Load configuration for quasi-single-axis framing and multi-axis synchronized X-ray flash photography

Abstract

The present invention discloses a load configuration for quasi-single-axis framing and multi-axis synchronous X-ray flash photography, comprising an anode base plate and a cathode disk; a plurality of anode heads are provided on the anode base plate; a plurality of first through holes are provided on the cathode disk, the positions of the first through holes corresponding to the positions of the anode heads, and metal wires for short-circuiting the cathode and anode are provided in the first through holes. By adopting different load series and parallel connection methods and metal wire and RPD structural parameters, the light emission time can be flexibly controlled and impedance matching with the pulse drive source can be achieved. The present invention provides a technical path for realizing quasi-coaxial framing flash photography; at the same time, the off-axis photography capability of the metal wire short-circuiting the RPD can be used to perform simultaneous multi-axis imaging of the object, thereby realizing three-dimensional reconstruction of the object.

Description

Technical Field

[0001] The invention belongs to the technical field of X-ray flash photography, and relates to a load configuration for quasi-single-axis framing and multi-axis synchronous X-ray flash photography. Background Art

[0002] Hard X-ray (>10keV) flash photography is an effective means of obtaining the density, velocity, structure, morphology and other characteristics of high-density and high-speed targets. It has important applications in the fields of materials, detonation, weapons and high-energy density physics. Among the main load configurations used to generate X-ray point sources, the rod-pinch diode (RPD) has the greatest potential for high resolution. Its typical configuration is as follows: Figure 1 As shown, one end of the rod-shaped anode is sharpened and extends a distance beyond the annular cathode disk, with the cathode and cathode electrodes coaxially positioned. Typical structural parameters include the anode rod diameter, the taper angle of the anode rod tip, the length of the anode rod extending above the cathode disk surface, the cathode disk thickness, the cathode disk hole diameter, and the cathode-anode gap (AK-gap) size. Under high current from a pulsed power source, the RPD's self-magnetic field focuses a high-energy electron beam onto the tip of the rod-shaped anode, generating bremsstrahlung radiation with photon energies exceeding 10 keV.

[0003] The impedance of vacuum gap RPD is relatively large and is usually driven by a large high-impedance pulse source. The pre-filled plasma RPD (Plasma-filled Rod-pinch Diode, PFRPD) greatly reduces the impedance of vacuum RPD, making it suitable for impedance matching with low-voltage, high-current, low-impedance small pulse sources, thus achieving miniaturization of X-ray flash cameras. Among them, the metal wire short-circuit RPD configuration is a form of PFRPD, which uses the plasma generated by the electric explosion of the metal wire to achieve the effect of plasma pre-filling. The configuration is as follows: Figure 2 As shown, several metal wires radially short-circuit the cathode disk and anode rod across the vacuum gap. By adjusting the quality and quantity of the metal wires and the structural parameters of the RPD, the RPD's light emission time and impedance matching with the pulse source can be controlled.

[0004] The current X-ray flash camera is based on the configuration of a single RPD load, and most of them use a vacuum gap RPD. When it is working, the high-energy electron beam is emitted from the edge of the cathode disk in the AK gap and grazes the tip of the anode rod from the side with the Larmor rotation radius. The point source it produces is not an ideal sphere, but a conical area with a similar shape to the tip of the anode rod, that is, the axial size is small and the radial size is large. This feature limits the resolution of its off-axis photography. In comparison, the anode and cathode plasma motion process of the RPD short-circuited with a metal wire is different: the high-energy electron beam starts from the equivalent cathode plasma shell and bombards the tip of the anode rod head-on, which will increase the near-sphericity of the point source, so that the flash photography load configuration of the RPD short-circuited with a metal wire has a certain off-axis photography capability. The working diagram of a single-load X-ray flash camera using a RPD short-circuited with a metal wire is shown in the figure. Figure 3 shown.

