Method for measuring and compensating drift and jitter of X-ray source position

Abstract

The invention provides a method for measuring and compensating drifting and jittering of the position of an X-ray source, and relates to the technical field of X-rays. The method for measuring and compensating the drift and jitter of the X light source position comprises the steps that the original point of the initial position of the X light source driven by a laser plasma accelerator is collected; collecting the real-time jitter offset of the X light source in the application time; counting a real-time jitter offset, and calculating to obtain an average jitter offset within a specified time; the position of the laser target spot is adjusted according to the average jitter offset, so that the offset of the X light source is fed back and pre-compensated; and correcting a corresponding result generated by the X light source through data post-processing. According to the invention, through the synergistic effect of the method for adjusting the position of the laser target spot and the method for post-processing the data, the high-frequency jitter of the average jitter offset and the real-time jitter offset generated in the application process is compensated and corrected, and the precision and accuracy of the obtained result are improved.

Description

Technical Field

[0001] The present application relates to the field of X-ray technology, and in particular to a method for measuring and compensating for the drift and jitter of the position of an X-ray source. Background Art

[0002] Laser plasma accelerator is a new accelerator technology that uses the ponderomotive force of ultrashort and ultra-intense laser beam pulses to accelerate charged particles in a plasma medium. It can produce an ultra-strong acceleration structure of 100GV / m in a rarefied plasma medium. It can also produce high-intensity 0.1-1GeV high-energy electron beams with ultra-fast time structures on the millimeter to centimeter scale. Its scale and cost are greatly reduced compared to traditional linear accelerators. It has great development potential in the construction of a new generation of accelerator-based scientific equipment and the application of miniaturized accelerator radiation sources.

[0003] While generating high-energy electron beams, laser plasma accelerators can generate multi-purpose ultrafast high-brightness X-ray sources covering everything from soft X-rays to high-energy gamma rays by combining multiple radiation generation modes. The desktop ultrafast X-ray source driven by the laser plasma accelerator combines many important features of traditional synchrotron radiation and free electron lasers, and is highly complementary to traditional light sources in parameter space. Therefore, it has broad application prospects in the fields of ultra-high-definition soft tissue imaging, non-destructive testing of dense samples, and analysis of ultrafast physical and chemical processes, and is expected to bring revolutionary changes to the high-end application of high-brightness X-rays in industry, medicine, and scientific research.

[0004] In the application of laser plasma accelerator to generate X-ray source, due to mechanical vibration interference and changes in ambient temperature and humidity, the direction of laser beam pulse will drift and jitter between shots (shot-to-shot fluctuation, referred to as shot-to-shot jitter) during long-term operation, resulting in corresponding drift and jitter in the transmission direction and generation position of the electron beam generated by the laser plasma accelerator, thereby causing the drift and jitter of the lateral source position of the subsequent X-ray source. The drift and jitter of the lateral source position of the X-ray source will increase the size of the equivalent light source on the one hand, for example, it can cause the degradation of spatial resolution in imaging applications; on the other hand, it will cause the center position of the equivalent light source to shift, for example, in the application of X-ray ultrafast near-edge absorption spectrum, it will cause the X-ray focusing process to change, thereby affecting the spectral and temporal resolution.

[0005] Therefore, it is necessary to provide a method that can accurately measure the offset of the lateral source position of an X-ray source driven by a laser plasma accelerator and provide feedback compensation. Summary of the invention

[0006] Based on this, the present application provides a method for measuring and compensating for the drift and jitter of the X-ray source position, so as to reduce the influence of the drift and jitter of the X-ray source position on the actual application results.

[0007] The method for measuring and compensating the drift and jitter of the X-ray source position provided in the present application includes:

[0008] Collect the initial position origin of the X-ray source driven by the laser plasma accelerator;

[0009] Synchronously collect the real-time jitter offset of the X-ray source within the application time;

[0010] Set a specified time within the application time, count the real-time jitter offset within the specified time, and calculate the average jitter offset within the specified time;

[0011] The position of the laser target is adjusted according to the average jitter offset, so as to provide feedback and pre-compensation for the offset of the X-ray source within a specified time;

[0012] According to the real-time jitter offset collected, the corresponding result generated by the X-ray source is corrected through data post-processing.

