High-efficiency X-ray imager with built-in transmission line and preparation method thereof

Abstract

The invention provides a high-efficiency X-ray imager containing a built-in transmission line and a preparation method of the high-efficiency X-ray imager. A conductive strip is arranged on the input surface of a lower micro-channel plate, conductive strips are arranged on the input surface and the output surface of an upper micro-channel plate, and the output surface of the upper micro-channel plate is oppositely attached to the input surface of the lower micro-channel plate; the conduction band strip units on the two faces are in one-to-one correspondence, and the micro-channels of the two micro-channel plates are in butt joint to form the micro-channel plate assembly. According to the micro-channel plate assembly, the two groups of micro-channels are in butt joint with each other, the gain is improved, detection of weak electronic signals is met, meanwhile, the design of the conductive strips and the built-in transmission lines formed by the conductive strips is combined, multi-mode polaritons are excited under the single frequency, and the requirement for parallel processing of multi-dimensional information is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric detection, in particular to a high-efficiency X-ray imager with built-in transmission lines and a preparation method thereof. BACKGROUND

[0002] Microchannel Plate (MCP) is a simple and compact electron multiplier device developed successfully in the late 1960s. Its shape is a thin round piece of millions of fine parallel hollow glass tubes. Each hollow tube channel acts like a continuous dynode multiplier, which can detect particles, electrons, X-rays and UV photons. It has the advantages of low power consumption, self-saturation, high-speed detection and low noise, and is widely used in various detectors.

[0003] The conventional MCP has a relatively low imaging efficiency for X-ray detection. In order to improve the imaging efficiency of the MCP, a material with high conversion efficiency can be plated on the input surface of the MCP as a reflective cathode, which can greatly improve the signal photon incidence to the MCP and enhance the imaging efficiency. The material used is mostly halide such as cesium iodide.

[0004] However, the existing MCP still has deficiencies in the imaging efficiency of weak electronic signals. At the same time, it can only transmit one kind of signal at a single frequency, which is difficult to meet the actual demand of multi-dimensional information parallel processing. SUMMARY

[0005] The present application aims to overcome the deficiencies of the prior art and provides a high-efficiency X-ray imager with built-in transmission lines and a preparation method thereof. By using a microchannel plate assembly, the gain is improved by butting two groups of microchannels against each other, which meets the detection of weak electronic signals. At the same time, by designing the built-in transmission lines composed of conductive strips, multiple modes of polaritons are excited at a single frequency, which meets the demand of multi-dimensional information parallel processing.

[0006] According to a first aspect of the present application, a high-efficiency X-ray imager with built-in transmission lines is provided, comprising:

[0007] A first microchannel plate substrate having a first surface and a second surface arranged oppositely, wherein the first surface is defined as a first input surface, and the second surface is defined as a first output surface;

[0008] A first conductive layer is prepared on the first input surface and the inner wall of the microchannel, and the first conductive layer is arranged to have a plurality of first conductive strip units independent of each other. A material film layer with photoelectric conversion function is prepared on the first input surface with the first conductive layer and the inner wall of the corresponding microchannel to form a reflective photoelectric cathode, and a dense and uniform protective layer is prepared on the surface of the reflective photoelectric cathode.

[0009] A second conductive layer is prepared on the first output surface and the inner wall of the microchannel. The second conductive layer is configured to have multiple independent second conductive strip units, thereby forming the first workpiece.

[0010] The second microchannel board substrate has a third side and a fourth side arranged opposite to each other, wherein the third side is defined as the second input side and the fourth side is defined as the second output side;

[0011] A third conductive layer is prepared on the second input surface and the inner wall of the microchannel, and the third conductive layer is configured to have multiple independent third conductive strip units;

[0012] A fourth conductive layer is prepared on the second output surface and the inner wall of the microchannel. The fourth conductive layer is configured as a continuous structure throughout and completely covers the first output surface, thereby forming the second workpiece.

[0013] A microchannel plate assembly is formed by stacking a first workpiece and a second workpiece, wherein a first output surface and a second input surface are fitted together and the microchannels of the first workpiece and the microchannels of the second workpiece are connected, and a second conductive layer and a third conductive layer constitute an internal transmission line.

[0014] As an optional implementation, each strip of the second conductive layer is arranged in a corresponding manner with each strip of the third conductive layer; when the first output surface is attached to the second input surface, each second conductive strip unit and each third conductive strip unit form a one-to-one correspondence.

[0015] As an optional implementation, the strip width of the first conductive strip unit is greater than the strip width of the second conductive strip unit.

[0016] As an optional implementation, the spacing between adjacent first conductive strip units is smaller than the spacing between adjacent second conductive strip units.

[0017] As an optional implementation, in the microchannel plate assembly, the microchannels of the first workpiece and the second workpiece are superimposed to form a V-shaped channel structure.

[0018] As an optional implementation, the diameter and thickness of the first microchannel plate substrate are both smaller than the diameter and thickness of the second microchannel plate substrate.

