CN106772528B - Method for measuring radiation dose distribution and nonuniformity of product - Google Patents
Method for measuring radiation dose distribution and nonuniformity of product Download PDFInfo
- Publication number
- CN106772528B CN106772528B CN201611063368.8A CN201611063368A CN106772528B CN 106772528 B CN106772528 B CN 106772528B CN 201611063368 A CN201611063368 A CN 201611063368A CN 106772528 B CN106772528 B CN 106772528B
- Authority
- CN
- China
- Prior art keywords
- paper
- product
- irradiation
- esr
- sample
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/02—Dosimeters
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- High Energy & Nuclear Physics (AREA)
- Molecular Biology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Abstract
The invention discloses a method for measuring the radiation dose distribution and the unevenness of a product, which is characterized in that a packaging paper box or measuring paper which is irradiated with the product is taken, the paper to be measured is extracted from different points, ESR signals of the paper are measured, and the radiation dose distribution and the unevenness of the product are calculated according to the positive correlation between the ESR signals induced in the paper by irradiation and the radiation dose of the product. The method does not need to arrange dosimeters before irradiation treatment to track the whole irradiation process of the product, and the problem of breakage or loss of the dosimeters does not occur; for thousands of cases of products, a large amount of manpower and detection cost can be saved; the method can also determine the half dose depth and the effective range of the electron beam irradiation.
Description
Technical Field
The invention relates to a product irradiation quality control technology in irradiation processing, in particular to a technology for measuring the irradiation dose nonuniformity and dose distribution of gamma, electron beam and X-ray products, and specifically relates to a method for calculating the irradiation dose distribution and the nonuniformity of the product by measuring EPR signals in paper materials.
Background
The irradiation technology is to adopt high-energy rays (gamma, electron beams and X rays) to perform irradiation treatment on food, medical supplies, chemical materials and three wastes to achieve the aims of keeping the products fresh, sterilizing and modifying. The method has the advantages of no temperature rise, no environmental pollution, no preservative residue, quickness, no need of opening the package, convenience for industrial production and the like. During the irradiation process, the irradiation quality of the product is realized by controlling the radiation dose. In order to achieve the desired radiation effect for the product or material, it is necessary to ensure that the product receives a minimum radiation dose, while too high a radiation dose may also deteriorate or cause undesirable product quality. Accordingly, the product irradiation dose distribution and its disparity concept are introduced. The radiation dose distribution of a product refers to the relative ratio u-D of absorbed doses at each site in the producti/DjThe unevenness (U) of which is equal to the maximum value (D) of the absorbed radiation dose of the batch of productsmax) And a minimum value (D)min x) Ratio of (i.e. U-D)max/Dmin. Reducing the non-uniformity of the product irradiation dose can improve the energy utilization of the irradiation device. Therefore, we focus more on the latter. The unevenness of the radiation dose distribution of the product is generally not more than 2 (national dose detection rule)The procedure JJG 591-1989. gamma. radiation source dosimetry).
The product irradiation is usually tracked by adopting a chemical or physical dosimeter, the dosimeter is generally attached to a product box or placed in the product, and the dosimeter is taken out after the product irradiation operation is finished and is measured and calculated to obtain the dosimeter. The method has the disadvantages that dosimeters are arranged before irradiation to track the whole irradiation process of the product, and the follow-up cannot be carried out; secondly, one dosimeter can only represent one site, and if some sites are not easy to arrange dosimeters or the placed sites are inaccurate or the dosimeters are broken or lost, the required result cannot be obtained.
The irradiation of the electron accelerator needs to measure the continuous distribution of the dose in advance and draw a dose depth curve so as to determine the half dose depth and the effective range. The conventional method for arranging dosimeters is very complicated and has large workload. Therefore, there is a great need for an inexpensive and convenient method to accomplish this task.
