Self-absorption correction method and device for radioactive sample with unknown components

Abstract

The invention discloses a self-absorption correction method and device for a radioactive sample with unknown components, and belongs to the technical field of radioactive source detection.The method comprises the steps that a gamma radioactive source is placed in a groove in the upper end of an upper fixing plate, and the gamma radioactive source serves as a photon source; an empty sample cylinder is placed at the upper end of the lower fixing plate, at the moment, photons emitted by the gamma radioactive source penetrate through the cylinder through a channel in the inner lead body and then are received by the detector, and spectrum unfolding is carried out to calculate the peak area net counting rate N1 of corresponding ray energy. When the method is used, nondestructive measurement can be realized, and compared with a traditional X-ray fluorescence method (XRF), the method has the advantages that a radioactive substance to be detected does not need to be destroyed to obtain a sample matrix, so that nondestructive measurement can be really realized; the cost is reduced, the traditional method needs to adopt X-ray fluorescence for sample component detection, and due to the fact that the method can bring further cost, the technology only needs one lead collimator to achieve all functions, and the cost is further reduced.

Description

Technical Field

[0001] The invention relates to the technical field of radioactive source detection, in particular to a self-absorption correction method for radioactive samples of unknown components and a device thereof. Background Art

[0002] When using a high-purity germanium gamma spectrometer to measure bulk radioactive samples, due to the presence of a certain density and height of the radioactive sample, a portion of the gamma photons will be absorbed by the sample matrix before hitting the detector, causing the number of gamma photons hitting the detector to decrease, ultimately affecting the measurement results. This phenomenon is called the self-absorption effect. Existing solutions are divided into two situations: the sample composition is known and the sample composition is unknown. When the sample composition is known, the XCOM database can be used to calculate the mass attenuation coefficient to calculate the self-absorption correction factor, or the Monte Carlo simulation method can be used to directly simulate and calculate the self-absorption correction factor. However, the above methods are all based on the situation where the sample composition is known; when the sample composition is unknown, the X-ray fluorescence method is often used to detect the sample composition, turning the unknown composition into a known composition, and then using the method with a known sample composition to make corrections;

[0003] X-ray fluorescence method measures specific components, making the unknown sample composition known, but this method requires destructive treatment of the radioactive sample to obtain the radioactive sample matrix, and cannot achieve non-destructive measurement; X-ray fluorescence method measures the obtained matrix sample, which will increase the measurement cost on the one hand, and on the other hand, will cause the loss of the matrix of the radioactive sample.

[0004] Therefore, the present invention provides a method and device for correcting self-absorption of radioactive samples of unknown components to solve the above-mentioned problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for correcting self-absorption of radioactive samples of unknown components to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for correcting self-absorption of radioactive samples of unknown components comprises the following steps:

[0008] Select the radiation source:

[0009] The radiation source is a gamma radiation source;

[0010] Step 1: Place the gamma radiation source in the groove at the upper end of the upper fixing plate so that the gamma radiation source serves as a photon source;

[0011] Step 2: Place the empty sample tube on the upper end of the lower fixed plate. At this time, the photons emitted by the gamma radiation source will pass through the channel in the inner lead body and then be received by the detector, and the spectrum will be analyzed to calculate the peak area net count rate N1 corresponding to the ray energy;

[0012] Step 3: Put the radioactive material into the cylinder, and then put the cylinder on the upper end of the lower fixed plate, so that the docking block and the rotating column are docked. At this time, the threaded rod will move upward. During the upward movement of the threaded rod, it will rotate downward through the rack block, so that the upper layer of the radioactive material is covered by the compression plate and the retraction plate, and then the cylinder is rotated. At this time, since the docking block and the rotating column are in a docking state, the rotating cylinder can drive the movable gear to rotate through the rotating ring. When the movable gear rotates, it will mesh with the fixed gear ring to rotate. At this time, the threaded rod will rotate. When the threaded rod rotates, the connecting ear will move downward along the installation cavity, so that the radioactive material is further compressed by a number of compression plates. When the compression is completed, the retraction plate is pushed along the movable track, so that the retraction plates are unfolded to expose the radioactive material;

[0013] By increasing the density of the radioactive material inside the cylinder, it is possible to avoid the reflection of photons in the gaps of the radioactive material, which would affect the accuracy of the inspection.

