Method for coupling a multichannel grazing incidence x-ray objective with a planar crystal dispersive element

Abstract

This invention relates to a coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element, comprising: first, adjusting the optical axes of the outgoing light paths of each channel to be parallel through X-ray imaging experiments, and indicating this through an autocollimator; then, placing a reference prism on the optical axis of the outgoing light path, wherein the reference prism includes a collimation reference plane and an angle reference plane on which the planar crystal is mounted, the angle between the collimation reference plane and the angle reference plane being equal to the Bragg angle of the planar crystal; finally, adjusting the reference prism until the central axis of the autocollimator is perpendicular to the collimation reference plane, at which point the incident angle on the planar crystal is equal to the Bragg angle. Compared with the prior art, this invention uses a reference prism with a Bragg angle between the collimation reference plane and the angle reference plane as the angle adjustment base for the planar crystal. By adjusting the collimation of the collimation reference plane with respect to the outgoing light path, the monochromatic energy point of the planar crystal can be ensured to be consistent with the working energy point of the X-ray imaging objective, which has the advantages of simple operation and high angle coupling accuracy.

Description

Technical Field

[0001] This invention belongs to the field of laser plasma X-ray imaging technology, and relates to a precise coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam splitter. Background Technology

[0002] High-quality diagnosis of crucial information such as the spatial distribution, temporal evolution, and energy spectrum characteristics of plasma is a vital research area in high energy density physics (HEDP) and inertial confinement fusion (ICF). By combining multi-channel grazing-incidence X-ray imaging objectives with a time-resolved framing camera, each imaging channel corresponds to the transient information of the plasma at a specific moment, allowing for the acquisition of the plasma's two-dimensional transient evolution behavior, i.e., its spatial distribution and temporal evolution information. Crystal spectrometers can obtain high-energy-resolution spectroscopic information within a specific energy range, while bent crystal imaging can obtain high-energy-resolution two-dimensional spatial distribution of the plasma at a specific energy point.

[0003] Coupling high spatial resolution multichannel X-ray imaging objectives with high energy spectral resolution planar crystal beam-splitting elements, and combining them with image recording equipment such as framing cameras, can develop X-ray diagnostic systems with high temporal, spatial, and spectral resolution capabilities. This has significant scientific and application value for improving HEDP and ICF research. The main challenge in developing such X-ray diagnostic systems lies in the precise coupling of the working angle between the X-ray imaging objectives and the planar crystal elements. HEDP and ICF physics experiments generally image the characteristic X-rays emitted by a target material. For example, the energy point of the Kα line of Cu is 8.04 keV (corresponding to a wavelength of 0.154 nm). Planar crystal elements operate based on the Bragg diffraction principle with near-normal incidence, 2dsinθ=kλ, where d is the lattice constant, λ is the working wavelength, and θ is the Bragg angle (i.e., grazing incidence angle). Its energy spectral resolution is λ / Δλ=tanθ / Δθ. At near-normal incidence angles, the grazing incidence angle is large, thus the planar crystal can achieve a high monochromatic reflection effect. However, it requires very high precision in adjusting the working angle. Even a tiny deviation Δθ in the working angle will cause the monochromatic X-ray energy point reflected by the planar crystal to deviate from the characteristic X-ray energy point emitted from the imaging objective, resulting in a sharp decrease in the final imaging light intensity of the X-ray diagnostic system, or even a complete absence of signal.

[0004] The precise coupling between a multi-channel X-ray imaging objective and a planar crystal beam splitter presents two main challenges. First, due to the fixed lattice constant, the Bragg angle for X-ray diffraction at a specific energy is a specific value. Therefore, the angle between the crystal beam splitter and the X-ray path is a special angle, not 90° perpendicular or 0° parallel. For example, the Bragg angle of the (2131) crystal plane of α-quartz on the Kα line of Cu is 88.7°. This special angle is difficult to accurately calibrate using conventional optical methods. Second, for multi-channel X-ray imaging objectives with a grazing incidence structure, the X-ray paths emitted from each channel are not consistent. They image at different positions on the image plane with different spatial ranges and angles. Therefore, the incident angles of each channel of the X-ray imaging objective when coupled with the planar crystal are different, increasing the difficulty of precise coupling. Summary of the Invention

[0005] The purpose of this invention is to provide a precise coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element, which solves the problems of poor consistency of incident angles or low adjustment accuracy and convenience when the X-ray imaging objective channels are coupled with the planar crystal.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element includes the following steps:

[0008] S1: By adjusting the X-ray imaging experiment, the optical axes of the outgoing optical paths of each channel of the multi-channel grazing incidence X-ray imaging objective are made parallel to each other, and the optical axes are indicated by the central axis of the autocollimator.

