Performance test method of focusing neutron monochromator
By using a combination of multi-layer single chips and support members in a neutron monochromator, combining laser and neutron beam detection, the problem of detection of single-crystal strip orientation accuracy and focus performance is solved, and efficient focus and alignment of neutron beams is achieved. , improves the overall performance of neutron monochromator.
Patent Information
- Application Number
- CN202111037431.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-09-06
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2041-09-06
AI Technical Summary
It is difficult to effectively detect and test the performance of neutron monochromator in the prior art, especially in the installation and adjustment of the focus neutron monochromator, and it is difficult to ensure the crystal plane orientation accuracy of the single crystal chip and the orientation accuracy of the single crystal strip. Influences the focus performance of the neutron beam.
Multiple single wafers are stacked into single crystal strips, supported and adjusted by support, laser inspection and neutron beam detection focus performance, combined with X-ray diffractometer and high-precision coordinate measuring instrument, measure and adjust the orientation of single crystal strips and curvature to ensure collimation and focus effects of the neutron beam.
Accurate detection and adjustment of the performance of neutron monochromator, improve the focus performance of neutron beams and the assembly quality of single crystal strips, ensure the collimation and focus effect of neutron beams, and reduce the single crystal strips. The effect of distortion on performance.
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Figure CN113655515B_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present invention relate to a neutron monochromator, and in particular to performance detection of a neutron monochromator. Background Art
[0002] White light neutron beam refers to the neutron beam drawn from the horizontal tangential channel of the reactor neutron source, and its wavelength distribution is related to the continuous Maxwell spectrum of the reactor moderator temperature. The neutron monochromator can obtain a quasi-neutron monochromatic beam with a fixed wavelength and fixed bandwidth from the white light neutron beam, that is, a neutron monochromatic beam. The focusing neutron monochromator can focus the neutron beam while obtaining a neutron beam with a fixed wavelength and fixed bandwidth. The focusing neutron monochromator can focus the neutron monochromatic beam in the horizontal direction and vertical direction simultaneously or separately. Summary of the invention
[0003] On the one hand, an embodiment of the present invention provides a performance testing method for a focusing neutron monochromator, wherein the focusing neutron monochromator includes a single crystal bar and a bracket, the single crystal bar is formed by stacking a plurality of single crystal chips, the single crystal chip is used to reflect and focus the neutron beam, and the support is used to support and adjust the posture of the single crystal chip. The performance testing method includes: before installing the single crystal chip to the support, measuring the crystal plane orientation accuracy of the single crystal chip; after installing the single crystal chip to the support, measuring the orientation of the single crystal bar; using a laser to check the focusing performance of the neutron monochromator; using neutrons to check the focusing performance of the neutron monochromator.
[0004] On the other hand, an embodiment of the present invention provides a testing device for testing the performance of a neutron monochromator, comprising: a lifting part, on which the focused neutron monochromator is arranged, and the lifting part is arranged to lift the focused neutron monochromator arranged thereon; a rotating part, on which the lifting part is arranged; and a beam limiting slit, which is arranged on the front side of the focused neutron monochromator, and the neutron beam is injected into the focused neutron monochromator after passing through the beam limiting slit. BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Other objects and advantages of the present invention will become apparent from the following description of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention.
[0006] Figure 1 is a schematic diagram of a performance testing method for a focusing neutron monochromator provided by an embodiment of the present invention;
[0007] Figure 2 is a schematic diagram of a focusing neutron monochromator provided by an embodiment of the present invention;
[0008] Figure 3It is a partially enlarged schematic diagram of a single crystal bar of a focusing neutron monochromator provided by an embodiment of the present invention;
[0009] Figure 4 The embodiment of the present invention provides a device for testing the focusing performance of a monochromator by laser;
[0010] Figure 5 It is a schematic diagram of a neutron optical path for focusing testing provided by an embodiment of the present invention.
[0011] Reference numerals:
[0012] 100-focusing neutron monochromator 200-lifting part
[0013] 300-rotating part 400-beam limiting slit
[0014] 500-Neutron Detector 600-Neutron Monochromator
[0015] 110-single crystal bar 120-support
[0016] 111-Single chip
[0017] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION
[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiment is one embodiment of the present invention, not all embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0019] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.
