Neutron conduit waviness measurement method

Abstract

The invention belongs to the field of neutron optical devices, and relates to a neutron conduit waviness measuring method. The method comprises the following steps: S1, defining a waviness parameter sigma as an index for measuring the flatness of a reflecting surface, and calculating through a specific formula; s2, a total station is used for being matched with an auto-collimation eyepiece, in an auto-collimation mode, light beams of the total station irradiate the reflection surface, the normal incidence state is determined, and the angle is recorded; s3, mounting the total station on a high-precision guide rail, sliding along the guide rail, repeating the step S2 at a plurality of positions at equal intervals, recording a current instrument angle, and transmitting the current instrument angle to a computer; s4, processing the data by using a spreadsheet template, and calculating waviness according to the geometrical shape; and S5, evaluating the waviness value and the normal accuracy of the side wall of the multi-section conduit, and analyzing the influence of the waviness value and the normal accuracy on neutron reflection. The neutron reflection quality and the multi-section guide rail butt joint integration quality can be evaluated more accurately, the method is suitable for guide pipes in various geometrical shapes, design and manufacturing can be guided, the production efficiency can be improved, and support is provided for device improvement.

Description

Technical Field

[0001] The invention belongs to the field of neutron optical devices, and in particular to a method for measuring the waviness of a neutron catheter. Background Art

[0002] In neutron optical devices, such as neutron guides, the incident angles at which neutrons are reflected are extremely small, typically between 0.1° and 1°. Therefore, the flatness of the mirror or substrate must be extremely high. However, deviations from the ideal flatness can alter reflection conditions, leading to neutron loss and reduced neutron flux.

[0003] Although existing methods exist for measuring corrugation, they still face deficiencies in terms of matching measurement accuracy, data analysis requirements, and adaptability to neutron catheters of different geometric shapes. This is especially true when dealing with complex curved surfaces or segmented approximate paths. It is difficult to balance the corrugation of a single catheter segment with the assembly accuracy of multiple catheter segments, making it impossible to accurately assess the impact of the current catheter corrugation on neutron reflection. Summary of the Invention

[0004] The object of the present invention is to provide a method for calculating the autocollimation configuration of a total station mounted on a high-precision guide rail, so as to solve the problems raised in the background art.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for measuring the waviness of a neutron catheter, comprising the following steps:

[0006] S1: Define the waviness parameters and calculate:

[0007] The waviness parameter σ is used as an indicator to measure the flatness of the reflective surface. It represents the standard deviation of the distribution of deviations between the actual surface normal direction and the nominal direction. Mathematically, it is calculated by the following formula:

[0008]

[0009] Among them, α i，R (x) and α i，N (x) are the actual normal direction and the normal direction of the standard plane, respectively, and n is the number of data points;

[0010] S2: Use a total station with an autocollimation eyepiece. In this autocollimation mode, the autocollimation beam emitted by the total station illuminates the optical reflective surface (i.e., the reflective surface of the catheter sidewall). When the "crosshairs" generated by the reflected beam coincide with the "crosshairs" target of the total station eyepiece, the normal incidence state is established. The angle displayed by the total station at this time is the direction of the normal line of the measured surface;

[0011] S3: Install the total station on a high-precision granite guide rail and slide the total station along the guide rail. Repeat the adjustment of the total station's position at multiple equally spaced positions, i.e., repeat the S2 step to make the autocollimated beam achieve normal incidence on the neutron optical device. Record the total station's position value at each position when normal incidence is established, and transmit the data to the computer for storage and analysis.

[0012] S4: Process the measured data using a spreadsheet template. Calculate the waviness using the appropriate formula based on the measured geometry.

[0013] S5: Evaluate the waviness value and the normal accuracy of the multi-segment duct sidewall, and analyze its impact on neutron reflection.

[0014] In this solution, preferably, in S1, for a straight neutron conduit, the nominal surface normal direction is a constant, and the simplified formula is:

[0015]

[0016] The preferred embodiment of this solution is that the curved neutron guide tube in S1 has the normal direction of the nominal surface changing with the position, taking into account the curvature radius R and the offset angle α. offset , the formula is:

[0017]

[0018] In this solution, preferably, the parabolic or elliptical conduit in S1 also uses a general formula to calculate the waviness, and attention should be paid to the precise positioning of the measurement point.

