Combined triple detector system for neutron small angle scattering spectrometer and detection method thereof

Abstract

The present invention provides a combined triple detector system for neutron small angle scattering spectrometer and a detection method thereof, including a double L-shaped detector and a main detector. The double L-shaped detector is located at the front end of the detector cavity close to the sample stage, and the main detector is located at the rear end of the detector cavity far from the sample stage. Neutrons with scattering angles in a preset large range are counted by the front-end L-shaped detector, and neutrons in a preset small range are counted by the rear-end main detector. The minimum scattering vector is obtained according to the maximum detection distance and the maximum collimation distance, the maximum scattering vector is obtained according to the detector size, and the scattering pattern meeting the preset requirements is obtained in combination with the detector position. The present invention develops a new design of a combined triple detector system for neutron small angle scattering, which can greatly improve the instantaneous range of neutron small angle scattering experiments, thereby improving the experimental detection efficiency. By using the combination of triple detectors, the simultaneous measurement of particles with different size distributions and different morphologies in the sample can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of neutron small-angle scattering detectors, and particularly to a combined triple-detector system for a neutron small-angle scattering spectrometer and a detection method thereof. Background Art

[0002] The neutron small-angle scattering detector system is one of the key components of a small-angle scattering spectrometer, and requires a sufficiently large detection area and high detection efficiency to obtain a larger scattering vector range and higher experimental efficiency required for experiments.

[0003] Patent document CN108872280A (application number: CN201811091387.0) discloses a detector positioning device for a small-angle neutron scattering spectrometer. This device moves the detector located in the vacuum chamber of the small-angle neutron scattering spectrometer, drives the wire-pulling sensor connected thereto to move, and the wire-pulling sensor transmits signals to a computer through an aviation plug; the computer controls the rotation of a stepper motor to drive the sliding of a conveyor belt, thereby driving an LED indicator on a movable slider to move a corresponding distance; the LED indicator provides real-time and accurate position information before, during, and after the movement of the detector by indicating a precisely calibrated scale.

[0004] The D22 neutron small-angle scattering spectrometer of the Institut Laue-Langevin (ILL) in France adopts a dual-detector system, including a square-shaped front detector and a main detector, and the scattering vector range is from 0.001 to The instantaneous scattering vector range can reach 25. Although a dual-detector system is adopted, there is still room for improvement in its scattering vector range and instantaneous scattering vector range, and it fails to detect the microscopic information of nanoparticles in the sub-nanometer to sub-micron scale range. Summary of the Invention

[0005] Aiming at the defects in the prior art, the purpose of the present invention is to provide a combined triple-detector system for a neutron small-angle scattering spectrometer and a detection method thereof.

[0006] According to the combined triple-detector system for a neutron small-angle scattering spectrometer provided by the present invention, it includes a double L-shaped detector and a main detector. The double L-shaped detector is located at the front end of the detector cavity close to the sample stage, and the main detector is located at the rear end of the detector cavity far from the sample stage;

[0007] The front-end L-shaped detector counts neutrons with scattering angles in a preset large range, and the rear-end main detector counts neutrons in a preset small range;

[0008] The minimum scattering vector is obtained according to the maximum detection distance and the maximum collimation distance, the maximum scattering vector is obtained according to the size of the detector, and a scattering pattern meeting the preset requirements is obtained in combination with the detector position.

[0009] Preferably, the scattering vector q is expressed within a preset small angle range as:

[0010]

[0011] The minimum scattering vector q min is expressed as:

[0012]

[0013]

[0014]

[0015] where L SS is the collimation distance; L SD is the detection distance; R1 is the source aperture radius; R2 is the sample aperture radius; δD is the detector pixel size; λ represents the neutron wavelength; θ represents the small-angle scattering solid angle; R min represents half of the maximum width of the detector.

[0016] Preferably, the maximum scattering vector q max is expressed as:

[0017]

[0018]

[0019]

[0020] where L front is the short side dimension of the front detector, and the long side dimension is the same as that of the rear detector. L rear is the size of the rear detector.