[0005] Existing X-ray flash cameras utilize a single RPD (resonance-produced device) for light output. This vacuum-gap RPD exhibits poor off-axis imaging capabilities. Furthermore, this configuration precludes framing. Furthermore, a single light source can only provide two-dimensional (2D) pose information about the object being measured. 3D reconstruction requires two or more flash cameras, each requiring synchronization of timing. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem that the configuration of the existing technology cannot achieve framing photography, and to provide a load configuration for quasi-single-axis framing and multi-axis synchronous X-ray flash photography. The present invention is applied to a pulse drive source with low impedance, sufficiently large current and high impedance, respectively. By adjusting the parameters of the metal wire and the structural parameters of the RPD, impedance matching is achieved with the drive source, and the light emission time of a single RPD is controlled to achieve time-sharing and multiple light emission under a single pulse to realize quasi-single-axis framing photography of objects at a longer distance, or to use multiple RPDs with the same parameters to emit light simultaneously under a single pulse to realize off-axis photography of the object, thereby obtaining a multi-axis image of the object and realizing three-dimensional reconstruction of the object through image algorithms.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a load configuration for quasi-single-axis framing and multi-axis synchronized X-ray stroboscopic photography, comprising:

[0009] an anode bottom plate, wherein a plurality of anode heads are arranged on the anode bottom plate;

[0010] The cathode disk is provided with a plurality of first through holes, the positions of the first through holes correspond to the positions of the anode heads, and metal wires for short-circuiting the cathode and the anode are arranged in the first through holes.

[0011] The further improvement of the above load configuration is:

[0012] An anode rod is installed on the anode head. The anode rod is arranged perpendicular to the anode bottom plate and has a sharpened end. The end extends out of the first through hole on the cathode disk and contacts the metal wire.

[0013] There are a plurality of metal wires, which are arranged in the first through hole of the cathode disk and are used to short-circuit the cathode disk and the anode rod.

[0014] The anode rod is in contact with each wire.

[0015] In a second aspect, the present invention provides a load configuration for quasi-single-axis framing and multi-axis synchronous X-ray stroboscopic photography, comprising:

[0016] an anode bottom plate, wherein a plurality of anode heads are arranged on the anode bottom plate;

[0017] An intermediate stage, wherein a plurality of second through holes are formed on the intermediate stage, and the positions of the second through holes correspond to the positions of the anode heads on the anode bottom plate; and a plurality of anode heads are also provided on the intermediate stage;

[0018] The cathode disk is provided with a plurality of first through holes, the positions of the first through holes corresponding to the positions of the anode heads on the intermediate stage; metal wires are provided in the first through holes and the second through holes.

[0019] The further improvement of the above load configuration is:

[0020] An anode rod is installed on the anode head. The anode rod is arranged perpendicular to the anode bottom plate or the middle stage, and the end thereof is sharpened; the end extends out of the first through hole or the second through hole and contacts the metal wire.

[0021] A connecting piece is provided in the middle of the intermediate stage, and the connecting piece is arranged perpendicular to the intermediate stage to suspend the intermediate stage on the cathode disk.

[0022] The connecting piece includes a horizontal rod and a vertical rod. The vertical rod is arranged perpendicular to the middle stage, one end of which is connected to the middle stage, and the other end is connected to the middle part of the horizontal rod. The horizontal rod is arranged parallel to the middle stage. A third through hole is opened in the middle of the cathode disk. The upper end of the vertical rod passes through the third through hole, and the horizontal rod is located above the third through hole. Insulators are provided in the gaps between the horizontal rod and the cathode disk, and between the vertical rod and the third through hole.

[0023] The cathode disk is also provided with a shading plate for shading the insulator.

[0024] There are a plurality of metal wires, which are arranged in the first through hole of the cathode disk and the second through hole of the intermediate stage, and are respectively used to short-circuit the cathode disk, the intermediate stage and the anode rod; the anode rod is in contact with each metal wire.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention utilizes various load series and parallel connection schemes, as well as metal wire and RPD structural parameters, to flexibly control light emission timing and achieve impedance matching with the pulse drive source. This invention provides a technical path for achieving quasi-coaxial framed flash photography. Furthermore, by utilizing the off-axis imaging capability of the RPD short-circuited by the metal wire, simultaneous multi-axis imaging of the object is achieved, enabling three-dimensional reconstruction of the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is a typical rod pinch diode configuration, where (a) is a cross-sectional view and (b) is a right side view.

[0029] Figure 2 It is a metal wire shorting rod pinch diode configuration, where (a) is a cross-sectional view and (b) is a right side view.

[0030] Figure 3 A cross-sectional view of the partial structure of a flash camera based on a rod-pinch diode.

[0031] Figure 4 This is a cross-sectional view of a flash camera load configuration of a parallel-rod pinch diode according to an embodiment of the present invention.

[0032] Figure 5 for Figure 4 Top view of .

[0033] Figure 6 This is a cross-sectional view of a flash photography load configuration of a series-connected rod-pinch diode according to an embodiment of the present invention.

