A three-dimensional imaging detector

Abstract

The present invention discloses a three-dimensional imaging detector to solve the technical problems of low time resolution and low counting rate of the existing position-sensitive anode detector. Specifically, it includes a sealed tube shell with a vacuum environment inside, an input window and a position-sensitive anode respectively arranged at both ends of the sealed tube shell, an input electrode ring, an electron multiplier and an output electrode ring all arranged in the sealed tube shell, as well as a time-to-digital conversion electronics module and multiple analog-to-digital conversion electronics modules; one side of the input window is covered with a photocathode; the input electrode ring and the output electrode ring are respectively arranged on both sides of the electron multiplier, and are both close to the electron multiplier; the time-to-digital conversion electronics module is connected to the output electrode ring through a capacitor; each analog-to-digital conversion electronics module is respectively connected to one or more pixels in the position-sensitive anode, so that each pixel in the position-sensitive anode is connected to an analog-to-digital conversion electronics module, and the analog-to-digital conversion electronics module is used for online data processing and output after aggregation.

Description

Technical Field

[0001] The invention relates to a detector, and in particular to a three-dimensional imaging detector. Background Art

[0002] With the continuous deepening of research and application of photoelectric detection devices, three-dimensional imaging devices with single-photon sensitivity, ultrafast response speed and high spatial resolution have become the core devices for detection of extreme time and space scales in the future. They play an important role in aerospace technologies such as low-light remote sensing, night long-range reconnaissance, deep space exploration, space situational awareness, biological single-molecule fluorescence lifetime imaging, time-resolved microscopy, quantum information, laser communication, artificial intelligence, autonomous driving, high-end medical equipment and many other fields.

[0003] The position-sensitive anode detector based on the microchannel plate converts photons into electrons and multiplies them, draws out the signal through the position-sensitive anode, and then processes it electronically to achieve two-dimensional imaging. Commonly used position-sensitive anodes include wedge-type anodes, vernier anodes, delay line anodes, cross-strip anodes, pixel anodes, etc. Wedge-type anodes, vernier anodes, and delay line anodes cannot respond to multiple events arriving at the same time; cross-strip anodes and pixel anodes can handle multiple events at the same time and achieve higher spatial resolution, but they need to rely on more readout paths. With the increase in the number of readout paths, the ADC electronics are complex and the time resolution of the detector is reduced. In applications such as lidar, the distance and depth information of the target to be measured depends on the time resolution of the detection. Improving the time resolution is crucial for three-dimensional imaging.

[0004] The Chinese patent "Single-photon 3D imaging system based on cross-strip anode detector", application number 201811328048.X, introduces the use of time-coherent single-photon counting algorithm and first-photon algorithm to achieve 3D imaging, but its signal is still extracted through the position-sensitive anode and processed by analog-to-digital conversion electronics ADC, and the time resolution is not high. The 2D spatial imaging capability of the cross-strip anode depends on solving the charge center of mass, and a multi-channel analog-to-digital conversion circuit ADC is required to process the signal, and the processing speed of the multi-channel ADC is difficult to improve. Summary of the invention

[0005] The purpose of the present invention is to provide a three-dimensional imaging detector to solve the technical problems of low time resolution and low counting rate of the existing position-sensitive anode detector.

[0006] The inventive concept of the present invention is:

[0007] The signal is extracted from the end of the electron multiplier or the position-sensitive anode and processed by TDC to obtain high time resolution, that is, high longitudinal depth resolution and distance resolution. At the same time, the signal is extracted from the position-sensitive anode and processed by ADC to obtain high two-dimensional imaging resolution. The two parts of the signal are combined to achieve high temporal and spatial resolution three-dimensional imaging.

[0008] In order to achieve the above-mentioned object, the present invention provides a three-dimensional imaging detector, which is special in that it comprises a sealed tube shell with a vacuum environment inside, an input window and a position-sensitive anode respectively arranged at both ends of the sealed tube shell, an input electrode ring, an electron multiplier and an output electrode ring all arranged in the middle of the sealed tube shell, a time-to-digital conversion electronics module and a plurality of analog-to-digital conversion electronics modules;

[0009] The input window is covered with a photocathode on one side close to the sealed tube shell;

[0010] The input electrode ring and the output electrode ring are respectively arranged on both sides of the electron multiplier, and are both arranged close to the electron multiplier;

[0011] The time-to-digital conversion electronics module is connected to the output electrode ring via a capacitor, and is used to process the output signal at the end of the electron multiplier and obtain its time information;

[0012] Each of the analog-to-digital conversion electronics modules is connected to one or more pixels in the position-sensitive anode, so that each pixel in the position-sensitive anode is connected to an analog-to-digital conversion electronics module, and the analog-to-digital conversion electronics module is used for online data processing and output after aggregation.