[0020] like Figures 1 to 3As shown, an embodiment of the present invention provides a performance testing method for a focusing neutron monochromator 100, wherein the focusing neutron monochromator 100 includes a single crystal bar 110 and a support 120, the single crystal bar 110 is formed by stacking a plurality of single crystal sheets 111, the single crystal sheet 111 is used to reflect and focus the neutron beam, and the support 120 is used to support and adjust the posture of the single crystal sheet 111, and the performance testing method includes: before installing the single crystal sheet 111 to the support 120, measuring the crystal plane orientation accuracy of the single crystal sheet 111; after installing the single crystal sheet 111 to the support 120, measuring the orientation of the single crystal bar 110; using a laser to check the focusing performance of the focusing neutron monochromator 100; using neutrons to check the focusing performance of the focusing neutron monochromator 100.
[0021] The number of the single crystal bars 110 is selected to be 9, but not limited thereto, and the number of the single crystal bars 110 can be increased or decreased according to actual conditions, and the focusing performance of the focusing neutron monochromator 100 can be achieved by adjusting the inclination angle of each single crystal bar 110. The single crystal bar 110 is formed by stacking a plurality of single crystal wafers 111, wherein the single crystal wafers 111 are cut symmetrically, and the number of the single crystal wafers 111 is selected to be 13, but not limited thereto, and the number of the single crystal wafers 111 can be increased or decreased according to actual conditions.
[0022] When measuring the orientation accuracy of the single crystal 111 plane, an X-ray diffractometer is used, but it is not limited to this. Different instruments can be selected for measurement according to actual conditions.
[0023] When measuring the orientation of the single crystal bar 110, the neutron beam is used to scan and irradiate the rotating single crystal bar 110, and the scanning center position is recorded. The orientation of each single crystal bar 110 is measured, and the orientation of each single crystal bar 110 is adjusted so that the surface of each single crystal bar 110 is located on the diffraction surface of the focusing neutron monochromator 100, and the relative error is less than 0.03 0 Measuring the orientation of the single crystal bar 110 can verify the assembly quality of the single crystal bar 110 and adjust the tilt angle of the single crystal bar 110 .
[0024] In the laser inspection of the focusing performance of the focusing neutron monochromator 100, a laser source is used to emit a laser beam, and the laser source is loaded on a high-precision coordinate measuring instrument. The high-precision coordinate instrument can control the movement of the laser source with perfect accuracy and reproducibility. While keeping the arrangement of the single crystal bar 110 unchanged, the laser beam is used to characterize the focusing neutron monochromator 100, and a parallel laser beam of the effective surface of the focusing neutron monochromator 100 is obtained.
[0025] Before using neutrons to test the focusing performance of the focusing neutron monochromator 100, a micrometer is used to detect the mechanical bending of the single crystal bar 110. The micrometer is set perpendicular to the single crystal bar 110 at the center of the single crystal bar 110 to measure the change in the center position of the single crystal bar 110 with the position of the horizontal focusing motor.
[0026] In the process of using neutrons to inspect the focusing performance of the focused neutron monochromator 100, a white light neutron beam is used to inspect the focused neutron monochromator 100. The white light neutron beam is reflected by the focused neutron monochromator 100 and irradiated to the neutron detector 500, and the neutron detector 500 can monitor the focusing effect of the neutron beam. The neutron detector 500 adjusts the focusing radius of curvature of the focused neutron monochromator 100 according to the neutron intensity and the beam spot size of the neutron beam irradiated on the neutron detector 500. Each single crystal bar 110 is adjusted in the same manner.
[0027] In some embodiments, the orientation of each of the single wafers 111 is measured.
[0028] When measuring the crystal plane orientation accuracy of the single crystal wafer 111, an X-ray diffractometer is used, but it is not limited to this. Different instruments are selected for measurement according to actual conditions to select the single crystal wafer 111 whose crystal plane orientation accuracy meets the requirement of less than ±3 minutes.
[0029] In some embodiments, the orientation of each single wafer 111 in the single wafer 111 is measured, and based on the orientation accuracy obtained from the measurement results, the single wafers 111 are divided into several groups, and the orientation accuracy of the group of single wafers 111 with the lowest orientation accuracy is measured again.
[0030] The single wafers 111 are classified according to their orientation accuracy, and divided into 9 groups according to their orientation accuracy from high to low. The single wafers 111 in the group with the lowest orientation accuracy among the 9 groups are subjected to orientation measurement again. The rocking curve of each single wafer 111 is measured and plotted, and the peak intensity, peak shape and centerline position of the rocking curve are analyzed to measure whether the orientation accuracy of the single wafer 111 is less than 3 points.
