A photon counting imaging detector with multi-band composite detection capability

Abstract

The utility model relates to a kind of photon counting imaging detector, specifically to a kind of photon counting imaging detector with multi-band composite detection capability, solve the technical problem that existing bit-sensitive anode detector cannot simultaneously detect multiple wavebands.The photon counting imaging detector with multi-band composite detection capability, including vacuum packaging pipe body array, and from below to above sequentially connected bit-sensitive anode assembly, detector frame, detector end cover;Vacuum packaging pipe body receiving end is set in the inside of installation grid and is upwards, and N×M vacuum packaging pipe body receiving end is respectively provided with same or different photoelectric cathode, for receiving different waveband target light signal, and it is converted into photoelectron;N×M vacuum packaging pipe body output end is respectively provided with high resistance collection layer, for receiving photoelectron and it is converted into electron cloud group signal output;Bit-sensitive anode assembly is used for inductive electron cloud group signal, and it is transported to external read-out electronics system and is handled.

Description

Technical Field

[0001] This utility model relates to a photon counting imaging detector, specifically a photon counting imaging detector with multi-band composite detection capability. Background Technology

[0002] Photon counting imaging detectors based on microchannel plates and position-sensitive anodes possess advantages such as high signal-to-noise ratio, good drift resistance, and good temporal stability. They also exhibit excellent temporal and spatial resolution and ultra-high detection sensitivity, playing a crucial role in fields such as space astronomy, biomedicine, and quantum information. These detectors primarily consist of an input window, a photoelectric conversion section (photocathode), an amplification and multiplication section (microchannel plate), and a position decoding section (position-sensitive anode and related external readout electronics). The photocathode's role in photoelectric conversion determines the detector's detection band. Photocathodes are typically differentiated by their response range; for example, CsI photocathodes are commonly used for detecting the FUV band (100-200nm), Cs2Te photocathodes are often used for detecting the NUV band (200-300nm), and dual-alkali or multi-alkali photocathodes (such as S20 and S25) can be used for detecting the visible light band.

[0003] Space targets are complex, typically encompassing multiple wavelengths including X-rays, ultraviolet, visible light, and infrared. Different detectors are required for different targets. A single position-sensitive anode photon counting imaging detector can only use one type of photocathode. If the target needs to cover multiple wavelengths beyond the detection range of a single position-sensitive anode photon counting imaging detector (such as detecting the FUV and visible light bands), multiple different position-sensitive anode photon counting imaging detectors are needed. Therefore, each position-sensitive anode photon counting imaging detector must have an external readout electronics system, significantly increasing the power consumption and complexity of the detection system. Utility Model Content

[0004] The purpose of this invention is to solve the technical problem that existing position-sensitive anode detectors cannot detect multiple bands simultaneously, and to provide a photon counting imaging detector with multi-band composite detection capability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A photon counting imaging detector with multi-band composite detection capability is characterized by comprising a vacuum-encapsulated tube array and, from bottom to top, a position-sensitive anode assembly, a detector frame, and a detector end cap.

[0007] The detector frame has N×M mounting grids;

[0008] The detector end cap has N×M mounting holes at positions corresponding to N×M mounting grids; N≥1, M≥1;

[0009] The vacuum-encapsulated tube array includes N×M vacuum-encapsulated tubes. The receiving ends of the vacuum-encapsulated tubes are arranged upwards inside the mounting grid, and the receiving ends of the N×M vacuum-encapsulated tubes are respectively provided with the same or different photocathodes to receive target light signals of different wavelengths and convert them into photoelectrons. The output ends of the N×M vacuum-encapsulated tubes are respectively provided with high-resistivity collection layers to receive photoelectrons and convert them into electron cloud signals for output.

[0010] Position-sensitive anode components are used to sense electron cloud signals and transmit them to an external readout electronics system for processing.

