An enhanced wide-field high-resolution soft X-ray imager

Abstract

The present invention belongs to the technical field of space environment detection equipment. Specifically, it relates to an enhanced wide-field high-resolution soft X-ray imager, which includes: a lobster-eye optical lens (1), a first square conical housing (2), a wide-angle lens assembly (3), a second square housing (4), and a back-illuminated CMOS image sensor (5); the two ends of the first square conical housing (2) are respectively provided with a first incident port and a first exit port; the two ends of the second square housing (4) are respectively provided with a second incident port and a second exit port; the first square conical housing (2) is docked with the second square housing (4), and the first exit port of the first square conical housing (2) overlaps with the second incident port of the second square housing (4); the lobster-eye optical lens (1) is fixedly arranged at the first incident port of the first square conical housing (2), the wide-angle lens assembly (3) is fixedly arranged in the second square housing (4), and the CMOS image sensor (5) is fixedly arranged at the second exit port of the second square housing (4).

Description

Technical Field

[0001] The present invention belongs to the technical field of space environment detection equipment, and specifically relates to an enhanced wide-field high-resolution soft X-ray imager. Background Art

[0002] The wide-field and high-resolution soft X-ray imager is an important device for studying the deep physical mechanism of the interaction between the solar wind and the Earth's magnetosphere, and can realize the panoramic image of the soft X-rays radiated by the Earth's magnetosphere to monitor space weather. When the solar wind blows towards the Earth, it contains a large number of highly charged heavy ions, such as O 7+ etc. A large number of highly charged ions collide with neutral atoms (such as H atoms) in the exosphere of the magnetosphere, causing electron transitions and radiating soft X-rays outward. This process is called Solar Wind Charge eXchange (SWCX). As the interaction between the solar wind and the magnetosphere strengthens, the intensity of the radiated soft X-ray light is greater. Therefore, dynamically depicting the intensity map of the soft X-rays radiated during the interaction process between the solar wind and the Earth's magnetosphere can obtain the macroscopic structure and evolution law of the Earth's magnetosphere, which is of great significance for studying scientific issues such as the internal driving force of space weather.

[0003] The Earth's magnetosphere spans dozens of Earth radii. To achieve panoramic imaging of the magnetosphere, the soft X-ray imager must have performance characteristics such as a wide field of view, high spatial resolution, and high sensitivity. Currently, wide-field soft X-ray imaging is mainly achieved based on the lobster-eye optical system; however, the ideal lobster-eye optical system requires the imaging focal plane to have an area that is 1 / 4 of the lens area and the imaging focal plane is a spherical structure with a curvature radius that is half of the lens curvature radius. Conventional soft X-ray sensors are small-sized (2.2 cm × 2.2 cm) and planar structures, which cannot meet the theoretical requirements. Currently, in order to meet the theoretical requirements, the method of splicing multiple small-sized soft X-ray sensors is used to increase the area of the imaging focal plane, which not only greatly increases the cost, but also has problems such as discontinuous field of view, sharp decline in off-axis resolution, and system electromagnetic compatibility caused by splicing. Summary of the Invention

[0004] To solve the above-mentioned defects existing in the prior art, the present invention proposes an enhanced wide-field high-resolution soft X-ray imager, which includes: a lobster-eye optical lens, a first square conical housing, a wide-angle lens assembly, a second square housing, and a back-illuminated CMOS image sensor;

[0005] The two ends of the first square conical housing are respectively provided with a first inlet and a first outlet; the two ends of the second square housing are respectively provided with a second inlet and a second outlet;

[0006] The first square conical housing is docked with the second square housing, and the first exit of the first square conical housing overlaps with the second entrance of the second square housing;

[0007] A lobster-eye optical lens is fixedly arranged at the first entrance of the first square conical housing, a wide-angle lens assembly is fixedly arranged inside the second square housing, and a CMOS image sensor is fixedly arranged at the second exit of the second square housing.

