Method and device for image bright field correction of laser plasma accelerators, electronic equipment and storage medium

Abstract

The application provides a method and device for image bright field correction of a laser plasma accelerator, an electronic device and a storage medium, and relates to the technical field of X-ray imaging. The method comprises the following steps: acquiring dark field and initial X-ray beam spot images of an X-ray bright field calibration detector and an X-ray imaging detector to obtain coordinates of an initial X-ray beam spot center; in the case that an imaging sample is moved in, acquiring real-time unprocessed X-ray beam spot images acquired by the X-ray bright field calibration detector and real-time unprocessed projection images acquired by the X-ray imaging detector to obtain real-time beam spot images and real-time imaging images, and obtaining coordinates of a real-time X-ray beam spot center; according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, obtaining an X-ray beam spot center, and obtaining a final real-time projection image. The application improves the accuracy of bright field correction by measuring the X-ray beam spot in real time and combining geometric space mapping and coordinate transformation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of X-ray imaging, in particular to a method and device for image bright field correction of a laser plasma accelerator, an electronic device and a storage medium. BACKGROUND

[0002] As a revolutionary accelerator technology, the laser plasma accelerator can realize efficient acceleration of electrons by driving the tail wave field of ultra-high acceleration gradient (> 100 MeV / mm) in a dilute plasma medium through an ultra-short and ultra-strong laser. Due to the micron-scale acceleration structure, the laser plasma accelerator can generate X-rays with micron-scale source size and femtosecond-scale pulse length. The laser-accelerated ultrafast X-ray source includes a wide-spectrum high-flux Betatron synchrotron X-ray source, a quasi-monochromatic full-light inverse Compton scattering X-ray source, and a high-energy micro-focus full-light bremsstrahlung source, which has the advantages of desktop scale, femtosecond-scale pulse length, micron-scale source size, ultra-high peak brightness, wide energy spectrum coverage, and adjustable energy and spectrum width, and has great application potential in quantum science, physics, biology, medicine, and other disciplines, as well as weapons, aerospace, high-end manufacturing, and other industrial fields, and is expected to drive a series of technological revolutions and form a new high-tech industry market.

[0003] However, for the laser plasma accelerator driven X-ray source, due to the factors such as the jitter of laser and plasma interaction parameters, mechanical vibration, and temperature and humidity changes, the shape distribution and transmission direction of the X-ray beam spot of the laser plasma accelerator driven X-ray source exist random jitter between shots and slow changes over a long period of time. In related imaging applications, especially in CT imaging, the traditional pre-acquisition bright field method is difficult to achieve accurate bright field correction, resulting in the inability to obtain accurate sample attenuation coefficients from the projection images, causing large errors in CT reconstruction results, and seriously limiting the further application of the laser plasma accelerator driven X-ray source in the imaging field.

[0004] Therefore, there is an urgent need for a method capable of real-time measurement of the X-ray beam spot and accurate bright field correction. SUMMARY

[0005] In order to solve at least one of the above problems, the present application provides a method and device for image bright field correction of a laser plasma accelerator, an electronic device and a storage medium.

[0006] According to a first aspect of the present application, at least one embodiment of the present application provides a method for image bright field correction of a laser plasma accelerator, the method comprising: acquiring dark field and initial X-ray beam spot images of an X-ray bright field calibration detector and an X-ray imaging detector to obtain coordinates of an initial X-ray beam spot center; in the case of imaging sample moving in, acquiring a real-time unprocessed X-ray beam spot image acquired by the X-ray bright field calibration detector and a real-time unprocessed projection image acquired by the X-ray imaging detector, obtaining a real-time beam spot image and a real-time imaging image according to the dark field of the X-ray bright field calibration detector and the X-ray imaging detector, the real-time unprocessed X-ray beam spot image and the real-time unprocessed projection image, and obtaining coordinates of a real-time X-ray beam spot center according to the real-time beam spot image; obtaining an X-ray beam spot center after coordinate translation transformation according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, and performing image bright field correction according to the real-time beam spot image, the real-time imaging image and the X-ray beam spot center to obtain a final real-time projection image.

