 The horizontal axis represents time, measured in milliseconds (ms), and the vertical axis represents the dose rate of radiation intensity, measured in mGy / min. Figure 11 There are five pulse segments. For example, the first pulse segment has a corresponding amplitude parameter, which can determine the corresponding ray intensity value D1 based on the parameter-ray intensity mapping relationship. The amplitude value of the first cathode control voltage pulse generated is controlled according to D1 (i.e., reaching the target voltage value V1 corresponding to D1). The second pulse segment has a corresponding amplitude parameter, which determines its corresponding ray intensity value D2. The ray intensity value D2 controls the amplitude value of the second cathode control voltage pulse generated (i.e., jumping to the corresponding target voltage value V2).

[0076] In summary, regardless of the physical quantity represented by the externally input amplitude parameter, the ultimate internal conversion purpose is to determine an accurate and desired command value for the cathode control voltage for each individual cathode 11 in the array that is about to be in the beam-emitting state during the high-frequency time-division scanning process of the multi-cathode array, so as to generate the required X-ray output. For the multi-cathode X-ray tube 1, these mapping relationship data used for conversion are independently calibrated, stored, and recalled for each cathode 11, thereby compensating for individual differences and ensuring that each cathode 11 can output a X-ray pulse of preset intensity according to its own characteristics. At the same time, by pre-storing differentiated mapping models at the hardware level, the external control logic and internal physical execution are decoupled; the system or operating terminal can flexibly choose the parameter input method with control voltage, emission current, or radiation intensity as the final control target. The first processor 32 calls the pre-stored mapping relationship to perform back-end data conversion. In multi-cathode control, this mechanism eliminates the need to pay attention to the physical differences such as the electron emission efficiency of each cathode 11 at the bottom layer. It only needs to issue a macroscopic expected output parameter instruction of the same dimension, which can automatically and separately calculate the precise bias voltage value required by different individual cathodes 11 in the driving array at the bottom layer.

[0077] In some exemplary embodiments, such as Figures 8 to 11 As shown, the time parameters include pulse width, pulse interval, and repetition period. The pulse width (on-time) is the duration of each single pulse emitted from X-ray tube 1; the pulse interval (off-time) is the time between two adjacent pulses without radiation output; and the repetition period (N) is the total number of pulse sequences that need to be repeated in one continuous scan.

[0078] In some specific embodiments, the pulse width sets the exposure duration of each X-ray pulse. In detection applications requiring rapid scanning, a smaller pulse width value can be set to suppress motion artifacts. The pulse interval sets the stop emission time between adjacent X-ray pulses. During the working cycle of the multi-cathode array, the cathode 11 stops emitting electrons during this pulse interval. This time window is used for the backend to complete signal readout, and simultaneously for the output port selector 39 to complete the electrical switching action from the current cathode channel to the next target cathode channel. The repetition period specifies the number of cycles of the preset pulse sequence. In applications requiring multi-view projection data acquisition (such as CT scanning), based on the repetition period N and the number of cathodes 11 M, the individual cathodes 11 in the array are controlled to emit pulses sequentially. By combining the settings of these three parameters—pulse width, pulse interval, and repetition period—different pulse timing modes can be configured. Specifically, assuming a first preset duration is set as the pulse width, a second preset duration is set as the pulse interval, and the number of cathodes 11 is set to M and the repetition period to N. Under this parameter configuration, a pulse sequence of total number M*N will be generated, that is, M cathodes 11 will each take turns emitting N times in a preset order, and each beam emission will be controlled by the pulse width and pulse interval set above.

[0079] In some exemplary embodiments, such as Figures 12 to 13 As shown, the cathode trigger signal sequence has the same pulse width as the pulse width in the time parameter, and the rising edge of the pulse in the cathode trigger signal sequence is used to trigger the turn-on, and the falling edge of the pulse in the cathode trigger signal sequence is used to trigger the turn-off; or, the cathode trigger signal sequence has a pulse width different from the pulse width in the time parameter, and the odd-numbered pulse signals in the cathode trigger signal sequence are used to trigger the turn-on, and the even-numbered pulse signals in the cathode trigger signal sequence are used to trigger the turn-off.

[0080] In some specific embodiments, the triggering method is the same width triggering, see reference. Figure 12 A timing diagram of the cathode trigger signal in some embodiments is shown. Figure 12 The horizontal axis represents the time axis, with units in milliseconds (ms), and the vertical axis represents the pulse signal axis of the trigger signal. Figure 12The diagram schematically illustrates the pulses of the cathode trigger signals for the three cathodes 11, i.e., M=3, with a repetition period N. Here, t=(1, 4, 7, 10, 13) represents the rising edge of the cathode trigger signal, serving as the action trigger command to instruct the cathode-gate voltage generator 34 to start outputting a voltage of a set amplitude value; t=(3, 6, 9, 12, 15) represents the falling edge of the cathode trigger signal, serving as the action shutdown command to instruct the cathode-gate voltage generator 34 to stop voltage output. The trigger signal output by the timing generator 33 is a digital square wave with a pulse width equal to a preset pulse width. The rising edge of this digital square wave serves as the on trigger signal, instructing the cathode-gate voltage generator 34 to start outputting voltage pulses; the falling edge of this digital square wave serves as the off trigger signal, instructing the cathode-gate voltage generator 34 to stop outputting. Furthermore, this square wave signal synchronously serves as the clock signal for the output port selector 39 to perform multi-cathode channel switching. In this triggering mode, the high-level duration of the control signal directly corresponds to the actual output time of the cathode-gate control voltage pulse.

[0081] In some specific embodiments, the triggering method is short pulse triggering. (See also...) Figure 13 A timing diagram of the cathode trigger signal is shown in some other embodiments. Figure 13 The horizontal axis represents the time axis, with units in milliseconds (ms), and the vertical axis represents the pulse signal axis of the trigger signal. Figure 13 There are five enable trigger signals and five disable trigger signals. In response to the enable trigger signal, the cathode voltage generator 34 is commanded to start outputting a voltage of a set amplitude value; in response to the disable trigger signal, the cathode voltage generator 34 is commanded to stop outputting voltage. The timing generator 33 outputs a series of narrow trigger pulses with fixed pulse widths. In the timing logic, the first and odd-numbered narrow pulses are used as enable trigger signals, and the adjacent second and even-numbered narrow pulses are used as disable trigger signals, and this cycle repeats. Under this configuration, the actual output width of the cathode control voltage pulse is determined by the time difference between adjacent odd-numbered and even-numbered narrow pulses. This triggering method decouples the direct correlation between the pulse width of the timing generator 33's output signal and the final voltage pulse width. The timing generator 33 only needs to output fixed narrow pulses to change the ray pulse width by adjusting the pulse interval, which is suitable for multi-cathode high-frequency switching control logic that requires frequent adjustment of pulse width parameters. In specific applications, the appropriate triggering method can be selected according to the hardware resource allocation of the controller and the timing control accuracy requirements.

