Crossed strip anode photon counting imaging detector splicing system and splicing method

Abstract

The present application relates to the technical field of spectral imaging detection, and particularly relates to a cross-bar anode photon counting imaging detector splicing system and a splicing method, which respectively cover ultraviolet, visible and near-infrared bands, each detector unit comprises a vacuum sealed tube composed of a glass window coated with a photocathode, a cylindrical micro-channel plate stack, a resistance anode and a cross-bar anode, and a position reading circuit, wherein the curvature radius of the cylindrical MCP stack is matched with the focal plane curvature radius of the Rowland circle spectrometer to improve the spectral resolution. Four detector units are connected in one-to-one correspondence to form a long strip electrode array in the direction perpendicular to the spectral imaging direction, and the position reading circuit is used for processing charge pulses to determine the electron cloud centroid position. The curvature radius of the cross-bar anode single-photon imaging detector unit can be matched with the curvature radius of the cylindrical focal plane of the Rowland circle spectrometer, the spectral resolution of the spectrometer is improved, and continuous imaging of a wide spectral band of 115 nm to 900 nm is realized.

Description

Technical Field

[0001] This invention belongs to the field of spectral imaging detection technology, and particularly relates to a stitching system and method for a cross-strip anode photon counting imaging detector. Background Technology

[0002] Modern direct-reading spectrometers typically employ a fixed grating-photoelectric direct-reading optical path design. In direct-reading spectrometers, the optical structure usually uses a Rowland circular optical path. Due to the special nature of the dispersive devices used, the optical structure can eliminate the need for the exit slit and focusing lens, simplifying the optical path. In a direct-reading spectrometer, the excitation source passes through an entrance slit, and then a concave grating disperses and images different wavelengths of light onto a cylindrical focal plane. Multiple CCDs, EMCCDs, or photodiodes are used for photoelectric imaging and detection at different wavelength spectral line positions on the cylindrical focal plane.

[0003] Due to the planar structure of CCDs, EMCCDs, and photomultiplier tubes, using multiple CCDs / EMCCDs or photomultiplier tubes for photoelectric imaging detection at different wavelength spectral line positions on the cylindrical focal plane in direct-reading spectrometers with Rowland's circular structure reduces spectral imaging resolution. Furthermore, for applications with very weak excitation sources, the signal-to-noise ratio using CCDs for detection will be very low, while photomultiplier tubes, being single-pixel detectors, are unsuitable for spectral imaging detection applications. Summary of the Invention

[0004] In view of this, the present invention aims to provide a stitching system and method for a cross-strip anode photon counting imaging detector.

[0005] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A cross-strip anode photon counting imaging detector stitching system includes: Four intersecting bar anode single-photon imaging detector units are used to cover the ultraviolet, visible, and near-infrared bands. Each intersecting bar anode single-photon imaging detector unit includes a glass window with a photocathode coated on its inner surface, a cylindrical microchannel plate stack, a resistive anode, a vacuum-sealed tube composed of intersecting bar anodes, and a position readout circuit. Photons pass through the glass window and are incident on the photocathode to generate photoelectrons. The photoelectrons are incident on the cylindrical microchannel plate stack and undergo electron multiplication to become an electron cloud. The electron cloud emitted from the cylindrical microchannel plate stack falls on the resistive anode. The electron cloud falls on the resistive anode and induces a charge pulse on the intersecting bar anode. The position readout circuit then processes the charge pulse to determine the centroid position of the electron cloud. The radius of curvature of the cylindrical microchannel plate stack matches the radius of curvature of the focal plane of the Roland circular spectrometer, and the four intersecting strip anode single-photon imaging detector units are connected one-to-one with the strip electrodes perpendicular to the spectral imaging direction to form a long strip electrode array. The position readout circuit includes a multi-channel preamplifier circuit, a multi-channel ADC circuit, and an FPGA, used to process charge pulses to determine the position of the electron cloud centroid.