[0019] As an optional implementation, the diameter of the micropores in the first microchannel plate substrate is smaller than the diameter of the micropores in the second microchannel plate substrate.

[0020] As an optional implementation, the depth to which the first conductive layer, the second conductive layer, the third conductive layer and the fourth conductive layer cover the inner wall of the microchannel is not less than 1 / tan(θ), where θ is the chamfer angle of the MCP.

[0021] As an optional implementation, the first conductive layer, the second conductive layer, the third conductive layer and the fourth conductive layer include one or more multilayer films prepared from copper, nickel and gold.

[0022] As an optional implementation, the reflective photocathode covers the entire first input surface and a predetermined depth of the inner wall of the microchannel, with a depth not less than 1 / tan(θ), where θ is the chamfer angle of the MCP.

[0023] As an optional implementation, the reflective photocathode is selected from materials that have high responsiveness to ultraviolet light and X-rays, including one or more of cesium iodide, copper iodide, potassium bromide, and potassium chloride.

[0024] As an optional implementation, the protective layer comprises a film prepared from one or more of silicon oxide, hafnium oxide, aluminum oxide, titanium oxide, and silicon nitride.

[0025] According to a second aspect of the present invention, a method for fabricating a high-efficiency X-ray imager with a built-in transmission line is provided, comprising the following steps:

[0026] A first conductive layer having multiple independent first conductive strip units is prepared on the input surface and the inner wall of the microchannel of the first microchannel substrate, and a second conductive layer having multiple independent second conductive strip units is prepared on the output surface and the inner wall of the microchannel of the first microchannel substrate.

[0027] A reflective photocathode is formed by preparing a material film layer with photoelectric conversion function in the entire area of ​​the first input surface with the first conductive layer and the inner wall of the corresponding microchannel, and a protective layer is prepared on the surface of the reflective photocathode to obtain the first workpiece;

[0028] A third conductive layer with multiple independent third conductive strip units is prepared on the input surface and the inner wall of the microchannel of the second microchannel plate substrate, and a fourth conductive layer that fully covers the output surface of the first microchannel plate is prepared on the output surface and the inner wall of the microchannel of the second microchannel plate substrate to obtain the second workpiece.

[0029] The first output surface is bonded to the second input surface, and each second conductive strip unit is made to correspond one-to-one with each third conductive strip unit. The microchannels of the first workpiece and the microchannels of the second workpiece are connected to form a microchannel assembly.

[0030] As an optional implementation, the strip width of the first conductive strip unit is greater than the strip width of the second conductive strip unit.

[0031] As an optional implementation, the spacing between adjacent first conductive strip units is smaller than the spacing between adjacent second conductive strip units.

[0032] As an optional implementation, the first conductive layer, the second conductive layer, the third conductive layer and the fourth conductive layer include one or more multilayer films prepared from copper, nickel and gold.

[0033] As can be seen from the above technical solutions of the present invention, the high-efficiency X-ray imager with built-in transmission line proposed in this invention has the following advantages:

[0034] 1. By stacking two workpieces and connecting the two microchannels, when an electronic signal is incident on the first MCP, the internal channel wall will generate secondary electrons due to primary electron bombardment, forming the first round of multiplication. These electronic signals amplified by the first MCP will continue to be incident on the second MCP, triggering a new round of secondary electron multiplication in its channel. This cascade multiplication effect allows the electronic signal to be amplified by two stages, and the gain can be greatly improved, thereby significantly enhancing the detection capability of weak signals.

[0035] 2. By setting conductive strips on the input surface of the lower workpiece and conductive strips on both the input and output surfaces of the upper workpiece, and stacking the two microchannel plates, this conductive strip structure can control the excitation conditions (such as period matching and wave vector coupling) and mode constraints of polaritons, thereby achieving the coexistence of multimode polaritons at a single frequency. Furthermore, this design of multiple independent strip units divides the electrodes into independent units through insulating strips. The insulating layer between adjacent strips blocks the direct coupling of electric fields, reducing the probability of overflowing electrons being captured by adjacent channels. At the same time, each strip corresponds to a set of channels, limiting the multiplication and output of electrons within the strip range, thereby effectively reducing crosstalk between channels. In this way, the requirements for parallel crosstalk-free processing of multidimensional information are met, providing a physical basis for multispectral imaging or on-chip multichannel communication. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of an exemplary high-efficiency X-ray imager with a built-in transmission line according to the present invention.

[0037] Figure 2 This is a schematic diagram of the input and output surfaces of the first microchannel plate substrate after the conductive layer has been deposited, as exemplified by this invention; wherein, Figure 2 Part A in the diagram is the input surface. Figure 2 Part B in the diagram is the output surface.

[0038] Figure 3This is a schematic diagram of the input and output surfaces of an exemplary second microchannel plate substrate after the conductive layer has been deposited; wherein, Figure 3 Part A in the diagram is the input surface. Figure 3 Part B in the diagram is the output surface.

[0039] Figure 4 This is a partially enlarged schematic diagram of an exemplary MCP component of the present invention.

[0040] Figure 5 This is a physical image of MPC1 in an embodiment of the present invention.

