Neutron optical collimator measurement method and device

Abstract

According to the neutron optical collimator measurement method and device provided by the invention, the laser beam penetrates through the diaphragm and is imaged on the receiving plate, and the angle is indirectly calculated by analyzing the projection geometrical relationship, so that the physical limitation of direct contact measurement is overcome, the deformation or damage risk of the flexible diaphragm caused by contact measurement is avoided, and the measurement accuracy is improved. And the precision characteristic requirement is met. A laser beam can extend into a narrow space in the collimator to measure small-angle / small-spacing diaphragm parameters, the interference of the characteristics of a flexible material is avoided, and the measurement result is more stable and reliable. Angle measurement can be converted into image processing and geometric calculation problems by utilizing accurate laser beams and the known distance from the laser to the receiving plate and combining projected image analysis, and high precision can be achieved.

Description

Technical Field

[0001] The present application relates to the technical field of neutron optical collimators, and in particular to a neutron optical collimator measurement method and device. Background Art

[0002] Neutron optical collimators are key optical components in neutron scattering spectrometers, primarily used to constrain the direction of the neutron beam, control divergence, improve resolution, and define the canonical volume of neutron diffraction. Neutron collimators use narrow slit channels formed by absorbent material to select neutron beams with nearly parallel directions, shield diverging or scattered neutrons, and ensure the collimation of the neutron beam. The extended slits of a radial collimator converge at a single point (the focal point), restricting the neutron beam to specific angles. Neutron collimators consist of thin, fan-shaped plates, subsequently referred to as diaphragms.

[0003] The small angle and spacing between the diaphragms of a neutron optical fine collimator, the confined space (narrow field of view), and the high precision of the flexible diaphragm (1 / 1000 degree or micron level) present significant measurement challenges. Due to the flexible material and precise properties of the diaphragms, direct contact measurement is not possible. Therefore, indirect measurement methods are required to obtain relevant characteristic parameters and then convert and calculate the angle value. However, traditional measurement methods such as scanning are susceptible to interference from material properties and on-site environmental factors, making it difficult to fully obtain information about the surface of the object being measured, resulting in low measurement efficiency and large errors. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a neutron optical collimator measurement method and device to solve the problems of low measurement efficiency and large measurement errors in existing measurement solutions for neutron optical collimators.

[0005] In an embodiment of the present application, a neutron optical collimator measurement method is provided. The collimator to be measured is arranged on a turntable. A first laser is located on the central axis of the turntable and is located inside the collimator to be measured. A receiving plate is arranged outside the collimator to be measured. The method comprises: When the turntable is at an initial rotation angle and an initial height, the laser beam emitted by the first laser irradiates the inner side of the collimator to be measured, passes through the diaphragm of the collimator to be measured, and reaches the receiving plate; Acquire a projection image of the receiving plate plane, and obtain a diaphragm projection geometric relationship based on the distance between the first laser and the receiving plate; According to the geometric relationship of the diaphragm projection, the diaphragm angle between two adjacent diaphragms of the collimator to be measured is obtained.

[0006] In this technical solution, a laser beam penetrates the diaphragm and forms an image on a receiving plate. The angle is then indirectly calculated by analyzing the projected geometry. This overcomes the physical limitations of direct contact measurement and avoids the risk of deformation or damage to the flexible diaphragm caused by contact measurement, thus meeting the requirements for its precision characteristics. The laser beam can penetrate the narrow space within the collimator to measure diaphragm parameters at small angles and small pitches, unaffected by the inherent properties of the flexible material, resulting in more stable and reliable measurement results. By utilizing a precise laser beam and the known distance from the laser to the receiving plate, combined with analysis of the projected image, angle measurement can be transformed into an image processing and geometric calculation problem, achieving high accuracy.

[0007] In some optional embodiments, obtaining the diaphragm angle between two adjacent diaphragms of the collimator to be measured according to the diaphragm projection geometric relationship includes: If the projection width of the central diaphragm in the projected image is less than the set threshold, the central diaphragm is parallel to the laser beam. In this case, the diaphragm angle is obtained using a unilateral recognition method. If the projection width of the central diaphragm in the projected image is greater than or equal to the set threshold, the central diaphragm is not parallel to the laser beam. In this case, the diaphragm angle is obtained using a bilateral recognition method.

