Method and system for re-screening dispersity of thermoluminescence detector

Abstract

The invention provides a method and a system for re-screening the dispersity of a thermoluminescent detector, which are used for providing a radiation field for screening the dispersity of the thermoluminescent detector by utilizing medical and industrial radiation source equipment, and optimizing the irradiation geometric condition of the thermoluminescent detector. Dependence of a dispersion screening process of the thermoluminescence detector on a special radiation source is eliminated, the hardware threshold is remarkably reduced, the operation process of re-screening of the thermoluminescence detector is simplified, and the overall quality and efficiency of thermoluminescence dose monitoring work are improved. The method comprises the following steps: processing measurement and reading data of thermoluminescence detectors, firstly removing the thermoluminescence detectors with measurement results except # imgabs0 #, then recalculating an average value # imgabs1 # of sampling inspection samples after abnormal values are removed, calculating a dispersity control range # imgabs2 # of the thermoluminescence detectors in the same batch, then removing the thermoluminescence detectors with measurement results except # imgabs3 #, and finally calculating the dispersity control range # imgabs2 # of the thermoluminescence detectors in the same batch. And the accuracy and reliability of a re-screening result are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of thermoluminescence detection, and in particular relates to a thermoluminescence detector dispersion multiple screening method and system. Background Art

[0002] A thermoluminescent detector (TLD) is a certain amount of thermoluminescent material, or a mixture of this material and other non-luminescent materials in a certain weight ratio with a certain mass, shape or size. When the detector is irradiated, it absorbs and stores part of the energy of the rays, and releases this energy in the form of light when the detector is heated during the measurement process. The amount of luminescence stimulated by heating is linearly related to the irradiation dose value within a certain range.

[0003] Thermoluminescent detectors are the core components of thermoluminescent dose monitoring. In the same batch, the sensitivity of different detectors varies greatly. Before leaving the factory, the manufacturer will use a special standard radiation source to screen and group thermoluminescent detectors, and divide thermoluminescent detectors with similar performance into one group to ensure the consistency of the measurement results of the entire batch of thermoluminescent detectors. During the use of thermoluminescent detectors, factors such as storage conditions, annealing and cooling conditions, and frequency of use will cause their performance to change, resulting in a decrease in the consistency of the measurement results of the entire batch of thermoluminescent detectors, affecting the accuracy and reliability of the measurement results. Therefore, it is necessary to regularly re-measure the dispersion of thermoluminescent detectors and eliminate dose sheets with large deviations to ensure the consistency of the measurement results.

[0004] At present, most of the units using thermoluminescence detectors have not carried out the work of re-screening the dispersion of thermoluminescence detectors during the use of thermoluminescence detectors. The main reasons include the following two aspects: (1) Lack of standard radiation source: Most users are not equipped with a special standard radiation source for screening the dispersion of thermoluminescence detectors, and are unable to provide a standard radiation field for complex screening of the dispersion of thermoluminescence detectors.

[0005] (2) Lack of standard guidance methods: There is currently no standard method for guiding the re-screening operation of thermoluminescence detectors, resulting in no standard method for reference for the re-screening of the dispersion of thermoluminescence detectors. Summary of the invention

[0006] The purpose of the present invention is to provide a method and system for multiplexing the dispersion of thermoluminescence detectors to overcome the above-mentioned technical problems existing in the prior art.

[0007] To this end, the technical solution provided by the present invention is as follows: A method for multiplexing the dispersion of a thermoluminescence detector, comprising the following steps: Step 1) Place the tray containing thermoluminescent detectors from the same production batch horizontally and irradiate them with a standard radiation source device; the standard radiation source device operates under rated working parameters, and the irradiation dose of the thermoluminescent detector is 1-10mSv; Step 2) storing the irradiated thermoluminescence detector; Step 3) Randomly select 50-100 thermoluminescent detectors from the same tray as the sampling samples, measure them with the thermoluminescent dosimeter reader, and calculate the average value of the measurement results of the selected thermoluminescent detectors and standard deviation S , remove the measurement results in Then recalculate the average value of the sample after removing the outliers. , and according to Get the dispersion control range of this batch of thermoluminescence detectors , remove the sample with the measurement result in Other thermoluminescent detectors; Step 4) Read the remaining thermoluminescence detectors in the tray. Those within the limit are retained, otherwise they are discarded, thus completing the multiple screening of thermoluminescence detectors in the entire tray. The standard radiation source equipment includes medical digital X-ray photography equipment, X-ray screen photography equipment, computer X-ray photography equipment, X-ray fluoroscopy equipment, digital subtraction angiography X-ray equipment, medical electronic linear accelerator, industrial X-ray flaw detector and industrial electronic linear accelerator.