[0082] In some exemplary embodiments, such as Figure 6 and Figure 7As shown, the anode controller 2 is connected to the timing generator 33. The timing generator 33 is also used to generate an anode trigger signal based on time parameters. The anode controller 2 is used to control the on and off of the anode voltage based on the anode trigger signal. Specifically, the anode controller 2 establishes a signal connection with the timing generator 33, making the application state of the anode voltage controlled by global timing logic. Specifically, the timing generator 33 generates an independent anode trigger signal based on time parameters (which may include data such as a time margin for early anode voltage on and a time margin for delayed anode voltage off). The anode controller 2 receives this anode trigger signal and controls the on and off of the anode voltage accordingly. Incorporating the control logic of the anode 13 into a unified timing synchronization ensures that, during the scanning task of the multi-cathode array, a stable accelerating electric field is established between the cathode 11 and the anode 13, or between the gate 12 and the anode 13, before the first cathode 11 begins emitting electrons. Simultaneously, the anode voltage is turned off only after all cathodes 11 in the array have completed their predetermined emission sequence and stopped emitting electrons. In multi-cathode applications, the timing of the anode trigger signal is configured to cover the duty cycle of all cathodes 11 to prevent voltage fluctuations caused by the establishment and deactivation of the anode voltage during electron acceleration from interfering with the X-ray energy spectrum characteristics. This control architecture achieves coordination between the electron emission action of cathode 11 and the anode voltage acceleration environment.

[0083] See also Figure 14 A timing diagram illustrating the generation process of the X-ray output dose rate in some embodiments is shown. Figure 14 The horizontal axis in the image represents the time axis, with the unit being milliseconds (ms). Figure 14 (a)(b)(c)(d)(e)(f) are time-aligned; where, Figure 14 (a) in the diagram is the timing diagram of the anode voltage trigger signal. Figure 14 (b) in the diagram is the timing diagram of the anode voltage. Figure 14 (c) in the diagram is the timing diagram of the cathode trigger signal. Figure 14 (d) in the diagram is the timing diagram of the cathode gate control voltage. Figure 14 (e) Cathode current timing diagram, Figure 14 (f) in the figure is the time series diagram of ray intensity; Figure 14 In (a), the vertical axis represents the pulse signal axis of the anode voltage trigger signal. Figure 14 In (b), the vertical axis represents the voltage amplitude of the anode voltage, with units of V. Figure 14 In (c), the vertical axis represents the pulse signal axis of the cathode voltage trigger signal. Figure 14 In the diagram (d), the vertical axis represents the voltage amplitude of the cathode control voltage, measured in V. Figure 14 In the diagram (e), the vertical axis represents the cathode current value, in mA. Figure 14The vertical axis of (f) in is the dose rate of radiation intensity, with the unit of mGy / min.

[0084] In some exemplary embodiments, as shown in Figure 14 (a) and Figure 14 (c), the anode trigger signal is a wide pulse that temporally contains the cathode trigger signal sequence, and the anode controller 2 is configured to: control the turn-on of the anode voltage at the rising edge of the wide pulse, and control the turn-off of the anode voltage at the falling edge of the wide pulse.

[0085] In some specific embodiments, with reference to Figure 14 (a), (b) and (c), the anode trigger signal is configured as a wide pulse signal that contains and covers the complete cathode trigger signal sequence in the time domain. The trigger time of the rising edge of the anode trigger signal is earlier than the trigger time of the rising edge of the first pulse in the cathode trigger signal sequence, and the trigger time of the falling edge of the anode trigger signal is later than the trigger time of the falling edge of the last pulse in the cathode trigger signal sequence. For example, assuming that the duration interval of the cathode trigger signal sequence of the multi-cathode array on the time axis is from t1 to t2, the wide pulse command received by the anode controller 2 is set to start at time t0 and end at time t3, which satisfies the logical relationship: t0<t1 and t3>t2. The above timing configuration of "turning on before the cathode sequence and turning off after the cathode sequence", with reference to Figure 14 (a), (b), (c) and (d), ensures that the anode voltage maintains a steady-state output during the entire period when the multi-cathode array works in turn; so that the cathodes 11 at different positions in the multi-cathode array work under a constant electric field during the process of focus switching and emitting independent pulses, avoiding the influence of transient voltage fluctuations or ripples generated by the frequent start and stop of the anode voltage source during the pulse sequence on the amplitude accuracy and radiation waveform of each pulse.

[0086] In some exemplary embodiments, the first processor 32 is configured to read the pulse working characteristic parameters stored in the first memory 31 according to a preset clock cycle, and send the serialized voltage amplitude command signal to the cathode-grid voltage generator 34 according to the time node for triggering turn-on in the cathode trigger signal sequence.

[0087] In some specific embodiments, the reading logic is executed according to a fixed clock cycle. The first processor 32 polls the first memory 31 based on an internally set clock cycle to read the pulse operating characteristic parameters required for the operation of the multi-cathode array. When the first processor 32 obtains parameter update data within the current reading cycle, it parses the time and amplitude parameters in the data. Subsequently, the first processor 32 instructs the timing generator 33 to reconstruct the trigger signal timing according to the parsed time parameters, and sends the corresponding updated voltage amplitude command signal to the cathode grid voltage generator 34 according to the start time node set by the cathode trigger signal, which is then routed to the target cathode 11 by the output port selector 39. The mechanism of this reading method is independent of the execution progress of the current beam pulse sequence, that is, the data acquisition action of the first processor 32 is controlled by a fixed time cycle. This logic is suitable for continuous scanning scenarios where the device needs to switch operating modes according to a set time frequency. For example, in imaging applications where the inspected object passes through continuously, the parameter register can be updated systematically according to the time progression, thereby periodically adjusting the beam output timing and amplitude settings of subsequent cathode channels.

[0088] In some exemplary embodiments, such as Figure 8 , Figure 12 and Figure 16 As shown, the first processor 32 is configured to: when the pulse width of the cathode trigger signal sequence is the same as the pulse width in the time parameters, in response to the falling edge of the pulse in the cathode trigger signal sequence, read the pulse operating characteristic parameters stored in the first memory 31, and in response to the rising edge of the next pulse in the cathode trigger signal sequence, send the serialized voltage amplitude command signal to the cathode-gate voltage generator 34; or, refer to [reference needed] Figure 13 and Figure 16As shown, the first processor 32 is configured to: when the pulse width of the cathode trigger signal sequence differs from the pulse width in the time parameters, in response to the even-numbered pulse signals in the cathode trigger signal sequence, read the pulse operating characteristic parameters stored in the first memory 31, and in response to the subsequent odd-numbered pulse signals in the cathode trigger signal sequence, send the serialized voltage amplitude command signal to the cathode grid voltage generator 34. The event-triggered reading logic operates by using the pulse interval between two effective X-ray pulses, with a specific hardware signal acting as an interrupt event to trigger the first processor 32 to execute parameter reading and control command issuance operations; before the current pulse ends and the pulse of the next target cathode 11 begins, it completes the loading of the next pulse parameters and the switching of multiple channels. This control method, utilizing pulse gaps for event-triggered parameter reading, supports independent calculation and setting of the single beam amplitude value of any specific cathode 11 in the multi-cathode array; parameter overwriting can be performed without waiting for the complete scan cycle to end, providing a response condition for dynamic pulse-level adjustments in response to changes in the inspection environment.

