A series type cross type X-ray microscopic imaging optical structure with equal magnification

Abstract

The application discloses a series connection type orthogonal equal-magnification X-ray microscopic imaging optical structure and relates to the technical field of microscopic imaging. The technical scheme is as follows: the optical structure comprises an object plane, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror and an image plane; the object plane is provided with an object point; the image plane is provided with an image point; the object plane, the first reflecting mirror, the second reflecting mirror, the third reflecting mirror and the image plane are sequentially arranged; the first reflecting mirror and the third reflecting mirror focus and image in the meridian direction; and the second reflecting mirror focuses and images in the sagittal direction. The optical structure helps to solve the problem that the magnification is inconsistent in the two focusing directions of the series connection type orthogonal grazing incidence X-ray microscopic imaging optical structure, reduces the image distortion caused by the inconsistent magnification, and improves the ability of X-ray microscopic imaging to depict the shape and contour of an object.

Description

Technical Field

[0001] This invention relates to the field of microscopic imaging technology, and more specifically, to a series-type orthogonal X-ray microscopic imaging optical structure with equal magnification. Background Technology

[0002] Laser inertial confinement fusion (ICF) is a controlled nuclear fusion technology still under development, but it holds significant importance for energy development, basic scientific research, and strategic defense. High-power laser targeting devices, exemplified by the US National Energy Facility (NIF), have the capability to compress megajoules of laser energy into extremely small spatiotemporal scales for research, pushing the state of fusion fuel to the edge of the ignition cliff.

[0003] High-precision X-ray imaging diagnostic equipment based on ultra-smooth mirrors has the characteristics of high spatial resolution, high light collection efficiency, and spectral band screening. It has become the key to revealing the physical state of implosion under extreme environments and is used as the main equipment in the study of multiple physical problems such as irradiation uniformity, implosion compression symmetry, hydrodynamic instability, and fuel mixing.

[0004] The Kirkpatrick-Baez (KB) microscope is a widely used tandem orthogonal grazing incidence optical structure in diagnostic science. Its basic principle is to achieve two-dimensional focusing imaging using two orthogonally placed meridional and sagittal mirrors. However, due to the tandem placement of the mirrors, the objectively limited length of the mirrors along the axis makes it difficult to achieve equal magnification in both imaging directions. In implosion diagnosis, this causes the problem of inconsistent image magnification ratios in the two directions, resulting in image distortion and making it difficult to discern the contours of the implosion hotspot.

[0005] To address the aforementioned shortcomings, this invention proposes a tandem orthogonal X-ray microscopy imaging optical structure with equal magnification. This achieves equal magnification imaging in both the horizontal and meridional directions, reducing image distortion caused by inconsistent magnification and enhancing the ability of X-ray microscopy to depict the contours of object-side targets. It can play a crucial role in high-precision (better than 3 μm) microscopic observations with a field of view of several hundred micrometers. Summary of the Invention

[0006] The purpose of this invention is to provide a tandem orthogonal X-ray microscopy imaging optical structure with equal magnification, which can improve the problem of inconsistent magnification in the two focusing directions of the tandem orthogonal grazing incidence X-ray microscopy imaging optical structure. This reduces image distortion caused by inconsistent magnification and improves the ability of X-ray microscopy to depict the contours of object-side targets. It can play an important role in high-precision (better than 3 μm) microscopic observations with a field of view of several hundred micrometers.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a series-type orthogonal X-ray microscopic imaging optical structure with equal magnification, comprising an object plane, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, and an image plane; the object plane is provided with an object point, and the image plane is provided with an image point; the object plane, the first reflecting mirror, the second reflecting mirror, the third reflecting mirror, and the image plane are arranged sequentially, the first reflecting mirror and the third reflecting mirror focus imaging in the meridional direction, and the second reflecting mirror focuses imaging in the sagittal direction.

[0008] The invention is further configured such that: the first and third reflecting mirrors form a separate dual-mirror structure to achieve imaging in the meridional direction (vertical direction); the second reflecting mirror is located between the first and third reflecting mirrors. The separate dual-mirror structure places the principal plane of the system in the meridional plane at the center of the second reflecting mirror, which coincides with the principal plane of the system in the sagittal plane, thereby achieving equal magnification in the two imaging directions.