[0008] When using standard radiation source equipment for irradiation in step 1), the useful beam emitted by the radiation source equipment irradiates the plane where the tray is located vertically, so that the distance from the target point of the X-ray tube to the center of the tray is 90-100 cm and the center of the tray coincides with the center of the useful beam, and the irradiation field of view is adjusted to the maximum and completely covers the tray.

[0009] Step 2) When storing the irradiated thermoluminescent detector, place it in a lead can or store it in a dark environment without other ionizing radiation sources and at a temperature not exceeding 100° C. Thermoluminescent detectors in different trays are stored separately for 1-3 days.

[0010] The specific process of step 3) is as follows: S1. Randomly select 50 to 100 thermoluminescence detectors from the same tray for measurement and reading, and place the measured thermoluminescence detectors in the measurement and reading order; S2. Calculate the average value of sample measurement results and the standard deviation of the measurement results S ;

[0011]

[0012] In the formula, For the sample i Thermoluminescence detector reading results, mSv; n is the number of samples of thermoluminescence detectors to be inspected, 50≤n≤100; S3. The measurement results of the random samples are recorded in Thermoluminescent detectors other than those above shall be eliminated; the number of remaining thermoluminescent detectors after elimination shall be no less than 50, otherwise they shall be supplemented; S4. Recalculate the average value of the sample after removing outliers , calculate the dispersion control range of this batch of thermoluminescence detectors , ; S5. Eliminate the sample samples with measurement results Other thermoluminescent detectors; S6. Read the remaining thermoluminescence detectors in the tray. The measurement results are Those within the range shall be retained, otherwise they shall be eliminated.

[0013] The tray is round or square, the radius of the round tray is no more than 10 cm, the side length of the square tray is no more than 20 cm, and the surface of the tray is flat and smooth.

[0014] Before step 1), all the thermoluminescent detectors that have been screened are annealed according to the standard conditions given at the factory.

[0015] After the thermoluminescent detectors are measured in S1, if the reading results of more than half of the thermoluminescent detectors in the sample are less than 1.0mSv or 1mGy, the thermoluminescent detectors are re-annealed and irradiated according to the standard conditions when leaving the factory; if the reading result given by the thermoluminescent dosimeter reader is a count, it is converted into a dose value using the scale factor given by the metering mechanism, and then a judgment is made.

[0016] When placing the thermoluminescent detectors, they are laid flat in the tray without overlapping or blocking each other. If the thermoluminescent detectors of the same batch to be screened cannot be placed in the same tray, they are divided into several trays for separate irradiation and screening.

[0017] A thermoluminescence detector dispersion multiple screening system comprises a tray, a standard radiation source and an inspection bed. The standard radiation source is used to provide a standard radiation field for the thermoluminescence detector dispersion multiple screening. The inspection bed is used to place the tray containing the thermoluminescence detector. The irradiation light of the standard radiation source completely covers the tray.

[0018] The beneficial effects of the present invention are: The method for multiple screening of the dispersion of thermoluminescence detectors provided by the present invention utilizes radiation source equipment in medicine and industry to provide a radiation field for the dispersion screening of thermoluminescence detectors, and optimizes the irradiation geometric conditions of the thermoluminescence detectors, thereby getting rid of the dependence of the dispersion screening process of the thermoluminescence detectors on a dedicated radiation source, significantly lowering the hardware threshold, simplifying the operational process of multiple screening of thermoluminescence detectors, and improving the overall quality and efficiency of thermoluminescence dose monitoring.