[0006] Optionally, the photocathode includes a cesium telluride cathode for the ultraviolet band, a dual-alkali cathode and a multi-alkali cathode for the visible band, and a gallium arsenide cathode for the near-infrared band.

[0007] Optionally, the resistive anode is a germanium film prepared on a ceramic substrate, the cross-shaped anode is located below the resistive anode with the anode side facing upward, the cross-shaped anode maintains zero-distance contact with the ceramic substrate, and the electron cloud induces charge pulses on the germanium film, which are then processed by the position readout circuit.

[0008] Optionally, the FPGA is used to perform pulse waveform filtering, peak finding and coordinate calculation, and transmits the data to a computer via optical fiber for image stitching.

[0009] A stitching method for the above-mentioned cross-strip anode photon counting imaging detector stitching system includes: In the Y direction, the strip electrodes are connected one by one and connected to the Y-direction multi-channel preamplifier circuit and multi-channel ADC circuit. In the X direction, the waveform quantization data of each cross-strip anode single-photon imaging detector unit is synchronously sent to the FPGA for filtering, peak finding and coordinate calculation.

[0010] Compared with the prior art, the present invention can achieve the following beneficial effects: This invention provides a stitching system and method for a cross-strip anode photon counting imaging detector, covering the ultraviolet, visible, and near-infrared bands. Each detector unit comprises a vacuum-sealed tube consisting of a glass window, a stack of cylindrical microchannel plates, a resistive anode, and cross-strip anodes, a position readout circuit, and image acquisition and processing software. The radius of curvature of the cylindrical microchannel plate stack matches the radius of curvature of the focal plane of a Rowland circle spectrometer, improving spectral resolution. Four detector units are connected one-to-one with corresponding strip electrodes perpendicular to the spectral imaging direction to form a long strip electrode array. The position readout circuit includes a multi-channel preamplifier circuit, a multi-channel ADC circuit, and an FPGA, used to process charge pulses to determine the position of the electron cloud centroid. By matching the radius of curvature of the cross-strip anode single-photon imaging detector unit with the radius of curvature of the cylindrical focal plane of the Rowland circle spectrometer, the spectral resolution of the spectrometer can be significantly improved, achieving continuous imaging across a wide spectral range of 115nm to 900nm. Furthermore, it allows for a more compact and simpler structure for the Rowland circle imaging spectrometer, making it more suitable for applications with very weak excitation sources. Attached Figure Description

[0011] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A structural cross-sectional view of the cross-strip anode photon counting imaging detector splicing system described in an embodiment of the present invention; Figure 2 A schematic diagram of the splicing method of the cross-strip anode photon counting imaging detector splicing system described in an embodiment of the present invention. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0013] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0014] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0015] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0016] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] like Figure 1 As shown in the embodiment of the present invention, a cross-strip anode photon counting imaging detector stitching system includes: Four intersecting bar anode single-photon imaging detector units are used to cover the ultraviolet, visible, and near-infrared bands. Each intersecting bar anode single-photon imaging detector unit includes a glass window 1 with a photocathode coated on its inner surface, a cylindrical microchannel plate stack 2, a resistive anode 3, an intersecting bar anode 4, and a position readout circuit. Photons pass through the glass window 1 and are incident on the photocathode to generate photoelectrons. The photoelectrons are incident on the cylindrical microchannel plate stack 2 and undergo electron multiplication to become an electron cloud. The electron cloud emitted from the cylindrical microchannel plate stack 2 falls on the resistive anode 3. The electron cloud falls on the resistive anode 3 and induces a charge pulse on the intersecting bar anode 4. The position readout circuit then processes the charge pulse to determine the centroid position of the electron cloud. The radius of curvature of the cylindrical microchannel plate stack 2 matches the radius of curvature of the focal plane of the Roland circular spectrometer, and the four intersecting strip anode single-photon imaging detector units are connected one-to-one with the strip electrodes perpendicular to the spectral imaging direction to form a long strip electrode array. The position readout circuit includes a multi-channel preamplifier circuit, a multi-channel ADC circuit, and an FPGA, used to process charge pulses to determine the position of the electron cloud centroid.