[0009] S2: Place the reference prism on the optical axis of the outgoing light path;

[0010] The reference prism includes a collimation reference plane and an angle reference plane. A planar crystal is provided on the angle reference plane. The angle between the collimation reference plane and the angle reference plane is equal to the Bragg angle of the planar crystal.

[0011] Adjust the reference prism until the central axis of the autocollimator is perpendicular to the collimation reference plane. At this point, the incident angle of the outgoing light from the multi-channel grazing incidence X-ray imaging objective on the planar crystal is equal to the Bragg angle of the planar crystal.

[0012] Furthermore, step S1 includes calibrating the parallelism of the multi-channel emitted X-rays:

[0013] In multi-channel X-ray imaging, the multi-channel grazing incidence X-ray imaging objective is adjusted, and the X-ray CCD is moved along the outgoing X-ray optical path until the relative positions of each imaging channel on the X-ray CCD remain unchanged as the X-ray CCD moves. At this point, the optical axes of each imaging channel are considered to be parallel to each other.

[0014] Furthermore, step S1 includes determining the X-ray emission axis:

[0015] In the outgoing optical path of one imaging channel of a multi-channel grazing incidence X-ray imaging objective, at least two marker apertures are set, and the light-blocking phases of the marker apertures are made to coincide and located at the center of the imaging spot of the X-ray CCD in the outgoing optical path. At this time, the straight line where the multiple marker apertures are located is the optical axis of the outgoing optical path.

[0016] An autocollimator is set at the far end of the optical axis. The autocollimator is adjusted so that its central axis coincides with the center of multiple marked aperture holes. At this time, the central axis of the autocollimator indicates the optical axis of the outgoing optical path.

[0017] Furthermore, step S1 includes determining the X-ray emission axis:

[0018] A simulated positioning point is placed in front of the X-ray CCD and adjusted to the center of the projection section of one imaging channel of the multi-channel grazing incidence X-ray imaging objective. Then, an autocollimator is used to replace the X-ray CCD, and the autocollimator is adjusted so that its central axis coincides with the simulated positioning point and the center of the projection section of the imaging channel. At this time, the central axis of the autocollimator indicates the optical axis of the outgoing light path.

[0019] Furthermore, the autocollimator is an internal focusing telescope;

[0020] The process of determining the X-ray emission axis also includes:

[0021] After the central axis of the internal focusing telescope coincides with the simulated positioning point and the center of the projection section of the imaging channel, a crystal angle reference mirror with a reticle is inserted at the rear end of the multi-channel grazing incidence X-ray imaging objective lens. The internal focusing telescope is adjusted to a parallel light emission state, and the working angle reference plane of the imaging channel is made to coincide with the optical axis of the internal focusing telescope by aligning the angle of the collimating crystal angle reference mirror.

[0022] The center of the reticle on the crystal angle reference mirror is then translated to the overall center position of the output optical axis of multiple imaging channels, while still ensuring that the crosshairs coincide. At this time, the working angle reference plane of the crystal angle reference mirror coincides with the output optical axis of the multi-channel grazing incidence X-ray imaging objective, and the center of the reticle of the crystal angle reference mirror represents the imaging center position of the KB objective.

[0023] Furthermore, the simulated positioning point is a simulated positioning ball.

[0024] Furthermore, the diameter of the simulated positioning ball is 400-600 μm.

[0025] Further, step S2 includes: adjusting the reference prism until the autocollimator and the collimation reference plane are initially aligned, then moving the reference prism under the monitoring of the autocollimator until the center of the collimation reference plane coincides with the center of the reticle on the crystal angle reference mirror, and adjusting the reference prism until the autocollimator and the collimation reference plane are completely aligned.