[0014] At this time, the photons emitted by the γ radiation source will be received by the detector after passing through the radioactive material, and the spectrum will be analyzed to calculate the peak area net count rate N2 corresponding to the ray energy;

[0015] Step 4: Calculate the mass attenuation coefficient of the energy photon in the sample according to the Beer-Lamber formula;

[0016] Step 5: Replace the gamma radiation source with different energies, repeat the process from step 2 to step 4, obtain the mass attenuation coefficient at different energies, and record the data;

[0017] Step 6: Obtain a set of data of E (energy)-μ (mass attenuation coefficient), take the natural logarithm of the data, use a fourth-order polynomial fit to obtain a fitting curve and fitting parameters, and achieve fitting output of mass attenuation coefficients at different energies;

[0018] Step 7: Calculation of self-absorption correction factor: Integrate the sample according to thickness to obtain the self-absorption correction factor.

[0019] As a further embodiment of the present invention, the gamma radiation source comprises 241 Am(@59.56keV), 133 Ba(@80.9979keV, 276.3989keV, 302.851keV, 356.1029keV, 383.8485keV), 137 Cs(@661.67keV), 152Eu(@121.78keV, 964.06keV, 1408.01keV), 60 Co(@1173.2keV, 1332.5keV).

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. When the present invention is used, non-destructive measurement can be achieved. Compared with the traditional X-ray fluorescence method (XRF), this technology does not need to destroy the radioactive material to be detected to obtain the sample matrix, and can truly achieve non-destructive measurement;

[0022] Cost reduction: Traditional methods require the use of X-ray fluorescence to detect sample composition, which will bring further costs. This technology only needs a lead collimator to achieve all functions, further reducing costs;

[0023] Clean and environmentally friendly. Since the traditional method needs to obtain the matrix components of radioactive materials, the original radioactive materials are destroyed during the processing, which easily leads to the leakage and loss of the components of the radioactive material samples, causing certain radioactive pollution. Since this method does not perform destructive processing, there is no radioactive leakage problem, which is cleaner and more environmentally friendly.

[0024] Compared with the more complicated processes of matrix sampling, sample processing, sample composition analysis, etc. in traditional methods, this technology only requires placing the lead collimator and the corresponding radioactive material on the detector to complete all operations, and the processing and installation are more convenient.

[0025] 2. When the present invention is used, by increasing the density of the radioactive material inside the cylinder, it is possible to avoid the reflection of photons in the gaps of the radioactive material to affect the accuracy of the inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure is a schematic diagram of the structure of a device for self-absorption correction of radioactive samples of unknown composition.

[0027] Figure 2 This is a diagram of the internal structure of a device used for self-absorption correction of radioactive samples of unknown composition.

[0028] Figure 3 This is a diagram showing the internal structure of a device used for self-absorption correction of radioactive samples of unknown composition.

[0029] Figure 4 This is a structural diagram of the lower fixing plate in a device for self-absorption correction of radioactive samples of unknown composition.

[0030] Figure 5 The diagram shows the structure of the sample tube in a device for self-absorption correction of radioactive samples of unknown composition.

[0031] Figure 6 The present invention is a cross-sectional view of a sample cylinder in a device for self-absorption correction of a radioactive sample of unknown composition.

[0032] Figure 7 The diagram shows the structure of a compression cover in a device for self-absorption correction of a radioactive sample of unknown composition.

[0033] Figure 8 This is a structural diagram of a compression plate in a device for self-absorption correction of a radioactive sample of unknown composition.

[0034] Fig. 9 This is a disassembled diagram of a compression plate in a device used for self-absorption correction of a radioactive sample of unknown composition.

[0035] Fig.10 This is a disassembled diagram of the lead collimator in a device used to correct self-absorption of a radioactive sample of unknown composition.

[0036] Fig.11 It is a curve diagram of mass attenuation coefficient at different energies in the present invention.

[0037] Fig.12 This is a simulation diagram of a device for self-absorption correction of a radioactive sample of unknown composition.

[0038] Fig.13 Schematic diagram of the thickness integration of radioactive materials.