[0008] In the above technical solution, the central diaphragm's projected width is used to determine its parallelism, automatically selecting the optimal algorithm. When the central diaphragm is determined to be parallel to the laser beam, its projected width is small (less than a set threshold), and unilateral recognition is employed. Unilateral recognition typically only requires analyzing information on one edge of the projected image, resulting in a significantly lower algorithmic complexity than bilateral recognition. When the central diaphragm is not parallel to the laser beam, its projected width is greater than or equal to the set threshold. Bilateral recognition simultaneously analyzes both edges, accurately capturing the offset caused by tilt and ensuring accurate calculations even in tilted conditions.

[0009] The central diaphragm of the projected image is determined by extracting the width information of each diaphragm in the projected image, drawing a diaphragm width curve based on the width information of each diaphragm, finding the diaphragm with the smallest width in the diaphragm width curve, and taking the diaphragm with the smallest width as the central diaphragm.

[0010] In some optional embodiments, obtaining the diaphragm angle by using a unilateral recognition method includes: According to the length of the central diaphragm along the beam direction and the interval difference between the adjacent diaphragms in the inner and outer sectors, the diaphragm angle is obtained: ; Where L is the length of the central diaphragm along the beam direction, and D is the spacing difference between adjacent diaphragms in the inner and outer sectors; ; is the inner sector distance between adjacent diaphragms, is the outer sector distance between adjacent diaphragms. Adjacent diaphragms are the adjacent diaphragms on both sides of the central diaphragm.

[0011] In the above technical solution, under ideal conditions, that is, when the laser beam is parallel to the central diaphragm, the diaphragm angle can be measured and accurately obtained by single-side identification. A diaphragm group is composed of a certain diaphragm and two adjacent diaphragms on the left and right. The length of the central diaphragm along the beam direction is , the interval difference between adjacent diaphragms in the inner and outer sectors is , the diaphragm angle between the central diaphragm and the adjacent diaphragm ; Obtain the inner sector diaphragm distance through the projection image , outer sector diaphragm distance , where the difference between the inner and outer intervals is .

[0012] In some optional embodiments, obtaining the diaphragm angle by using a bilateral recognition method includes: According to the interval difference between the inner and outer sectors of adjacent membranes and the radial effective length of the neutron absorption coating of adjacent membranes, the membrane angle is obtained: ; in, is the radial effective length of the neutron absorption coating on the central membrane, is the radial effective length of the neutron absorbing coating of adjacent membranes, and D is the interval difference between adjacent membranes in the inner sector and the outer sector; ; is the outer sector distance of the diaphragms on both sides, is the inner sector distance of the diaphragms on both sides; the total thickness of the diaphragm is ; The thickness of the diaphragm base is The thickness of the double-sided neutron absorption coating is .

[0013] In the above technical solution, the bilateral identification method is to solve the angle between the central diaphragm and an adjacent diaphragm based on the projection of the central diaphragm and the left and right diaphragms. The length of the central diaphragm along the beam direction is The difference in spacing between the central diaphragm and an adjacent diaphragm in the inner and outer sectors is , the radial effective length of the neutron absorption coating on the central membrane is The radial effective length of the neutron absorbing coating of the adjacent membrane is , the thickness of the membrane base of the adjacent membrane is The thickness of the neutron absorption coating on both sides of adjacent membranes is , then the total thickness of the diaphragm is , the pixel values ​​of the inner and outer projection images of adjacent diaphragms are , the camera calibration value is , the outer sector distance of the diaphragms on both sides of the central diaphragm is , the fan-shaped distance between the two sides of the diaphragm is , then the spacing difference between adjacent diaphragms in the inner and outer sectors is , the diaphragm angle can be calculated as: .

[0014] In some optional embodiments, the collimator to be measured rotates with the turntable, and the first laser does not rotate with the turntable; After obtaining the diaphragm angle between two adjacent diaphragms of the collimator to be measured according to the diaphragm projection geometric relationship, the method further includes: The turntable rotates to a set angle to measure the next diaphragm angle, and the process is repeated until the diaphragm angles between all two adjacent diaphragms are measured.

[0015] The set angle is usually the angle between adjacent diaphragms of a standard collimator.

[0016] In the above technical solution, by rotating the turntable, the system is upgraded from precise single-point measurement to fully automatic high-precision collimator performance analysis, which greatly improves detection efficiency, reduces labor costs and environmental requirements, and provides indispensable comprehensive data support for ensuring the ultimate performance of the neutron optical collimator and conducting strict quality control.