[0041] Figure 6 This is a physical image of MPC2 in an embodiment of the present invention.

[0042] Figure 7 This is a schematic diagram of the electronic imaging test results of MCP1 on a microchannel plate tester in an embodiment of the present invention.

[0043] Figure 8 This is a schematic diagram of the electronic imaging test results of MCP2 on a microchannel plate tester in an embodiment of the present invention.

[0044] Figure 9 This is a gain test diagram of the MCP component in an embodiment of the present invention; where A is the equivalent voltage pulse height and B is the pulse count. Detailed Implementation

[0045] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0046] Various aspects of the invention are described in this disclosure with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. The embodiments of this disclosure are not necessarily intended to encompass all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described below in more detail, can be implemented in any of a number of ways.

[0047] Microchannel plates are typically made from glass substrates and core glass substrates. They are produced through processes such as wire drawing, wire drawing, screen arrangement, screen pressing, screen cutting, polishing, etching, and hydrogen reduction. The required film layers are then deposited on both sides of the substrate, i.e. the input and output surfaces, to obtain the final product.

[0048] The microchannel plate substrate in this invention refers to a substrate made from skin glass and core glass as raw materials, and produced through processes such as wire drawing, multi-wire drawing, screen arrangement, screen pressing, screen cutting, polishing, etching, and hydrogen reduction.

[0049] Combination Figures 1-4 As shown, the exemplary high-efficiency X-ray imager of the present invention with a built-in transmission line includes a first workpiece 1 and a second workpiece 2 stacked in sequence.

[0050] The first workpiece 1 includes a first microchannel plate substrate 10, which has a first surface and a second surface disposed opposite to each other, wherein the first surface is defined as a first input surface and the second surface is defined as a first output surface.

[0051] like Figure 2 As shown in part A, a first conductive layer 11 is prepared on the first input surface and the inner wall of the microchannel. The first conductive layer is configured to have multiple independent second conductive strip units 11-1. A material film layer with photoelectric conversion function is prepared on the first input surface with the first conductive layer and the inner wall of the corresponding microchannel to form a reflective photocathode. A dense and uniformly thick protective layer is prepared on the surface of the reflective photocathode.

[0052] like Figure 2 As shown in part B, a second conductive layer 12 is prepared on the first output surface and the inner wall of the microchannel. The second conductive layer is configured to have multiple independent second conductive strip units 12-1.

[0053] The second workpiece 2 includes a second microchannel plate substrate 20, which has a third surface and a fourth surface arranged opposite to each other, wherein the third surface is defined as the second input surface and the fourth surface is defined as the second output surface.

[0054] like Figure 3 As shown in part A, a third conductive layer 21 is prepared on the second input surface and the inner wall of the microchannel. The third conductive layer is configured to have multiple independent third conductive strip units 21-1.

[0055] like Figure 3 As shown in part B, a fourth conductive layer 22 is prepared on the second output surface and the inner wall of the microchannel. The fourth conductive layer is configured as a continuous structure throughout the entire area and completely covers the first output surface.

[0056] The first output surface of the first workpiece 10 and the second input surface of the second workpiece 20 are fitted together, and each strip of the second conductive layer corresponds one-to-one with each strip unit of the third conductive layer. The microchannels 13 of the first workpiece and 23 of the second workpiece are then connected, thereby superimposing the microchannels of the first and second workpieces to form a structure like... Figure 4 The V-shaped channel structure shown in the diagram, and the corresponding second and third conductive strip units together form the built-in transmission lines of the component.

[0057] In some embodiments, to meet design requirements, the second and third conductive strip units, which serve as built-in transmission lines, should have identical dimensions.

[0058] In an optional example, the number of second conductive strip units is the same as the number of third conductive strip units, the strip width D2 of the second conductive strip unit is equal to the strip width D3 of the third conductive strip unit, and the spacing d2 between adjacent second conductive strip units is equal to the spacing d3 between adjacent third conductive strip units, so that each strip of the second conductive layer is correspondingly set with each strip of the third conductive layer.

[0059] In some embodiments, the first conductive layer serves as the signal input surface, and the second and third conductive layers serve as transmission lines. To improve transmission efficiency, the strip units of the second and third conductive layers should reduce electron consumption while ensuring transmission performance.

[0060] In an optional example, the strip width D1 of the first conductive strip unit is greater than the strip width D2 of the second conductive strip unit, and D1 is particularly preferred to be (1~2)D2.

[0061] In an optional example, the spacing d1 between adjacent first conductive strip units is smaller than the spacing d2 between adjacent second conductive strip units, and more preferably d2 = (1~2)d1.

[0062] In an optional example, the first and second workpieces are bonded together directly with non-conductive adhesive, thus the first and second workpieces are superimposed and bonded to form a microchannel plate assembly.

[0063] In other alternative examples, the bonded microchannel plate assembly is placed in a nitrogen chamber for ventilation, and then packaged to obtain the desired X-ray imager.