[0008] As one of the improvements of the above technical solution, the wide-angle lens assembly includes: a conical capillary array wide-angle lens and a fixed mounting cylinder;

[0009] The fixed mounting cylinder is arranged inside the second square housing, and the conical capillary array wide-angle lens is fixedly sleeved inside the fixed mounting cylinder;

[0010] The conical capillary array wide-angle lens has a conical structure, and its two ends are respectively a large entrance end and a small exit end; and the large entrance end of the conical capillary array wide-angle lens is set as a spherical surface; its small exit end is set as a plane; the large entrance end of the conical capillary array wide-angle lens is located at the second entrance of the second square housing, and the small exit end of the conical capillary array wide-angle lens is located at the second exit of the second square housing.

[0011] As one of the improvements of the above technical solution, the conical capillary array wide-angle lens includes a plurality of conical capillary wide-angle lenses, and the plurality of conical capillary wide-angle lenses form a conical structure; both ends of each conical capillary wide-angle lens are respectively a large entrance end and a small entrance end, its large entrance end is set as a spherical surface and is located at the second entrance of the second square housing; its small exit end is set as a plane and is located at the second exit of the second square housing.

[0012] As one of the improvements of the above technical solution, the distance between the conical capillary array wide-angle lens and the back-illuminated CMOS image sensor is 0 - 1 mm; the distance between the conical capillary array wide-angle lens and the lobster-eye optical lens is 375 mm; the curvature of the conical capillary array wide-angle lens is one-half of the curvature of the lobster-eye optical lens.

[0013] As one of the improvements of the above technical solution, the first entrance is a square conical opening, and the first exit is a square opening; both the second entrance and the second exit are square openings.

[0014] As one of the improvements of the above technical solution, the lobster-eye optical lens includes: a spherical metal support frame, a plurality of lobster-eye optical lenses, and a spherical metal pressing plate;

[0015] The spherical metal support frame is fixedly installed at the first incident port of the first square conical housing to form a spherical large-area light collection surface; the radius of curvature of the spherical metal support frame is consistent with the concave curvature radius of the lobster eye lens; the radius of curvature of the spherical metal pressing plate is consistent with the convex curvature radius of the lobster eye lens; multiple lobster eye optical lenses are arranged on the spherical metal support frame, and the multiple lobster eye optical lenses are arranged in an M*N array, and are fixed on the spherical metal support frame by a fixing device using a stress-free high-precision assembly method, and the spherical metal pressing plate is fixed above the multiple lobster eye optical lenses; wherein, both M and N are positive integers greater than 0.

[0016] As one of the improvements of the above technical solution, the lobster eye optical lens has a square structure; the spherical curvature radius of the lobster eye optical lens includes but is not limited to R750mm ± 1mm, the microchannel depth of the lobster eye optical lens includes but is not limited to 1.25mm ± 0.1mm; the microchannel opening width of the lobster eye optical lens includes but is not limited to 40μm ± 1μm; the microchannel wall thickness of the lobster eye optical lens includes but is not limited to 8μm ± 1μm; the coating material on the inner wall of the microchannel of the lobster eye optical lens includes but is not limited to a 20nm ± 2nm iridium metal film, and its surface roughness < 1nm.

[0017] As one of the improvements of the above technical solution, the lobster eye optical lens is provided with a microchannel, and the ratio of the depth to the width of the microchannel includes but is not limited to 31.25:1.

[0018] As one of the improvements of the above technical solution, the surface of the lobster eye optical lens is coated with a 100nm ± 10nm aluminum film filter.

[0019] As one of the improvements of the above technical solution, the pixels of the back-illuminated CMOS image sensor include but are not limited to 2048×2048, the pixel size includes but is not limited to 11μm×11μm, and the imaging area includes but is not limited to 2.2cm×2.2cm.