[0026] Furthermore, in step S2, the angular reference plane is composed of multiple reflective surfaces, and each reflective surface is provided with a planar crystal. The angle between the reflective surface and the collimation reference plane is equal to the Bragg angle of the planar crystal.

[0027] Furthermore, the multi-channel grazing incidence X-ray imaging objective includes a multi-channel KB imaging objective.

[0028] Compared with the prior art, the present invention has the following characteristics:

[0029] 1) High angular coupling accuracy between the multi-channel grazing incidence imaging objective and the planar crystal. This invention transforms the alignment of a specific Bragg diffraction angle, which is invisible to the naked eye in the X-ray band, into optical axis aiming and collimation visible to the naked eye in the visible light band through an optical prism with a specific angle. Angular accuracy from arcminutes to arcseconds can be achieved using conventional optical prism manufacturing processes and commonly used optical experimental methods such as optical axis aiming and collimation, resulting in high final coupling accuracy.

[0030] 2) Planar crystal replacement is simple and facilitates switching between different operating energy points. Diagnostic requirements for different operating energy points in physics experiments generally necessitate planar crystals with different Bragg diffraction angles and materials. The coupling method of this invention allows for simple switching between different planar crystals by fabricating optical prisms with different angular relationships, which is easy to implement in terms of both technology and operation, thus enabling the selection of different operating energy points. Attached Figure Description

[0031] Figure 1 A structural diagram of a multichannel X-ray grazing incidence imaging system;

[0032] Figure 2 A schematic diagram of the optical path arrangement of a multi-channel grazing incidence imaging objective in the meridional direction;

[0033] Figure 3 A schematic diagram of the optical path arrangement of a multi-channel grazing incidence imaging objective lens in the sagittal direction;

[0034] Figure 4 A schematic diagram of the method for calibrating the parallelism of X-rays emitted from each channel;

[0035] Figure 5 Determining the incident X-ray optical axis of the crystal monochromatic unit;

[0036] Figure 6 This is a schematic diagram of the flat crystal angle adjustment mirror structure; the collimation reference plane is located on the back side of the reference prism in the figure, and is set opposite to the planar crystal;

[0037] Figure 7 (a)(b) Diagram showing the positional relationship between the crosshairs of the outgoing beam and the crosshairs formed by the returning beam;

[0038] Figure 8 This is a schematic diagram of the overall optical path structure of the four-channel feature X-ray monochromatic imaging system in the embodiment;

[0039] Figure 9 Images of four channels at different locations on the same MCP gold microstrip.

[0040] Figure 10 For the embodiments, (a) a physical photograph (top) / schematic diagram (bottom) of the system using the internal focusing telescope to determine the output optical axis; (b) a physical photograph (top) / schematic diagram (bottom) of the simulated positioning sphere center; and (c) a physical photograph (top) / schematic diagram (bottom) of the KB reflector projection section center and the crosshair center of the internal focusing telescope being adjusted.

[0041] Figure 11 In the embodiment, (a) is a schematic diagram of the system indicating the output optical axis of the KB objective lens through the reference mirror; (b) is the reflection crosshair of the reference mirror before it is fully collimated; and (c) is the state where the reference crosshair and the reflection crosshair are completely coincident after it is fully collimated.

[0042] Figure 12 The following is a schematic diagram of the collimation process of the crystal reference prism on the mica crystal in the embodiment: (a) The angle collimation reference plane is roughly collimated with the internal focusing telescope; (b) The center of the angle collimation reference plane coincides with the reticle of the front reference mirror; (c) The angle collimation reference plane is completely collimated, corresponding to the crosshair situation.