[0018] In some implementations, photons pass through glass window 1 and strike the photocathode to generate photoelectrons. These photoelectrons then strike the cylindrical microchannel plate stack 2 and undergo electron multiplication to form a structure containing approximately 10-1 photoelectrons. 6 An electron cloud of electrons, emitted from the cylindrical microchannel plate stack 2, lands on the resistive anode 3 within the sealed tube. The resistive anode 3 is a germanium film fabricated on a ceramic substrate easily bonded to Kovar alloy. A cross-shaped anode 4 is located below the resistive anode, with the anode side facing upwards, maintaining zero distance from the germanium-coated ceramic substrate. Simultaneously, the electron cloud landing on the germanium film induces a charge pulse on the cross-shaped anode 4. The position readout circuit then processes this charge pulse to determine the centroid position of the electron cloud, i.e., the position of the incident photon. The position readout circuit mainly includes a multi-channel preamplifier circuit, a multi-channel ADC circuit, and an FPGA.

[0019] In some embodiments, the photocathode includes a cesium telluride cathode for the ultraviolet band, a dual-alkali cathode and a multi-alkali cathode for the visible band, and a gallium arsenide cathode for the near-infrared band. Based on the distribution of the ultraviolet band (115nm-400nm), the visible band (400-700nm), and the near-infrared band (700-900nm), these four types of cathodes can cover the spectral range of 115nm to 900nm.

[0020] In some embodiments, the FPGA is used to perform pulse waveform filtering, peak finding and coordinate calculation, and transmits the data to a computer via optical fiber for image stitching.

[0021] This invention provides a cross-strip anode photon counting imaging detector stitching system, covering the ultraviolet, visible, and near-infrared bands. Each unit consists of a glass window 1, a cylindrical microchannel plate stack 2, a resistive anode, a cross-strip anode, a position readout circuit, and image acquisition and processing software. The radius of curvature of the cylindrical microchannel plate stack 2 matches the radius of curvature of the focal plane of the Roland circle spectrometer, improving spectral resolution. Four detector units are connected one-to-one with strip electrodes perpendicular to the spectral imaging direction to form a long strip electrode array. The position readout circuit includes a multi-channel preamplifier circuit, a multi-channel ADC circuit, and an FPGA, used to process charge pulses to determine the position of the electron cloud centroid. By matching the radius of curvature of the cross-strip anode single-photon imaging detector unit with the radius of curvature of the cylindrical focal plane of the Roland circle spectrometer, the spectral resolution of the spectrometer can be significantly improved, achieving continuous imaging across a wide spectral range of 115nm to 900nm. Furthermore, it makes the Roland circle imaging spectrometer structure more compact and simpler, making it more suitable for applications with very weak excitation light sources.

[0022] Accordingly, this embodiment of the invention also provides a stitching method for the above-mentioned cross-strip anode photon counting imaging detector stitching system, comprising: In the Y direction, the strip electrodes are connected one by one and connected to the Y-direction multi-channel preamplifier circuit and multi-channel ADC circuit. In the X direction, the waveform quantization data of each cross-strip anode single-photon imaging detector unit is synchronously sent to the FPGA for filtering, peak finding and coordinate calculation.

[0023] Combination Figure 2 As shown, specifically, in the direction perpendicular to the spectral imaging direction, such as the corresponding Y direction, all the bar electrodes of the four intersecting bar anode single-photon imaging detector units in the Y direction are connected one-to-one to form a longer bar electrode array, which is connected to the Y-direction multi-channel preamplifier circuit and multi-channel ADC circuit. Then, the quantized data of the pulse waveform is sent to the FPGA, which performs filtering and peak finding for each pulse waveform. The quantized data of the X-direction waveform of each intersecting bar anode single-photon imaging detector unit is also sent to the FPGA simultaneously, which performs filtering and peak finding for each pulse waveform. Then, the peak data is sent to the FPGA to calculate the (X, Y) coordinates of each intersecting bar anode single-photon imaging detector unit, obtaining the spectral image data of the four intersecting bar anode single-photon imaging detector units. This data is transmitted to the computer through optical fiber, and the software stitches these four image data into a single spectral image.