[0020] The beneficial effects of the present invention compared with the prior art are:

[0021] The imager of the present invention can cover the energy band of 0.2keV to 5keV, can work in a cube satellite platform or a ground calibration system, and can achieve a high resolution with a spatial angular resolution better than 6 arc minutes in the full observation field of view of 9°×9°; in addition, in addition to maintaining the advantage of wide-field imaging, the imager of the present invention basically has no loss of spatial resolution in the off-axis field of view. By introducing a conical capillary array wide-angle lens, the imaging requirement for a large-area spherical focal plane is greatly reduced, the cost is greatly reduced, and at the same time, high-performance soft X-ray imaging with wide field of view, high spatial resolution, and high sensitivity is achieved. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of an enhanced wide-field high-resolution soft X-ray imager of the present invention;

[0023] Figure 2 is a schematic optical path diagram of soft X-rays of an enhanced wide-field high-resolution soft X-ray imager of the present invention;

[0024] Figure 3 is Figure 1 is a schematic structural diagram of a lobster-eye optical lens of an enhanced wide-field high-resolution soft X-ray imager of the present invention;

[0025] Figure 4 is Figure 1 is a schematic structural diagram of a wide-angle lens assembly of an enhanced wide-field high-resolution soft X-ray imager of the present invention.

[0026] Reference numerals:

[0027] 1, lobster-eye optical lens; 2, first square conical housing

[0028] 3, wide-angle lens assembly; 4, second square housing

[0029] 5, CMOS image sensor; 6, spherical metal support frame

[0030] 7, lobster-eye optical lens element; 8, metal pressing plate

[0031] 9, conical capillary array wide-angle lens; 10, fixed mounting cylinder

[0032] 11, mounting position Detailed implementation manners

[0033] The present invention will now be further described in conjunction with the accompanying drawings.

[0034] As Figure 1 shown, the present invention provides an enhanced wide-field high-resolution soft X-ray imager. Working process: Soft X-ray photons are incident through the front lobster-eye optical lens element. Visible light, ultraviolet light and other stray lights are absorbed by the aluminum film filter. The soft X-rays are reflected and focused on the theoretical focal plane through the microchannel holes in the lobster-eye optical lens element to form focused light. The focused light then enters from the head of the conical capillary array wide-angle lens and passes through the lens after 1 or multiple grazing incidence total reflections inside the capillary and converges on a conventional CMOS image sensor

[0035] The present invention provides an enhanced wide-field high-resolution soft X-ray imager. By introducing an improved wide-angle lens (i.e., a conical capillary array wide-angle lens), the lobster-eye optical path is improved, realizing the transfer and compression of the large-area spherical focusing focal plane area to match the actual detector. Based on a conventional single-chip soft X-ray sensor, it can simultaneously meet the performance requirements of wide field of view, high spatial resolution, and high sensitivity, effectively solving the problem of difficult matching of the large-area spherical imaging focal plane of the soft X-ray imager. The imager of the present invention is an enhanced wide-field high-spatial-resolution soft X-ray imager based on a single-chip conventional small-size sensor, which can operate at 0.2 keV to 5 keV, with a wide field of view of 9°×9°, a spatial resolution better than 6 arc minutes within the entire field of view, and an effective area reaching 10.5 cm2@0.5 keV. Its main structure includes 3×3 lobster-eye optical elements and a high-precision support frame, a set of high-transmission-efficiency wide-angle lenses based on an optimized capillary array, a high-performance back-illuminated CMOS image sensor, and other positioning and support structures.

[0036] It includes: a lobster-eye optical lens 1, a first square conical housing 2, a wide-angle lens assembly 3, a second square housing 4, and a back-illuminated CMOS image sensor 5;

[0037] The two ends of the first square conical housing 2 are respectively provided with a first entrance and a first exit; the two ends of the second square housing 4 are respectively provided with a second entrance and a second exit;

[0038] The first square conical housing 2 is docked with the second square housing 4, and the first exit of the first square conical housing 2 overlaps with the second entrance of the second square housing 4;

[0039] The lobster-eye optical lens 1 is fixedly arranged at the first entrance of the first square conical housing 2, the wide-angle lens assembly 3 is fixedly arranged inside the second square housing 4, and the back-illuminated CMOS image sensor 5 is fixedly arranged at the second exit of the second square housing 4. In this embodiment, the CMOS image sensor is a high-performance back-illuminated CMOS image sensor.