[0007] For example, in some embodiments of the present application, the acquiring of the dark field and the initial X-ray beam spot image of the X-ray bright field calibration detector and the X-ray imaging detector to obtain the coordinates of the initial X-ray beam spot center comprises: mapping the dark field and the initial X-ray beam spot image of the X-ray bright field calibration detector to a field of view plane of the X-ray imaging detector to obtain a first dark field and a first X-ray beam spot image; obtaining a first initial beam spot image according to the first dark field and the first X-ray beam spot image of the X-ray bright field calibration detector; obtaining a second initial beam spot image according to the dark field and the initial X-ray beam spot image of the X-ray imaging detector; fitting the first initial beam spot image or the second initial beam spot image to obtain the horizontal coordinate and the vertical coordinate of the initial X-ray beam spot center.

[0008] For example, in some embodiments of the present application, the real-time unprocessed X-ray beam spot image acquired by the X-ray bright field calibration detector and the real-time unprocessed projection image acquired by the X-ray imaging detector are acquired in the case of sample movement, the real-time beam spot image and the real-time imaging image are obtained according to the dark field of the X-ray bright field calibration detector and the X-ray imaging detector, the real-time X-ray beam spot center coordinates are obtained according to the real-time beam spot image, and the method comprises: mapping the real-time unprocessed X-ray beam spot image of the X-ray bright field calibration detector to the field plane of the X-ray imaging detector to obtain a third X-ray beam spot image; obtaining the real-time beam spot image according to the third X-ray beam spot image and the first dark field; obtaining the real-time imaging image according to the real-time unprocessed projection image and the dark field of the X-ray imaging detector; and fitting the real-time beam spot image to obtain the horizontal coordinate and the vertical coordinate of the real-time X-ray beam spot center.

[0009] For example, in some embodiments of the present application, the X-ray beam spot center after coordinate translation is obtained according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, and the final real-time projection image is obtained by performing image bright field correction according to the real-time beam spot image, the real-time imaging image and the X-ray beam spot center, and the method comprises: obtaining the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center according to the horizontal coordinate and the vertical coordinate of the initial X-ray beam spot center and the horizontal coordinate and the vertical coordinate of the real-time X-ray beam spot center; performing coordinate translation on the first initial beam spot image and the second initial beam spot image according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center to obtain the final X-ray beam spot center; and performing image bright field correction according to the real-time beam spot image, the real-time imaging image and the final X-ray beam spot center according to the following formula to obtain the final real-time projection image:

[0010]

[0011] wherein I is the final real-time projection image, A i is the real-time imaging image, B i is the real-time beam spot image, A'0, B'0 is the final X-ray beam spot center.

[0012] For example, in some embodiments of this application, an X-ray source is provided between the laser plasma accelerator and the X-ray bright field calibration detector to generate X-ray pulses under the drive of the laser plasma accelerator. The method further includes: adjusting the laser target angle of the laser plasma accelerator and the position of the X-ray source according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center.

[0013] For example, in some embodiments of this application, an electric optical frame is provided in the laser plasma accelerator, and adjusting the laser target angle of the laser plasma accelerator and the position of the X-ray source according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center includes:

[0014] Adjust the laser target angle of the motorized optical frame to adjust the laser target angle of the laser plasma accelerator;

[0015] The angle adjustment amount of the motorized optical frame is determined according to the following formula:

[0016]

[0017] The positional translation of the X-ray source is determined according to the following formula:

[0018]

[0019] Wherein, δx and δy are the coordinate differences between the real-time X-ray beam spot center and the initial X-ray beam spot center, l is the distance between the motorized optical frame and the X-ray source, and L is the distance between the X-ray source and the X-ray bright field calibration detector.

[0020] According to a second aspect of the present application, at least one embodiment of the present application provides a device for image bright field correction of a laser plasma accelerator, the device comprising: an X-ray source driven by the laser plasma accelerator to generate an X-ray pulse; an X-ray bright field calibration detector arranged between the X-ray source and an imaging sample, for collecting dark field and initial X-ray beam spot images when the imaging sample is not moved in, and for collecting real-time unprocessed X-ray beam spot images when the imaging sample is moved in; an X-ray imaging detector arranged after the imaging sample, for collecting dark field and initial X-ray beam spot images when the imaging sample is not moved in, and for collecting real-time unprocessed projection images when the imaging sample is moved in; a host computer configured to perform the method of any one of the first aspect, to obtain coordinates of an initial X-ray beam spot center according to the dark field and initial X-ray beam spot images of the X-ray bright field calibration detector and the X-ray imaging detector, to obtain real-time beam spot images and real-time imaging images according to the dark field, the real-time unprocessed X-ray beam spot images and the real-time unprocessed projection images of the X-ray bright field calibration detector and the X-ray imaging detector, and to obtain coordinates of a real-time X-ray beam spot center according to the real-time beam spot images, and to obtain an X-ray beam spot center after a coordinate translation transformation according to a coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, and to perform image bright field correction according to the real-time beam spot images, the real-time imaging images and the X-ray beam spot center to obtain a final real-time projection image.