[0009] The present invention is further configured such that the surface shape of the first reflecting mirror to the third reflecting mirror is a spherical mirror-spherical mirror, a cylindrical mirror-cylindrical mirror, or a hyperbolic cylindrical mirror-elliptical cylindrical mirror.

[0010] The invention is further configured such that a second reflecting mirror single-mirror configuration is adopted in the sagittal direction, wherein the surface shape of the second reflecting mirror is a spherical mirror, a cylindrical surface, or an elliptical cylindrical surface.

[0011] The present invention is further configured such that the radius of curvature of the double-mirror structure composed of the first and third reflecting mirrors is calculated using the following formula:

[0012]

[0013] Where R1 is the radius of curvature of the first reflecting mirror, R3 is the radius of curvature of the third reflecting mirror, M is the system magnification, u is the distance from the object point to the center of the second reflecting mirror, and θ1 is the grazing incidence angle of the first reflecting mirror.

[0014] The formula for calculating the radius of curvature of the second reflecting mirror is as follows:

[0015]

[0016] Where R2 is the radius of curvature of the second mirror, M is the system magnification, u is the distance from the object point to the center of the second mirror, and θ2 is the grazing incidence angle of the second mirror.

[0017] The formula for calculating the geometric light-gathering efficiency of a series-type orthogonal optical structure with equal magnification is as follows:

[0018]

[0019] Where θ1 is the grazing incidence angle of the first mirror, θ2 is the grazing incidence angle of the second mirror, L1 is the mirror length of the first mirror, L2 is the mirror length of the second mirror, and u is the distance from the object point to the center of the second mirror.

[0020] The formula for calculating the effective solid angle of reflectivity is:

[0021]

[0022] Wherein, η1, η2 and η3 are the reflectivities of the first, second and third reflecting mirrors, respectively.

[0023] In summary, this invention has the following beneficial effects: it can improve the problem of inconsistent magnification in the two directions of traditional tandem orthogonal grazing incidence X-ray microscopy optical structures; it reduces image distortion caused by inconsistent magnification; and it improves the ability of X-ray microscopy to depict the contours of objects. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the tandem orthogonal equal magnification X-ray microscopy imaging optical structure according to an embodiment of the present invention;

[0025] Figure 2 This is an imaging optical path diagram in the meridional direction (vertical direction) of an embodiment of the present invention;

[0026] Figure 3 This is an imaging optical path diagram of the arc sagittal direction (horizontal direction) according to an embodiment of the present invention;

[0027] Figure 4 This is the reflectivity curve of the Pt film coated on the mirror in this embodiment of the invention;

[0028] Figure 5 This is the curve showing the spatial resolution of the patented configuration in this embodiment as a function of the field of view (meridian direction);

[0029] Figure 6 This is the curve showing the spatial resolution of the patented configuration in this embodiment as a function of the field of view (sagittal direction);

[0030] Figure 7 This is the curve showing the effective light-gathering solid angle of the patented configuration in this embodiment of the invention as a function of the field of view (meridian direction);

[0031] Figure 8 This is the curve (sagittal direction) showing the effective light-gathering solid angle of the patented configuration in this embodiment of the invention as a function of the field of view. Detailed Implementation

[0032] The following is in conjunction with the appendix Figure 1-8 The present invention will be described in further detail below.

[0033] Example: A series-type orthogonal X-ray microscopy imaging optical structure with equal magnification, such as... Figure 1-8 As shown, it includes an object plane, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, and an image plane; the object plane has an object point, and the image plane has an image point; the object plane, the first reflecting mirror, the second reflecting mirror, the third reflecting mirror, and the image plane are arranged sequentially; the first and third reflecting mirrors focus and image in the meridional direction, and the second reflecting mirror focuses and image in the sagittal direction. A tandem orthogonal equal-magnification X-ray microscopy imaging optical structure is shown below. Figure 1 As shown, 1 is the object point; 2 is the object plane; 3 is the first reflecting mirror; 4 is the second reflecting mirror; 5 is the third reflecting mirror; 6 is the image plane; and 7 is the image point.