[0034] Figure 7 Schematic diagram of the principle of taking pictures of an object using dual X-ray point sources of the present invention.

[0035] Among them: 1-anode head, 2-anode rod, 3-cathode disk, 4-metal wire, 5-anode, 6-transmission line, 7-insulator, 8-cathode, 9-cavity, 10-measured object, 11-window, 12-high-energy X-ray, 13-imaging plate, 14-anode base plate, 15-intermediate stage, 16-light shield. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0039] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0041] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0042] The present invention is described in further detail below with reference to the accompanying drawings:

[0043] Example 1: Parallel load configuration

[0044] The parallel load configuration of the RPD with a metal wire short circuit is suitable for small pulse drive sources with low impedance and large enough current. Figure 4 and Figure 5 As shown: several anode heads share an anode base plate and are distributed on the same circumference; holes are opened at corresponding positions on the cathode plate so that the anode rod extends a certain distance from the upper surface of the cathode disk; metal wires are arranged on the upper surface of the cathode disk to short-circuit the cathode and cathode.

[0045] An embodiment of the present invention discloses a load configuration for quasi-single-axis framing and multi-axis synchronous X-ray flash photography, comprising an anode base plate 14 and a cathode disk 3. A plurality of anode heads 1 are provided on the anode base plate 14; a plurality of first through holes are provided on the cathode disk 3, the positions of the first through holes corresponding to the positions of the anode heads 1, and metal wires 4 for short-circuiting the cathode and the anode are provided in the first through holes. An anode rod 2 is mounted on the anode head 1, the anode rod 2 being arranged perpendicular to the anode base plate 14, with the end extending out of the first through hole on the cathode disk 3 and in contact with the metal wire 4. There are two metal wires 4, which are cross-arranged in the first through hole of the cathode disk 3 for short-circuiting the cathode disk 3 and the anode rod 2. The anode rod 2 is in contact with the intersection of the two metal wires.

[0046] like Figure 4 and Figure 5 As shown, Figure 4 and Figure 5 Taking four loads connected in parallel as an example, in practice, the number of RPD loads can be increased or decreased as needed. By adjusting the shorting wire parameters of each load and the RPD structure parameters, different light emission times can be achieved, achieving time-sharing light emission and enabling quasi-single-axis multi-frame photography of distant objects. By aligning the shorting wire parameters of each load and the RPD structure parameters, images of objects at close range can be obtained at the same time but on different axes, allowing for 3D reconstruction using graphics algorithms.

[0047] Example 2: Series load configuration

[0048] The series load configuration of the RPD with a metal wire short circuit is suitable for small pulse drive sources with high impedance. Figure 6 As shown in the front cross-sectional view: the overall load is divided into three levels: the anode base plate is the same as that in the parallel load configuration; the intermediate stage serves as the cathode of the RPD load on the anode base plate, with holes opened at the corresponding positions and metal wires arranged. It also serves as the anode base plate of another RPD load. The intermediate stage is suspended between the cathode and the anode base plate by a hanging column, and then fixed to the cathode disk by an insulator. Since the high-energy X-rays generated during light emission will greatly reduce the flashover strength of the insulation surface, a light-shielding structure is required for the insulator in actual applications, but the design of the insulator itself is not within the scope of this patent ( Figure 6The insulators in the figure are only schematic diagrams of their positions and do not represent the actual situation); a through hole for the intermediate-stage hanging column is set at the center of the cathode, a hole is opened and a metal wire is arranged at the corresponding position of the RPD load on the intermediate stage, and a light outlet hole is set at the corresponding position of the RPD load on the anode bottom plate.