[0021] For example, in some embodiments of the present application, further comprising: an electrically driven optical mirror frame arranged in the laser plasma accelerator; wherein the host computer is further configured to adjust a laser targeting angle of the electrically driven optical mirror frame according to a coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, to adjust a laser targeting angle of the laser plasma accelerator, and to adjust a position of the X-ray source.

[0022] According to a third aspect of the present application, at least one embodiment of the present application provides an electronic device, comprising: one or more processors; a memory configured to store one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors perform the method of any one of the first aspect.

[0023] According to a fourth aspect of the present application, at least one embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the method of any one of the first aspect.

[0024] Through the above example embodiments, the method and device for image bright field correction of a laser plasma accelerator provided by the present application realize dynamic tracking and correction of beam spot jitter and slow changes by real-time measurement of the X-ray beam spot and combining geometric space mapping and coordinate transformation, solve the problem that traditional pre-acquired bright field cannot adapt to real-time changes of the beam spot, significantly improve the accuracy of bright field correction, and especially in CT imaging, can effectively reduce reconstruction error, improve the measurement accuracy of sample attenuation coefficients, and expand the application prospect of the laser plasma accelerator driven X-ray source in the imaging field.

[0025] It should be understood that the foregoing general description and the following detailed description are only examples and are not limiting the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which example embodiments of the present application are shown by way of illustration. The following drawings described below are merely some embodiments of the present application and are not a limitation of the present application.

[0027] Figure 1 A method flowchart for image bright field correction of a laser plasma accelerator of an example embodiment is shown;

[0028] Figure 2 An image data processing schematic diagram of an implementation flow of the present application in imaging applications is shown;

[0029] Figure 3 An X-ray transmission direction compensation schematic diagram of the present application is shown;

[0030] Figure 4 An implementation flow schematic diagram of the present application in imaging applications is shown;

[0031] Figure 5 A device schematic diagram for image bright field correction of a laser plasma accelerator of an example embodiment is shown;

[0032] Figure 6 A schematic diagram of an X-ray bright field calibration probe is shown;

[0033] Figure 7 An effect diagram of performing the method of the present application is shown;

[0034] Figure 8 A structure diagram of an electronic device provided by the present application is shown. DETAILED DESCRIPTION

[0035] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the several views and, thus, description of the same elements will not be repeated.

[0036] The described features, structures, or characteristics can be combined in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the

[0037] The flow charts shown in the drawings are merely examples and do not necessarily include all of the content and operations / steps, nor are they necessarily performed in the order described. For example, some operations / steps can be further broken down, and some operations / steps can be combined or partially combined, so the actual order of execution can be changed according to actual conditions.

[0038] The terms "first", "second", and the like in the description and in the claims of the present application and the above drawings are used to distinguish between similar objects, not to describe a particular sequential order. Moreover, the terms "include", and "have", and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that comprises a list of steps or units is not limited to the listed steps or units, but can optionally further include other steps or units not listed, or can optionally further include other steps or units inherent to such processes, methods, products, or devices.

[0039] Those skilled in the art can understand that the drawings are only schematic views of example embodiments, and the modules or flows in the drawings are not necessarily essential for implementing the present application, and thus should not be used to limit the scope of protection of the present application.

[0040] In order to solve the problem of inaccurate bright field correction and poor imaging quality caused by jitter and slow changes in beam spot shape and transmission direction in imaging applications of laser plasma accelerator driven X-ray sources, the present application provides a method for precise bright field correction by real-time measurement of X-ray beam spots to improve imaging accuracy, especially the reconstruction quality of CT imaging.

[0041] The present application provides a method for image bright field correction of a laser plasma accelerator.

[0042] Figure 1A method flow chart of image bright field correction for a laser plasma accelerator is shown.

[0043] As shown in the drawings, Figure 1 The method of image bright field correction for a laser plasma accelerator comprises steps S1-S4.

[0044] Step S1, obtain the dark field and initial X-ray beam spot image of the X-ray bright field calibration detector and the X-ray imaging detector to obtain the coordinates of the initial X-ray beam spot center.