[0039] In the figure: 1, housing; 2, support seat; 3, support rod; 4, lower fixing plate; 5, upper fixing plate; 6, detector; 7, lead collimator; 8, sample tube; 9, compression cover;

[0040] 100, power gear ring; 101, driven gear; 102, mounting plate; 401, fixed gear ring; 402, rotating ring; 403, rotating column; 404, movable gear; 700, sleeve; 701, inner lead body; 702, first outer lead sleeve; 703, second outer lead sleeve; 704, third outer lead sleeve;

[0041] 800, cylinder; 801, bottom cavity; 802, installation cavity; 803, threaded rod; 804, docking block; 805, return spring; 806, shielding curtain;

[0042] 900, fixed ring; 901, movable ring; 902, connecting ear; 903, rack block; 904, compression plate; 905, positioning gear; 906, fixed block; 907, retracting plate; 908, movable track; 909, sliding block; 910, connecting rope. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the 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.

[0044] See also Figures 1 to 3 In the embodiment of the present invention, a device for self-absorption correction of radioactive samples of unknown components includes a support base 2, the outer part of the support base 2 is detachably connected to a shell 1, in order to facilitate the separation of the shell 1 from the support base 2, the shell 1 is threadedly connected to the support base 2, the upper end of the support base 2 is rotatably connected to a plurality of support rods 3, a lower fixing plate 4 is movably connected between the plurality of support rods 3, an upper fixing plate 5 is fixedly connected above the lower fixing plate 4, and the spacing between the lower fixing plate 4 and the upper fixing plate 5 can be adjusted. Specifically, in order to facilitate the upper and lower movement of the lower fixing plate 4 between the two support rods 3, two of the support rods 3 are provided with threads on their surfaces, and the other support rods 3 are optical axes, the lower fixing plate 4 is threadedly connected to the support rods 3, and the lower fixing plate 4 is slidably connected to the optical axis, more specifically, the interior of the lower fixing plate 4 is fixedly connected to a threaded sleeve, the threaded sleeve is threadedly connected to the support rod 3, and two sliding The upper and lower fixing plates 5 are connected to each other with the gears 102, 103 and 104 being connected to each other with the gears 106. The lower and upper fixing plates 5 are connected to each other with the gears 107 and 108 being connected to each other with the gears 109.

[0045] The upper end of the support seat 2 is located between the plurality of support rods 3 and is detachably connected with a detector 6 for receiving photons. Specifically, in order to facilitate the connection between the detector 6 and the support seat 2, a mounting plate 102 is fixedly connected inside the support seat 2, and the detector 6 and the mounting plate 102 are detachably connected by screws. More specifically, a plurality of extension rods are fixedly connected to the lower end of the mounting plate 102, and the extension rods pass through the power gear ring 100 and are fixedly connected to the support seat 2.

[0046] The lower ends of the upper fixing plate 5 and the lower fixing plate 4 are detachably connected with a lead collimator 7 for limiting photons. The upper end of the upper fixing plate 5 is provided with a groove for placing a radiation source. The upper end of the lower fixing plate 4 is provided with a sample tube 8 for containing radioactive substances. The radiation source is a gamma radiation source. The specific radiation source includes: 241 Am(@59.56keV), 133 Ba(@80.9979 keV, 276.3989keV, 302.851 keV, 356.1029 keV, 383.8485keV), 137 Cs(@661.67keV), 152 Eu(@121.78keV, 964.06keV, 1408.01keV), 60 Co(@1173.2keV, 1332.5keV).

[0047] Example 2, please refer to Figure 4 -

[0048] Figure 7 , the difference from the first embodiment is that the sample tube 8 is movably connected to a compression cover 9 for compressing radioactive substances, the sample tube 8 comprises a cylinder 800, a bottom cavity 801 connected to the lower fixing plate 4 is formed at the lower end of the cylinder 800, and a magnet ring is fixedly connected to the inside of the bottom cavity 801;