[0017] In some optional embodiments, after measuring the angles between all two adjacent membranes, the method further includes: The angle correction value is obtained according to the diaphragm angle between all two adjacent diaphragms at the initial height.

[0018] In the above technical solution, multiple measurement images are captured during the rotation of the optical turntable. Based on the observation of the angle between adjacent diaphragm groups during the rotation of the optical turntable, a function model is established to describe the relationship between the observed values ​​and the theoretical values: According to the equal relationship between adjacent angle adjustment values ​​and correction numbers, and theoretical observation values ​​and observation errors, the calculation model is constructed as follows: ; in, is the number of diaphragm images, is the angle adjustment value, is the angle correction number, is the theoretical observation value, is the observation error, and n is the total number of diaphragms.

[0019] The difference between the observed value and the theoretical value is constructed based on the least squares adjustment method, and the error equation is constructed based on the relationship between the observation error and the parameter to be determined (angle correction): According to the observation error , the parameters to be sought are , is the coefficient matrix in the error equation, is a constant term, then the error equation is: ; Considering the geometric characteristics of angle closure, additional constraints are introduced: Since the angle is closed (the sum is ), convert the angle sum condition into matrix form, that is, ; Parameters to be requested , is the coefficient matrix (elements are order vector), is a constant term related to the sum of angles, which can be organized as: ; The error equation and additional constraints are combined into a comprehensive error equation: ; in is a submatrix of the coefficient matrix of this equation, It is a matrix in the adjustment calculation process, used to process additional constraints to ensure that the unknown parameters are accurately obtained under the conditions of satisfying the relationship between the observation value and the position parameter (error equation) and the additional constraints. The indirect adjustment method with conditions is used, and the least squares principle is used to minimize the sum of the squares of the observation errors under the conditions of satisfying the error equation and the additional constraints, so as to obtain the unknown parameters. (angle correction) value: , thus finally determining the angle adjustment value .

[0020] In some optional embodiments, the turntable can move up and down along the central axis of the turntable; After obtaining the angle correction value based on the diaphragm angles between all two adjacent diaphragms at the initial height, the method further includes: Adjust the height of the turntable, measure the diaphragm angles between all two adjacent diaphragms at different height positions of the collimator to be measured, and calculate the angle correction value; repeat this process until the diaphragm angles between all adjacent diaphragms at all preset height positions of the collimator to be measured are measured.

[0021] In the above technical solution, the angle measurement of the full height space of the collimator is achieved through Z-axis scanning.

[0022] An embodiment of the present application provides a neutron optical collimator measurement device, comprising a turntable, a first laser, a receiving plate, and a controller; the turntable is rotatable about a central axis of the turntable and can also move up and down along the central axis of the turntable; a collimator to be measured is disposed on the turntable, the first laser is located on the central axis of the turntable, and the first laser is located inside the collimator to be measured, and the receiving plate is disposed outside the collimator to be measured; the controller is connected to the receiving plate, the first laser, and the turntable; The controller is used to execute any one of the above-mentioned neutron optical collimator measurement methods.

[0023] In some optional embodiments, the method further comprises: a second laser and a third laser; The second laser and the third laser are respectively installed on both sides of the bottom of the collimator to be measured; the second laser and the third laser are used to locate the installation position of the collimator to be measured on the turntable.