[0013] Optionally, the method for measuring and compensating for the drift and jitter of the X-ray source position provided by the present application further includes:

[0014] The positioning sample is placed between the X-ray detector and the X-ray light source. The plane of the X-ray detector is perpendicular to the transmission direction of the X-ray light source. The X-ray light source projects the positioning sample onto the X-ray detector.

[0015] Optionally, collecting the initial position origin of the X-ray source driven by the laser plasma accelerator includes:

[0016] The initial position information of the projection of the positioning sample formed by the X-ray light source penetrating the positioning sample in the initial stage is collected by the X-ray detector, so as to obtain the initial position origin of the X-ray light source.

[0017] Optionally, synchronously collecting the real-time jitter offset of the X-ray source within the application time includes:

[0018] The X-ray detector is used to collect the offset position information of the projection of the positioning sample formed by the transmission positioning sample after the position of the X-ray light source is offset and jittered;

[0019] The actual real-time jitter offset of the X-ray source is calculated based on the offset position information.

[0020] Optionally, calculating the actual real-time jitter offset of the X-ray source according to the offset position information includes:

[0021] The position offset Δd of the X-ray source is calculated by the following formula:

[0022] Δd=(-Δa×l) / L

[0023] Among them, Δa is the position change of the current position of the projection imaging result of the positioning sample relative to the initial position origin of the projection imaging result, l is the distance from the X-ray light source to the positioning sample along the longitudinal direction, and L is the distance from the positioning sample to the X-ray detector plane along the longitudinal direction.

[0024] Optionally, in the step of calculating the actual real-time jitter offset of the X-ray source according to the offset position information,

[0025] Make Δa larger than the effective width of the imaging surface point spread function under the imaging magnification ratio, and the imaging magnification ratio M=(L+l) / l.

[0026] Optionally, a specified time is set within the application time, real-time jitter offset within the specified time is counted, and an average jitter offset within the specified time is calculated, including:

[0027] Set multiple consecutive specified times within the application time;

[0028] The average jitter offset within a plurality of specified time periods is measured and calculated, and a trend curve of the offset of the X-ray source changing with time is obtained through the average jitter offset within a plurality of specified time periods.

[0029] Optionally, adjusting the position of the laser target point according to the average jitter offset, thereby providing feedback and pre-compensation for the offset of the X-ray source within a specified time includes:

[0030] The electric optical adjustment frame is used to move the position of the laser target point by an average jitter offset and in a direction opposite to the average jitter offset direction of the X-ray source to achieve pre-compensation.

[0031] Optionally, the method for measuring and compensating for the drift and jitter of the X-ray source position provided by the present application further includes:

[0032] The positioning sample projection of the positioning sample is decomposed along any two mutually perpendicular directions in the projection plane, so that the positioning sample projection of the positioning sample has a 2-dimensional property, so as to reduce the difficulty of extracting the position information.

[0033] Optionally, the positioning sample includes a thin sheet sample with a vertical hard edge structure, a circular thin sheet sample or a spherical sample.

[0034] The method for measuring and compensating the drift and jitter of the X-ray source position provided by the present application acquires the position difference of the X-ray source relative to its initial position origin in real time to obtain the real-time jitter offset of the X-ray source. In the case of the jitter of the lateral source position of the X-ray source driven by the laser plasma accelerator, the average jitter offset within the specified time Δt is calculated based on the real-time jitter offset data of the measured real-time lateral source position jitter of the X-ray source.