[0019] In this solution, the segmented approximate path or profile in S1 is preferably: for a nonlinear path approximated by a straight line segment, the bending angle α needs to be considered. bending The correction formula for the measured data is:

[0020]

[0021] Here, m is the number of line segments, and n is the number of data points in each segment.

[0022] This solution is preferred. In the S2, in the auto-collimation mode, the total station crosshairs and the reflected crosshairs are observed simultaneously through visual alignment and patient focusing, and the micro-motion screw is adjusted until the two crosshairs coincide with each other to complete the auto-collimation process and ensure the accuracy of each measurement.

[0023] Preferably, the density of data points in S3 is between every 50 mm and every 100 mm to ensure comprehensiveness and accuracy of measurement. The measurement position should be the center of each catheter unit and the corrugation measurement should be carried out along its entire length, and each side is assigned a statistically calculated corrugation value.

[0024] In this solution, the results in S5 are preferably used to evaluate the waviness value and the normal accuracy of the multi-section conduit sidewall, and to analyze their influence on neutron reflection to determine whether the design requirements and application standards are met.

[0025] Compared with the prior art, the technical effects and advantages of the present invention are:

[0026] This neutron guide tube waviness measurement method, through detailed calculation formulas and high-precision measurement equipment, can more accurately evaluate the waviness of neutron mirror optical devices and the normal accuracy of multi-segment guide tube side walls, thereby more effectively evaluating the neutron reflection quality and the docking integration quality of multi-segment guide rails, reducing neutron loss and improving neutron flux.

[0027] This technology is applicable to neutron guide tubes with straight, conical and other complex geometries, providing a universal waviness measurement method to meet the needs of different designs and application scenarios.

[0028] A clear definition and calculation method of waviness can help guide the design and manufacturing process of optical devices such as neutron guides, making the produced devices more in line with high performance requirements, reducing production costs and improving production efficiency.

[0029] Standardized data analysis processes can quickly and accurately process measurement data, promptly identify potential problems, and provide strong support for device improvement and optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A schematic diagram of reflection of an actual corrugated surface represented by the formula used in the present invention;

[0032] Figure 2 This is a diagram of the measurement principle of the present invention;

[0033] Figure 3 Schematic diagram of the total station self-collimation operation of the present invention. DETAILED DESCRIPTION

[0034] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0035] Unless otherwise defined, the directions of up, down, left, right, front, back, inside and outside involved in this document are based on the directions of up, down, left, right, front, back, inside and outside shown in the figures of the present invention, and are explained here together.

[0036] This embodiment provides Figures 1 to 3 A method for measuring neutron guide tube waviness is shown, comprising the following steps:

[0037] Definition and calculation of waviness: The waviness parameter σ is an indicator of the flatness of the reflective surface. It represents the standard deviation of the deviation distribution between the actual surface normal direction and the nominal direction. Mathematically, it is calculated using the following formula:

[0038]

[0039] Among them, α i，R (x) and α i，N (x) are the actual normal direction and the normal direction of the standard plane, respectively, and n is the number of data points.

[0040] Calculation of waviness for different geometries: For a straight neutron conduit, the nominal surface normal direction is constant. The simplified formula is:

[0041]

[0042] Curved neutron guide tube: the normal direction of the nominal surface changes with position, considering the curvature radius R and the offset angle α offset , the formula is:

[0043]

[0044] For other complex paths or profiles, such as parabolic or elliptical ducts, the waviness is calculated using the same general formula, but attention must be paid to the precise positioning of the measurement points.

[0045] Piecewise approximation of path or profile: For nonlinear paths approximated by straight line segments, the bending angle α needs to be taken into account. bending The correction formula for the measured data is:

[0046]

[0047] Here, m is the number of line segments, and n is the number of data points in each segment.

[0048] Measurement method:

[0049] Mount a high-precision total station on a high-precision granite beam. Install the autocollimation eyepiece and accessories on the total station, then aim at the reflector on the object being measured. Visually align and patiently adjust the focus until both the total station crosshairs and the reflector crosshairs are visible. Adjust the micro-screw until the two crosshairs overlap to complete autocollimation. The current angular position of the total station indicates the direction of the normal to the surface being measured.

[0050] After completing the normal alignment at the first measuring point, slide the total station along the beam and adjust the azimuth of the total station at multiple equally spaced positions so that the light beam is normally incident at each measuring position. Record the current instrument angle of the total station at each position and transmit the data to the computer for storage and analysis.