[0013] Furthermore, the number of the analog-to-digital conversion electronic modules is equal to the number of pixels in the position-sensitive anode, and each analog-to-digital conversion electronic module is connected to one of the pixels.

[0014] Further, the input window is made of fused quartz, magnesium fluoride, K9 glass or AVG anti-halation glass;

[0015] The photocathode is made of a semiconductor film or a metal film;

[0016] The electron multiplier is formed by stacking multiple layers of microchannel plates or multiple layers of microstructured metal meshes;

[0017] The position sensitive anode is a cross-strip anode, a multi-layer impedance anode or a pixel anode.

[0018] Meanwhile, the present invention also provides another three-dimensional imaging detector, which is special in that it comprises a sealed tube shell with a vacuum environment inside, an input window and a position-sensitive anode respectively arranged at both ends of the sealed tube shell, an input electrode ring, an electron multiplier and an output electrode ring all arranged in the middle of the sealed tube shell, and a plurality of electronic units;

[0019] The input window is covered with a photocathode on one side close to the sealed tube shell;

[0020] The input electrode ring and the output electrode ring are respectively arranged on both sides of the electron multiplier, and are both arranged close to the electron multiplier;

[0021] Each of the electronic units is respectively connected to one or more pixels in the position-sensitive anode, so that each pixel in the position-sensitive anode is connected to an electronic unit; the electronic unit includes a time-to-digital conversion electronic module and an analog-to-digital conversion electronic module. The time-to-digital conversion electronic module is connected to the corresponding pixel and is used to process the output signal at the end of the electron multiplier and obtain its time information; the analog-to-digital conversion electronic module is connected to the corresponding pixel and is used for online data processing and output after aggregation.

[0022] Furthermore, the number of the time-to-digital conversion electronic modules and the analog-to-digital conversion electronic modules are respectively equal to the number of pixels in the position-sensitive anode, and each time-to-digital conversion electronic module is connected to one pixel, and each analog-to-digital conversion electronic module is connected to one pixel.

[0023] Further, the input window is made of fused quartz, magnesium fluoride, K9 glass or AVG anti-halation glass;

[0024] The photocathode is made of a semiconductor film or a metal film;

[0025] The electron multiplier is formed by stacking multiple layers of microchannel plates or multiple layers of microstructured metal meshes;

[0026] The position sensitive anode is a cross-strip anode, a multi-layer impedance anode or a pixel anode.

[0027] Meanwhile, the present invention also provides a third three-dimensional imaging detector, which is special in that it comprises a sealed tube shell with a vacuum environment inside, an input window and a position-sensitive anode respectively arranged at both ends of the sealed tube shell, an input electrode ring, an electron multiplier, an output electrode ring and a metal grid all arranged in the middle of the sealed tube shell, a time-to-digital conversion electronics module and a plurality of analog-to-digital conversion electronics modules;

[0028] The input window is covered with a photocathode on one side close to the sealed tube shell;

[0029] The input electrode ring and the output electrode ring are respectively arranged on both sides of the electron multiplier, and are both arranged close to the electron multiplier;

[0030] The metal grid is arranged between the output electrode ring and the position-sensitive anode, and a gap is provided between the output electrode ring and the position-sensitive anode respectively;

[0031] The time-to-digital conversion electronics module is connected to the metal grid via a capacitor and is used to process the output signal at the end of the electron multiplier and obtain its time information;

[0032] Each of the analog-to-digital conversion electronics modules is connected to one or more pixels in the position-sensitive anode, so that each pixel in the position-sensitive anode is connected to an analog-to-digital conversion electronics module, and the analog-to-digital conversion electronics module is used for online data processing and output after aggregation.

[0033] Furthermore, the number of the analog-to-digital conversion electronic modules is equal to the number of pixels in the position-sensitive anode, and each analog-to-digital conversion electronic module is connected to one of the pixels.

[0034] Furthermore, the metal grid is provided with a plurality of insulating strips that cross each other horizontally and vertically, so as to divide the metal grid into a plurality of areas.