[0045] Specifically includes:

[0046] S1.1, obtain the dark field and initial X-ray beam spot image of the X-ray bright field calibration detector and the X-ray imaging detector.

[0047] Dark field D (dark field of X-ray imaging detector) and d (dark field of X-ray bright field calibration detector) are collected respectively, and the same X-ray beam spot image, i.e. initial untreated beam spot image G0 (initial X-ray beam spot image of X-ray imaging detector) and g0 (initial X-ray beam spot image of X-ray bright field calibration detector) are collected at the same time.

[0048] S1.2, map the dark field and initial X-ray beam spot image of the X-ray bright field calibration detector to the field of view plane of the X-ray imaging detector to obtain the first dark field and the first X-ray beam spot image.

[0049] The dark field and the initial untreated X-ray beam spot image obtained by the X-ray bright field calibration detector are mapped to the field of view plane of the X-ray imaging detector by field of view transformation, i.e. d→D ' , g0→G'0.

[0050] S1.3, obtain the first initial beam spot image according to the first dark field and the first X-ray beam spot image of the X-ray bright field calibration detector.

[0051] S1.4, obtain the second initial beam spot image according to the dark field and the initial untreated X-ray beam spot image G0 of the X-ray imaging detector.

[0052] The first initial beam spot image G'0-D' (denoted as B0, X-ray bright field calibration detector) and the second initial beam spot image G0-D (denoted as A0, X-ray imaging detector) after deducting the dark field are obtained.

[0053] S1.5, fit the first initial beam spot image or the second initial beam spot image to obtain the horizontal coordinate and the vertical coordinate of the initial X-ray beam spot center.

[0054] The form is as follows The function is fitted to A0 or B0 to obtain the horizontal coordinate x0 and the vertical coordinate y0 of the initial X-ray beam spot center.

[0055] Step S2, in the case of moving the imaging sample into the X-ray cone beam region, acquiring the real-time unprocessed X-ray beam spot image acquired by the X-ray bright field calibration detector and the real-time unprocessed projection image acquired by the X-ray imaging detector, obtaining the real-time beam spot image and the real-time imaging image according to the dark field, the real-time unprocessed X-ray beam spot image and the real-time unprocessed projection image of the X-ray bright field calibration detector and the X-ray imaging detector, and obtaining the coordinates of the real-time X-ray beam spot center according to the real-time beam spot image.

[0056] Specifically includes:

[0057] The imaging sample is moved into the X-ray cone beam region for single projection imaging.

[0058] S2.1, acquiring the real-time unprocessed X-ray beam spot image acquired by the X-ray bright field calibration detector and the real-time unprocessed projection image acquired by the X-ray imaging detector.

[0059] The X-ray imaging detector obtains the real-time unprocessed projection image I0, and the X-ray bright field calibration detector simultaneously obtains the real-time unprocessed X-ray beam spot image i0.

[0060] S2.2, mapping the real-time unprocessed X-ray beam spot image of the X-ray bright field calibration detector to the field of view plane of the X-ray imaging detector to obtain a third X-ray beam spot image.

[0061] The real-time unprocessed X-ray beam spot image obtained by the X-ray bright field calibration detector is mapped to the field of view plane of the X-ray imaging detector through field of view transformation to obtain a third X-ray beam spot image, i.e. i0→i ' 0.

[0062] S2.3, obtaining the real-time beam spot image according to the third X-ray beam spot image and the first dark field.

[0063] S2.4, obtaining the real-time imaging image according to the real-time unprocessed projection image and the dark field of the X-ray imaging detector.

[0064] The real-time imaging image I0-D (denoted as A i , X-ray imaging detector) after deducting the dark field and the real-time beam spot image I'0-D' (denoted as B i , X-ray bright field calibration detector) after deducting the dark field are obtained.

[0065] S2.5, fitting the real-time beam spot image to obtain the horizontal coordinate and the vertical coordinate of the real-time X-ray beam spot center.

[0066] The fitting is performed in the form of function of the real-time beam spot image B i fitting, the horizontal coordinate x'0 and the vertical coordinate y'0 of the real-time X-ray beam spot center are obtained.

[0067] Step S3, according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, the X-ray beam spot center after coordinate translation is obtained, and according to the real-time beam spot image, the real-time imaging image and the X-ray beam spot center, the image bright field correction is performed to obtain the final real-time projection image.