[0064] The microchannel plate assembly of the present invention:

[0065] (1) The upper microchannel is narrow and the lower microchannel is wide. The two microchannels form a V-shaped structure channel that is narrow at the top and wide at the bottom. The synergistic effect of the narrow channel to enhance the initial collision efficiency, the wide channel to expand the multiplication space, and the directional transmission to reduce losses significantly improves the cumulative effect of electron secondary emission and ultimately achieves higher gain.

[0066] The narrow channel at the top can "focus" the incident electrons, significantly increasing the probability of collisions between the electrons and the inner wall, quickly initiating secondary emission and generating a large number of secondary electrons in the first batch.

[0067] The wide channel below provides more space for the secondary electrons to diffuse. After the electron beam diffuses, it can still maintain high-frequency collisions with the inner wall, avoiding mutual interference or loss due to the narrow channel. This allows the secondary emission process to accumulate continuously, and the final output number of electrons is much higher than that of a single-channel structure.

[0068] Meanwhile, the V-shaped structure, with its narrow upper and wide lower angle design, forms a unidirectional guided channel trajectory. After being accelerated in the narrow channel, electrons are forced to move towards the output end when they enter the wide channel due to the change in channel angle. This significantly reduces the proportion of backscattered electrons. This directional transmission characteristic allows more electrons to participate in the secondary emission cycle, reducing ineffective losses and improving electron utilization.

[0069] This significantly enhances the cumulative effect of secondary electron emission, ultimately achieving higher gain.

[0070] (2) The setting of conductive strips and the size differentiation design and spatial correspondence of conductive strips, by adjusting the mode matching conditions and field distribution characteristics of polaritons, can achieve stable excitation and orderly transmission of multimode polaritons at a single frequency, thereby meeting the needs of parallel processing of multidimensional information.

[0071] The first conductive strip unit has a larger width and smaller spacing. This structure strengthens the confinement of the electromagnetic field inside the strip (due to the larger width, the carrier distribution is more concentrated), making it easier to excite low-order transverse electric modes. The mode field distribution diffuses symmetrically around the strip, and the energy is concentrated in the strip body. It has strong anti-interference ability and is suitable for carrying global information (such as intensity signals in a large area).

[0072] The second conductive strip is narrower and has a larger spacing. This structure weakens the constraint of the electromagnetic field (the larger spacing makes it easier for the electromagnetic field to diffuse into the gap), making it easier to excite higher-order transverse magnetic modes. The mode field is distributed at the edge of the strip to form standing wave peaks. It has high spatial resolution and is suitable for carrying localized information (such as detailed features of small areas).

[0073] Due to the significant difference in their size ratios, even at the same incident frequency, the coupling mode between the electromagnetic field and the strip is completely different, thus enabling the simultaneous excitation of more polariton modes.

[0074] The low-order transverse electric mode excited by the first conductive strip and the high-order transverse magnetic mode excited by the second conductive strip are coupled to each other through the electromagnetic field inside the microchannel (since they are on the same MCP, the electromagnetic field can penetrate and superimpose through the channel wall). However, due to the different distribution characteristics of the mode field (the low-order transverse electric mode is concentrated in the main body of the strip, and the high-order transverse magnetic mode is concentrated at the edge of the strip), the two do not interfere with each other and form a parallel coexistence state.

[0075] When the mode is transmitted to the second conductive strip, its precise alignment with the third conductive strip enables the efficient transfer of energy from the higher-order transverse magnetic mode to the lower workpiece through mirror coupling (one-to-one correspondence between strip positions). Meanwhile, the lower-order transverse electric mode, due to its wide field distribution range, can be transmitted to the corresponding area of ​​the lower workpiece through the superposition of the overall electromagnetic field. The information carried by different modes does not interfere with each other during transmission. Finally, the back-end circuit analyzes the characteristics of different modes (such as field distribution and polarization state) to achieve synchronous processing of multi-dimensional information.

[0076] In an optional example, the diameter and thickness of the first microchannel plate substrate are both smaller than the diameter and thickness of the second microchannel plate substrate, respectively. Preferably, the diameter of the second microchannel plate substrate is 1 to 2 times the diameter of the first microchannel plate substrate, and the thickness of the second microchannel plate substrate is 1 to 3 times the thickness of the second microchannel plate substrate. A thinner first microchannel plate substrate can increase the aspect ratio and further improve the gain.

[0077] In an optional example, the micropore diameter of the first microchannel plate substrate is smaller than that of the second microchannel plate substrate, preferably the micropore diameter of the second microchannel plate substrate is 1 to 2 times that of the micropore diameter of the first microchannel plate substrate, and more preferably 2 times.

[0078] In an optional example, the depth to which the first conductive layer, the second conductive layer, the third conductive layer and the fourth conductive layer cover the inner wall of the microchannel is not less than 1 / tan(θ), where θ is the chamfer angle of the MCP, and is particularly preferably 0.3 to 20 times the corresponding micropore diameter.

[0079] In an optional example, the first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer include a multilayer film prepared from one or more materials selected from copper, nickel, and gold.