[0043] Explanation of markings in the diagram:

[0044] 1-Five-dimensional electronic control console, 2-Multi-channel grazing incidence X-ray imaging objective lens, 3-Dual-beam common field X-ray CCD, 4-Flat crystal angle reference mirror, 5-Frame camera, 6-Planar crystal, 7-Optical prism, 701-Collimation reference plane, 702-Angle reference plane, 8-Marker aperture stop, 9-X-ray CCD, 10-Autocollimator, 11-Simulated positioning ball. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0046] A precise coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element includes: the angular reference planes of the X-ray imaging objective have different radii of curvature, so that while each channel maintains optimal spatial resolution for the same object point, the reflected X-rays are emitted parallel at certain spatial intervals; through adjustments in the X-ray imaging experiment, the optical axes of the reflected light paths of each channel of the grazing incidence imaging objective are made parallel to each other, and the optical axes are indicated by an autocollimator; then, an angular reference prism is placed in front of the image, and the crystal is attached to the angular reference plane of the reference prism. The angular reference plane of the reference prism has a specific angular relationship with the collimation reference plane. The collimation reference plane of the reference prism is adjusted so that it is perpendicular to the optical axis of the reflected light path indicated by the autocollimator. At this time, the incident angle of the X-rays emitted from each channel on the planar crystal is the same as the Bragg diffraction angle of the planar crystal, and the monochromatic energy point of the planar crystal is coupled with the working energy point of the X-ray imaging objective.

[0047] The parallelism of the optical axes of each channel's reflected light path is determined during X-ray imaging experiments by moving the recording device back and forth. If the image point spacing of each channel on the recording device remains unchanged during movement, the optical axes are considered parallel. Once the optical axes are parallel, their spatial orientation is defined by placing two circular apertures sequentially along the reflected light path. The recording device monitors and aligns the center of each aperture with the optical axis. The straight line defined by the centers of the two apertures is the optical axis of the objective lens's reflected light path. By placing an autocollimator at the distal end and adjusting its optical axis to coincide with this straight line, the position of the optical axis of the reflected light path can be indicated.

[0048] In some preferred embodiments, the reference prism can be fabricated into a structure with multiple angular reference planes. Multiple crystals are respectively bonded to reference planes with different angular reference planes. The collimation reference plane of the reference prism has different angles with these angular reference planes, enabling the X-ray diagnostic system to operate at multiple energy points.

[0049] This invention uses a reference prism with a Bragg angle between the collimation reference plane and the angle reference plane as the angle adjustment base for the planar crystal. By calibrating the optical axis of the collimation reference plane with respect to the outgoing light path, it can ensure that the monochromatic energy point of the planar crystal is consistent with the working energy point of the X-ray imaging objective. It has the advantages of simple operation and high angle coupling accuracy.

[0050] This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiment.

[0051] Example 1:

[0052] A precise coupling method between a multi-channel X-ray grazing incidence imaging objective and a planar crystal beam-splitting element, using an imaging system such as... Figure 1 As shown, it mainly includes a five-dimensional electronic control stage 1, an objective lens section and a planar crystal beam splitting unit. The objective lens section consists of a multi-channel grazing incidence X-ray imaging objective lens 2, an X-ray CCD 9 and a planar crystal angle reference lens 4. The beam splitting unit includes a planar crystal 6 and an optical prism 7.

[0053] This method can be divided into the following three steps:

[0054] The first step is to achieve mutual parallelism between the exit optical axes of the multi-channel grazing incidence X-ray imaging objectives. For example... Figure 8 As shown, two spherical mirrors A / C or B / D are arranged facing each other to form a mirror pair. Multiple mirror pairs are then arranged perpendicularly and orthogonally along the optical axis to form a multi-channel grazing-incidence X-ray imaging objective 2. The optical path arrangements in the meridional and sagittal directions of the multi-channel grazing-incidence X-ray imaging objective 2 are as follows: Figure 2 , 3 As shown, the multi-channel grazing incidence X-ray imaging objective 2 operates based on the principle that X-rays satisfy focusing imaging in the meridional and sagittal directions respectively. Therefore, each objective is independent in imaging in the meridional and sagittal directions. By controlling the relative position and angular orientation of the two spherical mirrors of each objective pair in the meridional and sagittal directions, the direction of the outgoing X-ray beam path formed by each objective pair can be controlled. In the X-ray imaging debugging experiment, the spacing of the final images formed by each channel on the recording surface can be detected using recording equipment such as an X-ray CCD9. If the image spacing changes when the recording equipment is moved along the optical axis, the X-ray beam paths of each channel are not parallel, and each objective pair needs further adjustment. This process is repeated until the image spacing at different positions does not change when the recording equipment is moved back and forth. Then, it can be considered that the outgoing X-ray beam paths of each channel are parallel to each other. Figure 4 This indicates that when different imaging channels are incident on the same planar crystal 6, the incident angles are all the same.