[0049] The cylinder 800 is also rotatably connected to a threaded rod 803 for driving the compression cover 9 to move up and down. The lower end of the threaded rod 803 passes through the bottom end of the cylinder 800. The lower end of the threaded rod 803 is fixedly connected to a docking block 804. The docking block 804 is set in a polygonal shape and is located in the bottom cavity 801. A return spring 805 is set between the docking block 804 and the inner top of the bottom cavity 801. The return spring 805 is sleeved on the outside of the threaded rod 803. Specifically, two installation cavities 802 are symmetrically opened on the inner wall of the cylinder 800. The threaded rod 803 is located in the installation cavity 802. In order to prevent the radioactive substances from affecting the rotation of the threaded rod 803, a foldable shielding curtain 806 is slidably connected to the interior of the installation cavity 802, and the upper end of the shielding curtain 806 is fixedly connected to the compression cover 9. Specifically, limiting grooves are symmetrically opened on the inner wall of the installation cavity 802, and the side ends of the shielding curtain 806 are located in the limiting grooves. The shielding curtain 806 can be positioned by the limiting grooves, and at the same time, the radioactive substances can be prevented from entering the installation cavity 802 through the gap between the shielding curtain 806 and the installation cavity 802.

[0050] Please refer to Figure 4The upper end of the lower fixed plate 4 is fixedly connected with a fixed gear ring 401, which is magnetic and can attract the magnet ring. The upper end of the lower fixed plate 4 is also rotatably connected with a rotating ring 402, which is located outside the fixed gear ring 401. The upper end of the rotating ring 402 is symmetrically rotatably connected with a rotating column 403, and the outer part of the rotating column 403 is fixedly connected with a movable gear 404, which is meshed with the fixed gear ring 401, and the upper end of the rotating column 403 is provided with a slot hole that docks with the docking block 804, and the shape of the slot hole corresponds to the shape of the docking block 804;

[0051] Please refer to Figure 7 The compression cover 9 includes a fixed ring 900, a movable ring 901 is slidably connected inside the fixed ring 900, and the movable ring 901 is fixedly connected to the fixed ring 900 through a plurality of connecting ropes 910. When the movable ring 901 does not move, the connecting ropes 910 are in a loose state. A rubber ring is fixedly connected to the outer wall of the fixed ring 900, and the rubber ring can increase the friction between the fixed ring 900 and the cylinder 800, and can also prevent the radioactive material from overflowing from the gap between the fixed ring 900 and the cylinder 800;

[0052] Two connecting ears 902 are symmetrically fixedly connected to the outer wall of the movable ring 901, and the two connecting ears 902 are threadedly connected to the threaded rod 803, and the connecting ears 902 are located in the installation cavity 802, and the connecting ears 902 can slide in the installation cavity 802;

[0053] Please refer to Figure 7 , the upper end of the movable ring 901 is fixedly connected with a plurality of rack blocks 903, the rack blocks 903 pass through the fixed ring 900, the internal rotation of the fixed ring 900 is connected with a plurality of compression plates 904, and one end of the compression plate 904 close to the fixed ring 900 is fixedly connected with a positioning gear 905, and the positioning gear 905 is meshed with the rack block 903;

[0054] Specifically, a plurality of fixed blocks 906 are fixedly connected to the inner wall of the fixed ring 900, and a plurality of compression plates 904 are rotatably connected to the fixed blocks 906 via rotating shafts;

[0055] See also Figure 8 The upper end of the compression plate 904 is slidably connected to the retracting plate 907, and the compression plate 904 and the retracting plate 907 can be spliced ​​to form a triangular plate. Specifically, the upper end of the compression plate 904 is provided with a movable track 908, and the lower end of the retracting plate 907 is rotatably connected to a sliding block 909, and the sliding block 909 is located in the movable track 908. More specifically, the upper end of the compression plate 904 is provided with an inclined surface, and the lower end of the retracting plate 907 is provided with a slope adapted to the inclined surface on the compression plate 904. Please refer to Fig. 9 .

[0056] For example 3, please refer to Fig.10 Based on Example 1, the lead collimator 7 includes a shell 700, a circular hole is opened at the bottom end of the shell 700, and the shell 700 is detachably connected to the lower fixing plate 4 and the upper fixing plate 5 by bolts. An inner lead body 701 is placed inside the shell 700, and a channel allowing photons to pass through is opened in the middle of the inner lead body 701, and the channel corresponds to the circular hole. The outside of the inner lead body 701 is sequentially sleeved with a first outer lead sleeve 702, a second outer lead sleeve 703 and a third outer lead sleeve 704. Specifically, the inner lead body 701, the first outer lead sleeve 702, the second outer lead sleeve 703 and the third outer lead sleeve 704 are all set to a truncated cone shape, and when the first outer lead sleeve 702, the second outer lead sleeve 703 and the third outer lead sleeve 704 are sleeved on each other, the gaps between them will be filled with lead paste.