[0080] In another preferred example, the first conductive layer consists of a nickel film, a copper film, and a gold film (Ni / Cu / Au) stacked sequentially, with each film having a thickness of 10 nm to 2000 nm. The nickel film serves as a connection layer between the channel plate and the copper film, ensuring the stability of the film; the copper film serves as a signal transmission layer, playing a signal transmission role; and the fabrication of the gold film increases signal collection efficiency and enhances signal sensitivity.

[0081] In another preferred example, in the first conductive layer, the nickel film has a thickness of 10 nm, the copper film has a thickness of 260 nm, and the gold film has a thickness of 100 nm.

[0082] The second, third, and fourth conductive layers are all composed of sequentially stacked nickel and copper (Ni / Cu) films, with a film thickness of 10 nm to 2000 nm.

[0083] In another preferred example, in the films of the second, third, and fourth conductive layers, the nickel film has a thickness of 10 nm and the copper film has a thickness of 260 nm.

[0084] In an optional example, the reflective photocathode covers the entire first input surface and a predetermined depth of the inner wall of the microchannel, the depth being not less than 1 / tan(θ), where θ is the chamfer angle of the MCP, and is particularly preferably 0.3 to 20 times the corresponding micropore diameter.

[0085] In an optional example, the reflective photocathode is selected from materials that are highly responsive to ultraviolet light and X-rays, including one or more of cesium iodide, copper iodide, potassium bromide, and potassium chloride, for example, a cesium iodide film with a thickness of 100 nm.

[0086] In an optional example, the protective layer comprises a film prepared from one or more of silicon oxide, hafnium oxide, aluminum oxide, titanium oxide, and silicon nitride, for example, an aluminum oxide film with a thickness of 1 nm.

[0087] Understandably, both reflective photocathodes and protective layers are existing technologies, and the materials and thickness can be selected according to the actual situation.

[0088] In another preferred embodiment of the present invention, a method for fabricating the aforementioned high-efficiency X-ray imager with a built-in transmission line is also provided, comprising the following steps:

[0089] A first conductive layer having multiple independent first conductive strip units is prepared on the input surface and the inner wall of the microchannel of the first microchannel substrate, and a second conductive layer having multiple independent second conductive strip units is prepared on the output surface and the inner wall of the microchannel of the first microchannel substrate.

[0090] A reflective photocathode is formed by preparing a material film layer with photoelectric conversion function in the entire area of ​​the first input surface with the first conductive layer and the inner wall of the corresponding microchannel, and a protective layer is prepared on the surface of the reflective photocathode to obtain the first workpiece;

[0091] A third conductive layer with multiple independent third conductive strip units is prepared on the input surface and the inner wall of the microchannel of the second microchannel plate substrate, and a fourth conductive layer that fully covers the output surface of the first microchannel plate is prepared on the output surface and the inner wall of the microchannel of the second microchannel plate substrate to obtain the second workpiece.

[0092] The first output surface is bonded to the second input surface, and each second conductive strip unit is made to correspond one-to-one with each third conductive strip unit. The microchannels of the first workpiece and the microchannels of the second workpiece are connected to form a microchannel assembly.

[0093] Below, we provide an exemplary method for fabricating a high-efficiency X-ray imager with a built-in transmission line, including the following specific steps:

[0094] 1. Preparation of conductive layer

[0095] (1) Prepare the MCP substrate that has been cleaned by hydrogen combustion; prepare the coating material, such as nickel, copper, and gold, and put the required coating material into the crucible of the coating machine; preferably, use nickel, copper, and gold materials for combined plating.

[0096] (2) The grid is installed in a fixture for MCP that can correct the bevel angle, and the grid is pressed with a matching pressure ring. Then the MCP is installed in the fixture and pressed with a polytetrafluoroethylene cap. It is then placed on the coating machine tool with the coating angle adjusted so that the coating depth is ≥1 / tan(θ), where θ is the bevel angle of the MCP. Preferably, the coating depth range is 0.3 to 20 times the corresponding micropore diameter.

[0097] (3) Set appropriate coating parameters. Pre-coating baking: temperature 50℃~200℃, time 10min~60min; coating pot number 1~3, set nickel, copper and gold respectively; set the film thickness 10nm~2000nm, tooling speed 1r / min~100r / min, coating rate 0.1nm / s~5nm / s for each pot number; automatically run the coating process.

[0098] (5) Coating flipping: Place the fixture with the MCP on the light, use the horsehair wire to fine adjust the position of the MCP so that the completed input surface microstrip position is aligned with the output surface grid position (the straight edge of the microstrip and the straight edge of the grid must be parallel under the light) and flip the coating to complete the coating process.

[0099] 2. Fabrication of reflective photocathode

[0100] (1) Prepare an MCP (denoted as MCP1, and another one as MPC2) that has been coated and needs to be coated with a reflective photocathode.

[0101] (2) The input surface is coated with a photocathode. The MCP1 is placed with the input surface facing down in a special fixture that can correct the bevel angle, and the MCP1 is pressed tightly with a polytetrafluoroethylene cap. It is then placed on a coating machine tool with the coating angle adjusted so that the coating depth is ≥1 / tan(θ), where θ is the bevel angle of the MCP1. Preferably, the coating depth range is 0.3 to 20 times the corresponding micropore diameter.