[0035] Through the data post-processing method, the position of the laser target is preliminarily adjusted according to the average jitter offset to eliminate the influence of the average jitter offset. In this way, the influence of the jitter and offset of the X-ray source on the results and effects in the actual application process is compensated. Through the data post-processing method, according to the real-time jitter offset data, the corresponding data of the results generated by the X-ray source collected in the actual application process is further corrected for the source position jitter data to correct the influence of the high-frequency jitter of the real-time jitter offset on the results.

[0036] By adjusting the position of the laser target and working together with data post-processing methods, the high-frequency jitter of the average jitter offset and the real-time jitter offset generated during the application process are compensated and corrected respectively, thereby reducing and eliminating the impact of jitter and offset on the results and effects in the actual application process, and improving the precision and accuracy of the results obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without exceeding the scope of protection required by the present application.

[0038] Figure 1 It is a schematic diagram of the process provided by the present application;

[0039] Figure 2 It is a working schematic diagram of placing the positioning sample between the X-ray detector and the X-ray source;

[0040] Figure 3 is a flow chart of step S120;

[0041] Figure 4 is a flowchart of step S130;

[0042] Figure 5 It is a schematic diagram of the structure of a thin-sheet sample with a vertical hard-edge structure;

[0043] Figure 6 It is a schematic diagram of the structure of a spherical sample;

[0044] Figure 7 is an imaging result diagram obtained without using the method shown in the present application;

[0045] Figure 8 This is an imaging result diagram obtained by using the method shown in this application.

[0046] Explanation of the reference numerals: 1. X-ray source; 2. Positioning sample; 3. X-ray detector. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0048] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a corresponding orientation, be constructed and operated in a corresponding orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0051] It should be noted that in this application, the transmission direction of the X-ray source 1 is referred to as the longitudinal direction, the plane perpendicular to the transmission direction of the X-ray source 1 is referred to as the transverse plane, and the position where the light-emitting point of the X-ray source 1 falls on the plane perpendicular to the transmission direction of the X-ray source 1 is referred to as the transverse source.

[0052] refer to Figure 1 and Figure 2 The method for measuring and compensating the drift and jitter of the position of the X-ray source 1 provided in the present application includes steps S110-S150.

[0053] In step S110, the initial position origin of the X-ray source 1 driven by the laser plasma accelerator is acquired.

[0054] The X-ray source 1 driven by the laser plasma accelerator may include a betatron ray source (a laser plasma accelerator self-generated synchrotron radiation source), an all-optical inverse Compton scattering source and an all-optical bremsstrahlung radiation source.

[0055] In step S120, the real-time jitter offset of the X-ray source 1 within the application time is synchronously collected, and the position difference between the real-time position of the X-ray source 1 and the initial position origin is collected. The position difference is the real-time jitter offset.

[0056] In step S130 , a specified time Δt is set within the application time, the real-time jitter offset within the specified time Δt is counted, and the average jitter offset within the specified time Δt is calculated.

[0057] The specified time Δt is selected as a time scale as small as possible based on the statistically valid average jitter offset. For example, the specified time Δt is selected as a time scale as small as possible based on the statistically obtained average jitter offset being greater than the standard deviation of the real-time jitter offset.

[0058] In step S140 , the position of the laser target is adjusted according to the average jitter offset, so as to feedback and pre-compensate the offset of the X-ray source 1 within the specified time Δt.

[0059] In step S150, the corresponding result generated by the X-ray source 1 is corrected through data post-processing according to the real-time jitter offset collected.

[0060] The real-time jitter offset of the X-ray source 1 is obtained by collecting the position difference of the X-ray source 1 relative to its initial position origin in real time. In the case of the transverse source position jitter of the X-ray source 1 driven by the laser plasma accelerator, the average jitter offset within the specified time Δt is calculated based on the real-time jitter offset data of the transverse source position jitter of the real-time X-ray source 1. The position of the laser target is preliminarily adjusted according to the average jitter offset to eliminate the influence caused by the average jitter offset. Through the data post-processing method, according to the real-time jitter offset data, the corresponding data of the result generated by the X-ray source 1 collected during the actual application process is further corrected for the source position jitter data to correct the influence of the high-frequency jitter of the real-time jitter offset on the result. For example, when the X-ray source 1 driven by the laser plasma accelerator is applied to imaging applications, the image to be imaged can be subjected to corresponding translation processing to compensate and reduce the influence of the position jitter and offset of the X-ray source 1 on the image. Or it can be seen that the X-ray source 1 driven by the laser plasma accelerator is applied to the spectrum.