[0055] The second step is to indicate the output optical axis using visible light. For example... Figure 5 As shown, firstly, two marker aperture stops 8 are placed before and after the exit optical path of one of the channels of the multi-channel grazing incidence X-ray imaging objective 2. The positions of the marker aperture stops are adjusted until the light blocking effect of the marker aperture stops 8 is located at the center of the image obtained by the recording device. At this point, the axes extending from the centers of the two marker aperture stops 8 can be considered to coincide with the exit optical axis of this channel and parallel to the exit optical axes of other channels. Subsequently, an internal focusing telescope, i.e., an autocollimator 10, is placed at the far end and its attitude is adjusted. The central axis of the internal focusing telescope is monitored and made to coincide with the centers of the two marker aperture stops 8 respectively. At this point, the central axis of the internal focusing telescope can replace the exit X-ray optical axis of the multi-channel grazing incidence imaging objective.

[0056] The third step is to ensure that the incident angle of the multi-channel grazing incidence X-ray imaging objective 2 is consistent with the Bragg angle of the planar crystal 6. Specifically, this is achieved by introducing a crystal with a specific cone angle... Figure 6 The optical prism 7 shown achieves the following: The optical prism 7 includes a collimation reference surface 701 and an angle reference surface 702, and the specific cone angle formed by the two is the same as the Bragg angle of the planar crystal 6. The planar crystal 6 is directly attached to the angle reference surface of the prism (if different imaging channels require operation at multiple energy points, a multi-angle reference surface is used, and multiple crystals are attached to different angle reference surfaces respectively). The optical prism 7 is fixed on the five-dimensional electronic control console 1, and its collimation reference surface 701 is adjusted to be roughly perpendicular to the incident light path. Then, the light path of the collimator 10 is adjusted to infinity (the beam exits as parallel light). The position and orientation of the optical prism 7 are finely adjusted by the five-dimensional electronic control console 1 until the parallel beam emitted from the collimator 10 returns along the original path through the collimation reference surface of the optical prism, that is, the crosshairs of the beam exiting from the collimator eyepiece and the crosshairs formed by the returning beam completely coincide, see Figure 7 (a) and (b) At this time, the collimation reference plane of the optical prism is precisely perpendicular to the optical axis of the autocollimator, thus ensuring the precise angle between the planar crystal 6 and the outgoing X-ray optical axis of the multi-channel grazing incidence X-ray imaging objective 2.

[0057] Example 2:

[0058] The multi-channel feature X-ray monochromatic imaging system in this example is as follows: Figure 1 As shown, a tandem four-channel KB-type X-ray microscope objective with low magnification is used as the imaging mechanism, namely as the multi-channel grazing incidence X-ray imaging objective 2. Two mica flat crystals are placed in front of the image as planar crystals 6, which serve as the overall optical path structure of the monochromatic beam splitter. The specific optical structure parameters are determined according to the requirements of field of view, spatial resolution and object-image distance, as shown in Table 1.

[0059] Table 1 Optical structural parameters of the four-channel KB objective lens

[0060]

[0061] Based on the aiming accuracy requirements, an aiming mechanism using a dual-beam common-field X-ray CCD9 coupled with a KB objective lens is adopted to achieve spatial positioning of the object point. To achieve dual-color imaging, four KB channels are emitted in parallel, and an angle positioning method is used to establish the angular accuracy requirements between the mica flat crystal and the four KB imaging channels. Specific technical requirements are as follows:

[0062] 1. Figure 8The overall optical path structure of the four-channel characteristic X-ray monochromatic imaging system consists of four spherical mirrors arranged in two pairs, orthogonally aligned along the optical axis. The system comprises an imaging objective and a monochromatic crystal. X-rays emitted from the object point are sequentially imaged by the four tandemly arranged spherical mirrors (AD), then monochromated by a mica flat crystal in front of the image plane before finally forming an image at the image plane of the 5-panel camera.