[0019] The present invention processes the data measured by the thermoluminescence detector, firstly eliminates the measurement results Then recalculate the average value of the sample after removing the outliers. , calculate the dispersion control range of this batch of thermoluminescence detectors , and then the measurement results are Thermoluminescence detectors other than those tested are randomly inspected and finally retained or eliminated, ensuring the accuracy and reliability of the multiple screening results. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the placement of the thermoluminescence detector tray in an embodiment of the present invention.

[0021] In the picture: 1. Tray; 2. X-ray tube; 3. Examination bed. DETAILED DESCRIPTION

[0022] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0023] Reference is now made to the exemplary embodiments of the present invention, however, the present invention may be implemented in many different forms and is not limited to the embodiments described herein, which are provided to fully and completely disclose the present invention and fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments are not intended to limit the present invention.

[0024] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0025] Example 1 The present invention provides a method for multiplexing the dispersion of a thermoluminescence detector, comprising the following steps: Step 1) Place the tray containing thermoluminescent detectors from the same production batch horizontally and irradiate them with a standard radiation source device; the standard radiation source device operates under rated working parameters, and the irradiation dose of the thermoluminescent detector is 1-10mSv; Step 2) storing the irradiated thermoluminescence detector; Step 3) Randomly select 50-100 thermoluminescent detectors from the same tray as the sampling samples, measure them with the thermoluminescent dosimeter reader, and calculate the average value of the measurement results of the selected thermoluminescent detectors and standard deviation S , remove the measurement results in Then recalculate the average value of the sample after removing the outliers. , and according to Get the dispersion control range of this batch of thermoluminescence detectors , remove the sample samples with measurement results in Other thermoluminescent detectors; Step 4) Read the remaining thermoluminescence detectors in the tray. Those within the limit are retained, otherwise they are discarded, thus completing the multiple screening of thermoluminescence detectors in the entire tray. The present invention ensures the accuracy and reliability of the multiple screening results by processing the data measured by the thermoluminescence detector.

[0026] Example 2 Based on Example 1, this example provides a method for complex screening of the dispersion of thermoluminescence detectors, wherein the standard radiation source equipment includes medical digital X-ray photography equipment, X-ray screen photography equipment, computer X-ray photography equipment, X-ray fluoroscopy equipment, digital subtraction angiography X-ray equipment, medical electron linear accelerator, industrial X-ray flaw detector and industrial electron linear accelerator.

[0027] These standard radiation source devices are widely distributed and easy to operate, which significantly reduces the hardware threshold for repeated screening work, effectively solves the technical difficulties encountered by many users in this link, and improves the overall quality and efficiency of thermoluminescence dose monitoring work.

[0028] Example 3 Based on Example 1, this example provides a method for complex screening of the dispersion of thermoluminescent detectors. When a standard radiation source device is used for irradiation in step 1), the useful beam emitted by the radiation source device vertically irradiates the plane where the tray 1 is located, so that the distance from the target point of the X-ray tube to the center of the tray is 90-100 cm and the center of the tray 1 coincides with the center of the useful beam, and the irradiation field of view is adjusted to the maximum and completely covers the tray 1.

[0029] This embodiment takes medical digital X-ray imaging equipment as an example. Figure 1 As shown, the tray 1 containing the thermoluminescent detector is horizontally placed on the digital X-ray photography equipment inspection bed 3 or the floor of the inspection room, and the head of the digital X-ray photography equipment is adjusted so that the useful beam vertically irradiates the plane where the tray 1 is located, the distance d from the target point of the X-ray tube 2 to the center of the tray 1 is 100 cm, the center of the tray 1 coincides with the center of the useful beam, and the irradiation field of view is adjusted to the maximum and completely covers the tray 1.

[0030] Digital X-ray equipment working parameters: a) Tube voltage: Select the most stable tube voltage between 70 kV and 100 kV, and select 80 kV in this embodiment.

[0031] b) Tube current-time product: The tube current-time product commonly used in clinical practice is selected, and 200 mAs is selected in this embodiment.

[0032] Example 4 On the basis of Example 1, this example provides a multiple screening method for the dispersion of thermoluminescence detectors, wherein step 2) when storing the irradiated thermoluminescence detectors, they are placed in a lead can or stored in a dark environment without other ionizing radiation sources and at a temperature not exceeding 100°C. The thermoluminescence detectors in different trays are stored separately for 1-3 days.