[0035] Further, the input window is made of fused quartz, magnesium fluoride, K9 glass or AVG anti-halation glass;

[0036] The photocathode is made of a semiconductor film or a metal film;

[0037] The electron multiplier is formed by stacking multiple layers of microchannel plates or multiple layers of microstructured metal meshes;

[0038] The position-sensitive anode is a cross-strip anode, a multi-layer impedance anode or a pixel anode;

[0039] The insulating strip is made of insulating ceramic.

[0040] Beneficial effects of the present invention:

[0041] 1. The three-dimensional imaging detector provided by the present invention combines a time-to-digital conversion electronics module and a multi-channel analog-to-digital conversion electronics module to simultaneously obtain high-precision time (i.e., longitudinal depth or distance) information and two-dimensional spatial information. By extracting a signal from the final stage of the electron multiplier or the position-sensitive anode and using the time-to-digital conversion electronics module to process the signal to obtain time information separately, the time resolution (i.e., longitudinal depth or distance resolution) and counting rate are improved.

[0042] 2. The present invention also sets a metal grid between the output electrode ring and the position-sensitive anode, and sets a plurality of insulating strips that cross horizontally and vertically on the metal grid, so as to divide the metal grid into a plurality of areas, thereby improving the ability of the detector to process multiple events at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of a three-dimensional imaging detector embodiment 1 of the present invention;

[0044] Figure 2 It is a structural schematic diagram of a three-dimensional imaging detector embodiment 2 of the present invention;

[0045] Figure 3 This is a schematic structural diagram of a three-dimensional imaging detector embodiment 3 of the present invention;

[0046] Figure 4 Schematic diagram of the structure of the metal grid in the embodiment of the present invention.

[0047] Figure Number:

[0048] 1-input window, 2-photocathode, 3-sealed tube shell, 4-input electrode ring, 5-electron multiplier, 6-output electrode ring, 7-position sensitive anode, 8-capacitor, 9-time digital conversion electronics module, 10-analog digital conversion electronics module, 11-metal grid. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The present invention simultaneously extracts signals from the end of the microchannel plate electron multiplier and the anode collector to perform high time resolution three-dimensional imaging. The signal from the end of the microchannel plate is processed by TDC time-to-digital conversion to provide high-precision time information; the signal from the position-sensitive anode collector is processed by ADC analog-to-digital conversion and calculation to provide a two-dimensional spatial image. The time information of TDC combined with the time-of-flight method can provide the depth and distance information of the target to achieve three-dimensional imaging. Compared with the traditional position-sensitive anode detector, a separate time signal acquisition and processing method is added, which improves the time resolution (i.e., longitudinal depth resolution) and counting rate. The designed three-dimensional imaging detector is specifically as follows:

[0051] Embodiment 1:

[0052] A three-dimensional imaging detector, such as Figure 1As shown, it includes a sealed tube shell 3 with a vacuum environment inside, an input window 1 and a position-sensitive anode 7 respectively arranged at both ends of the sealed tube shell 3, an input electrode ring 4, an electron multiplier 5 and an output electrode ring 6 all arranged in the middle of the sealed tube shell 3, as well as a time-to-digital conversion electronic module 9 and a plurality of analog-to-digital conversion electronic modules 10; the input window 1 is covered with a photocathode 2 on one side close to the sealed tube shell 3; the input window 1 is a light-transmitting optical glass or optical fiber panel material, such as fused quartz, magnesium fluoride, K9 glass, AVG anti-halation glass; the photocathode 2 is a semiconductor film or The metal film is used to convert the optical signal to be measured into an electronic signal; the input electrode ring 4 and the output electrode ring 6 are respectively arranged on both sides of the electron multiplier 5, and are both arranged close to the electron multiplier 5; the electron multiplier 5 is a multi-layer microchannel plate or a multi-layer microstructure metal mesh, which is used to multiply and amplify the electrons; the input electrode ring 4 is a metal material with good conductivity, which is used to introduce an input voltage to the electron multiplier; the output electrode ring 6 is a metal material with good conductivity, which is used to introduce an output voltage to the electron multiplier 5; the time digital conversion electronics module 9 is connected to the output electrode ring 6 through the capacitor 8 The electronic module 9 for time-to-digital conversion includes a preamplifier, a comparator and a time-to-digital converter. The preamplifier amplifies the weak electric signal, and then screens the signal output exceeding the set threshold value through the comparator Discriminator, and then digitally outputs it through the time-to-digital converter TDC. The capacitor 8 is used to isolate the DC current that supplies power to the electron multiplier and to lead out the pulse signal generated at the end of the electron multiplier. Each analog-to-digital conversion electronic module 10 is respectively connected to one or more pixels in the position-sensitive anode 7, so that each pixel in the position-sensitive anode 7 is connected to an analog-to-digital conversion electronic module 10, that is, an analog-to-digital conversion electronic module 10 can be connected to one or several pixels at the same time, until any pixel is connected to an analog-to-digital conversion electronic module 10. Of course, the optimal solution is that the number of analog-to-digital conversion electronic modules 10 is equal to the number of pixels in the position-sensitive anode 7, and each analog-to-digital conversion electronic module 10 is respectively connected to one pixel. The position-sensitive anode 7 is a cross-strip anode, a multi-layer impedance anode or a pixel anode with two-dimensional spatial resolution capability, and is used to collect electrons output by the electron multiplier 5; the analog-to-digital conversion electronics module 10 includes multiple preamplifiers, multiple waveform digitization modules ADC or ASIC, and a data aggregation module, which is used to amplify the multi-channel signals output by the position-sensitive anode 7 through preamplifiers, waveform digitization, online data processing and data aggregation, and then output them.