[0089] In some specific embodiments, a trigger sequence of the same width is used, in conjunction with the following reference. Figure 16 As shown, the first processor 32 detects the falling edge state of the cathode trigger signal. In response to this falling edge event (i.e., the moment that represents the end of the current beam emission operation), the processor triggers a read operation on the first memory 31 to obtain the amplitude parameters for the next target cathode 11. In response to the rising edge of the next pulse, the processor sends the converted voltage amplitude command signal to the cathode-gate voltage generator 34. This configuration utilizes the interval between the current falling edge and the rising edge of the next pulse to complete the parameter reading and issues the voltage amplitude command signal when the rising edge of the next pulse arrives.

[0090] In some specific embodiments, a short pulse trigger sequence is used, in conjunction with the following reference. Figure 16As shown, the first processor 32 detects an even number of trigger pulses and triggers a read operation in response to the arrival of these even-numbered pulse signals. Its execution logic is similar, utilizing the time window between the end of the current pulse emission and the start of the next pulse trigger to acquire new parameters and adjust the voltage. For example, the first processor 32 is configured to detect an even number of pulse signals in the sequence. Once it responds to an even number of pulse signals in the cathode trigger signal sequence (which also represents the occurrence of the current i-th pulse turn-off action), the first processor 32 reads the pulse operating characteristic parameters corresponding to the next (i.e., the i+1th) pulse stored in the first memory 31 and sends the parsed new serialized voltage amplitude command signal to the cathode-gate voltage generator 34 in advance. Thus, after an off-time interval, when the rising edge of the i+1th pulse arrives to request beam output, the internal hardware of the cathode-gate voltage generator 34 has already adjusted and stabilized at the new target voltage value.

[0091] In some exemplary embodiments, such as Figure 7 As shown, the cathode controller 3 also includes an input module 36, which is used to acquire the pulse operating characteristic parameters of the X-ray tube 1.

[0092] In some specific embodiments, the input module 36 is configured as a communication node to receive external data, acquire pulse operating characteristic parameters input from the outside, and transmit these parameters internally to update the data in the first memory 31. The input module 36 includes a human-machine interface device for operators to input local data, and a standard communication interface (such as an RS232 interface, industrial Ethernet interface, etc.) for receiving data frames from a host control system or programmable logic controller (PLC). By configuring the input module 36, it is possible to dynamically adjust scanning parameters based on the physical differences of the inspected object or feedback data from previous detection. For example, the external host computer system can generate targeted time and amplitude parameter instruction sets in real time according to the density distribution characteristics of the detection target. It can even generate differentiated amplitude control parameters for specific cathodes 11 at different spatial locations in a multi-cathode array, and send them to the first processor 32 through the input module 36 for processing, overwriting the existing data in the first memory 31. The first processor 32 calls the updated pulse operating characteristic parameters during subsequent parameter reading cycles or event triggers, thereby achieving dynamic adaptation of pulse control parameters to external detection conditions or closed-loop control requirements.

[0093] In some exemplary embodiments, such as Figure 7As shown, the cathode-gate voltage generator 34 includes a cathode-gate voltage sub-generator 342 and a voltage regulator 341. The cathode-gate voltage sub-generator 342 generates N cathode-gate control voltage pulses. The voltage regulator 341 is connected to the timing generator 33, the first processor 32, and the cathode-gate voltage sub-generator 342, respectively. The voltage regulator 341 controls the cathode-gate voltage sub-generator 342 to output N cathode-gate control voltage pulses according to the cathode trigger signal sequence and the voltage amplitude command signal. The cathode-gate voltage sub-generator 342 is configured to generate a base voltage power supply.

[0094] In some specific embodiments, the voltage regulator 341 is configured to perform voltage modulation control. The voltage regulator 341 synchronously receives a trigger signal from the timing generator 33, which defines the pulse's on / off timing. It also synchronously receives a voltage amplitude command signal from the first processor 32, which defines the output amplitude of the target pulse. Based on these two input signals, the voltage regulator 341 modulates the base voltage output of the cathode-gate voltage sub-generator 342 in real time, thereby delivering a voltage pulse with a preset absolute amplitude to the circuit within a set time window. This establishes driving conditions for the upcoming subsequent pulse and the predetermined target cathode 11. At the hardware level, the voltage regulator 341 can integrate a digital-to-analog converter and an amplification control circuit. Its operating logic involves converting the received digital voltage amplitude command into an analog control level and controlling the final output voltage via the voltage amplification control circuit. Through a high-low voltage separation design architecture, both the static stability of the base voltage output and the dynamic adjustability of the single pulse amplitude are considered. In the multi-cathode array architecture, by configuring the aforementioned output port selector 39 to perform time-division multiplexing, only one combination of cathode-gate voltage generator 342 and voltage regulator 341 needs to be configured to sequentially distribute the amplitude-modulated voltage pulses to the M cathodes 11 in the array; eliminating the hardware requirement of equipping each cathode 11 with a complete voltage generation link independently, effectively suppressing the engineering defect that the scale of the multi-focus device control hardware increases proportionally with the number of cathodes 11.

[0095] In some exemplary embodiments, such as Figure 13 As shown, the cathode controller 3 is also configured to adjust the amplitude of at least one of the N cathode grid control voltage pulses based on at least one of the emission current of the cathode 11, the operating current of the anode 13, and the radiation intensity. Thanks to the time-division multiplexing characteristic of the aforementioned output port selector 39, the entire multi-cathode array does not require redundant feedback loops; instead, it only needs to share a single global sampling and feedback module to achieve comprehensive array-level monitoring.

[0096] In some specific embodiments, during the actual operating cycle, the actual operating parameters of the target cathode 11 currently in the selected state can be collected in real time. These parameters include the actual emission current of the cathode 11, the corresponding anode operating current, or the intensity of the ultimately transmitted radiation. These real-time measured values ​​are then compared with the theoretical target value expected by the amplitude parameter corresponding to the cathode control voltage pulse. If a deviation is found during the comparison, the amplitude command of subsequent cathode control voltage pulses is dynamically adjusted and corrected according to the magnitude and direction of the deviation. This proactively compensates for output attenuation or abnormal changes caused by objective physical factors such as long-term aging of the X-ray tube 1, thermal drift due to ambient temperature, and fluctuations in external power supply. This dynamic compensation ensures that the actual physical performance (i.e., current magnitude or radiation dose intensity) of each cathode 11's output cathode control voltage pulse during its respective time-sharing operating period remains consistent with the preset amplitude parameter. The calculation and application of this closed-loop feedback adjustment can be performed independently for the specific feedback channel of each cathode 11, thereby enabling the ability to compensate for the objective individual characteristic differences between different cathodes 11 in a multi-cathode array and to achieve precise pulse amplitude control for the focus of each cathode 11.