[0040] Among them, the first square conical housing 2 is docked with the lobster-eye optical lens 1, and the first square conical housing 2 is a square-mouthed housing with a taper. The first entrance is a square conical opening, and the first exit is a square opening; both the second entrance and the second exit are square openings.

[0041] Among them, as Figure 3 shown, the lobster-eye optical lens 1 includes: a spherical metal support frame 6, a plurality of lobster-eye optical lenses 7, and a spherical metal pressing plate 8;

[0042] The spherical metal support frame 6 is fixedly installed at the first incident port of the first square conical housing 2 to form a spherical large-area light-gathering surface; the radius of curvature of the spherical metal support frame 6 is consistent with the concave curvature radius of the lobster-eye lens 7; the radius of curvature of the spherical metal pressing plate 8 is consistent with the convex curvature radius of the lobster-eye lens 7 to meet the requirement of a large observation field of view; multiple lobster-eye optical lenses 7 are arranged on the spherical metal support frame 6, and the multiple lobster-eye optical lenses 7 are arranged in an M*N array and are fixed on the spherical metal support frame 6 by a fixing device using a stress-free high-precision assembly method, and the spherical metal pressing plate 8 is fixed above the multiple lobster-eye optical lenses 7. Multiple glue application positions and positioning holes are reserved inside the frame of the spherical metal support frame 6, and the installation position of the support frame can be finely adjusted. Among them, both M and N are positive integers greater than 0.

[0043] Optionally, the lobster-eye optical lens 7 is a square structure with a size of 42.5 mm×42.5 mm (±0.1 mm); the spherical curvature radius of the lobster-eye optical lens 7 is R750 mm±1 mm, the micro-channel depth of the lobster-eye optical lens 7 is 1.25 mm±0.1 mm; the micro-channel square hole size (opening width) of the lobster-eye optical lens 7 is 40 μm±1 μm; the micro-channel wall thickness of the lobster-eye optical lens 7 is 8 μm±1 μm; the coating material of the inner wall of the micro-channel of the lobster-eye optical lens 7 is an iridium metal film, its surface roughness <1 nm, and the coating layer thickness is 20 nm±2 nm; the spatial resolution of the lobster-eye optical lens 7 is better than 5 angular minutes @1 keV, that is, the resolution of the lens itself.

[0044] In this embodiment, optionally, the lobster-eye optical lens 1 includes 9 lobster-eye optical lenses 7, which are integrally assembled in a 3×3 array form to ensure a large observation field of view of 9°×9°.

[0045] The lobster-eye optical lens 7 is provided with a micro-channel, and the ratio of the depth to the width of the micro-channel is 31.25:1 to ensure a spatial resolution better than 6 angular minutes.

[0046] The surface of the lobster-eye optical lens 7 is coated with an aluminum film filter with a thickness of 100 nm±10 nm to eliminate stray light interference such as visible light and ultraviolet light within the 9°×9° observation field of view. Among them, the thickness of the organic film of the aluminum film is 50 nm±10 nm.

[0047] The lobster-eye optical lenses 1 are arranged in a 3×3 pattern, and the spacing between adjacent lobster-eye optical lenses is 1 mm. Among them, the frame curvature of the spherical metal frame is 750 mm ± 1 mm, which is consistent with the radius of curvature of the concave surface of the lobster-eye optical lens; the distance from the vertex of the incident surface of the lobster-eye optical lens at the middle position to the vertex of the incident surface of the conical capillary array wide-angle lens 9 is 375 mm, and this distance is half of the radius of curvature of the lobster-eye lens); the radius of curvature of the incident surface of the conical capillary array wide-angle lens 9 is 375 mm, and this distance is half of the radius of curvature of the lobster-eye lens, and the distance between the incident surface and the exit surface (tube length) is 235 mm ± 1 mm. Therefore, if the radius of curvature of the lobster-eye lens changes, the radius of curvature of the incident surface of the conical capillary array wide-angle lens 9 will also change, and the distance from the vertex of the incident surface of the lobster-eye optical lens at the middle position to the vertex of the incident surface of the conical capillary array wide-angle lens 9 will also change accordingly.