[0068] Specifically, it includes:

[0069] S3.1, according to the horizontal coordinate and the vertical coordinate of the initial X-ray beam spot center and the horizontal coordinate and the vertical coordinate of the real-time X-ray beam spot center, the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center is obtained.

[0070] The coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center is obtained: δx=x'0-x0, δy=y'0-y0.

[0071] S3.2, according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, the first initial beam spot image and the second initial beam spot image are subjected to coordinate translation to obtain the X-ray beam spot center.

[0072] According to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, the first initial beam spot image and the second initial beam spot image are subjected to coordinate translation to obtain the final X-ray beam spot center, that is, A0(x-δx, y-δy) (denoted as A'0, X-ray imaging detector) and B0(x-δx, y-δy) (denoted as B'0, X-ray bright field calibration detector).

[0073] S3.3, according to the real-time beam spot image, the real-time imaging image and the final X-ray beam spot center, the image bright field correction is performed according to the following formula to obtain the final real-time projection image:

[0074]

[0075] Wherein, I is the final real-time projection image, as shown in i B i is the real-time beam spot image, A Figure 2 is the real-time imaging image, and A'0 and B'0 are the X-ray beam spot centers.

[0076] Step S4, according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, the laser target angle of the laser plasma accelerator and the position of the X-ray source are adjusted.

[0077] Specifically, it includes:

[0078] An X-ray source is disposed between the laser plasma accelerator and the X-ray bright field calibration detector, and an electric optical frame is disposed in the laser plasma accelerator.

[0079] S4.1, Adjust the laser target angle of the motorized optical frame to adjust the laser target angle of the laser plasma accelerator; determine the angle adjustment amount of the motorized optical frame according to the following formula:

[0080]

[0081] S4.2, determine the positional translation of the X-ray source according to the following formula:

[0082]

[0083] Among them, such as Figure 3 As shown, δx and δy are the coordinate differences between the real-time X-ray beam spot center and the initial X-ray beam spot center, l is the distance between the motorized optical frame and the X-ray source, and L is the distance between the X-ray source and the X-ray bright field calibration detector.

[0084] Repeat steps S2-S4 until the imaging application ends.

[0085] In imaging applications, it is necessary to acquire multiple projection images of the imaging sample from multiple angles (for example, in CT imaging, projection data at different angles needs to be obtained by rotating the sample to complete three-dimensional reconstruction).

[0086] Therefore, in order to track the dynamic changes of the beam spot in real time: such as Figure 4 As shown, each time a projected image is acquired (S2), the offset of the beam spot center is remeasured (S3), the brightness field correction parameters are updated (S3), and the transmission direction is compensated (S4). This ensures that each acquisition of a projected image is corrected based on the actual state of the current beam spot, thereby continuously ensuring the accuracy of the brightness field correction. Ultimately, this solves the imaging error problem caused by the dynamic changes of the beam spot and meets the accuracy requirements of imaging applications for multi-frame and multi-angle projection data.

[0087] This application also provides an apparatus for image brightness field correction in laser plasma accelerators.

[0088] like Figure 5 As shown, the apparatus for image brightness field correction in a laser plasma accelerator includes: an X-ray source, an X-ray brightness field calibration detector, an X-ray imaging detector, and a host computer (not shown in the figure). The imaging sample is positioned between the X-ray brightness field calibration detector and the X-ray imaging detector. The imaging sample is not specifically limited in its type.

[0089] The X-ray source is driven by a laser plasma accelerator, which generates a cone-beam X-ray pulse with a spatial intensity distribution.

[0090] There are no special restrictions on the type of X-ray source, including Betatron ray sources driven by laser-plasma accelerators, inverse Compton scattering sources driven by laser-plasma accelerators, and bremsstrahlung sources driven by laser-plasma accelerators.

[0091] The X-ray bright-field calibration detector is positioned between the X-ray source and the imaging sample to record the X-ray beam spot in real time. When the imaging sample is not moved in, it is used to acquire dark-field and initial X-ray beam spot images; when the imaging sample is moved in, it is used to acquire real-time unprocessed X-ray beam spot images. The detection plane of the X-ray bright-field calibration detector should be as parallel as possible to the plane of the X-ray imaging detector and perpendicular to the X-ray transmission direction.