[0102] 3. Preparation of protective film layer for cathode material

[0103] (1) Prepare the MCP (MCP1) with the photocathode already fabricated;

[0104] (2) Prepare a cathode protection film. Load MCP1 into a special deposition fixture and place the deposition fixture with MCP1 into the cavity of the atomic layer deposition equipment. Adjust the alumina deposition process so that the thickness of the deposited alumina film is about 1 nm.

[0105] 4. MCP component bonding

[0106] (1) Prepare non-conductive glue and the previously deposited MCP1 and MCP2.

[0107] Place MCP2 on the worktable with the input side facing up. Apply 3-5 drops of non-conductive adhesive to the center area. Align the conductive strip units on the output side of MCP1 with the conductive strip units on the input side of MCP2. Gently place it along the center area. Then, use a horsehair thread to fine-tune the position. Apply 1-2 drops of non-conductive adhesive to the edge where MCP1 and MCP2 meet using the horsehair thread. Finally, gently press MCP1 with the horsehair thread to complete the bonding of the components.

[0108] (3) Place the bonded MCP assembly in a nitrogen cabinet and ventilate for 24 hours. After ventilation, package the assembly to complete the X-ray imager preparation.

[0109] It is understandable that the roughness of the two sides of MCP1 is the same as that of the two sides of MCP2. Alternatively, the output surface of MPC1 may be rougher than the input surface, but the roughness of the input surface of MPC1 may be the same as that of the output surface of MPC2.

[0110] To facilitate better understanding, the present invention will be further described below with reference to specific examples, but the preparation process is not limited to this, and the content of the present invention is not limited to this.

[0111] Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0112] Example 1

[0113] The parameter design is shown in Table 1.

[0114] Table 1

[0115]

[0116]

[0117] 1. Fabrication of MCP substrate

[0118] (1) Polish the workpiece after the screen cutting corresponding to MCP1 using a classical polishing machine. The finished thickness is 0.12mm. Since the surface roughness of MCP after classical polishing is not as good as that of double-sided polishing machine, one side of MCP1 is smooth (Ra 1μm), which is called the smooth surface (input surface), and the other side is relatively rough (Ra 10μm), which is called the rough surface (output surface). The parameters of MCP1 are: aperture 6μm, diameter 44mm, and bevel angle 8°.

[0119] The workpiece after screen cutting corresponding to MCP2 was polished to a thickness of 0.25mm using a double-sided polishing machine (both sides roughness is Ra1μm). The parameters of MCP2 are: hole diameter 12μm, diameter 50mm, and bevel angle 8°.

[0120] (2) MCP is corroded and cleaned using a full-stirring process.

[0121] Set appropriate corrosion parameters: stir only without vibration throughout the process, adjust the stirring speed to 5r / s, stir with alcohol for 30 minutes - stir with pure water for 60 seconds - stir with acid for 40 minutes - stir with pure water for 30 minutes - stir with alcohol for 2 minutes - vacuum bake at 120℃ for one hour.

[0122] Set appropriate cleaning parameters: stir only, do not vibrate, adjust the stirring speed to 5r / s, stir pure water for 1 minute - stir acid for 5 minutes - stir water for 10 minutes - stir alcohol for 2 minutes - stir alcohol for 2 minutes - stir alcohol for 2 minutes.

[0123] For ease of description, the workpieces in the corresponding stages will be directly described as MPC1 and MPC2 below.

[0124] 2. The conductive layer is deposited using physical vapor deposition.

[0125] (1) Prepare MCP1 and MCP2 that have been cleaned by hydrogen combustion; resistance ≤50MΩ.

[0126] (2) Prepare the coating material. Put the required coating material (nickel, copper, gold) into the crucible of the coating machine.

[0127] (3) Install the grid into the MCP-specific fixture that can correct the bevel angle, and press the grid with a matching pressure ring. Then, install the MCP1 into the fixture and press the MCP with a polytetrafluoroethylene cap. Place it on the coating machine tool with the coating angle adjusted so that the coating depth is 0.5 times the micropore diameter.

[0128] (4) Perform MCP1 plating, set appropriate plating parameters, and bake before plating: temperature 200℃, time 10min; plating pot number 1 to 3, set nickel, copper and gold respectively; nickel film thickness 10nm, tooling speed 5r / min, plating rate 0.1nm / s; copper film thickness 260nm, tooling speed 5r / min, plating rate 1.5nm / s; gold film thickness 100nm, tooling speed 5r / min, plating rate 0.2nm / s; run the plating process automatically.

[0129] Coating flipping process: Place the fixture with MCP1 on the light source, and use a fine-tuning tool to adjust the position of MCP1 so that the completed input microstrip position is aligned with the output grid position (the straight edge of the microstrip and the straight edge of the grid must be parallel under the light). Perform flipping coating. Coating process: Pre-coating baking: temperature 200℃, time 10min; coating pot number 1-2, set for nickel and copper respectively; nickel film thickness 10nm, fixture rotation speed 5r / min, coating rate 0.1nm / s; copper film thickness 260nm, fixture rotation speed 5r / min, coating rate 1.5nm / s; automatic operation of the coating process.