[0057] Example 4, based on Examples 1-3, the detection method is as follows:

[0058] Step 1: Place the gamma radiation source in the groove at the upper end of the upper fixing plate 5 so that the gamma radiation source serves as a photon source;

[0059] Step 2: Place the empty sample tube 8 on the upper end of the lower fixed plate 4. At this time, the photons emitted by the gamma radiation source will pass through the channel in the inner lead body 701 and pass through the tube 800 and then be received by the detector 6, and the spectrum will be analyzed to calculate the peak area net count rate N1 corresponding to the ray energy;

[0060] Step 3: Put the radioactive material into the cylinder 800, and then put the cylinder 800 on the upper end of the lower fixed plate 4, so that the docking block 804 docks with the rotating column 403. At this time, the threaded rod 803 will move upward. During the upward movement of the threaded rod 803, it will rotate downward through the rack block 903, so that the upper layer of the radioactive material is covered by the compression plate 904 and the retracting plate 907. Then, the cylinder 800 is rotated. At this time, since the docking block 804 and the rotating column 403 are in a docking state, the rotating cylinder 800 can drive the movable gear 404 to rotate through the rotating ring 402. When the movable gear 404 rotates, it will mesh with the fixed gear ring 401 to rotate. At this time, the threaded rod 803 will rotate. When the threaded rod 803 rotates, the connecting ear 902 will move downward along the installation cavity 802, so that the radioactive material is further compressed by a plurality of compression plates 904. When the compression is completed, the retracting plate 907 is pushed along the movable track 908, so that the plurality of retracting plates 907 are unfolded to expose the radioactive material.

[0061] By increasing the density of the radioactive material inside the cylinder 800, it is possible to avoid the reflection of photons in the gaps of the radioactive material to affect the accuracy of the inspection;

[0062] At this time, the photons emitted by the gamma radiation source will be received by the detector 6 after passing through the radioactive material, and the spectrum will be analyzed to calculate the peak area net count rate N2 corresponding to the energy of the ray;

[0063] Step 4: Calculate the mass attenuation coefficient of the energy photon in the sample according to the Beer-Lamber formula;

[0064] The formula is:

[0065]

[0066] Step 5: Replace the gamma radiation source with different energy. The gamma radiation source includes: 241 Am(@59.56keV), 133 Ba(@80.9979keV、276.3989keV、302.851keV、356.1029keV、383.8485

[0067] keV), 137 Cs(@661.67keV), 152 Eu(@121.78keV, 964.06keV, 1408.01keV), 60 Co (@1173.2keV, 1332.5keV). 5 γ point sources covering low, medium and high energy ranges, repeat the process from step 2 to step 4, obtain the mass attenuation coefficient at different energies, and record the data, please refer to Fig.11 .

[0068] Step 6: Obtain a set of data of E (energy)-μ (mass attenuation coefficient), take the natural logarithm of the data, use a fourth-order polynomial fit to obtain the fitting curve and fitting parameters, and achieve the fitting output of the mass attenuation coefficient at different energies.

[0069] Fitting formula: ln(μ)=a+bln(E)+cln(E) 2 +dln(E) 3 +eln(E) 4

[0070] Step 7: Calculate the self-absorption correction factor using a simple analytical method. Integrate the sample by thickness to get the self-absorption correction factor: For a cylindrical sample with a thickness of h as shown in the figure below, please refer to Fig.13 ;

[0071] Beer-Lamber using rays

[0072] Formula, integrating the entire sample by thickness, yields the following relationship:

[0073] I=∫0 h I0*exp(-μ*x)·dx / h=I0*1-exp(-μ·h) / μ*h

[0074] Thus, the self-absorption correction factor C is obtained att for:

[0075] C att =I / I0=1-exp(-μ·h) / μ*h

[0076] The working principle of the present invention is:

[0077] When the thickness of the lead collimator 7 needs to be changed during use of the present invention, the housing 700 can be opened and then the first outer lead housing 702, the second outer lead housing 703 and the third outer lead housing 704 can be sequentially installed to prevent the photons from deviating from the track, thereby increasing the accuracy of detection;

[0078] When the radioactive material in the cylinder 800 needs to be taken out, the cylinder 800 is pulled upwards. When the cylinder 800 is separated from the fixed gear ring 401, the threaded rod 803 will be reset under the action of the reset spring 805, and the compression plate 904 will be opened, making it easier to pour out the radioactive material.