[0092] X-ray bright field calibration detectors include two types (such as...). Figure 6 (As shown): Scintillation screen X-ray detectors based on scintillation screens, optical imaging systems, and optical detectors (e.g., CCD, CMOS cameras); information recording X-ray detectors such as film or imaging plates (IP). To avoid the influence of the X-ray bright-field calibration detector on the X-ray spectrum, X-ray flux, and imaging resolution, the thickness of the photosensitive material (scintillation screen, film, or imaging plate) used in the X-ray bright-field calibration detector should be as thin as possible, provided that the signal-to-noise ratio of the signal acquired by the X-ray bright-field calibration detector is sufficient. Furthermore, to ensure the consistency of the X-ray signal response between the X-ray bright-field calibration detector and the X-ray imaging detector, it is recommended that the X-ray photosensitive material used in both detectors be the same. The X-ray cone region measured by the X-ray bright-field calibration detector should include the portion of the X-ray cone occupied by the imaging region.

[0093] The X-ray imaging detector is positioned behind the imaging sample to acquire dark field and initial X-ray beam spot images when the imaging sample is not moved in, and to acquire real-time unprocessed projection images when the imaging sample is moved in.

[0094] Because the installation angle of the detection plane of the X-ray bright-field calibration detector cannot guarantee absolute parallelism with the X-ray imaging detector, and because the optical imaging system of a scintillator-type X-ray detector suffers from field-of-view distortion, the X-ray bright-field calibration detector and the X-ray imaging detector should be geometrically calibrated in their field-of-view planes before imaging applications. This can be achieved using a commonly used method in optical systems—the Zhang Zhengyou calibration method—to establish the geometrical spatial mapping between the two. This application uses this as an example only, but is not limited to it.

[0095] The host computer is configured to calibrate the dark field and the initial X-ray beam spot image of the detector and the X-ray imaging detector according to the X-ray bright field, obtain the coordinates of the initial X-ray beam spot center, and is further configured to calibrate the dark field, the real-time unprocessed X-ray beam spot image and the real-time unprocessed projection image of the detector and the X-ray imaging detector according to the X-ray bright field, obtain the real-time beam spot image and the real-time imaging image, and is further configured to obtain the coordinates of the real-time X-ray beam spot center according to the real-time beam spot image, and obtain the X-ray beam spot center after coordinate translation transformation according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, and is further configured to perform image bright field correction according to the real-time beam spot image, the real-time imaging image and the X-ray beam spot center, to obtain the final real-time projection image.

[0096] The host computer is configured to perform the method for image bright field correction of the laser plasma accelerator as described above, and thus will not be described here in detail.

[0097] The device for image bright field correction of the laser plasma accelerator further comprises an electrically driven optical mirror frame, as shown in Figure 3 The electrically driven optical mirror frame is arranged in the laser plasma accelerator and is used to adjust the laser target angle in real time, thereby indirectly controlling the direction of the X-ray beam spot.

[0098] The host computer is further configured to adjust the laser target angle of the electrically driven optical mirror frame according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, so as to adjust the laser target angle of the laser plasma accelerator.

[0099] The host computer is further configured to adjust the position of the X-ray source according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center.

[0100] The method and device for image bright field correction of the laser plasma accelerator provided by the present application realize dynamic tracking and correction of beam spot jitter and slow changes by measuring the X-ray beam spot in real time and combining geometric space mapping and coordinate transformation, solve the problem that the traditional pre-acquired bright field cannot adapt to real-time changes of the beam spot, significantly improve the accuracy of bright field correction, effectively reduce the reconstruction error in CT imaging, improve the measurement accuracy of the sample attenuation coefficient, and expand the application prospect of the laser plasma accelerator driven X-ray source in the imaging field.

[0101] The present application will be further described below in combination with specific embodiments.

[0102] In the embodiment, the method is applied to an imaging experiment based on a laser plasma accelerator driven inverse Compton scattering X-ray source (projection imaging on a double-wire image quality meter). The driving main laser beam pulse used in the experiment has a pulse energy of 0.3 joules, a pulse width of 22 femtoseconds, and a focal point diameter of 12 microns (full width at half maximum); the counter-collision laser beam pulse has a pulse energy of 0.13 joules, a pulse width of 200 femtoseconds, and a focal point diameter of 7 microns (full width at half maximum). The plasma source is generated by a de Laval supersonic nozzle with an outlet diameter of 2 mm. The X-ray bright field calibration detector uses an imaging plate, and the X-ray detector uses a flat panel detector.

[0103] The experimental results are shown in Figure 7 The image bright field uniformity is significantly improved after correction by the method, and the detail definition is obviously improved, proving the effectiveness of the method.