[0049] An embodiment of the present invention discloses a load configuration for quasi-single-axis framing and multi-axis synchronized X-ray flash photography, comprising an anode base plate 14, an intermediate stage 15, and a cathode disk 3. Several anode heads 1 are provided on the anode base plate 14; several second through-holes are provided on the intermediate stage 15, the positions of which correspond to the anode heads 1 on the anode base plate 14; several anode heads 1 are also provided on the intermediate stage 15; several first through-holes are provided on the cathode disk 3, the positions of which correspond to the anode heads 1 on the intermediate stage 15; and metal wires 4 are provided in both the first and second through-holes. An anode rod 2 is mounted on the anode head 1, perpendicular to the anode base plate 14 or the intermediate stage 15, with its end extending through the first or second through-hole and contacting the metal wire 4. A connector is provided in the middle of the intermediate stage 15, perpendicular to the intermediate stage 15, suspending the intermediate stage 15 from the cathode disk 3. The connector includes a horizontal bar and a vertical bar. The vertical bar is arranged perpendicular to the intermediate stage 15, with one end connected to the intermediate stage 15 and the other end connected to the middle of the horizontal bar. The horizontal bar is arranged parallel to the intermediate stage 15. A third through-hole is provided in the middle of the cathode disk 3, through which the upper end of the vertical bar passes, with the horizontal bar positioned above the third through-hole. Insulators 7 are provided in the gaps between the horizontal bar and the cathode disk 3, and between the vertical bar and the third through-hole. A light shielding plate 16 is also provided on the cathode disk 3 to shield the insulators 7 from light. Two metal wires 4 are arranged crosswise in the first through-hole of the cathode disk 3, short-circuiting the cathode disk 3 and the anode rod 2. The anode rod 2 contacts the intersection of the two metal wires.

[0050] like Figure 6 As shown, Figure 6 Taking two loads connected in series as an example, in practice, the number of intermediate stages can be increased as needed to achieve the goal of connecting more loads in series. By adjusting the shorting wire parameters and RPD structure parameters of each load, different light emission times can be obtained, achieving time-sharing light emission, and performing quasi-single-axis multi-frame photography of distant objects. By aligning the shorting wire parameters and RPD structure parameters of each load, it is possible to obtain images of objects at close range at the same time but on different axes, and use graphics algorithms for 3D reconstruction.

[0051] Principle of the present invention:

[0052] (1) Parameter adjustment:

[0053] Load parameters include: the number of RPD loads connected in series or parallel; for a single RPD load: the total mass of the wires, the diameter of the anode rod, the taper angle of the anode rod tip, the length of the anode rod tip extending above the plane of the wires, the diameter of the cathode disk hole, and the cathode disk thickness. Experimental studies have shown that, given the same total wire mass, the arrangement (cross or parallel) and number of wires do not significantly change the load's operating characteristics.

[0054] The load configuration of a wire-shorted RPD can be considered a pure inductor during the initial short-circuit phase, but behaves as a resistor during the light-emitting phase. Due to the series-parallel rules for inductors / resistors (the inductance / resistance of multiple inductors / resistors connected in series is the sum of the inductance / resistance of each inductor / resistor; the inductance / resistance of multiple inductors / resistors connected in parallel is the sum of the reciprocals of the inductance / resistance of each parallel inductor / resistor), varying the number of loads can achieve impedance matching with different pulse power sources: the more loads in series, the greater the total load impedance; the more loads in parallel, the smaller the total load impedance. In other words, impedance matching with the pulse source can be achieved by using different numbers of RPDs in either series or parallel configurations.

[0055] Experiments have shown that by adjusting the total mass M of the metal wires (adjusting the number of wires or using wires of different diameters) and the length L of the anode rod tip extending from the plane of the metal wires (the two easiest adjustment methods), the impedance characteristics of the load and the light emission time can be effectively adjusted. In a laboratory experiment with a single RPD load on a 70kV, 400kA pulse source with a rise time of 400ns, the load impedance increased from 0.32Ω to 0.50Ω, and the light emission time was delayed from 198ns after the start of current loading to 250ns. The increase in M from 6×10 -6 g increases to 12×10 -6 g, the load impedance decreased from 0.32Ω to 0.23Ω, and the light emission time was delayed from 198ns after the start of current loading to 332ns. This means that by adjusting the shorting wire parameters and the RPD structure parameters, impedance matching with the pulse source can be achieved. By adjusting the parameters of each RPD load, time-sharing light emission can be achieved, allowing for quasi-single-axis framing of objects at a distance.

[0056] (2) Three-dimensional reconstruction of the object:

[0057] Experiments have shown that identical load configurations can achieve simultaneous light output, and parallel configurations can evenly distribute the light. Furthermore, experiments have shown that the side profile of the X-ray point source produced by the short-circuited RPD load is nearly circular, demonstrating a certain degree of off-axis imaging capability. By aligning the short-circuit wire parameters and RPD structural parameters for each load, it is possible to obtain simultaneous, non-axial images of objects at close range, enabling 3D reconstruction using graphics algorithms.