[0063] 2. To simplify the coupling between the planar mica and the imaging objective, the X-rays emitted from the object point are arranged so that they exit in parallel at a distance consistent with the 5-microstrip spacing of the framing camera (a=13mm) after passing through two mirrors. The optical path arrangement of mirrors A and C in the meridional direction of the characteristic X-ray monochromatic imaging system is as follows: Figure 2 As shown, R1 and θ3 are the radius of curvature and grazing angle of incidence of the first mirror, respectively. Since both mirrors image the same object point, and each mirror pair needs to satisfy the principle of focusing imaging, there are slight differences in the values ​​of R3 and R1, and R2 and R4. The optical path arrangement of the four-channel KB objective lens in the sagittal direction is as follows. Figure 3 As shown, to reduce the manufacturing difficulty of the spherical mirror, the radii of curvature of the preceding and subsequent mirrors in the meridional and sagittal directions are made the same, i.e., R1=R3 and R2=R4 (under the condition of strictly satisfying the focusing imaging principle, there are slight differences in the values ​​of R3 and R1, and R2 and R4, but in this embodiment, in order to reduce the manufacturing difficulty of the spherical mirror, it is made to be equal without affecting the results). The X-ray spacing before reflection by the mica flat crystal is approximately e=17.15mm (e is the image point spacing; the image point spacing that can be obtained in the laboratory is the direct measurement result after the objective lens imaging, while the image point spacing after crystal monochromaticization is indirectly guaranteed by the manufacturing accuracy of the prism). After reflection by the mica, the spacing at the image plane position is c=20mm, and the turning distance is approximately d=365mm. At the same time, the requirements of spatial resolution, light collection efficiency, and working object distance must be considered, and the optical structure parameters of the four-channel KB objective lens shown in Table 1 are finally obtained.

[0064] 3. The Bragg angles of the mica flat crystals at the energy points of 653.6 eV and 665.7 eV are approximately... a 1 = 71.7° and a 2=68.8°, the processing in this embodiment is as follows Figure 6 The form of the supporting prism base shown conforms to a specific angular relationship. Figure 1The optical prism 7 in the middle converts the angle calibration of the mica flat crystal into optical path collimation under visible light. The reference prism has three surfaces. The mica flat crystal is directly attached to the angle reference surface of the optical prism 7. The angle collimation reference surface on the back is adjusted for collimation under the monitoring of the internal focusing telescope. The other two mica crystal surfaces are optically cold-processed to have a specific angular relationship with the collimation reference surface, thereby ensuring that there is also a specific angle between the mica crystal surface and the output optical axis, ensuring that the mica crystal meets the X-ray Bragg diffraction conditions.

[0065] The coupling assembly of the mica crystal and the KB objective lens mainly involves matching the exit optical axis of the KB objective lens with the Bragg diffraction angle of the mica crystal. The specific detailed steps are as follows:

[0066] 1. The dual-beam common-field X-ray CCD used is a KOWA LM100JC lens coupled with a Basler acA2500-14gm model CCD. At a working object distance of nearly 1.5m, this embodiment uses a long focal length industrial lens CCD to perform object point aiming with dual spatial intersection and dual-beam deflection common-field aiming. That is, the light is appropriately deflected by two mirrors and then enters the same industrial lens CCD for imaging.

[0067] This example uses, for example Figure 5 The method shown calibrates the parallelism of the X-rays emitted from each channel. The backlight source used is a Cu target X-ray tube (8keV). To determine the parallelism of the optical axes of the four imaging channels through X-ray imaging at an energy point of 8keV, the optimal object point of the four-channel KB objective lens is first found by using X-ray coordinate grid imaging at an energy point of 8keV. Then, with the center of the coordinate grid as the reference point, the position of the X-ray CCD9 is moved back and forth on the emitted X-ray path, and the four KB imaging objectives are adjusted respectively until the spot spacing of the four imaging channels no longer changes on the X-ray CCD9. At this point, the optical axes of the four imaging channels can be considered to be parallel.