[0011] Furthermore, the vacuum-sealed tube includes a microchannel plate assembly and a housing; the upper end of the housing is provided with an input window, and the lower end is provided with a substrate, which is attached to the upper surface of the position-sensitive anode assembly; the photocathode is disposed on the lower surface of the input window; the microchannel plate assembly is disposed at the center of the housing, and an electric field is formed between the microchannel plate assembly and the photocathode for multiplying and amplifying photoelectrons and then transporting them to the high-resistivity collection layer; the high-resistivity collection layer is deposited on the upper surface of the substrate, and the high-resistivity collection layer and the position-sensitive anode assembly form a capacitor structure.

[0012] Furthermore, it also includes a degassing agent placed between the input window and the substrate to absorb the gas released during detector operation.

[0013] Furthermore, the position-sensitive anode assembly includes an anode substrate and a delay line anode, a cross bar anode, or a discrete multi-anode array disposed on the anode substrate; the width of the lower collecting metal electrode of the receiving surface of the delay line anode and the cross bar anode is greater than the width of its upper collecting metal electrode; both the lower collecting metal electrode and the upper collecting metal electrode are connected to an external readout electronics system via lead electrodes; each electrode of the discrete multi-anode array is square with a side length of 0.5mm to 10mm, and each electrode is connected to a lead electrode for connecting to an external readout electronics system.

[0014] Furthermore, the input windows of the N×M vacuum-sealed tubes all have the same thickness.

[0015] Furthermore, the microchannel plate assembly uses two microchannel plates cascaded in a V-shape or three microchannel plates cascaded in a Z-shape to improve gain performance.

[0016] Furthermore, the high-resistivity collection layer is made of Ge, and the substrate is made of alumina ceramic with a thickness of 0.5–4 mm.

[0017] Furthermore, the photocathode is a CsI cathode, a Cs2Te cathode, a multialkali cathode, or a semiconductor cathode.

[0018] Furthermore, the detector frame is provided with lead-out holes for passing high-voltage leads.

[0019] Furthermore, both the detector frame and the detector end cap are made of insulating material; N=2, M=2.

[0020] The beneficial effects of this utility model are:

[0021] 1. In the photon counting imaging detector with multi-band composite detection capability of this utility model, each vacuum-encapsulated tube can adopt a photocathode for different detection bands. After being combined with the corresponding external readout electronics system, it can realize the simultaneous detection and imaging of multiple band detection targets.

[0022] 2. In the photon counting imaging detector with multi-band composite detection capability of this utility model, multiple vacuum-encapsulated tubes share the same position-sensitive anode component. The position-sensitive anode component can simultaneously receive electron cloud signals output by different vacuum-encapsulated tubes. Therefore, the entire photon counting imaging detector only needs one set of external readout electronics system, which greatly reduces the power consumption and complexity of the external readout electronics system.

[0023] 3. In the photon counting imaging detector with multi-band composite detection capability of this utility model, each vacuum-encapsulated tube adopts the same photocathode, which can form a large-area spliced ​​detector array and expand the effective area of ​​the detector.

[0024] 4. This utility model provides a photon counting imaging detector with multi-band composite detection capability, which can simultaneously perform high temporal and spatial resolution multi-band composite detection and has important application value in the fields of space astronomy and biological fluorescence. Attached Figure Description

[0025] Figure 1 This is an exploded view of an embodiment of a photon counting imaging detector with multi-band composite detection capability according to this utility model;

[0026] Figure 2 This is an external schematic diagram of the vacuum-encapsulated tube in an embodiment of a photon counting imaging detector with multi-band composite detection capability according to this utility model;

[0027] Figure 3 yes Figure 2 Sectional view along AA;

[0028] Figure 4 This is a schematic diagram of the position-sensitive anode assembly structure formed by crossbar anodes attached to an anode substrate in an embodiment of a photon counting imaging detector with multi-band composite detection capability according to this utility model;

[0029] Figure 5 This is a schematic diagram of the position-sensitive anode assembly structure formed by the delay line anode being attached to the anode substrate in an embodiment of a photon counting imaging detector with multi-band composite detection capability according to this utility model.