[0130] (5) MCP2 plating is carried out. Plating process: pre-plating baking: temperature 200℃, time 10min; plating pot number 1~2, respectively set nickel and copper; nickel film thickness 10nm, tooling speed 5r / min, plating rate 0.1nm / s; copper film thickness 260nm, tooling speed 5r / min, plating rate 1.5nm / s; automatic operation of plating process.

[0131] Flip-over plating: Place the fixture with MCP2 mounted on the light source, and use a fine-tuning tool to adjust the position of MCP1 so that the completed input microstrip position is aligned with the output grid position (the straight edge of the microstrip and the straight edge of the grid must be parallel under the light source). Perform flip-over plating. Plating process: Pre-plating baking: temperature 200℃, time 10min; plating pan number 1-2, set for nickel and copper respectively; nickel film thickness 10nm, fixture rotation speed 5r / min, plating rate 0.1nm / s; copper film thickness 260nm, fixture rotation speed 5r / min, plating rate 1.5nm / s; automatic operation of the plating process.

[0132] 3. Preparation of MCP cathode materials

[0133] (1) Prepare the MCP1 that has been coated.

[0134] (2) The input surface is coated with a photocathode. The input surface of MCP1 is placed face down in a special fixture that can correct the bevel angle, and the MCP is pressed with a polytetrafluoroethylene cap. It is then placed on the coating machine tool with the coating angle adjusted so that the coating depth is 0.5 times the diameter of the micropore.

[0135] (3) Perform MCP1 plating and set appropriate plating parameters: pre-plating baking: temperature 200℃, time 10min; plating pot number 1, set cesium iodide powder; cesium iodide film thickness 100nm, tooling rotation speed 5r / min, plating rate 0.2nm / s; automatic operation of the plating process.

[0136] (4) After the coating process is completed, the MCP cathode material film layer is prepared immediately, or the MCP coated with cesium iodide is vacuum packaged.

[0137] 4. Preparation of protective film layer for MCP cathode material

[0138] (1) Prepare the MCP1 with the photocathode already prepared.

[0139] (2) Prepare a cathode protection film layer. Load MCP1 into a special deposition fixture and place the deposition fixture with MCP in the cavity of the atomic layer deposition equipment.

[0140] (3) Perform MCP1 deposition, the deposition material is alumina, and the film thickness is 1nm; set the atomic layer deposition equipment process: the precursor is trimethylaluminum and pure water, and the precursor cycle is set to 10 cycles; automatically run the deposition process.

[0141] 5. MCP component bonding

[0142] (1) Prepare non-conductive glue and deposited MCP1 (e.g.) Figure 5 (as shown) and MCP2 (as shown) Figure 6 (As shown).

[0143] (2) Place MCP2 on the workbench with the input side facing up. Apply 3-5 drops of non-conductive glue to the center area. Align the conductive strip on the output side of MCP1 with the conductive strip on the input side of MCP2 and gently place it along the center area (the output strip of MCP1 should overlap with the input strip of MCP2). Then, use a hair tie to make minor adjustments to the position. Apply 1-2 drops of non-conductive glue to the edge where MCP1 and MCP2 are in contact. Finally, gently press MCP1 with the hair tie to complete the bonding of the components.

[0144] (3) Place the bonded MCP assembly in a nitrogen cabinet and ventilate for 24 hours. After ventilation, package the assembly to complete the X-ray imager preparation.

[0145] Test

[0146] (1) The resistance of MCP1 and MCP2 was tested respectively, and the resistance was less than 50MΩ.

[0147] (2) The electron imaging results of MCP1 and MCP2 were tested separately, and the results are as follows: Figures 7-8 As shown in the figure, the imaging results correspond to their respective stripes (the results of the overlapping parts of the input and output surfaces); therefore, under the condition that the MPC component uses the input of MCP1 as the input of the whole component and the output of MCP2 as the output of the whole component, the component's electronic imaging test results are consistent with the MCP1 imaging test results.

[0148] (3) The gain of the single chip was measured at 800V, and the results are shown in Table 2.

[0149] (4) The gain of the MPC component was tested at 1600V, and the results are shown in Table 2 and... Figure 9 As shown.

[0150] Table 2

[0151] MPC1 MPC2 MPC assembly Gain 3848 4329 5 x 10e 5 ]]

[0152] The results above show that the X-ray imager of the present invention has a high gain. The gain of the MCP component can increase the gain of the MCP single chip by two orders of magnitude. From the pulse half-width spectrum, the overall signal distribution is Gaussian and the signal distribution spectrum is relatively reasonable, which can meet the requirements for detecting weak electronic signals and distinguishing various signals. At the same time, combined with the design of the conductive strips and the built-in transmission lines they form, each of the six strips can form a stable signal unit, which can excite multimode polaritons at a single frequency, meeting the requirements for parallel processing of multi-dimensional information.