[0097] In some exemplary embodiments, such as Figure 7 As shown, the X-ray source assembly also includes: an acquisition component 37, used to acquire the actual operating parameters of the X-ray tube 1 and generate measured values; and a feedback controller 38, which is connected to both the acquisition component 37 and the first processor 32. The feedback controller 38 is used to: convert the measured values ​​according to the mapping relationship between the measured values ​​and the amplitude parameters; compare the converted measured values ​​with the amplitude parameters; output a difference signal based on the comparison result; and output the difference signal to the first processor 32. The acquisition component 37 is configured to monitor the actual physical operating parameters of the X-ray tube 1 in real time, and to acquire measured values ​​characterizing the beam state, such as the emission current of the current cathode 11, the operating current of the anode 13, or the intensity of the emitted radiation from the X-ray tube 1. Under the multi-cathode time-sharing operating mechanism, the measured value acquired by the acquisition component 37 uniquely corresponds to the specific cathode 11 currently in the gated operating state within this time sequence interval.

[0098] In some specific embodiments, the feedback controller 38 is configured to execute a four-step closed-loop control logic: The first step is dimension conversion, where the feedback controller 38 converts the acquired measurement value into a representation value with the same physical dimensions as the amplitude parameter based on the built-in physical mapping relationship. For example, when the input amplitude parameter is defined as the desired current value, but the acquisition terminal acquires a voltage signal, it needs to be linearly or nonlinearly converted into an actual current value. The second step is deviation calculation, where the feedback controller 38 logically compares the converted actual measurement value with the preset amplitude parameter corresponding to the currently working cathode 11 and calculates the difference between the two. The third step is difference signal generation, where the feedback controller 38 generates a corresponding digital or analog difference signal based on the absolute value and polarity of the deviation using a closed-loop control algorithm (such as a proportional-integral-derivative PID control algorithm). The fourth step is signal output, where the difference signal is sent to the first processor 32 to initiate the compensation action at the execution end. By employing the above feedback control loop, it has the ability to automatically correct output drift caused by changes in external environmental parameters, long-term aging of internal components, or inherent differences in the emission characteristics of each cathode 11 in the multi-cathode array. This closed-loop mechanism ensures that the physical quantity of the actual emitted pulse of each cathode 11 in the array remains dynamically consistent with the preset target value during its corresponding working period. Given the discreteness of the physical characteristics of the M cathodes 11 in terms of materials and assembly, the above feedback calculation and compensation process is based on the independent establishment and execution of records for the specific cathode 11 currently in operation, thereby ensuring the consistency of the overall beam output characteristics of the array.

[0099] In some exemplary embodiments, such as Figure 7 As shown, the first processor 32 is further configured to adjust the amplitude value of at least one voltage amplitude command in the serialized voltage amplitude command signal according to the difference signal.

[0100] In some specific embodiments, after receiving the aforementioned difference signal, the first processor 32 parses the difference signal into a dynamic correction amount and superimposes or performs logical operations on it onto the original voltage amplitude command signal. For example, if the preceding difference signal indicates that the actual emission current of the cathode 11 currently in the selected state is less than 5% of the expected value, the first processor 32 will, when generating subsequent control pulses for that cathode 11, increase the amplitude value of the corresponding voltage amplitude command in the voltage amplitude command signal according to a logical ratio to compensate for the current loss in the tube. This adjustment action can be configured in timing to perform real-time fine-tuning compensation on the currently output wide pulse, or it can be configured to perform inter-pulse amplitude correction compensation on pulses emitted in subsequent cycles based on the measurement results of the current pulse. In these embodiments, the dynamic adjustment amount based on the measurement difference is recorded and updated separately for each independent cathode 11; this independent recording mechanism ensures that when the specific cathode 11 is selected again in the next timing cycle or switched to other cathodes 11 with different deviation records, the control voltage applied to the target cathode 11 has been accurately modulated by calling the dedicated correction parameters.

[0101] In some exemplary embodiments, such as Figure 7 As shown, the acquisition component 37 includes: a cathode current acquisition unit 371, located in the cathode controller 3, for acquiring the emission current of M cathodes 11; and / or an anode current acquisition unit 372, located in the anode controller 2, for acquiring the operating current of the anode 13 of the X-ray tube 1; and / or a sampling detector 373, located outside the X-ray tube 1, for acquiring the intensity of the radiation output from the X-ray tube 1. The cathode current acquisition unit 371, the anode current acquisition unit 372, and the sampling detector 373 can be used individually or in any combination according to the equipment control accuracy requirements. For example, in applications requiring output stability, the cathode current acquisition unit 371 and the anode current acquisition unit 372 can be deployed simultaneously, using the proportional relationship between the acquired cathode and anode current parameters for dual data verification and anomaly detection.

[0102] In some specific embodiments employing the cathode current acquisition unit 371, the acquisition unit is located inside the cathode controller 3 or directly connected in series in the emission circuit of each cathode 11, and is used to directly acquire the actual electron beam current parameters of the currently selected cathode 11 in the emission state. The physical measurement of the acquisition unit can be achieved by connecting a low-resistance sampling resistor in series in the circuit or by deploying a non-isolated / isolated Hall current sensor. For an array containing M cathodes 11, the cathode current acquisition unit 371 is configured to have M independent acquisition channels to acquire data from each cathode in parallel; or it is configured in a single-channel serial mode, maintaining hardware synchronization with the timing action of the output port selector 39, and sequentially acquiring the emission current of the cathode 11 currently in the conduction state in a time-division manner. In some other specific embodiments, the first memory 31 pre-stores a parameter-cathode current mapping relationship and a cathode current-voltage mapping relationship. The parameter-cathode current mapping relationship is used to map the amplitude parameter to the emission current of the cathode 11, and the cathode current-voltage mapping relationship is used to map the emission current of the cathode 11 to the cathode gate control voltage. The feedback controller 38 is configured to: convert the measured value according to the mapping relationship between the measured value and the amplitude parameter based on the amplitude parameter, the parameter-cathode current mapping relationship, and the cathode current-voltage mapping relationship; compare the converted measured value with the amplitude parameter; output a difference signal according to the comparison result; and output the difference signal to the first processor 32.