[0030] Figure 6 This is a schematic diagram of the position-sensitive anode component structure formed by attaching a multi-anode array to an anode substrate in an embodiment of a photon counting imaging detector with multi-band composite detection capability according to this utility model.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1-Position-sensitive anode assembly, 2-Vacuum-encapsulated tube, 21-Input window, 22-Photocathode, 23-Microchannel plate assembly, 24-Housing, 25-High-resistivity collection layer, 26-Substrate, 27-Degassing agent, 3-Detector frame, 4-Detector end cap. Detailed Implementation

[0033] like Figure 1 , Figure 2 As shown, a photon counting imaging detector with multi-band composite detection capability includes a vacuum-encapsulated tube array and a position-sensitive anode assembly 1, a detector frame 3, and a detector end cap 4 connected sequentially from bottom to top; the detector frame 3 is provided with N×M mounting grids; the detector end cap 4 is provided with N×M mounting holes at positions corresponding to the N×M mounting grids; N≥1, M≥1.

[0034] The vacuum-encapsulated tube array includes N×M vacuum-encapsulated tubes 2, with the receiving end of each vacuum-encapsulated tube 2 facing upwards and disposed inside the mounting bracket. Each of the N×M vacuum-encapsulated tubes 2 has the same or different photocathodes 22 at its receiving end, used to receive target light signals of different wavelengths and convert them into photoelectrons. Each of the N×M vacuum-encapsulated tubes 2 has a high-resistivity collection layer 25 at its output end, used to receive photoelectrons and convert them into electron cloud signals for output. The position-sensitive anode assembly 1 is used to sense the electron cloud signals and transmit them to an external readout electronics system for processing.

[0035] like Figure 3As shown, the vacuum-sealed tube 2 includes a getter 27, a microchannel plate assembly 23, and a housing 24. An input window 21 is located at the upper end of the housing 24, and a substrate 26 is located at the lower end. The substrate 26 is attached to the upper surface of the position-sensitive anode assembly 1. A photocathode 22 is disposed on the lower surface of the input window 21. The microchannel plate assembly 23 is located at the center of the housing 24, and an electric field is formed between the microchannel plate assembly 23 and the photocathode 22 to amplify and deliver photoelectrons to the high-resistivity collection layer 25. The high-resistivity collection layer 25 is deposited on the upper surface of the substrate 26, and a capacitor structure is formed between the high-resistivity collection layer 25 and the position-sensitive anode assembly 1. The high-resistivity collection layer 25 reads out the electron cloud signal using a mirror charge coupling method. The getter 27 is disposed between the input window 21 and the substrate 26 to absorb the gas released during detector operation.

[0036] Position-sensitive anode assembly 1 includes an anode substrate and a delay line anode, a crossbar anode, or a discrete multi-anode array disposed on the anode substrate. The delay line anode and the crossbar anode form electrodes that intersect each other perpendicularly. The width of the lower collecting metal electrode on the receiving surface (upper surface) of the delay line anode and the crossbar anode is greater than the width of its upper collecting metal electrode, thereby ensuring that the number of electrons collected by the upper and lower collecting metal electrodes on the receiving surface of the delay line anode and the crossbar anode is roughly equal, achieving a balanced output sensing signal. Both the lower and upper collecting metal electrodes are connected to an external readout electronics system via lead electrodes. The delay line anode has four electrodes, all connected to leads; the use of crossbar anodes offers advantages such as compact structure and good spatial and temporal resolution. Each electrode in the discrete multi-anode array is square, with a side length of 0.5mm to 10mm, and each electrode is connected to a lead electrode for connecting to an external readout electronics system.

[0037] like Figure 4 As shown, the cross-bar anodes are attached to the anode substrate and are mutually insulated to form a cross-electrode array, used to decode the centroid position of the induced electron cloud. Both the upper and lower collector electrode arrays of the cross-electrode array are connected to an external readout electronics system via lead electrodes; the upper and lower collector electrode arrays are isolated from each other by an insulating material. The width of the lower collector electrode is greater than the width of the upper collector electrode, thus ensuring that the amount of charge collected by the upper and lower collector electrodes is roughly equal, achieving a balanced output signal.