[0048] As Figure 2 shown, in a right-handed coordinate system with the incident direction of soft X-rays onto the lobster-eye optical lens as the positive direction of the Z-axis, perpendicular to the Z-axis and perpendicular to the paper and into the paper as the positive direction of the X-axis, the imager is entirely on the negative half-axis of the Z-axis, and the origin of coordinates is the center of curvature of the lobster-eye optical lens, which is also the center of curvature of the spherical entrance surface of the capillary array wide-angle lens inside the second square housing.

[0049] The lobster-eye optical lens located at the center position of the 3×3 array of lobster-eye optical lenses is perpendicular to the Z-axis, and the central coordinates are (0, 0, -750) mm. A width of 1 mm is covered on each of the four sides of its corresponding mounting slot. Glue injection holes are reserved at the corners and sides of the mounting slot. All the lobster-eye optical lenses are installed in sequence, and finally a spherical metal bar is added on the top for fixation; the conical capillary array wide-angle lens 9 is installed at a position 375 mm away from the center of the lobster-eye optical lens. The conical capillary array wide-angle lens 9 includes a plurality of conical capillaries arranged in an array. The single tubes of the internal conical capillary array are arranged and assembled in a shape similar to a cone. The length of each conical capillary is 235 mm ± 1 mm, and the area ratio of the incident surface to the exit surface is approximately 7:1; multiple fixing slots are provided inside the fixing sleeve to calibrate the capillary array, and three layers of square mounting positions, upper, middle, and lower, are provided on the outside of the fixing sleeve to connect with the second square housing 4; the CMOS image sensor is installed at a position 0 - 1 mm away from the exit of the conical capillary array wide-angle lens 9 to ensure that the photosensitive surface of the CMOS image sensor is as close as possible to the exit of the conical capillary array wide-angle lens 9. The central axes of the lobster-eye optical lens, the conical capillary array wide-angle lens 9, and the CMOS image sensor all coincide with the Z-axis, and the structure is symmetric about the X-axis and Y-axis.

[0050] AsFigure 4 As shown in the figure, the wide-angle lens assembly 3 includes a conical capillary array wide-angle lens 9 and a fixed mounting cylinder 10;

[0051] The fixed mounting cylinder 10 is arranged in the second square housing 4, and the conical capillary array wide-angle lens 9 is fixedly sleeved in the fixed mounting cylinder 10.

[0052] The conical capillary array wide-angle lens 9 has a conical structure, with its two ends being a large inlet end and a small outlet end respectively; and the large inlet end of the conical capillary array wide-angle lens 9 is set as a spherical surface; its small outlet end is set as a plane; the large inlet end of the conical capillary array wide-angle lens 9 is located at the second inlet of the second square housing 4, and the small outlet end of the conical capillary array wide-angle lens 9 is located at the second outlet of the second square housing 4.

[0053] The conical capillary array wide-angle lens 9 includes a plurality of conical capillary wide-angle lenses, and the plurality of conical capillary wide-angle lenses form a conical structure; the two ends of each conical capillary wide-angle lens are a large inlet end and a small inlet end respectively, its large inlet end is set as a spherical surface and is located at the second inlet of the second square housing 4; its small outlet end is set as a plane and is located at the second outlet of the second square housing 4.

[0054] Among them, the large inlet end of the conical capillary array wide-angle lens 9 is a spherical surface, the curvature radius of this spherical surface is 375 mm, and the size of this spherical surface (i.e., the effective incident surface aperture) is 7.46 mm × 7.46 mm; the small outlet end of the conical capillary array wide-angle lens 9 is a plane, the size of this plane (i.e., the effective exit surface aperture) is 2.8 mm × 2.8 mm, the flatness of the exit surface is ≤ 100 μm / cm, and the surface form deviation is ≤ 100 μm; the lateral length of this conical structure is 235 mm ± 1 mm; the diameter of the incident end of the capillary is 10 μm to 80 μm, and the efficiency uniformity is better than 80%. Among them, the curvature radius of the inlet spherical surface is half of the curvature radius of the lobster eye optical lens, and the exit plane matches the plane of the CMOS image sensor. The distance between the spherical vertex on the large inlet end of the conical capillary array wide-angle lens 9 and the lobster eye optical lens arranged on the spherical metal support frame is 375 mm (half of the curvature radius of the lobster eye lens), covering the observation field of view and efficiently transmitting soft X-ray photons.