[0053] Embodiment 2:

[0054] like Figure 2As shown, the structure of the three-dimensional imaging detector of this embodiment is basically the same as that of the three-dimensional imaging detector of Embodiment 1, except that the time-to-digital conversion electronic module 9 is directly connected to the position-sensitive anode 7, and no capacitor is required. It can be understood that one time-to-digital conversion electronic module 9 and one analog-to-digital conversion electronic module 10 constitute an electronic unit. The three-dimensional imaging detector includes multiple electronic units, each of which is respectively connected to one or more pixels in the position-sensitive anode 7, so that each pixel in the position-sensitive anode 7 is connected to an electronic unit. In this case, the output signal of each pixel in the position-sensitive anode 7 is divided into two paths, one of which is processed by the analog-to-digital conversion electronic module 10, and the other is processed by the time-to-digital conversion module 9.

[0055] Embodiment 3:

[0056] like Figure 3 As shown, the structure of the three-dimensional imaging detector of this embodiment is basically the same as that of the three-dimensional imaging detectors in Embodiments 1 and 2, except that a metal grid 11 is provided between the output electrode ring 6 and the position-sensitive anode 7, gaps are provided between the metal grid 7 and the output electrode ring 6 and the position-sensitive anode 7, and a time-to-digital conversion electronics module 9 is connected to the metal grid 11 via a capacitor 8; Figure 4 As shown, the metal grid 11 may also be provided with a plurality of ceramic insulating strips (i.e. Figure 4 The thick line portion is used to divide the metal grid 11 into multiple areas to improve the detector's ability to process multiple events at the same time.

[0057] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A three-dimensional imaging detector, characterized in that: It comprises a sealed tube shell (3) with a vacuum environment inside, an input window (1) and a position-sensitive anode (7) respectively arranged at both ends of the sealed tube shell (3), an input electrode ring (4), an electron multiplier (5) and an output electrode ring (6) all arranged in the middle of the sealed tube shell (3), a time-to-digital conversion electronics module (9) and a plurality of analog-to-digital conversion electronics modules (10); The input window (1) is covered with a photocathode (2) on one side close to the sealed tube shell (3); The input electrode ring (4) and the output electrode ring (6) are respectively arranged on both sides of the electron multiplier (5), and are both arranged close to the electron multiplier (5); The time-to-digital conversion electronics module (9) is connected to the output electrode ring (6) via a capacitor (8) and is used to process the output signal at the end of the electron multiplier (5) and obtain its time information; Each of the analog-to-digital conversion electronics modules (10) is respectively connected to one or more pixels in the position-sensitive anode (7), so that each pixel in the position-sensitive anode (7) is connected to an analog-to-digital conversion electronics module (10), and the analog-to-digital conversion electronics module (10) is used for online data processing and output after aggregation.

2. The three-dimensional imaging detector according to claim 1, characterized in that: The number of the analog-to-digital conversion electronic modules (10) is equal to the number of pixels in the position-sensitive anode (7), and each analog-to-digital conversion electronic module (10) is connected to one of the pixels.

3. The three-dimensional imaging detector according to claim 1 or 2, characterized in that: The input window (1) is made of fused quartz, magnesium fluoride, K9 glass or AVG anti-halation glass; The photocathode (2) is made of a semiconductor film or a metal film; The electron multiplier (5) is formed by stacking multiple layers of microchannel plates or multiple layers of microstructured metal meshes; The position-sensitive anode (7) is a cross-strip anode, a multi-layer impedance anode or a pixel anode.