[0024] In some optional embodiments, the receiving board includes a telecentric mirror and a CCD camera; and the first laser includes a double-telecentric mirror laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A schematic diagram of a neutron optical collimator measurement provided in an embodiment of the present application; Figure 2 A flowchart of the steps of a neutron optical collimator measurement method provided in an embodiment of the present application; Figure 3 A flowchart of the neutron optical collimator measurement process provided in an embodiment of the present application; Figure 4 Schematic diagram of the installation of the second laser and the third laser; Figure 5 A schematic diagram of the geometric relationship of the diaphragm projection when the central diaphragm provided in an embodiment of the present application is parallel to the laser beam; Figure 6 Schematic diagram of the geometric relationship of the diaphragm projection when the central diaphragm provided in an embodiment of the present application is not parallel to the laser beam. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0028] Please refer to Figure 1 , Figure 1 A schematic diagram of a neutron optical collimator measurement provided in an embodiment of the present application shows that the collimator to be measured is set on a turntable, the first laser is located on the central axis of the turntable, and the first laser is located inside the collimator to be measured, and a receiving plate is set outside the collimator to be measured; Please refer to Figure 2 , Figure 2 A flow chart of the steps of a neutron optical collimator measurement method provided in an embodiment of the present application, the measurement method includes: Step S1: When the turntable is at an initial rotation angle and an initial height, a laser beam emitted by a first laser irradiates the inner side of the collimator to be measured, passes through the diaphragm of the collimator to be measured, and reaches the receiving plate; Step S2, obtaining a projection image of the receiving plate plane, and obtaining a diaphragm projection geometric relationship based on the distance between the first laser and the receiving plate; The receiving plate includes a CCD camera that can capture the projection image of the laser beam emitted by the first laser after passing through the collimator to be measured and projected onto the plane of the receiving plate. The projection image includes the shadow area of ​​the diaphragm of the neutron optical collimator, thereby obtaining the projection width of the diaphragm. Based on the projection width of the diaphragm and the distance between the first laser and the receiving plate, the geometric relationship of the diaphragm projection on the horizontal plane can be obtained, for example Figure 5 、 Figure 6 shown.

[0029] Step S3: Obtain the diaphragm angle between two adjacent diaphragms of the collimator to be measured according to the diaphragm projection geometric relationship.

[0030] In an embodiment of the present application, a laser beam penetrates a diaphragm and forms an image on a receiving plate. The angle is then indirectly calculated by analyzing the projected geometric relationship. This overcomes the physical limitations of direct contact measurement, avoids the risk of deformation or damage to the flexible diaphragm caused by contact measurement, and meets the precision requirements. The laser beam can penetrate the narrow space inside the collimator to measure diaphragm parameters at small angles and small pitches, without being affected by the inherent properties of the flexible material, resulting in more stable and reliable measurement results. By utilizing a precise laser beam and the known distance from the laser to the receiving plate, combined with projected image analysis, angle measurement can be transformed into an image processing and geometric calculation problem, achieving high accuracy. Specifically, when performing angle measurement, the angle between the central diaphragm and the adjacent diaphragm is measured. The central diaphragm is the diaphragm with the smallest projected width in the projected image. If the central diaphragm is parallel to the laser beam, the angle between the central and adjacent diaphragms can be determined by unilateral identification based on the geometric relationship of one adjacent diaphragm. If the central diaphragm is not parallel to the laser beam, the angle between the central and adjacent diaphragms can be determined by bilateral identification based on the geometric relationship of the two adjacent diaphragms.

[0031] Please refer to Figure 3 , Figure 3 This is a flowchart of the neutron optical collimator measurement workflow provided in an embodiment of the present application.

[0032] In some optional embodiments, obtaining the diaphragm angle between two adjacent diaphragms of the collimator to be measured according to the diaphragm projection geometric relationship includes: If the projection width of the central diaphragm in the projected image is less than the set threshold, the central diaphragm is parallel to the laser beam. In this case, the diaphragm angle is obtained using the unilateral recognition method. If the projection width of the central diaphragm in the projected image is greater than or equal to the set threshold, the central diaphragm is not parallel to the laser beam. In this case, the diaphragm angle is obtained using the bilateral recognition method.

[0033] In this embodiment, the central diaphragm's projected width is used to determine the diaphragm's parallelism, automatically selecting the optimal algorithm. When the central diaphragm is determined to be parallel to the laser beam, its projected width is small (less than a set threshold), and unilateral recognition is employed. Unilateral recognition typically only requires analyzing information on one edge of the projected image, resulting in significantly lower algorithmic complexity than bilateral recognition. When the central diaphragm is nonparallel to the laser beam, its projected width is greater than or equal to the set threshold. Bilateral recognition simultaneously analyzes both edges, accurately capturing the offset caused by tilt and ensuring accurate calculations under tilt conditions.

[0034] The central diaphragm of the projected image is determined by extracting the width information of each diaphragm in the projected image, drawing a diaphragm width curve based on the width information of each diaphragm, finding the diaphragm with the smallest width in the diaphragm width curve, and taking the diaphragm with the smallest width as the central diaphragm.

[0035] Please refer to Figure 5 , Figure 5 Schematic diagram of the geometric relationship of the diaphragm projection when the central diaphragm provided in an embodiment of the present application is parallel to the laser beam.