[0021] Preferably, for an isotropic sample, its corresponding small-angle scattering pattern is a symmetric concentric ring pattern. Therefore, the three detectors are adjusted to three different positions to obtain three ranges of scattering vectors that meet the preset requirements and detect a more complete scattering pattern.

[0022] Preferably, for an anisotropic sample, its corresponding small-angle scattering pattern is an asymmetric pattern. Therefore, it is necessary to combine the first two L-shaped detectors into a loop for overall adjustment, and by adjusting the position of the loop detector back and forth and combining with the rear detector, a complete scattering pattern can be obtained.

[0023] According to the detection method of the combined three-detector system of the neutron small-angle scattering spectrometer provided by the present invention, a double L-shaped detector is arranged at the front end of the detector cavity close to the sample stage, and a main detector is arranged at the rear end of the detector cavity far from the sample stage;

[0024] Count neutrons with a scattering angle in a preset large range through the front-end L-shaped detector, and count neutrons in a preset small range through the back-end main detector;

[0025] Obtain the minimum scattering vector according to the maximum detection distance and the maximum collimation distance;

[0026] Obtain the maximum scattering vector according to the detector size;

[0027] Combine the detector positions to obtain a scattering pattern that meets the preset requirements.

[0028] Preferably, the scattering vector q is expressed in a preset small-angle range as:

[0029]

[0030] The minimum scattering vector q min is expressed as:

[0031]

[0032]

[0033]

[0034] where L SS is the collimation distance; L SD is the detection distance; R1 is the source aperture radius; R2 is the sample aperture radius; δD is the detector pixel size; λ represents the neutron wavelength; θ represents the small-angle scattering solid angle; R min represents half of the maximum width of the detector.

[0035] Preferably, the maximum scattering vector q max is expressed as:

[0036]

[0037]

[0038]

[0039] where L front is the short-side size of the front detector, and the long-side size is the same as that of the back detector. L rear is the size of the back detector.

[0040] Preferably, for an isotropic sample, its corresponding small-angle scattering pattern is a symmetric concentric ring pattern. Therefore, adjust the three detectors to three different positions to obtain three ranges of scattering vectors that meet the preset requirements and detect a more complete scattering pattern.

[0041] Preferably, for anisotropic samples, the corresponding small-angle scattering pattern is an asymmetric pattern. Therefore, it is necessary to combine the first two L-shaped detectors into a square-shaped whole for adjustment. By adjusting the position of the square-shaped detector back and forth and combining it with the rear detector, a complete scattering pattern can be obtained.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The present invention develops a new design of a combined three-detector system for neutron small-angle scattering, which can greatly improve the instantaneous range of neutron small-angle scattering experiments, thereby enhancing the experimental detection efficiency. By using the combination of three detectors, simultaneous measurement of particles with different size distributions and different morphologies in the sample can be achieved;

[0044] (2) By designing a completely new three-detector combination system, the present invention realizes the coverage of a larger scattering vector range and an instantaneous scattering vector range, and thus can meet the simultaneous measurement of particles with a larger size span, improving the experimental efficiency and accuracy; at the same time, the combination of three detectors can take into account the acquisition of scattering signals of isotropic and anisotropic samples, solving the problem of particle research by similar small-angle scattering spectrometers in the sub-nanometer and sub-micron scale ranges, and providing a more advanced and perfect technical platform for the research of nanostructures. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Other features, objects, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0046] Figure 1 is a schematic diagram of the combined three-detector system;

[0047] Figure 2 is a schematic diagram of the L-shaped detection mode;

[0048] Figure 3 is a schematic diagram of the square-shaped detection mode. DETAILED DESCRIPTION OF THE INVENTION

[0049] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0050] Example:

[0051] The present invention provides a combined three-detector system for small-angle neutron scattering, mainly including a front-end double L-shaped detector and a rear-end main detector. The double L-shaped detector is located at the front end of the detector cavity close to the sample stage, and the main detector is located at the rear end of the detector cavity far from the sample stage. The combined use of the three detectors can increase the range of the measured solid angle in small-angle scattering.