[0061] By adjusting the position of the laser target and working together with data post-processing methods, the high-frequency jitter of the average jitter offset and the real-time jitter offset generated during the application process are compensated and corrected respectively, thereby reducing and eliminating the impact of jitter and offset on the results and effects in the actual application process, and improving the precision and accuracy of the results obtained.

[0062] refer to Figure 1 and Figure 2 As an optional implementation, the method for measuring and compensating for the drift and jitter of the position of the X-ray source 1 provided in the present application also includes step S160.

[0063] In step S160 , the positioning sample 2 is placed between the X-ray detector 3 and the X-ray light source 1 , the plane of the X-ray detector 3 is perpendicular to the transmission direction of the X-ray light source 1 , and the X-ray light source 1 projects the positioning sample 2 onto the X-ray detector 3 for imaging.

[0064] like Figure 2 As shown, the positioning sample 2 is placed between the X-ray detector 3 and the X-ray light source 1, the distance between the positioning sample 2 and the X-ray light source 1 along the longitudinal direction is l, and the distance between the positioning sample 2 and the X-ray detector 3 along the longitudinal direction is L.

[0065] Among them, the horizontal placement position of the positioning sample 2 should comply with the principle of being close to the transmission center of the X-ray source 1 without blocking the X-ray source 1 and affecting the actual application results, so as to enable the positioning sample 2 to obtain an imaging result with a better signal-to-noise ratio.

[0066] refer to Figure 1 and Figure 2 As an optional implementation, step S110 includes collecting, through the X-ray detector 3, initial position information of the projection of the positioning sample 2 formed by the X-ray light source 1 transmitting the positioning sample 2 in the initial stage, thereby obtaining the initial position origin of the X-ray light source 1.

[0067] refer to Figure 2 and Figure 3 As an optional implementation, step S120 includes sub-steps S121-S122.

[0068] In sub-step S121, the X-ray detector 3 collects the offset position information of the positioning sample projection formed by the transmission positioning sample 2 after the position of the X-ray light source 1 is offset and jittered.

[0069] When the lateral source position of the X-ray source 1 is offset and jittered, the offset position information of the positioning sample projection formed by the positioning sample 2 whose transmission position is fixed by the X-ray light source 1 is collected by the X-ray detector 3. The position difference between the offset position of the positioning sample projection and the initial position origin is the change Δa of the characteristic position of the positioning sample 2.

[0070] In sub-step S122, the actual real-time jitter offset of the X-ray source 1 is calculated based on the offset position information.

[0071] The real-time jitter offset Δd of the lateral source position of the X-ray source 1 can be inferred by combining Δa with the distance l and the distance L of the positioning sample 2 relative to the X-ray source 1 and the X-ray detector 3 .

[0072] refer to Figure 1 and Figure 2 As an optional implementation, step S122 includes calculating the lateral source position offset Δd of the X-ray source 1 by the following formula.

[0073] Δd=(-Δa×l) / L

[0074] Among them, Δa is the position change of the current position of the projection imaging result of the positioning sample 2 relative to the initial position origin of the projection imaging result, l is the distance from the X-ray light source 1 to the positioning sample 2 along the longitudinal direction, and L is the distance from the positioning sample 2 to the X-ray detector plane along the longitudinal direction.

[0075] As an optional implementation, in sub-step S122, Δa is made larger than the effective width of the imaging surface point spread function under the imaging magnification ratio, and the imaging magnification ratio M=(L+l) / l.

