CN109471152B - Collimator device capable of automatically adjusting gamma ray flux and measuring system thereof - Google Patents
Collimator device capable of automatically adjusting gamma ray flux and measuring system thereof Download PDFInfo
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- CN109471152B CN109471152B CN201811068406.8A CN201811068406A CN109471152B CN 109471152 B CN109471152 B CN 109471152B CN 201811068406 A CN201811068406 A CN 201811068406A CN 109471152 B CN109471152 B CN 109471152B
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- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/36—Measuring spectral distribution of X-rays or of nuclear radiation spectrometry
Abstract
The invention provides a collimator device capable of automatically adjusting gamma ray flux and a measuring system. The servo motor and the gear box are connected with the screw rod through a gear assembly connecting rod and a gear assembly; the two guide rails are inwards inclined along the collimation window and symmetrically arranged at two sides by taking the detector as a center; the screw rod is driven by controlling the servo motor, and then the collimating port shielding sliding block is driven by the shielding block sliding connecting rod, so that the position of the collimating port shielding sliding block is adjusted, the size of a collimating window is changed, and the adjusting function of the gamma ray flux is realized. The device can automatically adjust the gamma ray flux entering the sensitive volume of the detector according to the initial measurement value, has similar adjusting function to low-energy to high-energy rays, is simple to operate and compact in structure, and is suitable for a nuclear power plant and a nuclear technology application radioactive waste detection system.
Description
Technical Field
The invention relates to the technical field of nuclear radiation detection, in particular to a collimator device capable of automatically adjusting gamma ray flux and a measurement system thereof, and particularly relates to a detection system collimator device capable of automatically adjusting gamma ray flux.
Background
Segmented Gamma Scanning (SGS) and Tomographic Gamma Scanning (TGS) have been widely used for detecting nuclear power plant barreled waste as important Non-Destructive analysis (NDA) techniques. The method is mainly characterized in that the method comprises the steps of measuring the count and the energy of gamma rays according to a radiation detector, measuring the energy spectrum of the gamma rays by combining a multi-channel analyzer, determining the species of nuclides, and reconstructing the activity according to the count rate to determine the activity of the nuclides. Gamma ray measurement is mostly performed by using a high-purity germanium detector.
There is a dead time for the measurement of gamma rays. Since it takes a certain time for the electronic circuitry of the detector to process each incoming photon, when the intensity of the ray entering the detector is too high, there is a case where the previous ray has not been processed and the next ray has entered, and the ray entering later at this time may not be processed, which is a dead time effect. Dead time is an important factor influencing the measurement accuracy of a high-purity germanium detector system, and the loss of measured counts can be caused by the fact that the dead time is large, namely the measured counts are smaller than actual values. Aiming at the SGS technology, when the dead time of the high-purity germanium detection system is longer due to the fact that the activity of a measured target is larger, the detection upper limit of the SGS measurement system can be widened by reducing the number of rays entering the sensitive volume of a detector. The existing method comprises the following steps: a shielding block is additionally arranged in front of the collimator, and the aperture size is changed by adjusting the whole structure of the collimator. In practical application, the purpose of reducing the number of rays entering a sensitive volume of a detector can be realized by adding a shielding block, but researches show that the method has great difference in attenuation effects on different energy rays, the high-energy rays have strong penetrating power, and the attenuation ratio is obviously smaller than that of low-energy rays, so that when the high-energy rays are normally measured, part of the low-energy rays cannot penetrate through the shielding block to enter the sensitive volume of the detector, and the measurement error is large or even the effective measurement cannot be carried out. The method for changing the size of the opening by adjusting the overall structure of the collimator can solve the problem that low-energy rays cannot be detected, but due to the defect of design, the overall structure needs to be adjusted by occupying a large space, and the method is not beneficial to popularization and application in an actual detection system. In addition, compared with the SGS technology, the TGS technology requires a collimator with a smaller opening, but at present, there is no collimator device that can automatically adjust the opening size and is compatible with both the SGS and TGS measurement systems.