[0055] The size of the back-illuminated CMOS image sensor is 2.2 cm × 2.2 cm, its pixel number is 2048 × 2048, and its pixel size is 11 μm × 11 μm.

[0056] The distance between the conical capillary array wide-angle lens 9 and the lobster eye optical lens 7 is 375 mm. The distance between the conical capillary array wide-angle lens 9 and the CMOS image sensor 5 is 0 - 1 mm. The radius of curvature of the conical capillary array wide-angle lens 9 is half of that of the lobster eye optical lens 7, which can reduce the degradation of imaging quality caused by defocus. The center of the lobster eye optical lens 7, the central axis of the conical capillary array wide-angle lens 9, and the central axis of the back-illuminated CMOS image sensor 5 are on the same straight line.

[0057] Through the additional wide-angle lens assembly 3, the theoretically required large-area spherical focal plane is transferred and compressed to the imaging focal plane of a single conventional back-illuminated CMOS image sensor 5. In the imager of the present invention, the lobster eye optical lenses 7 arranged in a 3×3 array are fixedly arranged on the spherical metal frame 6 at the first entrance, which can ensure an observation field of view of 9°×9°, and there is a margin at the edge of the field of view to achieve partial vignetting compensation. A conical capillary array wide-angle lens 9 is added in the imager. The main objective of the conical capillary array wide-angle lens 9 is to achieve high-efficiency transmission of the soft X-ray photons collected by the lobster eye optical lens 7. The large entrance end of the conical capillary array wide-angle lens 9 is spherical, matching the theoretically required large spherical area focal plane, and its small exit end is flat, matching the size and surface shape of the actual conventional CMOS image sensor. The conical capillary array wide-angle lens 9 can cover the entire observation field of view. Connected to the conical capillary array wide-angle lens 9 is the CMOS image sensor. To avoid the degradation of image quality caused by defocus, the photosensitive surface of the CMOS image sensor is as close as possible to the exit of the conical capillary array wide-angle lens 9, realizing wide-field, high-spatial-resolution, and high-sensitivity imaging of soft X-rays.

[0058] In the imager of the present invention, a conical capillary array wide-angle lens is introduced into the lobster eye optical path to transfer and compress the theoretically required large spherical area focal plane. Specifically, each lobster eye optical lens collects soft X-ray photons to achieve large-field soft X-ray photon collection. In the middle, high-efficiency soft X-ray transmission, spherical large-area focal plane transfer, and area compression are realized based on the conical capillary array wide-angle lens. At the back end, a CMOS image sensor is used as the imaging focal plane to realize the photoelectric information conversion and data processing of soft X-rays.

[0059] The imager of the present invention can be widely applied to scientific research fields such as manned lunar bases, planetary resource exploration, pulsar navigation, and magnetospheric prediction satellites, especially in the research on the dynamic evolution process of the interaction between the solar wind and the Earth's magnetosphere in the solar-terrestrial space. In addition, it can also be applied to social fields such as modern life medicine science and advanced material research, and the next generation of advanced lithography equipment.

[0060] The imager of the present invention provides an improved lobster eye optical path method, which can simultaneously achieve the characteristics of wide field of view, high spatial resolution, and high sensitivity, specifically as follows:

[0061] (1) Wide field of view

[0062] The soft X-ray imager uses lobster eye optical lenses to collect soft X-rays. The soft X-rays are focused through multiple total internal reflections in the microchannels provided inside the lobster eye optical lenses. The incident surface of the lobster eye optical lens is spherical. The observation field of view of the imager is related to the number of lobster eye optical lenses. Taking the soft X-ray panoramic imaging in the tip region as an example, the observation field of view needs to be greater than 9°×9°. The observation field of view corresponding to a single lobster eye optical lens (42.5mm×42.5mm, curvature radius 750mm) is 3.25°×3.25°. Therefore, to achieve the index of an observation field of view greater than 9°×9°, 9 lobster eye optical lenses are required and installed in a 3×3 array, as shown in Figure 2 the installation position 10.