[0051] Data point density and location: A series of data points are usually selected at equal intervals between every 50 mm and every 100 mm to cover the entire side of the catheter measurement section to ensure comprehensive measurement.

[0052] This technical solution quantifies the deviation distribution in the surface normal direction through detailed mathematical formulas, providing a scientific basis for the accurate assessment of waviness.

[0053] Corresponding corrugation calculation formulas have been developed for neutron catheters with straight, curved and other complex geometric shapes to ensure accurate assessment of corrugation in various situations, filling the gap in domestic neutron catheter corrugation measurement technology when dealing with catheters with complex geometric shapes.

[0054] For nonlinear paths approximated by straight line segments, a bending angle correction factor is introduced to improve the processing of measurement data, making the waviness calculation results more realistic and providing a reliable measurement method for this type of specially designed neutron guide tube.

[0055] By combining high-precision total stations and specialized spreadsheet templates, a complete measurement and analysis system was built, enabling efficient processing of the entire process from data collection to result evaluation, significantly improving the quality and efficiency of measurement work.

[0056] It should be noted that, in this article, relational terms such as one and two are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "including an element defined by ... does not exclude the presence of other identical elements in the process, method, article or device that includes the element."

[0057] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for measuring neutron conduit waviness, characterized in that: The following steps are involved: S1: Define the waviness parameters and calculate: The waviness parameter σ is used as an indicator to measure the flatness of the reflective surface. It represents the standard deviation of the distribution of deviations between the actual surface normal direction and the nominal direction. Mathematically, it is calculated by the following formula: Among them, α i，R (x) and α i，N (x) is the actual normal direction and the normal direction of the standard plane, and n is the number of data points; S2: Use a total station with an autocollimation eyepiece. In this autocollimation mode, the autocollimation beam emitted by the total station illuminates the optical reflective surface (i.e., the reflective surface of the catheter sidewall). When the "crosshairs" generated by the reflected beam coincide with the "crosshairs" target of the total station eyepiece, normal incidence is established. The angle displayed by the total station at this time is the direction of the normal line of the measured surface; S3: Install the total station on a high-precision granite guide rail. Slide the total station along the guide rail and repeatedly adjust the total station's position at multiple equally spaced positions. Repeat S2 to achieve normal incidence of the light beam on the neutron optical device. Record the total station's position at each position when normal incidence is established, and transmit the data to a computer for storage and analysis. S4: Process the measured data using a spreadsheet template. Calculate the waviness using the appropriate formula based on the measured geometry. S5: Evaluate the waviness value and the normal accuracy of the multi-segment duct sidewall, and analyze its impact on neutron reflection.

2. The method for measuring neutron conduit waviness according to claim 1, wherein: In S1, for a straight neutron guide tube, the nominal surface normal direction is a constant, and the simplified formula is:

3. The method for measuring neutron conduit waviness according to claim 2, wherein: The curved neutron guide tube in S1: the normal direction of the nominal surface varies with position, considering the curvature radius R and the offset angle α offset , the formula is:

4. The method for measuring neutron conduit waviness according to claim 3, wherein: For the parabolic or elliptical conduit in S1, the waviness is also calculated using the general formula, but attention must be paid to the precise positioning of the measuring points.

5. The method for measuring neutron conduit waviness according to claim 4, characterized in that: The segmented approximate path or profile in S1: For a nonlinear path approximated by a straight line segment, the bending angle α needs to be considered. bending The correction formula for the measured data is: Here, m is the number of line segments, and n is the number of data points in each segment.

6. The method for measuring neutron conduit waviness according to claim 5, characterized in that: In the S2, in the autocollimation mode, the device is automatically aligned by visual alignment and patient focus adjustment until the total station crosshairs and the reflected crosshairs are observed at the same time. The micro-motion screw is then adjusted until the two crosshairs coincide with each other to complete the autocollimation process of the device, thereby ensuring the accuracy of each measurement.

7. The method for measuring neutron conduit waviness according to claim 6, characterized in that: The data point density in S3 is between every 50 mm and every 100 mm to ensure comprehensive measurement. The measurement position should be the center of each catheter unit and the corrugation measurement along its entire length, and each side is assigned a statistically calculated corrugation value.

8. The method for measuring neutron conduit waviness according to claim 7, characterized in that: The result evaluation in S5 includes analyzing the waviness value and the normal accuracy of the multi-section catheter sidewall, evaluating the catheter integration accuracy and its impact on neutron reflection, and determining whether the design requirements and application standards are met.

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