[0103] In some specific embodiments employing an anode current collector 372, the collector is located inside the anode controller 2 or connected in series in the anode voltage return loop to measure the bombardment electron flow that actually reaches the target surface of the anode 13. Physically, the anode operating current is attenuated by a combination of factors, including the initial emission current of the cathode 11, the electron transmittance of the gate 12 under a specific electrode structure, and the electron capture rate of the anode 13. Compared to the cathode current, the data characterization of the anode operating current more directly reflects the effective electron number density ultimately participating in the generation of X-ray bremsstrahlung within the tube. In other specific embodiments, the first memory 31 pre-stores a parameter-anode current mapping relationship and an anode current-voltage mapping relationship. The parameter-anode current mapping relationship is used to map the amplitude parameter to the operating current of the anode 13, and the anode current-voltage mapping relationship is used to map the operating current of the anode 13 to the cathode gate control voltage. The feedback controller 38 is configured to: convert the measured value according to the mapping relationship between the measured value and the amplitude parameter based on the amplitude parameter, the parameter-anode current mapping relationship, and the anode current-voltage mapping relationship; compare the converted measured value with the amplitude parameter; output a difference signal according to the comparison result; and output the difference signal to the first processor 32.

[0104] In some specific embodiments employing the sampling detector 373, the sampling detector 373 is disposed as an independent sensing component in the external space of the X-ray tube 1, for example, mechanically fixed to the flange or tube seat surface near the X-ray exit window, for directly measuring the X-ray photon flux or dose rate output from the tube shell; this method is a non-contact radiation measurement, and the physical quantity obtained directly characterizes the effective field strength level that ultimately penetrates the inspected object. In other specific embodiments, the first memory 31 pre-stores parameter-ray intensity mapping relationships and ray intensity-voltage mapping relationships. The parameter-ray intensity mapping relationship is used to map the amplitude parameter with the ray intensity output by the X-ray tube 1, and the ray intensity-voltage mapping relationship is used to map the ray intensity output by the X-ray tube 1 with the cathode control voltage; the feedback controller 38 is configured to: convert the measured value according to the mapping relationship between the measured value and the amplitude parameter based on the amplitude parameter, the parameter-ray intensity mapping relationship, and the ray intensity-voltage mapping relationship; compare the converted measured value with the amplitude parameter; output a difference signal according to the comparison result; and output the difference signal to the first processor 32.

[0105] In some exemplary embodiments, such as Figure 3 and Figure 4 As shown, the X-ray tube 1 includes M grids 12, each corresponding to one of the M cathodes 11 to form M cathode-grid pairs. An output port selector 39 is connected to each of the M grids 12. The output port selector 39 is configured to select one cathode 11 and grid 12 corresponding to one of the M cathode-grid pairs at any given time. Alternatively, the M grids 12 are connected in series to the output port selector 39, which is configured to select one of the M grids 12 and M cathodes 11 at any given time. The first configuration of the output port selector 39 employs an independent pairing control mechanism, providing superior inter-electrode crosstalk immunity and supporting independent adjustment and compensation of the microscopic distribution parameters of each cathode-grid unit. The second configuration of the output port selector 39 adopts a shared grid 12 topology, reducing the number of connections and hardware layout complexity of the multi-cathode X-ray tube 1 by decreasing the selection channel dimension.

[0106] In some specific embodiments, please refer to the following: Figure 3As shown, M gates 12 correspond one-to-one with M cathodes 11, forming independent cathode-gate pairs. The output port selector 39 is internally configured with a bipolar gating channel matching the number of independent cathode-gate pairs. Each gating channel simultaneously physically connects a specific cathode feed terminal to its corresponding gate feed terminal. When the timing execution of the activation command requires the conduction of a target cathode 11, the output port selector 39 synchronously closes the electrical nodes of that target cathode 11 and its dedicated gate 12, forming a complete control loop within the local space. This electrical architecture achieves electrical isolation and independent bias state control for each cathode-gate pair within the space.

[0107] In other specific embodiments, see also Figure 4 As shown, M gates 12 are connected in series and share a single gating node. These M gates 12 are electrically interconnected either inside the X-ray tube 1 cavity or outside its pins, forming a common gate terminal with the same potential. In this architecture, the control electrode of the cathode control voltage is continuously applied to this common gate, and the gating switch action of the output port selector 39 is configured to be performed only on the leads corresponding to the M cathodes 11. That is, the selector is only controlled to complete the routing switch of the target activated cathode 11 potential terminal. This electrical architecture reduces the number of vacuum feedthrough pins of the X-ray tube 1 and the size of the gating channel resources on the control side.

[0108] In some exemplary embodiments, such as Figure 5 As shown, the X-ray tube 1 includes an anode 13 and M anode targets 14. The anode 13 is connected to an anode controller 2. The M anode targets 14 are disposed on the anode 13 and correspond one-to-one with the M cathodes 11 to form M cathode-anode target pairs. The anode controller 2 is used to generate an electric field applied between the M cathode-anode target pairs. This structure simplifies the insulation design of the anode controller 2 and reduces hardware redundancy. Furthermore, it ensures, from an electrostatic field mechanism perspective, that all heterogeneous cathodes 11 within the array face spatially consistent accelerating electric field strengths when entering their respective working time slots.

[0109] In some specific embodiments, the anode 13 corresponds to M anode targets 14. The M anode targets 14 and M cathodes 11 are spatially distributed to form a one-to-one cathode-anode target pair. The M anode targets 14 are disposed on the anode 13, and the anode 13 constitutes a unique common anode high-voltage access terminal. The output of the anode controller 2 only needs to establish an electrical connection with this common anode high-voltage access terminal to apply an equivalent static high voltage to the M cathode-anode target pairs in the X-ray tube 1 simultaneously in geometric space. The electric field shaping mechanism based on this structure is as follows: when the anode controller 2 outputs a stable voltage to the common anode voltage access terminal, M sets of physically isolated electrostatic acceleration fields are established inside the vacuum tube shell, with the surfaces of the M cathodes 11 as zero potential reference surfaces and the surfaces of the corresponding anode targets 14 as voltage target surfaces. Under the premise of this background electric field, regardless of which cathode 11 surface the bottom output port selector 39 controls to perform electron emission according to the timing sequence, the acceleration electric field environment between the specific beam-emitting cathode 11 and its corresponding anode target 14 is in a stable dwelling state that has been established.

[0110] like Figure 2A and Figure 15 As shown, the X-ray source assembly includes an X-ray tube 1, which includes M cathodes 11, a grid 12, and an anode 13. The control method of the X-ray source assembly according to the embodiments of this application may include steps S100 to S300.

[0111] In step S100, N cathode control voltage pulses are generated according to the pulse operating characteristic parameters of X-ray tube 1 to generate cathode control voltage. The N cathode control voltage pulses are arranged at time intervals, and at least two of the N cathode control voltage pulses have different amplitude values. N is a positive integer greater than or equal to 2.