[0033] In order to ensure the accuracy and reliability of the multiple screening, the thermoluminescence detector should be stored in a place without other ionizing radiation sources. It is advisable to avoid strong light exposure during the storage process. It should be stored in dark conditions as much as possible. The storage environment should be dry and clean, and avoid being in an environment exceeding 100°C. If conditions permit, the thermoluminescence detector can be stored in a lead can. The storage time is preferably 1 to 3 days, the shortest should not be less than 1 day, and the longest should not exceed 5 days.

[0034] Example 5 On the basis of Example 1, this example provides a method for multiple screening of dispersion of thermoluminescence detectors, and the specific process of step 3) is as follows: S1. Randomly select 50 to 100 thermoluminescence detectors from the same tray 1 for measurement and reading, and place the measured thermoluminescence detectors in the measurement and reading order; S2. Calculate the average value of sample measurement results and the standard deviation of the measurement results S ;

[0035]

[0036] In the formula, For the sample iThermoluminescence detector reading results, mSv; n is the number of samples of thermoluminescence detectors to be inspected, 50≤n≤100; S3. The measurement results of the random samples are recorded in Thermoluminescent detectors other than those above shall be eliminated; the number of remaining thermoluminescent detectors after elimination shall be no less than 50, otherwise they shall be supplemented; S4. Recalculate the average value of the sample after removing outliers , calculate the dispersion control range of this batch of thermoluminescence detectors , ; S5. Eliminate the sample samples with measurement results Other thermoluminescent detectors; S6. Read the remaining thermoluminescence detectors in the tray. The measurement results are Those within the range shall be retained, otherwise they shall be eliminated.

[0037] The tray 1 is round or square, the radius of the round tray is no more than 10 cm, the side length of the square tray is no more than 20 cm, and the surface of the tray 1 is flat and smooth.

[0038] Before step 1), all the thermoluminescent detectors that have been screened are annealed according to the standard conditions given at the factory.

[0039] After the thermoluminescence detectors are measured in S1, if the measurement results of more than half of the thermoluminescence detectors in the sample are less than 1.0 mSv or 1.0 mGy, the thermoluminescence detectors are re-annealed and irradiated according to the standard conditions at the factory.

[0040] After the thermoluminescent detector is measured in S1, if the measurement result given by the thermoluminescent dosimeter reader is a count, it is converted into a dose value using the scale factor given by the metering mechanism, and then a judgment is made.

[0041] When placing the thermoluminescent detectors, they are laid flat in the tray 1 without overlapping or blocking each other; if the thermoluminescent detectors of the same batch to be screened cannot be placed in the same tray 1, they are divided into several trays 1 for separate irradiation and screening.

[0042] The present invention processes the data measured by the thermoluminescence detector, firstly eliminates the measurement results Then recalculate the average value of the sample after removing the outliers. , calculate the dispersion control range of this batch of thermoluminescence detectors , and then the measurement results are Thermoluminescence detectors other than those tested are randomly inspected and finally retained or eliminated, ensuring the accuracy and reliability of the multiple screening results.

[0043] Example 6 This embodiment provides a thermoluminescence detector dispersion multiple screening system, including a tray, a standard radiation source and an examination bed, wherein the standard radiation source is used to provide a standard radiation field for the thermoluminescence detector dispersion multiple screening, the examination bed is used to place a tray containing the thermoluminescence detectors, and the irradiation light of the standard radiation source completely covers the tray.

[0044] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A method for multiplexing the dispersion of thermoluminescence detectors, characterized in that: The following steps are involved: Step 1) Place the tray containing thermoluminescent detectors from the same production batch horizontally and irradiate them with a standard radiation source device; the standard radiation source device operates under rated working parameters, and the irradiation dose of the thermoluminescent detector is 1-10mSv; Step 2) storing the irradiated thermoluminescence detector; Step 3) Randomly select 50-100 thermoluminescent detectors from the same tray as the sampling samples, measure them with the thermoluminescent dosimeter reader, and calculate the average value of the measurement results of the selected thermoluminescent detectors and standard deviation S , remove the measurement results in Then recalculate the average value of the sample after removing the outliers. , and according to Get the dispersion control range of this batch of thermoluminescence detectors , remove the sample with the measurement result in Other thermoluminescent detectors; Step 4) Read the remaining thermoluminescence detectors in the tray. Those within the limit are retained, otherwise they are discarded, thus completing the multiple screening of thermoluminescence detectors in the entire tray.