[0079] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for correcting self-absorption of radioactive samples of unknown components, characterized in that: The following steps are involved: Select the radiation source: The radiation source is a gamma radiation source; Step 1: placing a gamma radiation source in a groove at the upper end of the upper fixing plate (5) so that the gamma radiation source serves as a photon source; Step 2: Place an empty sample tube (8) on the upper end of the lower fixed plate (4). At this time, the photons emitted by the gamma radiation source will pass through the channel in the inner lead body (701) through the tube body (800) and then be received by the detector (6). The spectrum is analyzed and the peak area net count rate N1 corresponding to the ray energy is calculated; Step 3: Place the radioactive material into the cylinder (800), then place the cylinder (800) on the upper end of the lower fixed plate (4), so that the docking block (804) docks with the rotating column (403), and the threaded rod (803) moves upward. During the upward movement of the threaded rod (803), the rack block (903) rotates downward, so that the compression plate (904) and the retracting plate (907) cover the upper layer of the radioactive material, and then rotate the cylinder (800). At this time, since the docking block (804) and the rotating column (403) are in a docking state, the rotating cylinder ( 800) can drive the movable gear (404) to rotate through the rotating ring (402), and when the movable gear (404) rotates, it will mesh with the fixed gear ring (401) to rotate, and at this time the threaded rod (803) will rotate, and when the threaded rod (803) rotates, the connecting ear (902) will move downward along the installation cavity (802), so that the radioactive material is further compressed by the plurality of compression plates (904), and when the compression is completed, the retracting plates (907) are pushed along the movable track (908), so that the plurality of retracting plates (907) are unfolded to expose the radioactive material; By increasing the density of the radioactive material inside the cylinder (800), it is possible to avoid the reflection of photons in the gaps of the radioactive material, which would affect the accuracy of the inspection. At this time, the photons emitted by the gamma radiation source will be received by the detector (6) after passing through the radioactive material, and the spectrum will be analyzed to calculate the peak area net count rate N2 corresponding to the energy of the ray; Step 4: Follow the Beer- Lamber formula, calculate the mass attenuation coefficient of the energy photon in the sample; Step 5: Replace the gamma radiation source with different energies, repeat the process from step 2 to step 4, obtain the mass attenuation coefficient at different energies, and record the data; Step 6: Obtain E (Energy) - A set of data of μ (mass attenuation coefficient), taking the natural logarithm of the data, using a fourth-order polynomial fitting to obtain the fitting curve and fitting parameters, and realizing the fitting output of the mass attenuation coefficient at different energies; Step 7: Calculation of self-absorption correction factor: Integrate the sample according to thickness to obtain the self-absorption correction factor.

2. A method for correcting self-absorption of radioactive samples of unknown components according to claim 1, characterized in that: The gamma radiation source includes 241 Am(@59.56keV), 133 Ba(@80.9979 keV, 276.3989keV, 302.851keV, 356.1029keV, 383.8485keV), 137 Cs(@661.67keV), 152 Eu(@121.78keV、964.06keV、1408.01keV)、 60 Co (@1173.2keV, 1332.5keV).

3. A device for correcting self-absorption of radioactive samples of unknown components, used in the method for correcting self-absorption of radioactive samples of unknown components according to claim 1, characterized in that: The invention comprises a support seat (2), the outer part of which is detachably connected to a shell (1), the upper end of which is rotatably connected to a plurality of support rods (3), a lower fixing plate (4) is movably connected between the plurality of support rods (3), an upper fixing plate (5) is fixedly connected above the lower fixing plate (4), and the spacing between the lower fixing plate (4) and the upper fixing plate (5) can be adjusted, and in order to facilitate the rotation of the support rods (3), the upper end of the support seat (2) is rotatably connected to a power gear ring (100), and the outer walls of the two support rods (3) with threads are fixedly connected to driven gears (101), and the driven gears (101) and the power gear ring (100) are meshed with each other.