In view of the defects of the collimator device of the measuring system, the invention provides the collimator device capable of automatically adjusting the gamma ray flux, and the shielding slide block capable of changing the size of the collimation opening is arranged inside the collimation opening to realize the adjustment of the ray flux.
Disclosure of Invention
In view of the defects in the prior art, the invention aims to provide a collimator device capable of automatically adjusting the flux of gamma rays and a measurement system thereof.
The collimator device capable of automatically adjusting the gamma ray flux comprises an outer collimator shield and a cavity formed by the inner space of the outer collimator shield; the front section of the collimator outer shield is provided with a collimation window, the rear section of the collimator outer shield is provided with a through hole, the through hole is connected with a detector, and gamma rays can enter the detector from the collimation window; the cavity is internally provided with the collimating aperture shielding sliding block assembly and the shielding sliding block automatic adjusting device, the size of the collimating aperture shielding sliding block assembly can be adjusted by the movement of the collimating aperture shielding sliding block assembly, and the shielding sliding block automatic adjusting device controls the movement of the collimating aperture shielding sliding block assembly.
Preferably, the automatic shielding slider adjusting device comprises a servo motor, a gear box, a gear assembly connecting rod, a guide rail assembly, a lead screw and a gear assembly;
the servo motor and the gear box are arranged on the outer surface of the collimator outer shield, and the gear assembly connecting rod, the guide rail assembly, the lead screw and the gear assembly are arranged in the cavity;
the servo motor is connected with a gear box;
the gear box is connected with the screw rod through a gear assembly connecting rod and a gear assembly;
the lead screw is connected with the collimating port shielding sliding block assembly;
the guide rail assembly is arranged along the axial direction of the collimator outer shielding body, the axial direction is parallel or approximately parallel to the detector, in order to increase the adjusting range, the connecting angle of the guide rail assembly and the collimating window is not consistent with the connecting angle of the guide rail assembly and the other end of the collimator outer shielding body, and the effect is that the distance between the two shielding sliding blocks at the collimator window is smaller than the distance in the collimator cavity;
the servo motor drives the collimating aperture shielding sliding block assembly to move along the guide rail assembly through the driving lead screw.
Preferably, the collimator further comprises a base and a lead shielding block fixing assembly, wherein the collimator outer shielding body mainly comprises a collimator inner lining and a lead shielding block;
the inner lining of the collimator is made of steel and is a skeleton structure of the outer shielding body of the collimator, and the functions of strengthening structural strength and fixing a lead shielding block are achieved.
The through holes are arranged on the inner liner of the collimator and face the incidence direction of gamma rays, and the lead shielding blocks are positioned on two sides of the inner liner of the collimator and are mutually matched and connected and are used for shielding the gamma rays incident from the side surface;
the lead shielding block is fixedly arranged on the base through a lead shielding block fixing component.
Preferably, the automatic adjusting device for the shielding sliding block further comprises a limit switch, and the limit switch can limit the movement range of the shielding sliding block assembly along the lead screw and prevent the shielding sliding block assembly from interfering and colliding with the wall surface. .
Preferably, the number of the limit switches is at least two, and the two limit switches are respectively arranged at two ends of the screw rod.
Preferably, the guide rail assembly mainly comprises a first guide rail and a second guide rail; the collimating aperture shielding sliding block component mainly comprises a first sliding block and a second sliding block; the first sliding block can slide on the first guide rail, and the second sliding block can slide on the second guide rail; the first sliding block and the second sliding block are connected with the lead screw through the shielding block sliding connecting rod, and the distance between the first sliding block and the detector and the distance between the second sliding block and the detector are kept the same.
The invention provides a measuring system capable of automatically adjusting gamma ray flux, which comprises the collimator device capable of automatically adjusting gamma ray flux as claimed in the claim, and further comprises a software control device; the software control device is connected with the servo motor and the detector.