[0036] In some optional embodiments, the diaphragm angle is obtained by using a unilateral recognition method, including: According to the length of the central diaphragm along the beam direction and the interval difference between the adjacent diaphragms in the inner and outer sectors, the diaphragm angle is obtained: ; Where L is the length of the central diaphragm along the beam direction, and D is the spacing difference between adjacent diaphragms in the inner and outer sectors; ; is the inner sector distance between adjacent diaphragms, is the outer sector distance between adjacent diaphragms. Adjacent diaphragms are the diaphragms on both sides of the central diaphragm.

[0037] In the embodiment of the present application, under ideal conditions, that is, when the laser beam is parallel to the central diaphragm, the diaphragm angle can be measured and accurately obtained by single-side identification. A diaphragm group is composed of a certain diaphragm and two adjacent diaphragms on the left and right. The length of the central diaphragm along the beam direction is , the interval difference between adjacent diaphragms in the inner and outer sectors is , the diaphragm angle between the central diaphragm and the adjacent diaphragm ; Obtain the inner sector diaphragm distance through the projection image , outer sector diaphragm distance , where the difference between the inner and outer intervals is .

[0038] Please refer to Figure 6 , Figure 6 Schematic diagram of the geometric relationship of the diaphragm projection when the central diaphragm provided in an embodiment of the present application is not parallel to the laser beam.

[0039] In some optional embodiments, the diaphragm angle is obtained using a bilateral recognition method, including: According to the interval difference between the inner and outer sectors of adjacent membranes and the radial effective length of the neutron absorption coating of adjacent membranes, the membrane angle is obtained: ; in, is the radial effective length of the neutron absorption coating on the central membrane, is the radial effective length of the neutron absorbing coating of adjacent membranes, and D is the interval difference between adjacent membranes in the inner sector and the outer sector; ; is the outer sector distance of the diaphragms on both sides, is the inner sector distance of the diaphragms on both sides; the total thickness of the diaphragm is ; The thickness of the diaphragm base is The thickness of the double-sided neutron absorption coating is .

[0040] In the embodiment of the present application, the bilateral identification method is to solve the angle between the central diaphragm and an adjacent diaphragm based on the projection of the central diaphragm and the left and right diaphragms. The length of the central diaphragm along the beam direction is The difference in spacing between the central diaphragm and an adjacent diaphragm in the inner and outer sectors is , the radial effective length of the neutron absorption coating on the central membrane is The radial effective length of the neutron absorbing coating of the adjacent membrane is , the thickness of the membrane base of the adjacent membrane is The thickness of the neutron absorption coating on both sides of adjacent membranes is , then the total thickness of the diaphragm is , the pixel values ​​of the inner and outer projection images of adjacent diaphragms are , the camera calibration value is , the outer sector distance of the diaphragms on both sides of the central diaphragm is , the fan-shaped distance between the two sides of the diaphragm is , then the spacing difference between adjacent diaphragms in the inner and outer sectors is , the diaphragm angle can be calculated as: .

[0041] In some optional embodiments, the collimator to be measured rotates with the turntable, and the first laser does not rotate with the turntable; After obtaining the diaphragm angle between two adjacent diaphragms of the collimator to be measured according to the diaphragm projection geometric relationship, the method further includes: The turntable rotates to the set angle, measures the next diaphragm angle, and repeats the process until the diaphragm angles between all two adjacent diaphragms are measured.

[0042] The set angle is usually the angle between adjacent diaphragms of a standard collimator, which is 0.1°-2°, for example, 1.5°.

[0043] In the embodiment of the present application, by rotating the turntable, the precision single-point measurement is upgraded to fully automatic high-precision collimator performance analysis, which greatly improves the detection efficiency, reduces labor costs and environmental requirements, and provides indispensable comprehensive data support for ensuring the final performance of the neutron optical collimator and conducting strict quality control.

[0044] In some optional embodiments, after measuring the angles between all two adjacent membranes, the method further includes: The angle correction value is obtained according to the diaphragm angle between all two adjacent diaphragms at the initial height.

[0045] In the embodiment of the present application, multiple measurement images are captured during the rotation of the optical turntable. Based on the observation of the angle between adjacent diaphragm groups during the rotation of the optical turntable, a function model is established to describe the relationship between the observed value and the theoretical value: According to the equal relationship between adjacent angle adjustment values ​​and correction numbers, and theoretical observation values ​​and observation errors, the calculation model is constructed as follows: ; in, is the number of diaphragm images, is the angle adjustment value, is the angle correction number, is the theoretical observation value, is the observation error, and n is the total number of diaphragms.