[0052] The front-end L-shaped detector can count neutrons with larger scattering angles, and the rear-end main detector can count the remaining neutrons with smaller scattering angles. The schematic diagram is as Figure 1 shown.

[0053] To meet the requirements of long range and high efficiency of the small-angle neutron scattering spectrometer, the design of the corresponding detector system is considered from the following aspects:

[0054] 1) Scattering vector range

[0055] To achieve the target scattering vector range, necessary calculations are carried out in combination with the collimation distance L SS and the detection distance L SD .

[0056] The scattering vector q can be approximately expressed in the small-angle range as:

[0057]

[0058] The minimum scattering vector q min can be expressed as:

[0059]

[0060] Where:

[0061]

[0062]

[0063] L SS is the collimation distance, L SD is the detection distance, R1 is the source aperture radius, R2 is the sample aperture radius, and δD is the detector pixel size.

[0064] λ represents the neutron wavelength; θ represents the small-angle scattering solid angle; R min represents half of the maximum width of the detector.

[0065] Therefore, the minimum scattering vector is mainly determined by the maximum detection distance and the maximum collimation distance.

[0066] The maximum scattering vector q max can be expressed as:

[0067]

[0068] Wherein:

[0069]

[0070]

[0071] L front is the short side dimension of the front detector, and the long side dimension is the same as that of the rear detector. L rear is the dimension of the rear detector.

[0072] Therefore, the maximum scattering vector is mainly determined by the detector size.

[0073] In order to cover a relatively wide range of scattering vectors q, detectors with a larger effective detection area are required. The three-detector system adopted by the Luoshu spectrometer can cover the scattering vector range q from 0.0001 to which corresponds to the range of particle sizes that can be studied in the sub-nanometer to sub-micron range.

[0074] 2) Instantaneous scattering vector range q max / q min

[0075] The instantaneous scattering vector range reflects the maximum scattering vector span that can be detected in a single experiment, and determines the single-experiment efficiency of the small-angle scattering spectrometer.

[0076] Compare the instantaneous scattering vector range q max / q min of the Luoshu spectrometer at a fixed wavelength and different detection distances. The maximum value can reach 326, which can reach the advanced level of similar spectrometers.

[0077] 3) L-shaped / loop-shaped mode

[0078] L-shaped mode:

[0079] As Figure 2 shown, for an isotropic sample, its corresponding small-angle scattering pattern is a symmetric concentric ring pattern. Therefore, the three detectors can be adjusted to three different positions to obtain three relatively fine scattering vector ranges and detect a more complete scattering pattern.

[0080] According to the range of particle sizes to be studied, by combining different positions of the three detectors, three different detection distances can be determined, which can reduce the multiple adjustments of the detection distance in the experiment and improve the experimental efficiency.

[0081] Loop-shaped mode:

[0082] As Figure 3As shown, for anisotropic samples, the corresponding small-angle scattering pattern is an asymmetric pattern. Therefore, it is necessary to combine the first two L-shaped detectors into a square-shaped whole for adjustment. By adjusting the position of the square-shaped detector back and forth and combining it with the rear detector, a complete scattering pattern can be obtained.

[0083] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0084] Those skilled in the art know that in addition to implementing the system, device, and their respective modules provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system, device, and their respective modules provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers, etc. to achieve the same program. Therefore, the system, device, and their respective modules provided by the present invention can be regarded as a hardware component, and the modules included therein for implementing various programs can also be regarded as the structure within the hardware component; the modules for implementing various functions can also be regarded as either software programs for implementing the method or the structure within the hardware component.

[0085] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined arbitrarily.