[0112] In step S200, a cathode-gate control voltage is applied between the M cathodes 11 and the gate 12 to control the M cathodes 11 to emit electrons, where M is a positive integer greater than or equal to 2.

[0113] In step S300, an electric field is applied between the anode 13 and the M cathodes 11 to control electrons to pass through the grid 12 and strike the anode 13 to emit X-rays.

[0114] Specifically, in step S100, the first processor 32 obtains pulse operating characteristic parameters for M cathodes 11 in the multi-cathode array from the first memory 31 or the input module 36. Subsequently, the timing generator 33 generates a cathode trigger signal sequence to control the on and off states based on the parsed time parameters (including pulse width, pulse interval, repetition period, and the number of cathodes 11 participating in the scan). Simultaneously, the first processor 32 generates a voltage amplitude command signal corresponding to each target cathode 11 based on the parsed amplitude parameters. Finally, the cathode-gate voltage generator 34 outputs an actual voltage pulse with an absolute value matching the voltage amplitude command under the pulse control of the cathode trigger signal. For example, if the sequence contains M cathodes 11 and the repetition period N is 5; when the time parameters are configured as a pulse width of 5 μs, a pulse interval of 10 μs, and the amplitude parameter matrix is ​​configured for each cathode and each repetition period, the physical execution result of step S100 is to generate a set of MN cathode-gate control voltage waveform entities at the hardware level, each with the aforementioned exact time interval and different voltage amplitudes, and ready to be allocated to different target cathodes 11 according to a predetermined timing sequence.

[0115] Specifically, in step S200, the serialized cathode control voltage generated in step S100 is directed and applied to the actual physical load. In this embodiment, the cathode control voltage is applied time-divisionally between a specific target cathode 11 and gate 12 via the output port selector 39, according to the channel switching timing synchronized with the trigger signal. In the physical beam emission mechanism of the X-ray tube 1, the local electric field strength applied between the cathode 11 and gate 12, i.e., the absolute amplitude of the cathode control voltage, directly determines the degree of suppression or extraction of the potential barrier on the cathode 11 surface, and thus determines the number of electrons emitted from the cathode 11 per unit time, i.e., the cathode emission current. After the amplitude of the applied cathode control voltage pulse reaches an inherent voltage threshold, the cathode emits electrons. In this case, when a higher amplitude cathode control voltage is applied, the electron beam current emitted by the cathode 11 increases; conversely, it decreases. Through the pre-generated pulse sequences of varying amplitudes in step S100, step S200 enables the control of the electron beam current intensity emitted by the currently selected cathode 11 within the timing window of each independent cathode control voltage pulse.

[0116] Specifically, in step S300, the anode controller 2 provides acceleration kinetic energy to electrons by applying a static high-voltage electric field between the cathode 11 and the anode 13. The timing of establishing and removing this anode high-voltage electric field is controlled by the aforementioned global timing logic. For example, the anode controller 2 is set to turn on the voltage output before the multi-cathode array is about to emit the first beam pulse, i.e., before the arrival of the first cathode control voltage pulse, and then turn off the voltage after the multi-cathode array completes the entire scan and the last beam pulse ends. This timing configuration ensures that a constant potential difference is maintained between the cathode and anode 13 throughout the entire working cycle in which each cathode 11 takes turns emitting electrons. This stable high-voltage electric field effectively accelerates the primary electron group emitted by the currently selected cathode 11 in step S200, giving it sufficient kinetic energy to bombard the target material of the anode 13, ultimately generating X-rays through bremsstrahlung radiation. In this process, the electron beam intensity determined by the cathode control voltage in step S200 directly and proportionally determines the dose intensity of the final output X-rays.

[0117] In summary, through the implementation of steps S100 to S300, this embodiment of the application achieves independent control of the decoupled output pulse amplitude of each focal point of each independent cathode 11 in the multi-cathode array. Step S100 generates a control pulse sequence with variable amplitude in the time domain; step S200 applies this sequence time-divisionally between different cathodes to modulate the number of electron emissions; and step S300 provides a stable accelerating electric field throughout the process to achieve electron kinetic energy conversion. The coordinated operation of the above steps allows the beam intensity of each pulse emitted from any focal point in the multi-cathode X-ray source array to be individually quantized and set according to preset parameters. This achieves architecture-level "pulse-by-pulse amplitude modulation," effectively solving the technical problems of oversaturation or extremely low signal-to-noise ratio of the detection signal due to fixed pulse intensity, and the excessively large hardware requirements for multi-focal array switching control.

[0118] like Figure 17 As shown, in an exemplary embodiment, the control method for the X-ray source assembly according to the embodiments of this application may further include steps S410 to S420.

[0119] In step S410, at least one of the following is collected: the cathode control voltage, the emission current of the cathode 11, the operating current of the anode 13, and the radiation intensity.

[0120] In step S420, the amplitude value of at least one of the N cathode control voltage pulses is adjusted according to at least one of the emission current of the cathode 11, the operating current of the anode 13, and the radiation intensity.

[0121] Specifically, in step S410, refer to [reference needed]. Figure 16As shown, during the execution of step S410, the current operating parameters of the X-ray tube 1 are acquired in real time. Regarding the specific configuration of the object under inspection: when selecting to collect the cathode emission current, an electrical signal is acquired using a current sampling resistor or Hall-effect isolation sensor arranged in the cathode 11 voltage circuit; when selecting to collect the anode operating current, an electrical signal is acquired using a current sampling device arranged in the anode voltage control circuit; when selecting to collect the radiation intensity, a radiation signal is acquired using a sampling detector 373 (such as a scintillator detector or ionization chamber) arranged on the external exit beam path of the X-ray tube 1. In the time-division multiplexing architecture of the multi-cathode array, the above signal acquisition actions are time-domain aligned with the operating window of the specific cathode 11 currently selected for beam emission. Therefore, the physical signal acquired by the acquisition end is uniquely identified and associated with the currently operating cathode 11. The acquired analog physical signal is then sent to a signal conditioning circuit and an analog-to-digital converter, converted into a digital measurement value that can be directly compared by a digital signal processor or microcontroller.

[0122] For details, please refer to step S420. Figure 16 As shown, during the execution of step S420, the control command is corrected in a closed loop based on the measured value obtained in step S410. For example, the feedback controller 38 extracts the digital measured value of the current acquisition cycle and compares it with the target amplitude parameter corresponding to the current output cathode 11 in the preset pulse operating characteristic parameters to calculate the output deviation; subsequently, the feedback controller 38 generates a difference compensation signal based on the deviation and outputs the signal to the voltage regulator 341. In this embodiment, the voltage regulator 341 corrects the voltage amplitude command signal in the subsequent timing sequence based on the difference compensation signal. For example, if the actual emission current of cathode N is detected to be 5% lower than its set target value, the voltage regulator 341 will increase the driving voltage amplitude command of the pulse when re-selecting cathode N and generating a cathode gate control voltage pulse for it in the next round, thereby compensating for physical loss or emission efficiency attenuation. Since the closed-loop adjustment amount is based on the comparison between the measured value and the target parameters of each cathode 11, the above adjustment process is performed independently for each cathode 11 in the multi-cathode array to balance the differences in physical characteristics of different cathodes 11 and ensure that the ray intensity of each perspective can comply with the exposure scheduling of the imaging system.