Preferably, the software control device comprises a detector data acquisition module, a dead time comparison module, a ray flux regulation judgment module and a driving regulation module; the detector data acquisition module acquires the counting rate of the detector; the dead time comparison module compares the counting rate with a dead time threshold value to obtain a comparison result; the ray flux adjustment judging module judges whether to adjust the flux and the adjustment amplitude according to the comparison result to obtain a judgment result; and the driving adjusting module sends a driving signal to the servo motor according to the judgment result.
Preferably, the counting rate is calculated by:
in the formula
α for adjusting the count rate of the n-th energy gamma ray detected by the detector when the rear shielding slide block is at the i-th positionnEmitting an nth energy gamma ray branch ratio for the radionuclide in the waste; a is the activity of the radionuclide in Bq; enξ, for shielding the detection efficiency of the nth energy gamma ray when the sliding block is at the first position, namely the original detection efficiency, wherein the first position is a position without regulation functionniIs the attenuation ratio of the detection efficiency of the nth energy gamma ray when the shielding sliding block is positioned at the ith position, namely the adjustment coefficient, and ξniEstablishing a database, automatically checking values according to ray energy and slide block position numbers when in use, and implementing correction of activity reconstruction:
Ar＝A'/ξni
wherein A' is the radioactivity activity given by the reconstruction of the detection system and is obtained by calculating the original detection efficiency, ArIs the activity after correction.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention adjusts the size of the opening of the collimating opening by utilizing the sliding of the shielding sliding block, thereby adjusting the flux of rays entering the collimator, generating no obvious difference on different energy rays and well considering the detection requirements of low-energy rays and high-energy rays.
2. The sliding block is arranged in the collimation window, the size of the collimation window is adjusted through the movement of the sliding block, the overall appearance of the collimator is not influenced, the requirement for additional assembly of an external detection system is not required, and meanwhile, the internal sliding block is relatively small in size and mass and can be conveniently subjected to automatic control.
3. According to the invention, a plurality of slide block positions are set according to the ray flux regulation proportion, a regulation coefficient database is established, the regulation gear and the slide block positions are determined after pre-measurement, a servo motor instruction is given, a shielding block is automatically moved to a set position, the regulation coefficients are automatically extracted after measurement, and the radioactivity activity result is corrected.
4. The invention has simple mechanical structure and control logic, high operation reliability, convenient integration with the existing detection system, no need of modifying the conventional measurement process and correcting the efficiency scale data of the existing detection system, and is beneficial to the popularization and application of the device.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a side view of an external appearance of a detector and collimator arrangement;
FIG. 2 is a front view of the detector and collimator assembly;
FIG. 3 is a schematic diagram of an external shield of a collimator assembly;
FIGS. 4 and 5 are structural views of internal components of the collimator device;
FIGS. 6 and 7 are schematic views of the adjusting position of the adjusting slider inside the collimator device;
FIG. 8 is a schematic view of the internal principal dimensions of the collimator arrangement;
FIG. 9 is a graph of the relationship between the different positions Δ x of the adjustment slider and the opening width Δ y;
fig. 10 is a graph of the adjustment coefficient for different energy rays with the adjustment slider in different positions.
The figures show that:
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
The invention discloses a collimator device capable of automatically adjusting gamma ray flux, which utilizes the inner space of a collimator collimating port to adjust the size of a collimating window by the movement of the position of a shielding slide block, thereby adjusting the flux of the entering gamma ray. The device can guarantee the measurement accuracy of different radioactivity level garbage bins, widens detection upper limit of a detection system, and meets the size requirement of the SGS and TGS technologies for aligning to the straight opening.
As shown in fig. 1 and 2, the collimator device capable of automatically adjusting the gamma ray flux includes a collimator outer shield 2, a cavity formed by the inner space of the collimator outer shield 2; the front section of the collimator outer shield 2 is provided with a collimation window, preferably, the collimation window is rectangular, the rear section of the collimator outer shield 2 is provided with a through hole, the through hole is connected with the detector 1, gamma rays can enter the detector 1 from the collimation window, the rear section of the collimator outer shield 2 is provided with a collimator lining 5, the collimator lining 5 is provided with a through hole, preferably, the through hole is circular.