[0034] The imaging optical path in the meridional direction (vertical direction) of the optical structure is as follows: Figure 2 As shown, the first and third reflecting mirrors form a separate dual-mirror structure, achieving imaging in the meridional direction (vertical direction). The second reflecting mirror is located between the first and third reflecting mirrors. The separate dual-mirror structure places the principal plane of the system in the meridional plane at the center of the second reflecting mirror, coinciding with the principal plane of the system in the sagittal plane, achieving equal magnification in both imaging directions. This separate dual-mirror configuration allows for high-resolution imaging over a large field of view in a single direction. The surface shapes of the first and third reflecting mirrors are spherical mirror-spherical mirror, cylindrical mirror-cylindrical mirror, or hyperbolic cylindrical mirror-elliptical cylindrical mirror. In the sagittal direction, a single-mirror configuration with the second reflecting mirror is used, and the surface shape of the second reflecting mirror is spherical, cylindrical, or elliptical cylindrical.

[0035] The formula for calculating the radius of curvature of the double-mirror structure consisting of the first and third reflecting mirrors is as follows:

[0036]

[0037] Where R1 is the radius of curvature of the first reflecting mirror, R3 is the radius of curvature of the third reflecting mirror, M is the system magnification, u is the distance from the object point to the center of the second reflecting mirror, and θ1 is the grazing incidence angle of the first reflecting mirror; if aspherical mirrors such as hyperbolic cylindrical or elliptical cylindrical surfaces are used, the radius of curvature of the first reflecting mirror is used as the reference value for fitting.

[0038] The formula for calculating the radius of curvature of the second reflecting mirror is as follows:

[0039]

[0040] Where R2 is the radius of curvature of the second mirror, M is the system magnification, u is the distance from the object point to the center of the second mirror, and θ2 is the grazing incidence angle of the second mirror; if an aspherical mirror is used, the above radius of curvature values ​​are reference values ​​for fitting.

[0041] The formula for calculating the geometric light-gathering efficiency of a series-type orthogonal optical structure with equal magnification is as follows:

[0042]

[0043] Where θ1 is the grazing incidence angle of the first mirror, θ2 is the grazing incidence angle of the second mirror, L1 is the mirror length of the first mirror, L2 is the mirror length of the second mirror, and u is the distance from the object point to the center of the second mirror.

[0044] The formula for calculating the effective solid angle of reflectivity is:

[0045]

[0046] Wherein, η1, η2 and η3 are the reflectivities of the first, second and third reflecting mirrors, respectively.

[0047] A set of hard X-ray microscope optical structures operating at several keV energy points. Its purpose is to meet the demand for high-precision hard X-ray imaging diagnostics with equivalent magnification for observing implosion processes in inertial confinement fusion.

[0048] The system-level technical specifications are summarized in Table 1. The design operating energy point of the optical structure is 0-10.3 keV, and the design grazing incidence angle is 0.45°. The system object distance is 250 mm, and the magnification is 20×. The specific optical structural parameters of the reflector are shown in Table 2.

[0049] The first and third reflecting mirrors employ a hyperbolic cylindrical-elliptical cylindrical dual-mirror combination structure to achieve high-precision imaging in the meridional (vertical) direction. This enables high-resolution imaging of object-side targets within a ±0.5mm field of view. By adjusting the working angles of the first and third reflecting mirrors, the system's principal plane can be positioned at the center of the second reflecting mirror. Under this condition, the optical structure possesses the same magnification in both the meridional and sagittal directions. According to equation (1), the fitted radius of curvature of the first and third reflecting mirrors is calculated to be 121.3m.

[0050] The second reflecting mirror is a concave spherical mirror, which realizes imaging in the sagittal direction (horizontal direction). According to equation (2), the radius of curvature of the reflecting mirror can be calculated to be 60.6m.

[0051] According to equation (3), the geometric solid angle of the light-gathering structure is 2.0 × 10⁻⁶. -7 A broadband high-reflectivity Pt film is deposited on the surface of the mirror. The reflectivity curve of the Pt film is shown in the figure. Figure 4 As shown. Assuming the reflectivity of the thin film is 77.7%, according to equation (4), the effective light-gathering solid angle of the system is 9.4 × 10⁻⁶. -8 sr.