[0123] Through the implementation of steps S410 to S420, this embodiment of the application achieves real-time monitoring and automatic correction of pulse output deviation. This closed-loop control mechanism effectively suppresses long-term output drift caused by objective physical factors such as ambient temperature fluctuations, changes in tube vacuum, and aging of voltage components, ensuring the consistency between the actual output physical quantity of each pulse and the expected set value, further improving the absolute accuracy of pulse-by-pulse amplitude modulation. Furthermore, in the distributed multi-cathode architecture, this feedback mechanism, through independent channel calculation compensation, effectively smooths out the inherent differences in beam output characteristics of each cathode 11's focal point caused by material and assembly tolerances, ensuring baseline consistency of multi-view switching scanning images.

[0124] In an exemplary embodiment, the X-ray source assembly further includes an output port selector 39, which is connected to the gate 12 and the M cathodes 11 respectively. The control method of the X-ray source assembly according to the embodiments of this application may further include step S510.

[0125] In step S510, one of the M cathodes 11 is selected at a certain moment.

[0126] Specifically, in step S510, during the execution of step S510, the control signal is routed and distributed in the spatial dimension using a controlled electrical switching element. Since only a single-channel cathode-gate voltage generator 34 is configured, the generated voltage pulse sequence needs to be sequentially distributed to the nodes of each physical cathode 11 via the output port selector 39. In the specific execution logic, the control terminal of the output port selector 39 receives the gating synchronization signal from the timing generator 33. Before each preset cathode-gate control voltage pulse arrives, the selector closes the electrical path of the corresponding target cathode 11 and disconnects the other paths according to the polling order defined by the pulse operating characteristic parameters, such as the total number of cathodes M and the repetition period N. For example, for a tube with M=3, in three consecutive pulse triggering cycles, the selector will sequentially select the channel in the first cycle, the channel in the second cycle, and the channel in the third cycle, and repeat this action in subsequent cycles. The switching of the gating signal is restricted to the off-time between adjacent beam pulses to prevent the cathode control voltage pulse from being applied to the wrong cathode 11 or to generate arc crosstalk between electrodes.

[0127] By implementing step S510, this embodiment of the application enables a single cathode-gate voltage generator 34 to provide precise, variable-amplitude control voltage pulses to M physically separated independent cathodes 11. This eliminates redundant voltage control modules at the architectural level, reducing the hardware size, wiring dimensions, and manufacturing cost of the multi-cathode array, while maintaining the ability to perform independent addressing and pulse-by-pulse amplitude modulation control on any node of any cathode 11 in the array.

[0128] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application.

Claims

1. An X-ray source assembly, characterized in that, include: An X-ray tube comprising M cathodes, a grid, and an anode, wherein the X-ray tube is controlled such that electrons emitted from the M cathodes pass through the grid and strike the anode to emit X-rays, wherein M is a positive integer greater than or equal to 2; An anode controller, connected to both the anode and the M cathodes, for generating an electric field applied between the anode and the M cathodes; or the anode controller connected to both the anode and the gate, for generating an electric field applied between the anode and the gate; and A cathode controller, connected to the M cathodes and the gate respectively, is used to generate cathode-gate control voltages applied between the M cathodes and the gate respectively. The cathode control voltage applied to each cathode comprises N cathode control voltage pulses, which are time-sequentially arranged, and at least two of the N cathode control voltage pulses have unequal amplitude values, where N is a positive integer greater than or equal to 2.

2. The X-ray source assembly according to claim 1, characterized in that, The cathode controller includes: An output port selector is connected to the gate and the M cathodes respectively, and the output port selector is used to select one of the M cathodes at a time.

3. The X-ray source assembly according to claim 2, characterized in that, The cathode controller is configured to generate the N cathode control voltage pulses according to the pulse operating characteristic parameters of the X-ray tube. The pulse operating characteristic parameters include time parameters and amplitude parameters. The time parameters are used to determine the timing sequence of the N cathode control voltage pulses, and the amplitude parameters are used to determine the amplitude values ​​of the N cathode control voltage pulses.

4. The X-ray source assembly according to claim 3, characterized in that, The cathode controller includes a timing generator and a cathode-gate voltage generator. The timing generator is used to generate a cathode trigger signal sequence according to the timing parameters. The cathode-gate voltage generator is connected to the timing generator and is used to generate the N cathode-gate control voltage pulses according to the cathode trigger signal sequence and the amplitude parameters.

5. The X-ray source assembly according to claim 3 or 4, characterized in that, The amplitude parameter is data that has a mapping relationship with at least one of the following: the cathode control voltage, the cathode emission current, the anode operating current, and the radiation intensity.

6. The X-ray source assembly according to claim 5, characterized in that, The cathode controller is further configured to adjust the amplitude value of at least one of the N cathode control voltage pulses based on at least one of the cathode emission current, the anode operating current, and the ray intensity.

7. The X-ray source assembly according to claim 4, characterized in that, The cathode controller further includes a first memory and a first processor, the first processor being connected to the first memory, the timing generator, and the cathode gate voltage generator, respectively; The first memory is used to store the pulse operating characteristic parameters, and the first processor is configured to: read the pulse operating characteristic parameters stored in the first memory; instruct the timing generator to generate the cathode trigger signal sequence according to the time parameter in the pulse operating characteristic parameters; generate a serialized voltage amplitude command signal according to the amplitude parameter in the pulse operating characteristic parameters; and send the serialized voltage amplitude command signal to the cathode-gate voltage generator according to the time nodes in the cathode trigger signal sequence, so that the cathode-gate voltage generator generates the N cathode-gate control voltage pulses.

8. The X-ray source assembly according to claim 7, characterized in that, The time parameters include pulse width, pulse interval, and repetition period.

9. The X-ray source assembly according to claim 8, characterized in that, The cathode trigger signal sequence has the same pulse width as the pulse width in the time parameter, the rising edge of the pulse in the cathode trigger signal sequence is used to trigger the turn-on, and the falling edge of the pulse in the cathode trigger signal sequence is used to trigger the turn-off; or, The cathode trigger signal sequence has a pulse width that is different from the pulse width in the time parameter. The odd-numbered pulse signals in the cathode trigger signal sequence are used to trigger the turn-on, and the even-numbered pulse signals in the cathode trigger signal sequence are used to trigger the turn-off.

10. The X-ray source assembly according to claim 9, characterized in that, The anode controller is connected to the timing generator, and the timing generator is also used to generate an anode trigger signal according to the time parameter. The anode controller is used to control the opening and closing of the high voltage output applied to the anode according to the anode trigger signal.