As shown in fig. 3, the detector 1 extends into the cavity inside the external shield 2 of the collimator through the through hole, and can shield the rays of the environment background; when the collimator device is installed, a probe of the detector 1 penetrates through a circular through hole of a collimator lining 5 to be connected and combined, and only rays passing through a rectangular collimation window at the front end of the collimator device can enter the sensitive volume of the detector; the two ends of the collimation opening in the cavity are provided with the collimation opening shielding sliding block assembly 12 and the shielding sliding block automatic adjusting device, the size of the collimation opening can be adjusted through the movement of the collimation opening shielding sliding block assembly 12, and the shielding sliding block automatic adjusting device controls the movement of the collimation opening shielding sliding block assembly 12.
As shown in fig. 4 and 5, the automatic shielding slider adjusting device includes a servo motor 3, a gear box 4, a gear assembly connecting rod 11, a guide rail assembly 13, a lead screw 14, and a gear assembly 15; the servo motor 3 and the gear box 4 are arranged on the outer surface of the collimator outer shield 2, specifically, the outer side of the collimator inner lining 5, and the gear assembly connecting rod 11, the guide rail assembly 13, the lead screw 14 and the gear assembly 15 are arranged in the cavity; the servo motor 3 is connected with a gear transmission case 4; the gear box 4 is connected with a screw 14 through a gear assembly connecting rod 11 and a gear assembly 15; the lead screw 14 is connected with the collimating aperture shielding slider assembly 12; the guide rail assembly 13 is arranged along the axial direction of the collimator outer shielding body 2, the axial direction is parallel or approximately parallel to the detector 1, the adjusting range is further increased, the connecting angle between the guide rail assembly 13 and the collimating window is inconsistent with the connecting angle between the guide rail assembly 13 and the other end of the collimator outer shielding body 2, and the distance between the first sliding block 121 and the second sliding block 122 arranged on the collimator window is smaller than the distance in the collimator chamber; the servo motor 3 drives the collimating aperture shielding slide block assembly to move along the guide rail assembly 13 by driving the lead screw 14. The screw rod 14 is driven by controlling the servo motor 3, and then the shielding slide block is driven by the shielding block sliding connecting rod, so that the position of the shielding slide block is adjusted, the size of the collimation window is changed, and the adjusting function of the gamma ray flux is realized.
Specifically, the collimator device capable of automatically adjusting the gamma ray flux further comprises a base 10 and a lead shielding block fixing assembly 7, wherein the collimator outer shielding body 2 mainly comprises a collimator lining 5 and a lead shielding block 6; the material of the collimator lining 5 is preferably steel, and the collimator lining 5 serves as a framework structure of the collimator outer shielding body 2 to reinforce the structural strength and fix the lead shielding block 6. The collimator lining 5 is arranged at the rear end of the collimator outer shielding body 2, the lead shielding blocks 6 are arranged at two sides of the collimator outer shielding body 2, and the collimator lining 5 is connected with the lead shielding blocks 6; as shown in fig. 3, the lead shield 6 is fixedly mounted on the base 10 by a lead shield fixing member 7. A bolt groove 9 is formed in the base 10, the lead shielding block fixing assembly 7 is fixed in the bolt groove 9 through a bolt 8, and the collimator device is integrally fixed, so that the collimator device is guaranteed not to move in the measuring process; when the collimator is installed, the shielding block fixing component 7 is buckled on the lead shielding block 6 of the collimator outer shielding body 2 and fixed at the base 10 through the bolt 8.