[0104] Figure 8 A structural diagram of an electronic device provided by the application is shown.

[0105] Referring to Figure 8 , Figure 8 An electronic device is provided, including a processor and a memory. The memory stores computer instructions, and when the computer instructions are executed by the processor, the processor executes the computer instructions to implement the method shown in Figures 1-5 and the detailed solutions.

[0106] It should be understood that the above-mentioned device embodiments are only illustrative, and the device disclosed by the application can also be implemented in other ways. For example, the division of units / modules in the above-mentioned embodiments is only a logical functional division, and another division mode can be used in actual implementation. For example, multiple units, modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0107] In addition, unless specifically stated, each functional unit / module in each embodiment of the application can be integrated in one unit / module, or each unit / module can exist physically, or two or more units / modules can be integrated together. The integrated unit / module can be realized in the form of hardware or in the form of a software program module.

[0108] If the integrated units / modules are implemented in the form of hardware, the hardware can be a digital circuit, an analog circuit, etc. The physical implementation of the hardware structure includes, but is not limited to, a transistor, a memristor, etc. Unless otherwise specified, the processor or chip can be any appropriate hardware processor, such as a CPU, a GPU, an FPGA, a DSP, an ASIC, etc. Unless otherwise specified, the on-chip cache, the off-chip memory, the storage can be any appropriate magnetic storage medium or magneto-optical storage medium, such as a resistive random access memory (RRAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), an enhanced dynamic random access memory (EDRAM), a high-bandwidth memory (HBM), a hybrid memory cube (HMC), etc.

[0109] If the integrated units / modules are implemented in the form of software program modules and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method of the embodiments of the present disclosure. The aforementioned storage medium includes a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0110] The embodiments of the present application also provide a non-transitory computer storage medium storing a computer program, which, when executed by a plurality of processors, causes the processors to perform the method and detailed solutions as shown in Figures 1-5 .

[0111] It should be clearly understood that the present application describes how to form and use specific examples, but the present application is not limited to any details of these examples. On the contrary, based on the teachings of the disclosure, these principles can be applied to many other embodiments.

[0112] Furthermore, it is noted that the aforementioned figures are only schematic representations of processes included in the method according to the exemplary embodiments of the present application, and are not intended to limit the present application. It is readily appreciated that the processes depicted in the aforementioned figures do not necessarily indicate or imply the timing of the processes. Additionally, it is readily appreciated that the processes can be executed in a synchronous or asynchronous manner, for example, in multiple modules.

[0113] The exemplary embodiments of the present application are specifically shown and described above. It is to be understood that the present application is not limited to the detailed construction, arrangements, or implementation methods described herein; on the contrary, the present application is intended to cover various modifications and equivalent arrangements included within the scope and spirit of the appended claims.

Claims

1. A method for image-brightness correction of a laser-plasma accelerator, characterized in that, The method comprises: obtaining dark field and initial X-ray beam spot images of an X-ray bright field calibration detector and an X-ray imaging detector to obtain coordinates of an initial X-ray beam spot center; in the case of sample movement into imaging, obtaining a real-time unprocessed X-ray beam spot image obtained by the X-ray bright field calibration detector and a real-time unprocessed projection image obtained by the X-ray imaging detector, obtaining a real-time beam spot image and a real-time imaging image according to the dark fields of the X-ray bright field calibration detector and the X-ray imaging detector, the real-time unprocessed X-ray beam spot image and the real-time unprocessed projection image, and obtaining coordinates of a real-time X-ray beam spot center according to the real-time beam spot image; obtaining an X-ray beam spot center after coordinate translation according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, and performing image bright field correction according to the real-time beam spot image, the real-time imaging image and the X-ray beam spot center to obtain a final real-time projection image.

2. The method of claim 1, wherein, The method comprises: mapping the dark field and the initial X-ray beam spot image of the X-ray bright field calibration detector to a field of view plane of the X-ray imaging detector to obtain a first dark field and a first X-ray beam spot image; obtaining a first initial beam spot image according to the first dark field and the first X-ray beam spot image of the X-ray bright field calibration detector; obtaining a second initial beam spot image according to the dark field and the initial X-ray beam spot image of the X-ray imaging detector; fitting the first initial beam spot image or the second initial beam spot image to obtain the horizontal coordinate and the vertical coordinate of the initial X-ray beam spot center.