[0038] like Figure 5As shown, the delay line anode is attached to the anode substrate, forming two layers of vertically intersecting serpentine metal electrodes. These two layers are isolated by an insulating material. The width of the lower serpentine metal electrode is greater than that of the upper one, ensuring that the charge collected by both layers is roughly equal, thus achieving a balanced output signal. The outputs from both the upper and lower serpentine metal electrodes are connected to an external readout electronics system via lead electrodes.

[0039] like Figure 6 As shown, a discrete multi-anode array is attached to the anode substrate to form a metal electrode array. Each metal electrode unit adopts a square structure, and the metal electrode units are isolated and insulated from each other. Each metal electrode unit needs to be connected to a lead electrode, which is then connected to an external readout electronics system.

[0040] The photocathodes 22 of the N×M vacuum-encapsulated tubes 2 may be identical or different, and can be selected according to the wavelength band to be detected. Specifically, CsI cathodes, Cs2Te cathodes, multi-alkali cathodes (S20 or S25, etc.), and semiconductor cathodes can be used. The microchannel plate assembly 23 uses two microchannel plates cascaded in a V-shape or three microchannel plates cascaded in a Z-shape. Single or multiple microchannel plates cascaded can improve gain performance. The detector frame 3 is provided with lead-out holes for high-voltage leads to pass through. The high-resistivity collection layer 25 is made of Ge, and the substrate 26 is made of 95% alumina (Al2O3) ceramic with a thickness of 0.5-4 mm. The detector frame 3 and the detector end cap 4 are both made of insulating material, which fixes the N×M vacuum-encapsulated tubes 2 in the mounting cavity.

[0041] In this embodiment, the position-sensitive anode assembly 1 uses a delayed line anode attached to the anode substrate to form two layers of vertically intersecting serpentine metal electrodes. The wavelengths to be detected are the far-ultraviolet band and the visible light band. The input windows 21 of the two vacuum-encapsulated tubes 2 are all of the same thickness, and the input windows 21 are made of magnesium fluoride and quartz respectively. The lower surface of each input window 21 is fabricated with a photocathode 22 to form a transmission cathode, so as to ensure that the photosensitive surface of each vacuum-encapsulated tube 2 is consistent, which is convenient for matching with the external electronic learning system. The far-ultraviolet light detection photocathode 22 can be a CsI cathode and the detection photocathode 22 can be an S20 cathode in the visible light band. The receiving area of ​​the photocathode 22 is 30mm×30mm. The two vacuum-encapsulated tubes 2 share the same large-area array position-sensitive anode assembly 1. The electron cloud signals output by different vacuum-encapsulated tubes 2 can be received by the same large-area array position-sensitive anode assembly 1. The effective area of ​​the large-area array position-sensitive anode assembly 1 is 100mm×100mm. The effective area of ​​a single vacuum-encapsulated tube array is 30mm×30mm. The distance between the cathode surface of the input window 21 and the upper surface of the microchannel plate assembly 23 is 0.2mm. The microchannel plate assembly 23 in the vacuum-encapsulated tube body 2 uses two microchannel plates cascaded in a V-shape. The high-resistivity collection layer 25 is made of a semiconductor film (such as Ge) and is fabricated on a ceramic substrate 26 with a thickness of 3 mm.

[0042] First, fix the large-area array position-sensitive anode assembly 1 to the detector frame 3, reliably connect each high-voltage electrode in the vacuum-encapsulated tube 2 to the high-voltage lead, then install the two vacuum-encapsulated tubes 2 on the upper part of the receiving surface of the position-sensitive anode assembly 1, and then make the base 26 of the vacuum-encapsulated tube 2 close to the upper surface of the position-sensitive anode assembly 1; lead the high-voltage lead out from the side lead-out hole of the detector frame 3, and after checking and confirming, install the detector end cap 4 to the detector frame 3, and form an independent detection unit with the vacuum-encapsulated tube 2 and the position-sensitive anode assembly 1, thus completing the assembly of the detector with multi-band composite detection capability.