[0068] 2. After adjusting the output optical axes of the four channels to be parallel to each other, use... Figure 5 The outgoing optical axis is indicated by placing approximately 500 mm of the image plane X-ray CCD9 in front of it. A simulated positioning ball 11 with a diameter of m is used and adjusted to a certain channel (lower left channel, such as...). Figure 9 The center position of the coordinate network imaging (i.e., the origin of the coordinate system, which is also the center of the KB objective lens projection section) is shown in the figure. Then, the X-ray CCD9 is replaced with an internal focusing telescope, as shown in the figure. Figure 10As shown, adjust the crosshair center of the internal focusing telescope to the center of the simulated positioning sphere 11 and the center of the KB reflector's projection section. At this point, the axis of the internal focusing telescope coincides with the output optical axis of the KB objective lens's working angle reference plane (the indication accuracy of the reflector's projection section center is estimated with an upper limit of 0.5mm; the corresponding angular deviation at a distance of approximately 2000mm is approximately 0.015°). [Crystal angle reference mirror]

[0069] Then, insert the flat angle reference mirror 4 at the rear end of the KB objective lens. It has a reticle for marking the horizontal and vertical directions. Figure 11 a) Adjust the internal focusing telescope to parallel light emission mode and align the collimating reference mirror at the correct angle. Figure 11 (b) is the reflecting crosshair of the reference mirror before it is fully collimated, and it has a certain angle of deviation from the reference crosshair. Figure 11 (c) shows the state after complete collimation where the reference crosshairs and the reflecting crosshairs are completely aligned. The working angle reference plane of the reflector is completely aligned with the optical axis of the internal focusing telescope (i.e., the KB imaging optical axis). Its accuracy is determined by the collimation accuracy of the internal focusing telescope and is better than 10 arcseconds (i.e., 0.003°). Then, the center of the reticle on the reference reflector is translated to the center position of the output optical axis of the four imaging channels, while still ensuring that the crosshairs are aligned. After this step, the reference reflector and the KB objective lens body are cured together with epoxy resin. At this point, the working angle reference plane of the reference reflector is aligned with the output optical axis of the KB objective lens, and the center of the reflector reticle represents the imaging center position of the KB objective lens.

[0070] 3. Then, install the crystal monochromatic part in front of the image, including the mica flat crystal, the optical prism 7 (i.e., the flat crystal angle calibration prism), and the related angle adjustment mechanism for adjusting the optical prism 7. This includes the following steps:

[0071] a) Roughly align the angle collimation reference plane of the flat crystal angle calibration prism with the internal focusing telescope (e.g., ...). Figure 12 (as shown in a)

[0072] b) Under the monitoring of the internal focusing telescope, move the position of the reference prism so that the center of the angle collimation reference plane coincides with the center of the reticle on the flat angle reference mirror 4 (e.g., Figure 12 (as shown in b)

[0073] c) Align the angle reference plane 702 completely using a three-dimensional angle adjustment stage (e.g., ...). Figure 12 (as shown in c).

[0074] Since the angular relationship between the mica flat crystal and the angular reference plane 702 has been ensured by measuring the angle during the optical cold processing of the reference prism, the angular relationship between the mica crystal and the output optical axis of the KB objective lens is also naturally ensured at this time.

[0075] After the above steps are completed, the four-channel characteristic X-ray monochromatic imaging system is finally completed. It is then installed and debugged on-site, and its performance is measured as shown in Table 2.

[0076] Table 2 Performance Test Table of Four-Channel Characteristic X-ray Monochrome Imaging System

[0077]

[0078] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element, characterized in that, Includes the following steps: S1: By adjusting the X-ray imaging experiment, the optical axes of the outgoing optical paths of each channel of the multi-channel grazing incidence X-ray imaging objective (2) are made parallel to each other, and the optical axes are indicated by the autocollimator (10). S2: Place the optical prism (7) on the optical axis of the outgoing light path; The optical prism (7) includes a collimation reference plane (701) and an angle reference plane (702). A planar crystal (6) is provided on the angle reference plane (702). The angle between the collimation reference plane (701) and the angle reference plane (702) is equal to the Bragg angle of the planar crystal (6). Adjust the optical prism (7) until the central axis of the autocollimator (10) is perpendicular to the collimation reference plane (701). At this time, the incident angle of the outgoing light from the multi-channel grazing incidence X-ray imaging objective (2) on the planar crystal (6) is equal to the Bragg angle of the planar crystal (6).

2. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element according to claim 1, characterized in that, Step S1 includes the calibration of the parallelism of the multi-channel emitted X-rays: During multi-channel X-ray imaging, the multi-channel grazing incidence X-ray imaging objective (2) is adjusted, and the X-ray CCD (9) is moved along the outgoing X-ray path until the relative positions of each imaging channel on the X-ray CCD (9) remain unchanged during the movement. Then, the optical axes of each imaging channel are considered to be parallel to each other.

3. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitter according to claim 2, characterized in that, Step S1 includes determining the X-ray emission axis: In the outgoing optical path of one imaging channel of the multi-channel grazing incidence X-ray imaging objective (2), at least two marker aperture stops (8) are set, and the light blocking phases of the marker aperture stops (8) are made to coincide and located at the center of the imaging spot of the X-ray CCD in the outgoing optical path. At this time, the straight line where the multiple marker aperture stops (8) are located is the optical axis of the outgoing optical path. An autocollimator (10) is set at the far end of the optical axis. The autocollimator (10) is adjusted so that its central axis coincides with the center of multiple marked aperture stops (8). At this time, the central axis of the autocollimator (10) indicates the optical axis of the outgoing optical path.

4. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element according to claim 2, characterized in that, Step S1 includes determining the X-ray emission axis: A simulated positioning point is placed in front of the X-ray CCD (9) and adjusted to the center of the projection section of one imaging channel of the multi-channel grazing incidence X-ray imaging objective (2). Then, an autocollimator (10) is used to replace the X-ray CCD (9), and the autocollimator (10) is adjusted so that its central axis coincides with the simulated positioning point and the center of the projection section of the imaging channel. At this time, the central axis of the autocollimator (10) indicates the optical axis of the outgoing light path.

5. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitter according to claim 4, characterized in that, The process of determining the X-ray emission axis also includes: When the central axis of the autocollimator (10) coincides with the simulated positioning point and the center of the projection section of the imaging channel, a crystal angle reference mirror (4) with a reticle is inserted at the rear end of the multi-channel grazing incidence X-ray imaging objective (2). The autocollimator (10) is adjusted to the parallel light emission state, and the working angle reference plane of the imaging channel is made to coincide with the optical axis of the internal focusing telescope by aligning the collimator crystal angle reference mirror (4). Then, the center of the reticle on the crystal angle reference mirror (4) is translated to the overall center position of the output optical axis of multiple imaging channels, while still ensuring that the crosshairs coincide; at this time, the working angle reference plane of the crystal angle reference mirror (4) coincides with the output optical axis of the multi-channel grazing incidence X-ray imaging objective (2), and the center of the reticle of the crystal angle reference mirror (4) represents the imaging center position of the KB objective.

6. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitter according to claim 5, characterized in that, The simulated positioning point is a simulated positioning ball (11).

7. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element according to claim 6, characterized in that, The diameter of the simulated positioning ball (11) is 400-600μm.

8. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element according to claim 5, characterized in that, Step S2 includes: Adjust the optical prism (7) until the autocollimator (10) and the collimation reference plane (701) are initially collimated. Then, under the monitoring of the autocollimator (10), move the optical prism (7) until the center of the collimation reference plane coincides with the center of the reticle on the crystal angle reference mirror (4). Adjust the optical prism (7) until the autocollimator (10) and the collimation reference plane (701) are completely collimated.

9. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitter according to claim 1, characterized in that, In step S2, the angle reference plane (702) is composed of multiple reflection surfaces, and planar crystals (6) are respectively provided on the reflection surfaces. The angle between the reflection surface and the collimation reference plane (701) is equal to the Bragg angle of the planar crystal (6).

10. The coupling method between a multi-channel grazing incidence X-ray imaging objective and a planar crystal beam-splitting element according to claim 1, characterized in that, The multi-channel grazing incidence X-ray imaging objective includes a multi-channel KB imaging objective.

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