[0024] This invention provides a stitching system and method for a cross-strip anode photon counting imaging detector, covering the ultraviolet, visible, and near-infrared bands. Each detector unit comprises a vacuum-sealed tube consisting of a glass window coated with a photocathode, a stack of cylindrical microchannel plates, a resistive anode, a cross-strip anode, a position readout circuit, and image acquisition and processing software. The radius of curvature of the cylindrical microchannel plate stack matches the radius of curvature of the focal plane of the Roland circle spectrometer, improving spectral resolution. Four detector units are connected one-to-one with corresponding strip electrodes perpendicular to the spectral imaging direction to form a long strip electrode array. The position readout circuit includes a multi-channel preamplifier circuit, a multi-channel ADC circuit, and an FPGA, used to process charge pulses to determine the position of the electron cloud centroid. By matching the radius of curvature of the cross-strip anode single-photon imaging detector unit with the radius of curvature of the cylindrical focal plane of the Roland circle spectrometer, the spectral resolution of the spectrometer can be significantly improved, achieving continuous imaging across a wide spectral range of 115nm to 900nm. Furthermore, it allows for a more compact and simpler structure for the Roland circle imaging spectrometer, making it more suitable for applications with very weak excitation sources.

[0025] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A stitching system for a cross-strip anode photon counting imaging detector, characterized in that, include: Four intersecting bar anode single-photon imaging detector units are used to cover the ultraviolet, visible, and near-infrared bands. Each intersecting bar anode single-photon imaging detector unit includes a vacuum-sealed tube consisting of a glass window with a photocathode coated on its inner surface, a cylindrical microchannel plate stack, a resistive anode, and intersecting bar anodes, as well as a position readout circuit. Photons pass through the glass window and are incident on the photocathode to generate photoelectrons. The photoelectrons are incident on the cylindrical microchannel plate stack and undergo electron multiplication to become an electron cloud. The electron cloud emitted from the cylindrical microchannel plate stack falls on the resistive anode, and the electron cloud falls on the resistive anode and induces a charge pulse on the intersecting bar anode. The position readout circuit then processes the charge pulse to determine the centroid position of the electron cloud. The radius of curvature of the cylindrical microchannel plate stack matches the radius of curvature of the focal plane of the Roland circular spectrometer, and the four intersecting strip anode single-photon imaging detector units are connected one-to-one with the strip electrodes perpendicular to the spectral imaging direction to form a long strip electrode array. The position readout circuit includes a multi-channel preamplifier circuit, a multi-channel ADC circuit, and an FPGA, used to process charge pulses to determine the position of the electron cloud centroid.

2. The cross-strip anode photon counting imaging detector stitching system according to claim 1, characterized in that, The photocathode includes a cesium telluride cathode for the ultraviolet band, a dual-alkali cathode and a multi-alkali cathode for the visible band, and a gallium arsenide cathode for the near-infrared band.

3. The system according to claim 1, characterized in that, The resistive anode is a germanium film prepared on a ceramic substrate. The cross-shaped anode is located below the resistive anode with the anode side facing upward. The cross-shaped anode maintains zero-distance contact with the ceramic substrate. After the electron cloud induces a charge pulse on the germanium film, it is processed by the position readout circuit.

4. The system according to claim 1, characterized in that, The FPGA is used to perform pulse waveform filtering, peak finding, and coordinate calculation, and transmits the data to a computer via optical fiber for image stitching.

5. A splicing method applied to the splicing system of the cross-strip anode photon counting imaging detector according to any one of claims 1 to 4, characterized in that, include: In the Y direction, the strip electrodes are connected one by one and connected to the Y-direction multi-channel preamplifier circuit and multi-channel ADC circuit. In the X direction, the waveform quantization data of each cross-strip anode single-photon imaging detector unit is synchronously sent to the FPGA for filtering, peak finding and coordinate calculation.

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