[0063] (2) High spatial resolution and high sensitivity

[0064] The spatial resolution of the enhanced wide field of view and high resolution soft X-ray imager of the present invention is mainly determined by the ratio of the depth to the width of the microchannels provided inside the lobster eye optical lens 7. Different depth-to-width ratios of the microchannels can theoretically achieve different spatial resolutions; theoretically, the larger the depth-to-width ratio, the higher the spatial resolution ability, and the ultimate spatial resolution ability is equal to the opening size of the microchannels. To achieve the same spatial resolution in all directions within the observation field of view, the conical capillary array wide-angle lens 9 is required.

[0065] In the present invention, the depth-to-width ratio of the microchannels is set to 31.25:1. Generally, the size of the imaging focal spot is described by the full width at half maxima (FWHM). The table shows the focal spot width corresponding to half of the peak height. After simulation, theoretically, the full width at half maximum of the imaging focal spot is 0.04mm, and the corresponding spatial resolution is 22’. The spatial angular resolution corresponding to the full width of the focal spot is 3.67’, which can still meet the requirement of a high spatial resolution better than 6 angular minutes.

[0066] If the image plane is spliced by multiple planar sensors, only the central optical axis direction can achieve the maximum spatial resolution, and the resolution will decrease in other field of view directions, resulting in blurred images. However, the present invention introduces a conical capillary array wide-angle lens 9 into the imaging optical path, guiding the large-area spherical theoretical focal plane to a single conventional CMOS image sensor. Within the image plane of this CMOS image sensor, the spatial resolution remains basically unchanged. Therefore, high spatial resolution performance within the entire field of view can be achieved.

[0067] When in use, the enhanced wide-field high-resolution soft X-ray imager of the present invention is simple and convenient to operate. The light source is within the 9°×9° field of view of the lobster-eye optical lens. After the incident soft X-rays enter the soft X-ray imager, the collected soft X-rays are focused by the conical capillary array wide-angle lens 9, and an image of the soft X-rays can be obtained on the CMOS image sensor at the exit of the conical capillary array wide-angle lens 9.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An enhanced wide-field high-resolution soft X-ray imager, characterized in that, It includes: A lobster-eye optical lens (1), a first square pyramid-shaped housing (2), a wide-angle lens assembly (3), a second square housing (4), and a back-illuminated CMOS image sensor (5); The two ends of the first square pyramid-shaped housing (2) are respectively provided with a first entrance and a first exit; the two ends of the second square housing (4) are respectively provided with a second entrance and a second exit; The first square pyramid-shaped housing (2) is docked with the second square housing (4), and the first exit of the first square pyramid-shaped housing (2) overlaps with the second entrance of the second square housing (4); The first entrance of the first square pyramid-shaped housing (2) is fixedly provided with the lobster-eye optical lens (1), the wide-angle lens assembly (3) is fixedly arranged in the second square housing (4), and the back-illuminated CMOS image sensor (5) is fixedly arranged at the second exit of the second square housing (4); The wide-angle lens assembly (3) includes a conical capillary array wide-angle lens (9), the conical capillary array wide-angle lens (9) has a conical structure, and its two ends are respectively a large entrance end and a small exit end; the conical capillary array wide-angle lens (9) includes a plurality of conical capillary wide-angle lenses, and the plurality of conical capillary wide-angle lenses form a conical structure; X-rays pass through the lens after 1 or more grazing incidence total reflections inside the capillary; The two ends of each conical capillary wide-angle lens are respectively a large entrance end and a small entrance end, its large entrance end is set as a spherical surface and is located at the second entrance of the second square housing (4); its small exit end is set as a plane and is located at the second exit of the second square housing (4).