The automatic shielding slider adjusting device further comprises a limit switch 16, and the limit switch 16 can limit the movement range of the shielding slider assembly 12 along the lead screw 14 and prevent interference and collision with a wall surface. The number of the limit switches 16 is at least two, and the limit switches 16 are respectively arranged at two ends of the screw rod 14. The limit switch 16 limits the moving range of the collimating port shielding sliding block assembly between a first position and a second position, limits the adjusting range of the collimating port shielding sliding block assembly, and plays a role of a protection device. As shown in fig. 6, the first slider 121 and the second slider 122 are located at the first position, and when the first position is located, the collimating window is adjusted to the minimum opening size; as shown in fig. 7, the first and second sliders 121 and 122 are located at the second position, and when the second position is reached, the collimating window is adjusted to the maximum opening size.
As shown in fig. 4 and 5, the guide rail assembly 13 is composed of a first guide rail 131 and a second guide rail 132; the first guide rail 131 and the second guide rail 132 are inclined inward along the front end of the collimator outer shield 2, are symmetrically installed on both sides with the detector as the center, and are arranged in a splayed shape from the outside to the inside along the collimating window. The collimating aperture shielding slide block assembly 12 is composed of a first slide block 121 and a second slide block 122; the first slider 121 is slidable on the first guide rail 131, and the second slider 122 is slidable on the second guide rail 132; the first slider 121 and the second slider 122 are connected with the lead screw 14 through the shielding block sliding connecting rod 17, and the distance between the first slider 121 and the detector 1 and the distance between the second slider 122 and the detector 1 are kept the same, so that the synchronous movement of the shielding slider assembly of the collimation opening is ensured. Through the automatic adjustment of the collimating aperture shielding sliding block assembly 12, the positions of the first sliding block 121 and the second sliding block 122 can be changed, and then the size of the opening of the collimating window is changed, so that the automatic adjustment of the gamma ray flux is realized. The device can automatically adjust the gamma ray flux entering the sensitive volume of the detector according to the initial measurement value, has similar adjusting function to low-energy to high-energy rays, is simple to operate and compact in structure, and is suitable for a nuclear power plant and a nuclear technology application radioactive waste detection system.
As shown in fig. 8, the inside major dimensions of the collimator device are marked, and the actual manufacturing can refer to the dimensions shown in the figure and can be changed according to a certain proportion.
The invention also discloses a measuring system capable of automatically adjusting the gamma ray flux, which comprises the collimator device capable of automatically adjusting the gamma ray flux and a software control device; the software control device is connected with the servo motor 3 and the detector 1. The software control device comprises a detector data acquisition module, a dead time comparison module, a ray flux regulation judgment module and a driving regulation module; the detector data acquisition module is used for acquiring counting rate and dead time parameters of the detector 1; the dead time comparison module is used for comparing the counting rate with a dead time threshold; the ray flux adjustment judging module judges whether to adjust the flux and the adjustment amplitude according to the comparison result of the dead time comparison module; and the driving adjusting module sends a driving signal to the servo motor 3 according to the result of the ray flux adjusting judging module. Set for I +1 different slider positions in slider track direction, do not possess the regulatory function from the innermost end and begin as 0 th position, number in proper order: and 0, 1, 2, …, I, … and I, determining whether the adjustment of the ray flux and the adjustment amplitude are required or not according to the primary measurement result and the dead time of the 0 position detector, determining the position number, giving a rotary stroke signal to the servo motor, driving the lead screw, and driving the adjusting shielding slide block to reach the corresponding position, so that the size of the opening of the collimation window is changed, and the function of adjusting the ray flux is realized.
When the radioactive substance is measured, the high-purity germanium detector 1 is used for detecting gamma rays emitted by the radioactive substance, the data measured by the detector 1 can obtain radionuclide information in the radioactive substance through spectral analysis, and the activity of the radionuclide can be obtained through reconstruction calculation. In order to eliminate the influence of the environment on the measurement, a lead shielding and collimator device is added outside the detector crystal. The detector 1 and the collimator device are fixed on a detector platform, and activity reconstruction is carried out on the radioactive substance according to the measuring method of the SGS technology and the TGS technology. If the radioactive intensity of the radioactive substance is high, it is easy to cause a plurality of gamma rays to enter the detector crystal within a short time, so that the detector 1 cannot correctly distinguish and output the count of the gamma rays, i.e. a dead time effect occurs.