[0058] The basic principle of three-dimensional reconstruction is as follows Figure 7 As shown. Taking two X-ray point sources as an example, if the positions of the two point sources (which can be roughly considered as the position of the anode rod tip when the load is installed) and the position of the imaging plate are known, the object can be reconstructed in three dimensions using two X-ray images of the object. A certain measured point on the object will generate corresponding points on the two images: the corresponding point generated by point source 1 is recorded as A, and the corresponding point generated by point source 2 is recorded as B. Then, in space, the intersection of the line connecting point A and point source 1 and the line connecting point B and point source 2 is the spatial position of the measured point on the object. By restoring the above spatial positions of several points on the object, the object can be reconstructed in three dimensions.

[0059] In practice, due to the viewing angle, it can be difficult to distinguish corresponding points in two X-ray images of an object. However, reconstruction can be performed by using more axes: the spatial line connecting the corresponding point of a measured point on the imaging plate and the corresponding X-ray point source will still intersect at the spatial position of the measured point on the object. 3D reconstruction using more axes (three or more) can reduce reconstruction errors and provide more corresponding point groups when the viewing angle makes it difficult to distinguish corresponding points in multiple images of a measured point.

[0060] At the same time, "anchor points" of varying densities (e.g., small spheres made of high-density materials like lead, tungsten, and gold) can be attached to the object. Due to their varying attenuation of X-rays, these anchor points appear in varying grayscales during X-ray imaging, making them easy to identify. These anchor points can be used to mark certain characteristic points on the object (e.g., the intersection of straight edges, or the starting and ending points of a crack to be detected).

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. Load configuration for quasi-single-axis framing and multi-axis synchronous X-ray flash photography, characterized in that: include: an anode bottom plate (14), wherein a plurality of anode heads (1) are provided on the anode bottom plate (14); A cathode disk (3), wherein a plurality of first through holes are formed on the cathode disk (3), the positions of the first through holes corresponding to the positions of the anode head (1), and metal wires (4) for short-circuiting the cathode and cathode are provided in the first through holes; An anode rod (2) is mounted on the anode head (1), the anode rod (2) being arranged perpendicular to the anode bottom plate (14) and having a sharpened end; the end extending out of a first through hole on the cathode disk (3) and in contact with a metal wire (4); the metal wires (4) are in plurality and arranged in the first through hole of the cathode disk (3) for short-circuiting the cathode disk (3) and the anode rod (2); the anode rod (2) is in contact with each metal wire.

2. Load configuration for quasi-single-axis framing and multi-axis synchronous X-ray flash photography, characterized in that: include: an anode bottom plate (14), wherein a plurality of anode heads (1) are provided on the anode bottom plate (14); An intermediate stage (15), wherein a plurality of second through holes are provided on the intermediate stage (15), and the positions of the second through holes correspond to the positions of the anode heads (1) on the anode bottom plate (14); and a plurality of anode heads (1) are also provided on the intermediate stage (15); A cathode disk (3), wherein a plurality of first through holes are formed on the cathode disk (3), and the positions of the first through holes correspond to the positions of the anode heads (1) on the intermediate stage (15); metal wires (4) are provided in both the first through holes and the second through holes; An anode rod (2) is mounted on the anode head (1), the anode rod (2) is arranged perpendicular to the anode bottom plate (14) or the intermediate stage (15), and the end thereof is sharpened; the end thereof extends out of the first through hole or the second through hole and contacts the metal wire (4); a connecting piece is arranged in the middle of the intermediate stage (15), the connecting piece is arranged perpendicular to the intermediate stage (15), and the intermediate stage (15) is suspended on the cathode disk (3); the connecting piece includes a horizontal rod and a vertical rod, the vertical rod is arranged perpendicular to the intermediate stage (15), one end is connected to the intermediate stage (15), and the other end is connected to the middle of the horizontal rod; the horizontal rod is arranged parallel to the intermediate stage (15); a third through hole is opened in the middle of the cathode disk (3), the upper end of the vertical rod passes through the third through hole, and the horizontal rod is located above the third through hole; an insulator (7) is arranged in the gap between the horizontal rod and the cathode disk (3), and between the vertical rod and the third through hole; The metal wires (4) are in plurality and are arranged in the first through hole of the cathode disk (3) and the second through hole of the intermediate stage (15), respectively used to short-circuit the cathode disk (3), the intermediate stage (15) and the anode rod (2); the anode rod (2) is in contact with each metal wire.

3. The load configuration for quasi-single-axis framing and multi-axis synchronous X-ray stroboscopic photography according to claim 2, characterized in that: A light shielding plate (16) is also provided on the cathode disk (3) for shielding the insulator (7).

Images