2. The enhanced wide-field high-resolution soft X-ray imager according to claim 1, wherein The wide-angle lens assembly (3) includes: a fixed mounting cylinder (10); The fixed mounting cylinder (10) is arranged in the second square housing (4), and the conical capillary array wide-angle lens (9) is fixedly sleeved in the fixed mounting cylinder (10); And the large entrance end of the conical capillary array wide-angle lens (9) is set as a spherical surface; its small exit end is set as a plane; the large entrance end of the conical capillary array wide-angle lens (9) is located at the second entrance of the second square housing (4), and the small exit end of the conical capillary array wide-angle lens (9) is located at the second exit of the second square housing.

3. The enhanced wide-field high-resolution soft X-ray imager according to claim 2, wherein The distance between the conical capillary array wide-angle lens (9) and the back-illuminated CMOS image sensor (5) is 0 to 1 mm; the distance between the conical capillary array wide-angle lens (9) and the lobster-eye optical lens (7) is half of the curvature radius of the lobster-eye optical lens (7); the curvature of the conical capillary array wide-angle lens (9) is half of the curvature of the lobster-eye optical lens (7); The spherical surface formed by the conical capillary array wide-angle lens (9) and the lobster-eye optical lens (7) is a concentric spherical surface.

4. The enhanced wide-field high-resolution soft X-ray imager according to claim 1, characterized in that, The first entrance is a square pyramid opening, the first exit is a square opening; both the second entrance and the second exit are square openings.

5. The enhanced wide-field high-resolution soft X-ray imager according to claim 1, wherein The lobster-eye optical lens (1) includes: a spherical metal support frame (6), a plurality of lobster-eye optical lenses (7), and a spherical metal pressing plate (8); The spherical metal support frame (6) is fixedly installed at the first incident port of the first square conical housing (2) to form a spherical large-area light collecting surface; the radius of curvature of the spherical metal support frame (6) is the same as the concave radius of curvature of the lobster eye lens (7); the radius of curvature of the spherical metal pressing plate (8) is the same as the convex radius of curvature of the lobster eye lens (7). A plurality of lobster eye optical lenses (7) are arranged on the spherical metal support frame (6), and the plurality of lobster eye optical lenses (7) are arranged in an M*N array, and are fixed on the spherical metal support frame (6) by a fixing device using a stress-free high-precision assembly method, and the spherical metal pressing plate (8) is fixed above the plurality of lobster eye optical lenses (7); wherein, both M and N are positive integers greater than 0.

6. The enhanced wide-field high-resolution soft X-ray imager according to claim 5, characterized in that The lobster eye optical lens (7) has a square structure; the spherical radius of curvature of the lobster eye optical lens is R750mm ± 1mm, the microchannel depth of the lobster eye optical lens is 1.25mm ± 0.1mm; the microchannel opening width of the lobster eye optical lens is 40μm ± 1μm; the microchannel wall thickness of the lobster eye optical lens is 8μm ± 1μm; the coating material on the inner wall of the microchannel of the lobster eye optical lens is an iridium metal film with a thickness of 20nm ± 2nm, and its surface roughness < 1nm.

7. The enhanced wide-field high-resolution soft X-ray imager according to claim 5, wherein The lobster eye optical lens (7) is provided with a microchannel, and the ratio of the depth to the width of the microchannel is 31.25:

1.

8. The enhanced wide-field high-resolution soft X-ray imager according to claim 5, wherein The surface of the lobster eye optical lens is coated with an aluminum film filter with a thickness of 100nm ± 10nm.

9. The enhanced wide-field high-resolution soft X-ray imager according to claim 5, characterized in that, The pixels of the back-illuminated CMOS image sensor (5) are 2048×2048, the pixel size is 11μm×11μm, and the imaging area is 2.2cm×2.2cm. In a right-handed coordinate system with the incident direction of soft X-rays onto the lobster eye optical lens as the positive direction of the Z-axis, perpendicular to the Z-axis and perpendicular to the paper and into the paper as the positive direction of the X-axis, the CMOS image sensor is on the negative half-axis of the Z-axis, and the origin of coordinates is the center of curvature of the lobster eye optical lens.

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