[0031] In some embodiments, in the step of measuring the orientation of the single crystal bar 110 after mounting the single crystal wafer 111 on the support 120 , the neutron beam is injected into the focusing neutron monochromator 100 after being adjusted.
[0032] The neutron beam is adjusted to obtain a collimated monochromatic neutron beam, which is used to detect the single crystal bar 110 of the focused neutron monochromator 100. The collimated monochromatic neutron beam can eliminate the interference of neutrons of different wavelengths in the white light neutron beam on the detection result.
[0033] like Figure 4 As shown, in some embodiments, the beam spot of the neutron beam is adjusted.
[0034] The neutron beam irradiates the single crystal bar 110 of the focusing neutron monochromator 100 through the beam limiting slit 400. The beam limiting slit 400 can limit the beam spot size so that the beam spot size is no larger than the width of the single crystal bar 110. Each single crystal bar 110 can be measured separately, making the measurement data more accurate.
[0035] In some embodiments, in the step of measuring the orientation of the single crystal bar 110 after mounting the single crystal chip 111 on the support member 120, the focusing neutron monochromator 100 is rotated along a vertical axis, during which the orientation of the single crystal bar 110 of the focusing neutron monochromator 100 is measured.
[0036] The rotating part 300 is adjusted so that it can rotate around an axis perpendicular to the placement surface. The single crystal bar 110 rotates with the rotation of the rotating part 300. The neutron beam is irradiated on the single crystal rotating around the axis of the placement surface for scanning, and the vertical scanning center position is recorded. The scanning center position can clearly determine the vertical orientation of each single crystal bar 110.
[0037] In some embodiments, the focusing neutron monochromator 100 is further included in that the focusing neutron monochromator 100 is rotated along a tilt axis, during which the orientation of the single crystal bar 110 of the focusing neutron monochromator 100 is measured.
[0038] The tilt axis is selected to be parallel to the placement surface, and the rotating part 300 is adjusted so that the rotating part 300 can rotate around the axis parallel to the placement surface, and the single crystal bar 110 rotates with the rotation of the rotating part 300. The neutron beam is irradiated on the single crystal rotating around the axis parallel to the placement surface for scanning, and the horizontal scanning center position is recorded. The scanning center position can clearly determine the horizontal orientation of each single crystal bar 110. Combined with the vertical scanning center position, the orientation of each single crystal bar 110 can be clearly determined.
[0039] In some embodiments, when the focusing performance of the focusing neutron monochromator 100 is tested by laser, the distortion amount of the single crystal bar 110 is adjusted according to the test result.
[0040] Fixing the single crystal bar 110 on the support 120 will cause the single crystal bar 110 to be twisted. Scanning the single crystal bar 110 with a laser beam in a direction parallel to the placement surface can detect whether the single crystal bar 110 is twisted. By adjusting the adjustment module on the support 120, the twisting amount of the single crystal bar 110 can be adjusted to a minimum, thereby reducing the influence of the twisting amount of the single crystal bar 110 on the performance of the focused neutron monochromator 100.
[0041] In some embodiments, using laser to inspect the focusing performance of the focusing neutron monochromator 100 further includes: adjusting the horizontal focusing of the focusing neutron monochromator 100; and detecting the vertical focusing of the focusing neutron monochromator 100 while keeping the horizontal focusing unchanged.
[0042] In adjusting the horizontal focus of the focusing neutron monochromator 100, the initial horizontal curvature radius of each single crystal bar 110 is set, while maintaining other orientation settings of the single crystal bar 110, and the curvature radius of the single crystal bar 110 is measured by the laser beam. While maintaining the horizontal focus of the focusing neutron monochromator 100 unchanged, the vertical displacement of the reflected laser beam of each single crystal bar 110 during the vertical focusing process is measured and recorded. The vertical curvature value of the single crystal bar 110 can be calculated based on the vertical displacement of the reflected laser beam and the distance between the focusing neutron monochromator 100 and the canvas receiving the reflected laser beam.
[0043] like Figure 5 As shown, in some embodiments, when using neutrons to test the focusing performance of the focusing neutron monochromator 100 , the neutron beam is injected into the focusing neutron monochromator 100 after being adjusted.
[0044] Before the neutron beam is injected into the focusing neutron monochromator 100, it is adjusted to a monochromatic neutron beam through the neutron monochromator 600. The monochromatic neutron beam is injected into the focusing neutron monochromator 100, and the focusing performance of the focusing neutron monochromator 100 is tested. Adjusting the neutron beam to a monochromatic neutron beam can eliminate the influence of neutron beams of different wavelengths on the test results.