The invention discloses a measuring system capable of automatically adjusting gamma ray flux, which is characterized in that when in actual measurement, a detector 1 is utilized to carry out initial measurement on radioactive waste, according to counting rate and dead time parameters provided by the detector, control software is used for comparing set dead time threshold values to determine whether the adjustment of the gamma ray flux is needed or not, the adjustment amplitude is determined, the set position of a collimating port shielding sliding block component 12 is determined, a signal is sent to a servo motor 3 to drive a lead screw 14, and the lead screw component 13 slides to a specified position along a guide rail component 13, so that the size of the collimating port is changed, and the function of adjusting the gamma ray flux entering a sensitive volume of the detector is realized.
At this time, the obtained detector count rates are:
in the formula
α for adjusting the count rate of the n-th energy gamma ray detected by the detector when the rear shielding slide block is at the i-th positionnEmitting an nth energy gamma ray branch ratio for the radionuclide in the waste; a is the radioactivity of the radionuclide, in Bq; enξ, for shielding the detection efficiency of the nth energy gamma ray when the sliding block is at the first position, namely the original detection efficiency, wherein the first position is a position without regulation functionniIs the attenuation ratio of the detection efficiency of the nth energy gamma ray when the shielding sliding block is positioned at the ith position, namely the adjustment coefficient, and ξniEstablishing a database, automatically checking values according to ray energy and slide block position numbers when in use, and implementing correction of activity reconstruction:
Ar＝A'/ξni
wherein A' is the radioactivity activity given by the reconstruction of the detection system and is obtained by calculating the original detection efficiency, ArIs the activity after correction. Through the regulation, the detection accuracy of the detection system to different radiation level waste barrels is ensured, the detection upper limit of the measurement system is widened, and the measurement requirements of low energy to high energy rays can be considered due to the fact that the ray flux is regulated instead of the shielding material directly absorbing rays.
Through the regulation, the detection accuracy of the detection system to different radiation level waste barrels is ensured, the detection upper limit of the measurement system is widened, and the measurement requirements of low energy to high energy rays can be considered.
Table 1 shows the adjustment coefficient ξ of the collimator shielding slider at different positions under typical nuclides, and it can be found that the attenuation effects of the invention on low-energy and high-energy rays are basically consistent, the adjustment range is about 0.25 to 1, and the detection upper limit can be expanded by 4 times. Meanwhile, if a regulation method that lead shielding materials are adopted to absorb gamma rays is adopted, the attenuation effects of the gamma rays with different energies are inconsistent. For example, a 2cm lead block emits a gamma ray of 1.33MeV for the Co-60 species attenuated to 0.2871, while a gamma ray of 0.356MeV for the Ba-133 species attenuated to 0.002, which differs by a factor of 100, resulting in an inefficient measurement of the Ba-133 species.
TABLE 1 comparison of the Regulation coefficients of the invention and the Block absorption Gamma ray method
In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
Claims (8)
1. The collimator device capable of automatically adjusting the gamma ray flux is characterized by comprising an outer collimator shield (2) and a cavity formed by the inner space of the outer collimator shield (2);
a collimation window is arranged at the front section of the collimator outer shield (2), a through hole is arranged at the rear section of the collimator outer shield (2), the through hole is connected with the detector (1), and gamma rays can enter the detector (1) from the collimation window;
the cavity is internally provided with a collimating port shielding sliding block component (12) and an automatic shielding sliding block adjusting device, the size of a collimating window can be adjusted by the movement of the collimating port shielding sliding block component (12), and the automatic shielding sliding block adjusting device controls the movement of the collimating port shielding sliding block component (12);
the automatic shielding slider adjusting device comprises a servo motor (3), a gear transmission case (4), a gear assembly connecting rod (11), a guide rail assembly (13), a screw rod (14) and a gear assembly (15);
the servo motor (3) and the gear box (4) are arranged on the outer surface of the collimator outer shielding body (2), and the gear assembly connecting rod (11), the guide rail assembly (13), the lead screw (14) and the gear assembly (15) are arranged in the cavity;
the servo motor (3) is connected with a gear transmission case (4);
the gear box (4) is connected with a screw rod (14) through a gear assembly connecting rod (11) and a gear assembly (15);
the lead screw (14) is connected with the collimating port shielding sliding block assembly (12);
the guide rail assembly (13) is arranged along the axial direction of the collimator outer shielding body (2), the axial direction is parallel or approximately parallel to the detector (1), and the connection angle of the guide rail assembly (13) and the collimation window is different from the connection angle of the guide rail assembly (13) and the other end of the collimator outer shielding body (2);
the servo motor (3) drives the collimating aperture shielding sliding block assembly (12) to move along the guide rail assembly (13) through the driving lead screw (14).