4. A three-dimensional imaging detector, characterized in that: It comprises a sealed tube shell (3) with a vacuum environment inside, an input window (1) and a position-sensitive anode (7) respectively arranged at both ends of the sealed tube shell (3), an input electrode ring (4), an electron multiplier (5) and an output electrode ring (6) all arranged in the middle of the sealed tube shell (3), and a plurality of electronic units; The input window (1) is covered with a photocathode (2) on one side close to the sealed tube shell (3); The input electrode ring (4) and the output electrode ring (6) are respectively arranged on both sides of the electron multiplier (5), and are both arranged close to the electron multiplier (5); Each of the electronic units is respectively connected to one or more pixels in the position-sensitive anode (7), so that each pixel in the position-sensitive anode (7) is connected to an electronic unit; the electronic unit comprises a time-to-digital conversion electronic module (9) and an analog-to-digital conversion electronic module (10); the time-to-digital conversion electronic module (9) is connected to the corresponding pixel and is used to process the output signal at the end of the electron multiplier (5) and obtain its time information; the analog-to-digital conversion electronic module (10) is connected to the corresponding pixel and is used for online data processing and output after aggregation.

5. The three-dimensional imaging detector according to claim 4, characterized in that: The number of the time-to-digital conversion electronic modules (9) and the analog-to-digital conversion electronic modules (10) are respectively equal to the number of pixels in the position-sensitive anode (7), and each time-to-digital conversion electronic module (9) is connected to one of the pixels, and each analog-to-digital conversion electronic module (10) is connected to one of the pixels.

6. The three-dimensional imaging detector according to claim 4 or 5, characterized in that: The input window (1) is made of fused quartz, magnesium fluoride, K9 glass or AVG anti-halation glass; The photocathode (2) is made of a semiconductor film or a metal film; The electron multiplier (5) is formed by stacking multiple layers of microchannel plates or multiple layers of microstructured metal meshes; The position-sensitive anode (7) is a cross-strip anode, a multi-layer impedance anode or a pixel anode.

7. A three-dimensional imaging detector, characterized in that: It comprises a sealed tube shell (3) with a vacuum environment inside, an input window (1) and a position-sensitive anode (7) respectively arranged at both ends of the sealed tube shell (3), an input electrode ring (4), an electron multiplier (5), an output electrode ring (6) and a metal grid (11) all arranged in the middle of the sealed tube shell (3), a time digital conversion electronics module (9) and a plurality of analog digital conversion electronics modules (10); The input window (1) is covered with a photocathode (2) on one side close to the sealed tube shell (3); The input electrode ring (4) and the output electrode ring (6) are respectively arranged on both sides of the electron multiplier (5), and are both arranged close to the electron multiplier (5); The metal grid (11) is arranged between the output electrode ring (6) and the position-sensitive anode (7), and gaps are respectively provided between the output electrode ring (6) and the position-sensitive anode (7); The time-to-digital conversion electronics module (9) is connected to the metal grid (11) via a capacitor (8) and is used to process the output signal at the end of the electron multiplier (5) and obtain its time information; Each of the analog-to-digital conversion electronics modules (10) is respectively connected to one or more pixels in the position-sensitive anode (7), so that each pixel in the position-sensitive anode (7) is connected to an analog-to-digital conversion electronics module (10), and the analog-to-digital conversion electronics module (10) is used for online data processing and output after aggregation.

8. The three-dimensional imaging detector according to claim 7, characterized in that: The number of the analog-to-digital conversion electronic modules (10) is equal to the number of pixels in the position-sensitive anode (7), and each analog-to-digital conversion electronic module (10) is connected to one of the pixels.

9. The three-dimensional imaging detector according to claim 7 or 8, characterized in that: The metal grid (11) is provided with a plurality of insulating strips that cross each other horizontally and vertically, and are used to divide the metal grid (11) into a plurality of areas.

10. The three-dimensional imaging detector according to claim 9, characterized in that: The input window (1) is made of fused quartz, magnesium fluoride, K9 glass or AVG anti-halation glass; The photocathode (2) is made of a semiconductor film or a metal film; The electron multiplier (5) is formed by stacking multiple layers of microchannel plates or multiple layers of microstructured metal meshes; The position-sensitive anode (7) is a cross-strip anode, a multi-layer impedance anode or a pixel anode; The insulating strip is made of insulating ceramic.

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