[0076] refer to Figure 2 and Figure 4As an optional implementation, step S130 includes sub-steps S131-S132.

[0077] In sub-step S131 , a plurality of consecutive designated times Δt are set within the application time.

[0078] In sub-step S132, the average jitter offset within a plurality of specified time periods Δt is measured and calculated, and a trend curve of the offset variation over time of the X-ray source 1 is obtained through the average jitter offset within a plurality of specified time periods Δt. The trend curve of the lateral source position of the X-ray source 1 varying over time is obtained by measuring and calculating the average jitter offset of the lateral source position of the X-ray source 1 within a series of a plurality of specified time periods Δt, so as to predict the drift and implement pre-compensation.

[0079] refer to Figure 1 and Figure 2 As an optional implementation, step S140 includes using an electric optical adjustment frame to move the position of the laser target point by an average jitter offset and in a direction opposite to the average jitter offset direction of the X-ray source 1 to achieve pre-compensation.

[0080] When a series of average jitter offsets within a plurality of consecutive specified time periods Δt are measured and calculated, steps S130 and S140 are executed cyclically, so that the electric optical adjustment frame adjusts the lateral position of the laser target in advance along the compensation direction according to the trend curve of the offset of the X-ray source 1 changing with time, so as to realize pre-compensation and feedback.

[0081] refer to Figure 1 , Figure 5 and Figure 6 As an optional implementation, the method for measuring and compensating for the drift and jitter of the position of the X-ray source 1 provided in the present application also includes step S170.

[0082] In step S170, the positioning sample projection of the positioning sample 2 is decomposed along any two mutually perpendicular directions in the projection plane, so that the positioning sample projection of the positioning sample 2 has a two-dimensional property, so as to reduce the difficulty of extracting the position information.

[0083] As an optional embodiment, the positioning sample 2 includes: Figure 5 The thin sheet sample with vertical hard edge structure shown, the circular thin sheet sample or the Figure 6 Spherical specimen shown.

[0084] For example, when the positioning sample 2 is a thin sheet sample with a vertical hard edge structure, the position change of the two vertical hard edges can be analyzed to obtain the real-time jitter offset of the X-ray source 1 in the horizontal direction. When the positioning sample 2 is a circular thin sheet sample or a spherical sample, the position change of the center of the circle or the center of the sphere can be analyzed to obtain the real-time jitter offset of the X-ray source 1 in the horizontal direction.

[0085] like Figure 7 and Figure 8 As shown, the method of the present application is applied to an imaging experiment based on a laser plasma accelerator driving an all-optical inverse Compton scattering X-ray source 1. The energy of the main laser beam pulse used in the experiment to drive the target is about 0.35J (joule), the pulse width is about 25fs (femtoseconds), and the half-height full width of the focus diameter is about 13μm (micrometer); the pulse energy of the collision laser beam is about 0.15J (joule), the pulse width is about 25fs (femtoseconds), and the half-height full width of the focus diameter is about 7μm (micrometer). The plasma source is generated by a De Laval type supersonic nozzle with an outlet diameter of 2mm (millimeter). This imaging application experiment uses a flat-panel detector to project and image a 100μm (micrometer) thick stainless steel sheet. The pixel size of the flat-panel detector is 50μm (micrometer), and the imaging magnification ratio of the projection imaging is about 2.5. During the imaging application process, the spherical positioning sample is imaged synchronously to measure the offset of the lateral source position of the X-ray source 1. Among them, the imaging magnification ratio of the spherical positioning sample imaging is about 2.8.

[0086] Figure 7 : The original image of the stainless steel sheet obtained without using the method shown in the present application and the modulation transfer function (MTF) of the image edge. It can be seen from the figure that, according to the spatial frequency corresponding to MTF=0.1, the image resolution of the original image of the stainless steel sheet obtained without using the method shown in the present application is about 75μm (micrometer).