[0046] The difference between the observed value and the theoretical value is constructed based on the least squares adjustment method, and the error equation is constructed based on the relationship between the observation error and the parameter to be determined (angle correction): According to the observation error , the parameters to be sought are , is the coefficient matrix in the error equation, is a constant term, then the error equation is: ; Considering the geometric characteristics of angle closure, additional constraints are introduced: Since the angle is closed (the sum is ), convert the angle sum condition into matrix form, that is, ; Parameters to be requested , is the coefficient matrix (elements are order vector), is a constant term related to the sum of angles, which can be organized as: ; The error equation and additional constraints are combined into a comprehensive error equation: ; in is a submatrix of the coefficient matrix of this equation, It is a matrix in the adjustment calculation process, used to process additional constraints to ensure that the unknown parameters are accurately obtained under the conditions of satisfying the relationship between the observation value and the position parameter (error equation) and the additional constraints. The indirect adjustment method with conditions is used, and the least squares principle is used to minimize the sum of the squares of the observation errors under the conditions of satisfying the error equation and the additional constraints, so as to obtain the unknown parameters. (angle correction) value: , thus finally determining the angle adjustment value .

[0047] In some optional embodiments, the turntable can move up and down along the central axis of the turntable; After obtaining the angle correction value based on the diaphragm angle between all two adjacent diaphragms at the initial height, it also includes: Adjust the height of the turntable, measure the diaphragm angles between all two adjacent diaphragms at different heights of the collimator to be measured, and calculate the angle correction value; repeat this process until the diaphragm angles between all adjacent diaphragms at all preset heights of the collimator to be measured are measured.

[0048] The height of the diaphragm is generally 100 mm to 1900 mm, for example 724 mm. In this embodiment, when adjusting the height of the turntable, 1% of the diaphragm height may be used as the adjustment step value.

[0049] In the embodiment of the present application, the angle measurement of the full height space of the collimator is achieved through Z-axis scanning.

[0050] An embodiment of the present application provides a neutron optical collimator measurement device, comprising a turntable, a first laser, a receiving board, and a controller; the turntable can rotate about a central axis of the turntable and can also move up and down along the central axis of the turntable; a collimator to be measured is disposed on the turntable, the first laser is located on the central axis of the turntable, and the first laser is located inside the collimator to be measured, and a receiving board is disposed outside the collimator to be measured; the controller is connected to the receiving board, the first laser, and the turntable; The controller is configured to execute any one of the above neutron optical collimator measurement methods.

[0051] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the installation of the second laser and the third laser.

[0052] In some optional embodiments, the method further comprises: a second laser and a third laser; The second laser and the third laser are respectively installed on both sides of the bottom of the collimator to be measured; the second laser and the third laser are used to locate the installation position of the collimator to be measured on the turntable.

[0053] Specifically, the second laser and the third laser are usually installed on both sides of the bottom of the collimator to be measured, and the second laser and the third laser are respectively parallel to the two outermost diaphragms of the collimator to be measured. If the laser points irradiated by the second laser and the third laser are located within the calibrated circular area, it is considered that the collimator to be measured is installed in the specified position; if the laser points irradiated by the second laser and the third laser are beyond the calibrated circular area, it is considered that the collimator to be measured is not installed in the specified position.

[0054] In some optional embodiments, the receiving board includes a telecentric mirror and a CCD camera; and the first laser includes a double-telecentric mirror laser.

[0055] A telecentric lens is a specially designed optical lens whose core characteristic is that the principal ray (optical axis) is parallel to the imaging plane, thereby eliminating the perspective distortion (the effect of near objects appearing larger and farther away) caused by variations in object distance in traditional lenses. This characteristic is achieved by placing an aperture stop (the aperture stop is located on the focal plane) within the lens. A CCD camera is an image sensor based on a charge-coupled device (CCD). The CCD converts light signals into electrical charges through the photoelectric effect. Internal circuitry then transfers these charges line by line and outputs them as digital signals, ultimately forming an image.