[0052] Table 1 System-level technical specifications of optical structures

[0053]

[0054]

[0055] Table 2 Optical structural parameters of the mirror

[0056]

[0057] a The equation of the hyperbolic cylinder is: x 2 / a 2 -z 2 / b 2 =1;

[0058] b The equation of the ellipsoidal cylinder is: x 2 / a 2 +z 2 / b 2 =1;

[0059] c The equation of the sphere is: x 2 +y 2 =R 2 ;

[0060] Figure 5 and Figure 6 The spatial resolution versus field of view curves in the meridional and sagittal directions are presented respectively. The RMS value of the spot radius is used as the evaluation criterion for the spatial resolution of the optical structure. In the meridional direction, the system resolution is better than 0.21 μm within a field of view of ±0.5 mm. In the sagittal direction, constrained by the optical configuration, the system resolution is better than 6.0 μm within a field of view of ±0.5 mm.

[0061] Figure 7 and Figure 8 Curves depicting the effective solid angle of light collection in the meridional and sagittal directions under an 8keV energy point are presented. The effective solid angle of light collection in the central field of view is 9.4 × 10⁻⁶. -8 sr is consistent with the calculation result.

[0062] This system features a large field of view, high resolution, and equal magnification, and is expected to play an important role in high-precision X-ray diagnostics of laser inertial confinement fusion in the future.

[0063] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A series-type orthogonal X-ray microscopy imaging optical structure with equal magnification, characterized in that: It includes an object plane, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, and an image plane; the object plane has an object point, and the image plane has an image point; the object plane, the first reflecting mirror, the second reflecting mirror, the third reflecting mirror, and the image plane are arranged in sequence, the first reflecting mirror and the third reflecting mirror focus the image in the meridional direction, and the second reflecting mirror focuses the image in the sagittal direction; The first and third reflecting mirrors form a separate dual-mirror structure to achieve imaging in the meridional direction (vertical direction); the second reflecting mirror is located between the first and third reflecting mirrors. The separate dual-mirror structure places the principal plane of the system in the meridional plane at the center of the second reflecting mirror, which coincides with the principal plane of the system in the sagittal plane, achieving equal magnification in the two imaging directions. The formula for calculating the radius of curvature of the double-mirror structure consisting of the first and third reflecting mirrors is as follows: (1) Where R1 is the radius of curvature of the first reflecting mirror, R3 is the radius of curvature of the third reflecting mirror, M is the system magnification, u is the distance from the object point to the center of the second reflecting mirror, and θ1 is the grazing incidence angle of the first reflecting mirror. The formula for calculating the radius of curvature of the second reflecting mirror is as follows: (2) Where R2 is the radius of curvature of the second mirror, M is the system magnification, u is the distance from the object point to the center of the second mirror, and θ2 is the grazing incidence angle of the second mirror. The formula for calculating the geometric light-gathering efficiency of a series-type orthogonal optical structure with equal magnification is as follows: (3) Where θ1 is the grazing incidence angle of the first mirror, θ2 is the grazing incidence angle of the second mirror, L1 is the mirror length of the first mirror, L2 is the mirror length of the second mirror, and u is the distance from the object point to the center of the second mirror. The formula for calculating the effective solid angle of reflectivity is: (4) Wherein, η1, η2 and η3 are the reflectivities of the first, second and third reflecting mirrors, respectively.

2. The tandem orthogonal equal-magnification X-ray microscopy imaging optical structure according to claim 1, characterized in that: The surface shape of the first to third reflecting mirrors is either a spherical mirror-spherical mirror, a cylindrical mirror-cylindrical mirror, or a hyperbolic cylindrical mirror-elliptical cylindrical mirror.

3. The tandem orthogonal equal-magnification X-ray microscopy imaging optical structure according to claim 1, characterized in that: A second reflecting mirror single-mirror configuration is adopted in the sagittal direction. The surface shape of the second reflecting mirror is a spherical mirror, a cylindrical surface, or an elliptical cylindrical surface.

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