2. The method for multiplexing dispersion of thermoluminescence detectors according to claim 1, characterized in that: The standard radiation source equipment includes medical digital X-ray photography equipment, X-ray screen photography equipment, computer X-ray photography equipment, X-ray fluoroscopy equipment, digital subtraction angiography X-ray equipment, medical electronic linear accelerator, industrial X-ray flaw detector and industrial electronic linear accelerator.

3. The method for multiplexing dispersion of thermoluminescence detectors according to claim 1, characterized in that: When using standard radiation source equipment for irradiation in step 1), the useful beam emitted by the radiation source equipment irradiates the plane where the tray is located vertically, so that the distance from the target point of the X-ray tube to the center of the tray is 90-100 cm and the center of the tray coincides with the center of the useful beam, and the irradiation field of view is adjusted to the maximum and completely covers the tray.

4. The method for multiplexing dispersion of thermoluminescence detectors according to claim 1, characterized in that: Step 2) When storing the irradiated thermoluminescent detector, place it in a lead can or store it in a dark environment without other ionizing radiation sources and at a temperature not exceeding 100° C. Thermoluminescent detectors in different trays are stored separately for 1-3 days.

5. The method for multiplexing dispersion of thermoluminescence detectors according to claim 1, characterized in that: The specific process of step 3) is as follows: S1. Randomly select 50 to 100 thermoluminescence detectors from the same tray for measurement and reading, and place the measured thermoluminescence detectors in the measurement and reading order; S2. Calculate the average value of sample measurement results and the standard deviation of the measurement results S ; In the formula, For the sample i Thermoluminescence detector reading results, mSv; n is the number of samples of thermoluminescence detectors to be inspected, 50≤n≤100; S3. The measurement results of the random samples are recorded in Thermoluminescent detectors other than those above shall be eliminated; the number of remaining thermoluminescent detectors after elimination shall be no less than 50, otherwise they shall be supplemented; S4. Recalculate the average value of the sample after removing outliers , calculate the dispersion control range of this batch of thermoluminescence detectors , ; S5. Eliminate the sample samples with measurement results Other thermoluminescent detectors; S6. Read the remaining thermoluminescence detectors in the tray. The measurement results are Those within the range shall be retained, otherwise they shall be eliminated.

6. The method for multiplexing dispersion of thermoluminescence detectors according to claim 1, characterized in that: The tray is round or square, the radius of the round tray is no more than 10 cm, the side length of the square tray is no more than 20 cm, and the surface of the tray is flat and smooth.

7. The method for multiplexing dispersion of thermoluminescence detectors according to claim 1, characterized in that: Before step 1), all the thermoluminescent detectors that have been screened are annealed according to the standard conditions given at the factory.

8. The method for multiplexing the dispersion of thermoluminescence detectors according to claim 5, characterized in that: After the thermoluminescence detectors are measured in S1, if the reading results of more than half of the thermoluminescence detectors in the sample are less than 1.0 mSv or 1.0 mGy, the thermoluminescence detectors are re-annealed and irradiated according to the standard conditions at the factory; If the reading result given by the thermoluminescent dosimeter reader is counts, it is converted into a dose value using the scale factor given by the metering mechanism before being judged.

9. A method for multiplexing dispersion of thermoluminescence detectors according to any one of claims 1 to 9, characterized in that: When placing the thermoluminescent detectors, they are laid flat in the tray without overlapping or blocking each other. If the thermoluminescent detectors of the same batch to be screened cannot be placed in the same tray, they are divided into several trays for separate irradiation and screening.

10. A thermoluminescence detector dispersion multiple screening system, characterized in that: It includes a tray, a standard radiation source and an inspection bed. The standard radiation source is used to provide a standard radiation field for multiple screening of dispersion of thermoluminescence detectors. The inspection bed is used to place the tray containing the thermoluminescence detectors. The irradiation light of the standard radiation source completely covers the tray.

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