3. The method of claim 2, wherein, The method comprises: mapping the real-time unprocessed X-ray beam spot image of the X-ray bright field calibration detector to a field of view plane of the X-ray imaging detector to obtain a third X-ray beam spot image; obtaining the real-time beam spot image according to the third X-ray beam spot image and the first dark field; obtaining the real-time imaging image according to the real-time unprocessed projection image and the dark field of the X-ray imaging detector; fitting the real-time beam spot image to obtain the horizontal coordinate and the vertical coordinate of the real-time X-ray beam spot center.

4. The method of claim 3, wherein, The X-ray beam spot center after the coordinate translation transformation is obtained according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, and image bright field correction is performed according to the real-time beam spot image, the real-time imaging image and the X-ray beam spot center, to obtain a final real-time projection image, including: The coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center is obtained according to the horizontal and vertical coordinates of the initial X-ray beam spot center and the horizontal and vertical coordinates of the real-time X-ray beam spot center; The first initial beam spot image and the second initial beam spot image are subjected to coordinate translation transformation according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, to obtain the final X-ray beam spot center; Image bright field correction is performed according to the real-time beam spot image, the real-time imaging image and the final X-ray beam spot center, according to the following formula, to obtain a final real-time projection image: where I is the final real-time projection image, A i is the real-time imaging image, B i is the real-time beam spot image, A'0, B'0are the final X-ray beam spot centers.

5. The method of claim 1, wherein, An X-ray source is arranged between the laser plasma accelerator and the X-ray bright field calibration detector, for generating an X-ray pulse under the driving of the laser plasma accelerator, and the method further includes: According to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, the laser target angle of the laser plasma accelerator and the position of the X-ray source are adjusted.

6. The method of claim 5, wherein, An electric optical mirror frame is arranged in the laser plasma accelerator, and the adjustment of the laser target angle of the laser plasma accelerator and the position of the X-ray source according to the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center includes: The laser target angle of the electric optical mirror frame is adjusted to adjust the laser target angle of the laser plasma accelerator; The angle adjustment amount of the electric optical mirror frame is determined according to the following formula: The position translation amount of the X-ray source is determined according to the following formula: wherein δ x , δ y is the coordinate difference between the real-time X-ray beam spot center and the initial X-ray beam spot center, l is the distance between the motorized optical bench and the X-ray source, and L is the distance between the X-ray source and the X-ray bright-field calibration detector.

7. An apparatus for image-brightness correction of a laser-plasma accelerator, characterized in that, The device includes: An X-ray source driven by the laser plasma accelerator to generate an X-ray pulse; An X-ray bright field calibration detector arranged between the X-ray source and an imaging sample, for collecting a dark field and an initial X-ray beam spot image when the imaging sample is not moved in, and collecting a real-time unprocessed X-ray beam spot image when the imaging sample is moved in; An X-ray imaging detector arranged behind the imaging sample, for collecting a dark field and an initial X-ray beam spot image when the imaging sample is not moved in, and collecting a real-time unprocessed projection image when the imaging sample is moved in; A host computer configured to perform the method of any of claims 1-6, to calibrate a dark field of a detector and an initial X-ray beam spot image of an X-ray imaging detector based on the X-ray bright field, to obtain coordinates of an initial X-ray beam spot center, to calibrate the dark field of the detector and the X-ray imaging detector based on the X-ray bright field, the real-time unprocessed X-ray beam spot image and the real-time unprocessed projection image, to obtain a real-time beam spot image and a real-time imaging image, to obtain coordinates of a real-time X-ray beam spot center based on the real-time beam spot image, and to obtain a coordinate-translated X-ray beam spot center based on a difference between the coordinates of the real-time X-ray beam spot center and the initial X-ray beam spot center, and to perform image bright field correction based on the real-time beam spot image, the real-time imaging image and the X-ray beam spot center to obtain a final real-time projection image.

8. The apparatus of claim 7, wherein, Further comprising: An electro-optical mount disposed in the laser plasma accelerator; wherein the host computer is further configured to adjust a laser targeting angle of the electro-optical mount based on a difference between the coordinates of the real-time X-ray beam spot center and the initial X-ray beam spot center to adjust a laser targeting angle of the laser plasma accelerator, and to adjust a position of the X-ray source.

9. An electronic device, comprising: Further comprising: one or more processors; a memory configured to store one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors perform the method of any of claims 1-6.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program, when executed by a processor, performs the method of any of claims 1-6.

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