11. The X-ray source assembly according to claim 10, characterized in that, The anode trigger signal is a wide pulse that includes the cathode trigger signal sequence in timing. The anode controller is configured to: turn on the high voltage output applied to the anode at the rising edge of the wide pulse, and turn off the high voltage output applied to the anode at the falling edge of the wide pulse.

12. The X-ray source assembly according to any one of claims 9-11, characterized in that, The first processor is configured to read the pulse operating characteristic parameters stored in the first memory according to a preset clock cycle, and send the serialized voltage amplitude command signal to the cathode gate voltage generator according to the time node used to trigger the turn-on in the cathode trigger signal sequence.

13. The X-ray source assembly according to any one of claims 9-11, characterized in that, The first processor is configured to: when the pulse width of the cathode trigger signal sequence is the same as the pulse width in the time parameter, in response to the falling edge of the pulse in the cathode trigger signal sequence, read the pulse operating characteristic parameter stored in the first memory, and in response to the rising edge of the next pulse in the cathode trigger signal sequence, send the serialized voltage amplitude command signal to the cathode gate voltage generator; or, The first processor is configured to: when the pulse width of the cathode trigger signal sequence is different from the pulse width in the time parameter, in response to the even-numbered pulse signals in the cathode trigger signal sequence, read the pulse operating characteristic parameters stored in the first memory, and in response to the subsequent odd-numbered pulse signals in the cathode trigger signal sequence, send the serialized voltage amplitude command signal to the cathode gate voltage generator.

14. The X-ray source assembly according to any one of claims 2-4 and 6-11, characterized in that, The cathode controller also includes an input module for acquiring the pulse operating characteristic parameters of the X-ray tube.

15. The X-ray source assembly according to any one of claims 7-11, characterized in that, The cathode-gate voltage generator includes a cathode-gate voltage sub-generator and a voltage regulator. The cathode-gate voltage sub-generator is used to generate the N cathode-gate control voltage pulses. The voltage regulator is connected to the timing generator, the first processor and the cathode-gate voltage sub-generator respectively. The voltage regulator is used to control the cathode-gate voltage sub-generator to output the N cathode-gate control voltage pulses according to the cathode trigger signal sequence and the voltage amplitude command signal.

16. The X-ray source assembly according to claim 15, characterized in that, Also includes: The acquisition component is used to acquire the actual operating parameters of the X-ray tube and generate measurement values; as well as A feedback controller is connected to both the acquisition component and the first processor. The feedback controller is configured to: convert the measured value according to the mapping relationship between the measured value and the amplitude parameter; compare the converted measured value with the amplitude parameter; and output a difference signal based on the comparison result. And output the difference signal to the first processor.

17. The X-ray source assembly according to claim 16, characterized in that, The first processor is further configured to adjust the amplitude value of at least one voltage amplitude command in the serialized voltage amplitude command signal according to the difference signal.

18. The X-ray source assembly according to claim 17, characterized in that, The acquisition component includes: A cathode current collector, installed in the cathode controller, is used to collect the emission current of the M cathodes; and / or, An anode current collector, installed in the anode controller, is used to collect the operating current of the anode of the X-ray tube; and / or, A sampling detector is installed outside the X-ray tube to collect the intensity of the radiation output from the X-ray tube.

19. The X-ray source assembly according to claim 18, characterized in that, The first memory pre-stores a parameter-voltage mapping relationship, which is used to map the amplitude parameter to the cathode control voltage; the first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter and the parameter-voltage mapping relationship. or, The first memory pre-stores a parameter-cathode current mapping relationship and a cathode current-voltage mapping relationship. The parameter-cathode current mapping relationship is used to map the amplitude parameter to the emission current of the M cathodes, and the cathode current-voltage mapping relationship is used to map the emission current of the M cathodes to the cathode gate control voltage. The first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-cathode current mapping relationship, and the cathode current-voltage mapping relationship. or, The first memory pre-stores a parameter-anode current mapping relationship and an anode current-voltage mapping relationship. The parameter-anode current mapping relationship is used to map the amplitude parameter to the operating current of the anode, and the anode current-voltage mapping relationship is used to map the operating current of the anode to the cathode gate control voltage. The first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-anode current mapping relationship, and the anode current-voltage mapping relationship. or, The first memory pre-stores a parameter-ray intensity mapping relationship and a ray intensity-voltage mapping relationship. The parameter-ray intensity mapping relationship is used to map the amplitude parameter to the ray intensity output by the X-ray tube, and the ray intensity-voltage mapping relationship is used to map the ray intensity output by the X-ray tube to the cathode control voltage. The first processor is configured to determine the voltage amplitude command signal based on the amplitude parameter, the parameter-ray intensity mapping relationship, and the ray intensity-voltage mapping relationship.

20. The X-ray source assembly according to claim 19, characterized in that, The X-ray tube includes M grids, each of which corresponds one-to-one with one of the M cathodes, forming M cathode-grid pairs; wherein, The output port selector is connected to each of the M gates, and the output port selector is configured to select, at any given time, the cathode and gate corresponding to one of the M cathode-gate pairs, or... The M gates are connected in series to the output port selector, which is configured to select one of the M cathodes and turn on the M gates at a given time.

21. The X-ray source assembly according to claim 19 or 20, characterized in that, The X-ray tube includes M anode targets, the anode is connected to the anode controller, the M anode targets are disposed on the anode and correspond one-to-one with the M cathodes to form M cathode-anode target pairs, and the anode controller is used to generate an electric field applied between the M cathode-anode target pairs.

22. A method for controlling an X-ray source assembly, the X-ray source assembly comprising an X-ray tube, the X-ray tube comprising M cathodes, grids, and anodes, characterized in that, The method includes: N cathode control voltage pulses are generated according to the pulse operating characteristic parameters of the X-ray tube to generate cathode control voltage. The N cathode control voltage pulses are arranged at time intervals, and at least two of the N cathode control voltage pulses have different amplitude values. N is a positive integer greater than or equal to 2, and M is a positive integer greater than or equal to 2. The cathode-gate control voltage is applied between the M cathodes and the gate to control the M cathodes to emit electrons; and An electric field is applied between the anode and the M cathodes to control the electrons to pass through the gate and strike the anode to emit X-rays.

23. The control method for an X-ray source assembly according to claim 22, characterized in that, The method further includes: Collect at least one of the following: cathode control voltage, cathode emission current, anode operating current, and radiation intensity; and The amplitude value of at least one of the N cathode control voltage pulses is adjusted according to at least one of the emission current of the cathode, the operating current of the anode, and the radiation intensity.

24. The control method for an X-ray source assembly according to claim 22, characterized in that, The X-ray source assembly further includes an output port selector, which is connected to the gate and the M cathodes respectively. The method further includes: At one time, one of the M cathodes is selected.

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