2. The collimator device capable of automatically adjusting gamma ray flux according to claim 1, further comprising a base (10), a lead shielding block fixing assembly (7), wherein the collimator outer shielding body (2) mainly consists of a collimator inner lining (5) and a lead shielding block (6);
the through hole is formed in the collimator lining (5) and faces the incidence direction of gamma rays, the lead shielding block (6) is located on the side face of the collimator lining (5), and the collimator lining (5) is connected with the lead shielding block (6);
the lead shielding block (6) is fixedly arranged on the base (10) by a lead shielding block fixing component (7).
3. The collimator device capable of automatically adjusting gamma ray flux according to claim 1, wherein the shielding slider automatic adjusting device further comprises a limit switch (16), the limit switch (16) being capable of limiting the range of motion of the collimating port shielding slider assembly (12) along the lead screw (14).
4. The collimator device capable of automatically adjusting the flux of gamma rays according to claim 3, wherein there are at least two limit switches (16), and the two limit switches (16) are respectively disposed at two ends of the lead screw (14).
5. The collimator device capable of automatically adjusting gamma-ray flux according to claim 1, wherein the guide rail assembly (13) is mainly composed of a first guide rail (131), a second guide rail (132);
the collimating aperture shielding sliding block assembly mainly comprises a first sliding block (121) and a second sliding block (122);
the first slider (121) can slide on the first guide rail (131), and the second slider (122) can slide on the second guide rail (132);
the first sliding block (121) and the second sliding block (122) are connected with the lead screw (14) through the shielding block sliding connecting rod (17), and the distance between the first sliding block (121) and the detector (1) and the distance between the second sliding block (122) and the detector (1) are kept the same.
6. An automatically adjustable gamma-ray flux measurement system, comprising an automatically adjustable gamma-ray flux collimator device as claimed in any one of claims 1 to 5, further comprising software control means;
the software control device is connected with the servo motor (3) and the detector (1).
7. The system for measuring the flux of gamma rays automatically regulated according to claim 6, wherein the software control device comprises a detector data acquisition module, a dead time comparison module, a ray flux regulation judgment module and a driving regulation module;
the detector data acquisition module acquires the counting rate of the detector (1);
the dead time comparison module compares the counting rate with a dead time threshold value to obtain a comparison result;
the ray flux adjustment judging module judges whether to adjust the flux and the adjustment amplitude according to the comparison result to obtain a judgment result;
and the driving adjusting module sends a driving signal to the servo motor (3) according to the judgment result.