[0087] Figure 8 The transmission image of the stainless steel sheet obtained by using the method shown in the present invention, and the MTF (modulation transfer function) of the image edge, the resolution obtained corresponding to the spatial frequency when MTF=0.1 is about 27μm (micrometer). It can be seen that the method shown in the present application effectively compensates for the influence of the image resolution reduction caused by the lateral source position jitter of the X-ray source 1.

[0088] It should be noted that the resolution in this application refers to the smallest size that can be measured by the entire system. The smaller the resolution value, the clearer the image, and the better the resolution of the image.

[0089] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. A method for measuring and compensating for the drift and jitter of the X-ray source position, characterized in that: include: Collect the initial position origin of the X-ray source driven by the laser plasma accelerator; Synchronously collecting the real-time jitter offset of the X-ray source within the application time; Setting a specified time within the application time, counting the real-time jitter offset within the specified time, and calculating the average jitter offset within the specified time; Adjusting the position of the laser target point according to the average jitter offset, thereby providing feedback and pre-compensation for the offset of the X-ray source within the specified time; According to the real-time jitter offset collected, the corresponding result generated by the X-ray source is corrected through data post-processing.

2. The method according to claim 1, characterized in that Also includes: The positioning sample is placed between the X-ray detector and the X-ray light source, the plane of the X-ray detector is perpendicular to the transmission direction of the X-ray light source, and the X-ray light source projects the positioning sample onto the X-ray detector for imaging.

3. The method according to claim 2, characterized in that The initial position origin of the X-ray source driven by the laser plasma accelerator includes: The X-ray detector collects initial position information of the positioning sample projection formed by the X-ray light source transmitting the positioning sample in the initial stage, thereby acquiring the initial position origin of the X-ray light source.

4. The method according to claim 2, characterized in that: The real-time jitter offset of the X-ray source collected synchronously during the application time includes: The X-ray detector is used to collect offset position information of the projection of the positioning sample formed by transmitting the positioning sample after the X-ray light source position is offset and jittered; The actual real-time jitter offset of the X-ray source is calculated according to the offset position information.

5. The method according to claim 4, characterized in that Calculating the actual real-time jitter offset of the X-ray source according to the offset position information includes: The position offset Δd of the X-ray source is calculated by the following formula: Δd=(-Δa×l) / L Among them, Δa is the position change of the current position of the projection imaging result of the positioning sample relative to the initial position origin of the projection imaging result, l is the distance from the position of the X-ray light source to the positioning sample along the longitudinal direction, and L is the distance from the positioning sample to the X-ray detector plane along the longitudinal direction.

6. The method according to claim 5, characterized in that In the step of calculating the actual real-time jitter offset of the X-ray source according to the offset position information, Δa is made larger than the effective width of the imaging surface point spread function under the imaging magnification ratio, wherein the imaging magnification ratio M=(L+l) / l.

7. The method according to claim 1, characterized in that Setting a specified time within the application time, counting the real-time jitter offset within the specified time, and calculating the average jitter offset within the specified time includes: Setting a plurality of consecutive designated times within the application time; The average jitter offsets within the multiple specified times are measured and calculated, and a trend curve of the offset of the X-ray source changing with time is obtained through the average jitter offsets within the multiple specified times.

8. The method according to claim 1, characterized in that Adjusting the position of the laser target point according to the average jitter offset, thereby providing feedback and pre-compensating for the offset of the X-ray source within the specified time, includes: The position of the laser target is moved by the electric optical adjustment frame at the average jitter offset and in a direction opposite to the average jitter offset direction of the X-ray source to achieve pre-compensation.

9. The method according to claim 2, characterized in that: Also includes: The positioning sample projection of the positioning sample is decomposed along any two mutually perpendicular directions in the projection plane, so that the positioning sample projection of the positioning sample has a two-dimensional property, so as to reduce the difficulty of extracting the position information.

10. The method according to claim 2, characterized in that The positioning sample includes a thin sheet sample with a vertical hard edge structure, a circular thin sheet sample or a spherical sample.

Images