[0056] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0057] In addition, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0058] Furthermore, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0059] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0060] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A neutron optical collimator measurement method, characterized in that: The collimator to be measured is arranged on a turntable, the first laser is located on the central axis of the turntable, and the first laser is located inside the collimator to be measured, and a receiving plate is arranged outside the collimator to be measured; The method comprises: When the turntable is at an initial rotation angle and an initial height, the laser beam emitted by the first laser irradiates the inner side of the collimator to be measured, passes through the diaphragm of the collimator to be measured, and reaches the receiving plate; Acquire a projection image of the receiving plate plane, and obtain a diaphragm projection geometric relationship based on the distance between the first laser and the receiving plate; According to the geometric relationship of the diaphragm projection, the diaphragm angle between two adjacent diaphragms of the collimator to be measured is obtained.

2. The method according to claim 1, wherein The step of obtaining the diaphragm angle between two adjacent diaphragms of the collimator to be measured according to the diaphragm projection geometric relationship includes: If the projection width of the central diaphragm in the projected image is less than a set threshold, the diaphragm angle is obtained using a unilateral recognition method; If the projection width of the central diaphragm in the projection image is greater than or equal to a set threshold, the diaphragm angle is obtained by using a bilateral recognition method.

3. The method according to claim 2, wherein The method of obtaining the diaphragm angle by using a unilateral recognition method includes: According to the length of the central diaphragm along the beam direction and the interval difference between the adjacent diaphragms in the inner and outer sectors, the diaphragm angle is obtained: ； Where L is the length of the central diaphragm along the beam direction, and D is the spacing difference between adjacent diaphragms in the inner and outer sectors; ; is the inner sector distance between adjacent diaphragms, is the outer sector distance between adjacent diaphragms.

4. The method according to claim 2, wherein The method of obtaining the diaphragm angle by using a bilateral recognition method includes: According to the interval difference between the inner and outer sectors of adjacent membranes and the radial effective length of the neutron absorption coating of adjacent membranes, the membrane angle is obtained: ； in, is the radial effective length of the neutron absorption coating on the central membrane, is the radial effective length of the neutron absorbing coating of adjacent membranes, and D is the interval difference between adjacent membranes in the inner sector and the outer sector; ; is the outer sector distance of the diaphragms on both sides, is the inner sector distance of the diaphragms on both sides; the total thickness of the diaphragm is ; The thickness of the diaphragm base is The thickness of the double-sided neutron absorption coating is .

5. The method according to claim 1, wherein The collimator to be measured rotates with the turntable, and the first laser does not rotate with the turntable; After obtaining the diaphragm angle between two adjacent diaphragms of the collimator to be measured according to the diaphragm projection geometric relationship, the method further includes: The turntable rotates to a set angle to measure the next diaphragm angle, and the process is repeated until the diaphragm angles between all two adjacent diaphragms are measured.

6. The method according to claim 5, wherein After the measurement of the diaphragm angles between all two adjacent diaphragms is completed, the method further includes: The angle correction value is obtained according to the diaphragm angle between all two adjacent diaphragms at the initial height.

7. The method according to claim 6, wherein The turntable can move up and down along the central axis of the turntable; After obtaining the angle correction value based on the diaphragm angles between all two adjacent diaphragms at the initial height, the method further includes: Adjust the height of the turntable, measure the diaphragm angles between all two adjacent diaphragms at different height positions of the collimator to be measured, and calculate the angle correction value; repeat this process until the diaphragm angles between all adjacent diaphragms at all preset height positions of the collimator to be measured are measured.

8. A neutron optical collimator measuring device, characterized in that: The device comprises a turntable, a first laser, a receiving board, and a controller; the turntable can rotate around the central axis of the turntable and can also move up and down along the central axis of the turntable; the collimator to be measured is arranged on the turntable, the first laser is located on the central axis of the turntable, and the first laser is located inside the collimator to be measured, and the receiving board is arranged outside the collimator to be measured; the controller is connected to the receiving board, the first laser, and the turntable; The controller is used to execute the neutron optical collimator measurement method according to any one of claims 1 to 6.

9. The device according to claim 8, wherein Also includes: a second laser and a third laser; The second laser and the third laser are respectively installed on two sides of the bottom of the collimator to be measured; The second laser and the third laser are used to locate the installation position of the collimator to be measured on the turntable.

10. The device according to claim 8, wherein The receiving board includes a telecentric mirror and a CCD camera; the first laser includes a double-telecentric mirror laser.

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