4. The device for self-absorption correction of radioactive samples of unknown components according to claim 3, characterized in that: The upper end of the support seat (2) is located between a plurality of support rods (3) and is detachably connected to a detector (6) for receiving photons.

5. The device for self-absorption correction of radioactive samples of unknown components according to claim 3, characterized in that: The lower ends of the upper fixing plate (5) and the lower fixing plate (4) are detachably connected with a lead collimator (7) for limiting photons, the upper end of the upper fixing plate (5) is provided with a groove for placing a radiation source, and the upper end of the lower fixing plate (4) is provided with a sample cylinder (8) for containing radioactive substances.

6. The device for self-absorption correction of radioactive samples of unknown components according to claim 5, characterized in that: The sample tube (8) is movably connected to a compression cover (9) for compressing radioactive substances. The sample tube (8) comprises a tube body (800). A bottom cavity (801) is provided at the lower end of the tube body (800) and is connected to a lower fixed plate (4). A magnet ring is fixedly connected to the inside of the bottom cavity (801).

7. The device for self-absorption correction of radioactive samples of unknown components according to claim 6, characterized in that: The interior of the cylinder (800) is also rotatably connected to a threaded rod (803) for driving the compression cover (9) to move up and down. The lower end of the threaded rod (803) passes through the bottom end of the cylinder (800). The lower end of the threaded rod (803) is fixedly connected to a docking block (804). A return spring (805) is provided between the docking block (804) and the internal top end of the bottom cavity (801). In order to prevent radioactive substances from affecting the rotation of the threaded rod (803), the interior of the installation cavity (802) is slidably connected to a foldable shielding curtain (806), and the upper end of the shielding curtain (806) is fixedly connected to the compression cover (9).

8. The device for self-absorption correction of radioactive samples of unknown components according to claim 7, characterized in that: The upper end of the lower fixed plate (4) is fixedly connected to a fixed gear ring (401), the fixed gear ring (401) is magnetic and can attract the magnet ring. The upper end of the lower fixed plate (4) is also rotatably connected to a rotating ring (402), the upper end of the rotating ring (402) is symmetrically rotatably connected to a rotating column (403), the outside of the rotating column (403) is fixedly connected to a movable gear (404), the movable gear (404) is meshed with the fixed gear ring (401), and the upper end of the rotating column (403) is provided with a slot hole for docking with a docking block (804).

9. The device for self-absorption correction of radioactive samples of unknown components according to claim 6, characterized in that: The compression cover (9) comprises a fixed ring (900), the interior of the fixed ring (900) is slidably connected to a movable ring (901), the movable ring (901) and the fixed ring (900) are fixedly connected via a plurality of connecting ropes (910), a rubber ring is fixedly connected to the outer wall of the fixed ring (900), and the rubber ring can increase the friction between the fixed ring (900) and the cylinder (800).

10. The device for self-absorption correction of radioactive samples of unknown components according to claim 9, characterized in that: Two connecting ears (902) are symmetrically fixedly connected to the outer wall of the movable ring (901), the two connecting ears (902) are threadedly connected to the threaded rod (803), and the connecting ears (902) are located in the installation cavity (802); The upper end of the movable ring (901) is fixedly connected to a plurality of rack blocks (903), the rack blocks (903) pass through the fixed ring (900), the interior of the fixed ring (900) is rotatably connected to a plurality of compression plates (904), and one end of the compression plate (904) close to the fixed ring (900) is fixedly connected to a positioning gear (905), and the positioning gear (905) is meshed with the rack block (903); The upper end of the compression plate (904) is slidably connected to an inner retracting plate (907), and the compression plate (904) and the inner retracting plate (907) can be spliced ​​to form a triangular plate; The lead collimator (7) comprises a casing (700), a circular hole is provided at the bottom end of the casing (700), the casing (700) is detachably connected to the lower fixing plate (4) and the upper fixing plate (5) by bolts, an inner lead body (701) is placed inside the casing (700), a channel for allowing photons to pass through is provided in the middle of the inner lead body (701), and the channel corresponds to the circular hole, and a first outer lead sleeve (702), a second outer lead sleeve (703) and a third outer lead sleeve (704) are sequentially provided outside the inner lead body (701).

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