8. The system of claim 7, wherein the count rate is calculated by:
in the formula
α for adjusting the count rate of the n-th energy gamma ray detected by the detector when the rear shielding slide block is at the i-th positionnEmitting an nth energy gamma ray branch ratio for the radionuclide in the waste; a is the radioactivity of the radionuclide, in Bq; enξ, when the slide block is at the 0 th position, the detection efficiency of the gamma ray with the nth energy is shielded, namely the original detection efficiency, wherein the 0 th position is a position without an adjusting functionniIs the attenuation ratio of the detection efficiency of the nth energy gamma ray when the shielding sliding block is positioned at the ith position, namely the adjustment coefficient, and ξniEstablishing a database, automatically checking values according to ray energy and slide block position numbers when in use, and implementing correction of activity reconstruction:
Ar＝A'/ξni
wherein A' is the radioactivity activity given by the reconstruction of the detection system and is obtained by calculating the original detection efficiency, ArIs the activity after correction.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201811068406.8A CN109471152B (en) | 2018-09-13 | 2018-09-13 | Collimator device capable of automatically adjusting gamma ray flux and measuring system thereof |
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| CN201811068406.8A CN109471152B (en) | 2018-09-13 | 2018-09-13 | Collimator device capable of automatically adjusting gamma ray flux and measuring system thereof |
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| CN109471152A CN109471152A (en) | 2019-03-15 |
| CN109471152B true CN109471152B (en) | 2020-09-15 |
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| CN112295113A (en) * | 2019-08-02 | 2021-02-02 | 上海西门子医疗器械有限公司 | Collimator shell, collimator and radiation imaging equipment |
| CN111650398B (en) * | 2020-05-29 | 2021-08-06 | 上海交通大学 | Device for measuring two-dimensional flow field inside circular tube by LDV (laser direct-current voltage) |
| CN112034504A (en) * | 2020-07-30 | 2020-12-04 | 武汉雅洛诗商贸有限公司 | Atmospheric radioactive scene radiation level detection station |
| CN115798775A (en) * | 2021-09-09 | 2023-03-14 | 同方威视技术股份有限公司 | Ray collimation apparatus and radiation inspection apparatus |
| CN114188049A (en) * | 2021-12-02 | 2022-03-15 | 中国核动力研究设计院 | Ray monitoring device, monitoring method, monitoring system and storage medium |
| CN115429303B (en) * | 2022-08-24 | 2023-07-25 | 瑞石心禾(河北)医疗科技有限公司 | Cylindrical multi-pinhole collimator and imaging device thereof |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3487218A (en) * | 1965-03-25 | 1969-12-30 | Euratom | Neutron collimator with a variable passage cross section |
| DE2118426C3 (en) * | 1971-04-16 | 1973-11-22 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Neutron collimator |
| FR2331867A1 (en) * | 1975-11-14 | 1977-06-10 | Commissariat Energie Atomique | Collimator for neutron beam from a nuclear reactor - esp. water moderated, ensuring easier handling and minimum irradiation |
| JP3848087B2 (en) * | 2001-01-18 | 2006-11-22 | アロカ株式会社 | Radiation detector |
| CN100512906C (en) * | 2003-12-31 | 2009-07-15 | 深圳市尊瑞科技有限公司 | Collimation aperture variable collimation device and varying method thereof |
| CN101339819B (en) * | 2007-07-05 | 2012-03-07 | 同方威视技术股份有限公司 | Remote controllable collimator with four parts independently moving |
| JP6308714B2 (en) * | 2012-08-28 | 2018-04-11 | キヤノン株式会社 | Radiation generating tube and radiation generating apparatus provided with the radiation generating tube |
| CN203673839U (en) * | 2012-12-08 | 2014-06-25 | 成都威铭科技有限公司 | Variable field collimator |
| JP6645965B2 (en) * | 2013-12-11 | 2020-02-14 | コントローラッド システムズ、インコーポレイテッドＣｏｎｔｒｏｌｒａｄ Ｓｙｓｔｅｍｓ，Ｉｎｃ． | X-ray reduction system |
| CN104793235B (en) * | 2015-03-25 | 2017-12-15 | 上海交通大学 | Radwaste detection system detector dead time self-checking device |
| US9711251B2 (en) * | 2015-08-05 | 2017-07-18 | Jefferson Science Associates, Llc | Apparatus and method for variable angle slant hole collimator |
| CN105242298B (en) * | 2015-09-07 | 2018-07-06 | 上海交通大学 | Transmission source stores self-checking device and radwaste detection system |
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