[0153] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A high-efficiency X-ray imager with a built-in transmission line, characterized in that, include: The first microchannel board substrate has a first surface and a second surface disposed opposite to each other, wherein the first surface is defined as a first input surface and the second surface is defined as a first output surface; A first conductive layer is prepared on the first input surface and the inner wall of the microchannel. The first conductive layer is configured to have multiple independent first conductive strip units. A material film layer with photoelectric conversion function is prepared on the first input surface with the first conductive layer and the inner wall of the corresponding microchannel to form a reflective photocathode. A dense and uniformly thick protective layer is prepared on the surface of the reflective photocathode. A second conductive layer is prepared on the first output surface and the inner wall of the microchannel. The second conductive layer is configured to have multiple independent second conductive strip units, thereby forming the first workpiece. The second microchannel board substrate has a third side and a fourth side arranged opposite to each other, wherein the third side is defined as the second input side and the fourth side is defined as the second output side; A third conductive layer is prepared on the second input surface and the inner wall of the microchannel, and the third conductive layer is configured to have multiple independent third conductive strip units; A fourth conductive layer is prepared on the second output surface and the inner wall of the microchannel. The fourth conductive layer is configured as a continuous structure throughout and completely covers the first output surface, thereby forming the second workpiece. A microchannel plate assembly is formed by stacking a first workpiece and a second workpiece, wherein a first output surface and a second input surface are fitted together and the microchannels of the first workpiece and the microchannels of the second workpiece are connected, and a second conductive layer and a third conductive layer constitute an internal transmission line.

2. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, Each strip of the second conductive layer is arranged in a corresponding manner to each strip of the third conductive layer; when the first output surface is attached to the second input surface, each second conductive strip unit forms a one-to-one correspondence with each third conductive strip unit.

3. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The width of the first conductive strip unit is greater than the width of the second conductive strip unit.

4. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The spacing between adjacent first conductive strip units is smaller than the spacing between adjacent second conductive strip units.

5. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, In the microchannel plate assembly, the microchannels of the first workpiece and the second workpiece are superimposed to form a V-shaped channel structure.

6. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The diameter and thickness of the first microchannel plate substrate are both smaller than the diameter and thickness of the second microchannel plate substrate, respectively.

7. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The diameter of the micropores in the first microchannel plate substrate is smaller than the diameter of the micropores in the second microchannel plate substrate.

8. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The depth to which the first, second, third, and fourth conductive layers cover the inner wall of the microchannel is not less than 1 / tan(θ), where θ is the chamfer angle of the MCP.

9. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer include multilayer films prepared from one or more of copper, nickel, and gold.

10. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The reflective photocathode covers the entire first input surface and a predetermined depth of the inner wall of the microchannel, with a depth not less than 1 / tan(θ), where θ is the chamfer angle of the MCP.

11. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The reflective photocathode is selected from materials that have high responsiveness to ultraviolet light and X-rays, including one or more of cesium iodide, copper iodide, potassium bromide, and potassium chloride.

12. The high-efficiency X-ray imager with built-in transmission line according to claim 1, characterized in that, The protective layer comprises a film prepared from one or more of silicon oxide, hafnium oxide, aluminum oxide, titanium oxide, and silicon nitride.

13. A method for fabricating a high-efficiency X-ray imager with a built-in transmission line, characterized in that, Includes the following steps: A first conductive layer having multiple independent first conductive strip units is prepared on the input surface and the inner wall of the microchannel of the first microchannel substrate, and a second conductive layer having multiple independent second conductive strip units is prepared on the output surface and the inner wall of the microchannel of the first microchannel substrate. A reflective photocathode is formed by preparing a material film layer with photoelectric conversion function in the entire area of ​​the first input surface with the first conductive layer and the inner wall of the corresponding microchannel, and a protective layer is prepared on the surface of the reflective photocathode to obtain the first workpiece; A third conductive layer with multiple independent third conductive strip units is prepared on the input surface and the inner wall of the microchannel of the second microchannel plate substrate, and a fourth conductive layer that fully covers the output surface of the first microchannel plate is prepared on the output surface and the inner wall of the microchannel of the second microchannel plate substrate to obtain the second workpiece. The first output surface is bonded to the second input surface, and each second conductive strip unit is made to correspond one-to-one with each third conductive strip unit. The microchannels of the first workpiece and the microchannels of the second workpiece are connected to form a microchannel assembly.

14. The method for fabricating a high-efficiency X-ray imager with a built-in transmission line according to claim 13, characterized in that, The width of the first conductive strip unit is greater than the width of the second conductive strip unit.

15. The method for fabricating a high-efficiency X-ray imager with a built-in transmission line according to claim 13, characterized in that, The spacing between adjacent first conductive strip units is smaller than the spacing between adjacent second conductive strip units.

16. The method for fabricating a high-efficiency X-ray imager with a built-in transmission line according to claim 13, characterized in that, The first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer include multilayer films prepared from one or more of copper, nickel, and gold.

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