Claims

1. A combined triple-detector system for a neutron small-angle scattering spectrometer, characterized in that, It includes a double L-shaped detector and a main detector. The double L-shaped detector is located at the front end of the detector cavity close to the sample stage, and the main detector is located at the rear end of the detector cavity far from the sample stage. The front-end L-shaped detector counts neutrons with scattering angles in a preset large range, and the rear-end main detector counts neutrons in a preset small range. The minimum scattering vector is obtained according to the maximum detection distance and the maximum collimation distance. The maximum scattering vector is obtained according to the size of the detector. The scattering pattern meeting the preset requirements is obtained by combining the detector positions.

2. The combined triple detector system of the small angle neutron scattering spectrometer according to claim 1, characterized in that, The scattering vector q is expressed within a preset small-angle range as: Minimum scattering vector q min Expressed as: Among them, L SS is the collimation distance; L SD is the detection distance; R1 is the source aperture radius; R2 is the sample aperture radius; δD is the detector pixel size; λ represents the neutron wavelength; θ represents the small-angle scattering solid angle; R min represents half of the maximum width of the detector.

3. The combined triple detector system of the small angle neutron scattering spectrometer according to claim 1, characterized in that, Maximum scattering vector q max It is expressed as: Among them, L front is the short side dimension of the front detector, and the long side dimension is the same as that of the rear detector. L rear is the dimension of the rear detector.

4. The combined triple-detector system for neutron small-angle scattering spectrometer according to claim 1, characterized in that, For an isotropic sample, its corresponding small-angle scattering pattern is a symmetric concentric ring pattern. Therefore, the three detectors are adjusted to three different positions to obtain three sections of scattering vector ranges meeting the preset requirements and detect a more complete scattering pattern.

5. The combined triple detector system for neutron small angle scattering spectrometer according to claim 1, characterized in that, For an anisotropic sample, its corresponding small-angle scattering pattern is an asymmetric pattern. Therefore, the first two L-shaped detectors need to be combined into a whole for loop-shaped adjustment. By adjusting the position of the loop-shaped detector back and forth and combining with the rear detector, a complete scattering pattern is obtained.

6. A detection method based on a combined three-detector system of a small-angle neutron scattering spectrometer, characterized in that, The double L-shaped detector is set at the front end of the detector cavity close to the sample stage, and the main detector is set at the rear end of the detector cavity far from the sample stage. The front-end L-shaped detector counts neutrons with scattering angles in a preset large range, and the rear-end main detector counts neutrons in a preset small range. The minimum scattering vector is obtained according to the maximum detection distance and the maximum collimation distance. The maximum scattering vector is obtained according to the size of the detector. The scattering pattern meeting the preset requirements is obtained by combining the detector positions.

7. The detection method of the combined triple detector system based on a small angle neutron scattering spectrometer according to claim 6, characterized in that, The scattering vector q is expressed within a preset small-angle range as: Minimum scattering vector q min Expressed as: Among them, L SS is the collimation distance; L SD is the detection distance; R1 is the source aperture radius; R2 is the sample aperture radius; δD is the detector pixel size; λ represents the neutron wavelength; θ represents the small-angle scattering solid angle; R min represents half of the maximum width of the detector.

8. The detection method of the combined three-detector system based on a small-angle neutron scattering spectrometer according to claim 6, characterized in that Maximum scattering vector q max is expressed as: Among them, L front is the short side dimension of the front detector, and the long side dimension is the same as that of the rear detector. L rear is the dimension of the rear detector.

9. The detection method of the combined triple-detector system based on a small-angle neutron scattering spectrometer according to claim 6, wherein For an isotropic sample, its corresponding small-angle scattering pattern is a symmetric concentric ring pattern. Therefore, the three detectors are adjusted to three different positions to obtain three sections of scattering vector ranges meeting the preset requirements and detect a more complete scattering pattern.

10. The detection method of the combined three-detector system based on a neutron small-angle scattering spectrometer according to claim 6, characterized in that, For an anisotropic sample, its corresponding small-angle scattering pattern is an asymmetric pattern. Therefore, the first two L-shaped detectors need to be combined into a whole for loop-shaped adjustment. By adjusting the position of the loop-shaped detector back and forth and combining with the rear detector, a complete scattering pattern is obtained.

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