[0045] like Figure 4 As shown, an embodiment of the present invention provides a testing device for testing the performance of a focused neutron monochromator, comprising: a lifting part, the focused neutron monochromator is arranged on the lifting part, and the lifting part is arranged to lift the focused neutron monochromator arranged thereon; a rotating part, the lifting part is fixed to the rotating part, and the rotating part can be brought to the lifting part for rotation; a beam limiting slit, the beam limiting slit is arranged on one side of the lifting part and the rotating part, and the neutron beam is injected into the focused neutron monochromator after passing through the beam limiting slit.
[0046] The lifting part 200 can make the focusing neutron monochromator 100 disposed on the lifting part 200 move up and down in a direction perpendicular to the placement surface, which can make the use of the testing device more convenient.
[0047] The rotating part 300 can rotate around a certain tilt angle, wherein the tilt angle is usually between -10° and 10°, so that the testing device can detect the focused neutron monochromator 100 from different angles of the focused neutron monochromator 100 .
[0048] The beam limiting slit 400 can adjust the beam spot size of the injected neutron beam, wherein the beam spot size satisfies that it is not larger than the width of the single crystal bar 110, and each single crystal bar 110 can be detected separately, so that the detection data of the detection device is more accurate. The size of the slit of the beam limiting slit 400 is adjustable, and the size of the slit can be increased or decreased according to actual use conditions, so that the beam limiting slit 400 can adjust the beam spot size of the neutron beam more conveniently.
[0049] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.
[0050] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.
Claims
1. A performance test method for a focusing neutron monochromator, characterized in that: in, The focusing neutron monochromator comprises a single crystal bar and a support, wherein the single crystal bar is formed by stacking a plurality of single crystal sheets, the single crystal sheet is used to reflect and focus the neutron beam, and the support is used to support and adjust the posture of the single crystal sheet, and the test device is as follows: A lifting part, the focusing neutron monochromator is arranged on the lifting part, and the lifting part is configured to lift and lower the focusing neutron monochromator arranged thereon; A rotating part, the lifting part is fixed to the rotating part, and the rotating part can be brought to the lifting part for rotation; A beam limiting slit, wherein the beam limiting slit is arranged at one side of the lifting part and the rotating part, and the neutron beam is incident into the focusing neutron monochromator after passing through the beam limiting slit; The performance testing method comprises: Before mounting the single crystal wafer on the support member, measuring the crystal plane orientation accuracy of the single crystal wafer; After mounting the single crystal wafer on the support, measuring the orientation of the single crystal strip; Using laser to test the focusing performance of the focusing neutron monochromator; Using neutrons to test the focusing performance of the focusing neutron monochromator; measuring the orientation of each of the single crystal sheets; Based on the orientation accuracy obtained from the measurement results, the single wafers are divided into several groups, The orientation measurement of the single wafers of the group of single wafers with the lowest orientation accuracy is performed again.
2. The method according to claim 1, wherein: In the step of measuring the orientation of the single crystal strip after the single crystal wafer is mounted on the support, After being adjusted, the neutron beam is injected into the focusing neutron monochromator.
3. The method according to claim 2, wherein: The beam spot of the neutron beam is adjusted.
4. The method according to claim 1, wherein: In the step of measuring the orientation of the single crystal strip after the single crystal wafer is mounted on the support, The focusing neutron monochromator is rotated along a vertical axis, during which the orientation of the single crystal strip of the focusing neutron monochromator is measured.
5. The method according to claim 4, wherein: The method also includes: the focusing neutron monochromator is rotated along the tilt axis, during which the orientation of the single crystal strip of the focusing neutron monochromator is measured.
6. The method according to claim 1, wherein: In testing the focusing performance of the focusing neutron monochromator using laser, The twisting amount of the single crystal strip is adjusted according to the inspection result.
7. The method according to claim 6, wherein: Using laser to test the focusing performance of the focusing neutron monochromator also includes: adjusting the horizontal focus of the focusing neutron monochromator; The vertical focus of the focusing neutron monochromator is detected while keeping the horizontal focus unchanged.
8. The method according to claim 1, wherein: In testing the focusing performance of the focusing neutron monochromator using neutrons, After being adjusted, the neutron beam is injected into the focusing neutron monochromator.