Claims

1. A photon counting imaging detector with multi-band composite detection capability, characterized in that: It includes a vacuum-encapsulated tube array, and a position-sensitive anode assembly (1), a detector frame (3), and a detector end cap (4) connected from bottom to top; The detector frame (3) is provided with N×M mounting grids; The detector end cap (4) has N×M mounting holes at positions corresponding to N×M mounting grids; N≥1, M≥1; The vacuum-encapsulated tube array includes N×M vacuum-encapsulated tubes (2), with the receiving end of each vacuum-encapsulated tube (2) facing upwards and disposed inside the mounting bracket. The receiving ends of the N×M vacuum-encapsulated tubes (2) are respectively provided with the same or different photocathodes (22) for receiving target light signals of different wavelengths and converting them into photoelectrons. The output ends of the N×M vacuum-encapsulated tubes (2) are respectively provided with high-resistivity collection layers (25) for receiving photoelectrons and converting them into electron cloud signal output. The position-sensitive anode assembly (1) is used to sense the electron cloud signal and transmit it to an external readout electronics system for processing.

2. The photon counting imaging detector with multi-band composite detection capability according to claim 1, characterized in that: The vacuum-sealed tube (2) includes a microchannel plate assembly (23) and a housing (24); The upper end of the housing (24) is provided with an input window (21), and the lower end is provided with a base (26). The base (26) is attached to the upper surface of the position-sensitive anode assembly (1). The photocathode (22) is disposed on the lower surface of the input window (21); The microchannel plate assembly (23) is located at the center of the housing (24), and an electric field is formed between the microchannel plate assembly (23) and the photocathode (22) to amplify and deliver photoelectrons to the high-resistivity collection layer (25). The high-resistivity collection layer (25) is deposited on the upper surface of the substrate (26), and the high-resistivity collection layer (25) and the position-sensitive anode assembly (1) form a capacitor structure.

3. The photon counting imaging detector with multi-band composite detection capability according to claim 2, characterized in that: It also includes a degassing agent (27) disposed between the input window (21) and the substrate (26) for absorbing the gas released when the detector is working.

4. A photon counting imaging detector with multi-band composite detection capability according to claim 3, characterized in that: The position-sensitive anode assembly (1) includes an anode substrate and a delay line anode, a cross bar anode, or a discrete multi-anode array disposed on the anode substrate; The width of the lower collecting metal electrode on the receiving surface of the delay line anode and the cross bar anode is greater than the width of the upper collecting metal electrode; both the lower collecting metal electrode and the upper collecting metal electrode are connected to an external readout electronics system via lead electrodes; Each electrode of the discrete multi-anode array is square with a side length of 0.5mm to 10mm, and each electrode is connected to a lead wire.

5. A photon counting imaging detector with multi-band composite detection capability according to claim 4, characterized in that: The input windows (21) of N×M vacuum-sealed tubes (2) all have the same thickness.

6. A photon counting imaging detector with multi-band composite detection capability according to claim 5, characterized in that: The microchannel plate assembly (23) consists of two microchannel plates cascaded in a V-shape or three microchannel plates cascaded in a Z-shape, used to improve gain performance.

7. A photon counting imaging detector with multi-band composite detection capability according to claim 6, characterized in that: The high-resistivity collection layer (25) is made of Ge, and the substrate (26) is made of alumina ceramic with a thickness of 0.5 to 4 mm.

8. A photon counting imaging detector with multi-band composite detection capability according to claim 7, characterized in that: The photocathode (22) is a CsI cathode, a Cs2Te cathode, a multialkali cathode, or a semiconductor cathode.

9. A photon counting imaging detector with multi-band composite detection capability according to claim 8, characterized in that: The detector frame (3) is provided with an outlet hole for passing through a high-voltage lead.

10. A photon counting imaging detector with multi-band composite detection capability according to claim 9, characterized in that: Both the detector frame (3) and the detector end cap (4) are made of insulating material; The N=2, M=2.

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