Disclosure of Invention
The invention aims to extract paper from a packaging carton after product irradiation according to the test result that ESR signals induced in the paper by irradiation are in positive correlation with the irradiation dose of a product, measure the ESR signals and calculate the relative change of the ESR signal intensity so as to obtain the relative change of the irradiation dose, namely the dose distribution and the unevenness of the product.
The object of the invention can be achieved by the following measures:
a method for measuring the radiation dose distribution and the unevenness of a product comprises the following steps: taking a packaging paper box or measuring paper which is irradiated and treated with the product, extracting the paper to be measured from different points, measuring ESR signals of the paper to be measured, and calculating the distribution and the unevenness of the irradiation dose of the product according to the positive correlation between the ESR signals induced in the paper by irradiation and the irradiation dose of the product.
In one embodiment, the assay method of the present invention comprises: after the product is subjected to irradiation treatment, taking a packaging carton or measuring paper which is inside or outside the product and is subjected to irradiation treatment together with the product, respectively extracting paper materials to be detected from at least two sites of the packaging carton or the measuring paper, taking the packaging carton or the measuring paper which is not subjected to irradiation treatment in the same batch as a contrast sample to be detected and extracting the contrast paper material, or taking the packaging carton or the measuring paper which is subjected to irradiation treatment in the same batch as the contrast sample to be detected and extracting the contrast paper material after annealing treatment, measuring ESR signals of the paper materials to be detected and the contrast paper material, and calculating the irradiation dose distribution and the unevenness of the product according to the ESR signal intensity of each paper material.
The source of the packaging paper box or the measuring paper in the method is the same batch of processed products with consistent chemical components, or the same batch of processed products in an accelerator transmission line or a cobalt source irradiation hanging box.
In the method, the control paper material can be directly obtained from the same batch of packaging cartons or measuring paper which is not subjected to irradiation treatment, or indirectly obtained by annealing treatment, and the specific annealing treatment comprises the following steps: and (3) drying the packaging carton or the test paper which is subjected to the same irradiation treatment at the temperature of 90-110 ℃ for 2-6 hours, removing a background signal, and then carrying out ESR (equivalent series resistance) test and calculation.
The determination paper in the invention can be paper which is placed inside or outside the product and is specially used for determination in the method, and can also be paper which is placed inside or outside the product and is used for partial packaging, supporting, blocking or other functions.
The paper to be tested in the method can be selected from a plurality of positions, the simplest mode is to select two positions, and three or more positions can be selected, so that the dose distribution and the unevenness data of a plurality of products can be obtained, and the average or other processing can be carried out on the product. Taking two points as an example, the method for calculating the product dose distribution and the non-uniformity thereof is as follows: u ═ DPaper material 1 to be tested/DPaper material 2 to be tested＝(SPaper material 1 to be tested-SControl paper)/(SPaper material 2 to be tested-SControl paper) In which S isPaper material 1 to be tested、SPaper material 2 to be testedRespectively is the integral value S of the ESR signal intensity of the paper material to be tested on different positions to the g valueThe control paper isThe integral value of the ESR signal intensity of the control paper to the g value is 1.965-2.040 and DPaper material 1 to be tested、DPaper material 2 to be testedThe radiation absorbed doses at different sites are respectively the paper to be measuredAnd (4) normalizing the product dose distribution.
In a preferred embodiment, the sampling and preparing method of the paper to be tested comprises: selecting irradiation dose monitoring sites i and j on paper to be extracted, extracting a paper material sample i and a paper material sample j from an interlayer of the inner walls of the paper at the sites i and j, cutting the paper material sample into a rectangle, weighing, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, and pushing the tube bottom to ensure that the sample height is in a test area. Furthermore, the side length of a rectangle cut by the paper material sample is 2-4cm, the weight of the rectangle is 0.100-0.300 g, and the height of the sample in a testing area of an ESR testing tube is not higher than 3 cm.
The paper material sample in the method is selected from the paper inner wall interlayer instead of the surface layer or the innermost layer, so that the influence of ultraviolet and natural radiation on the outer layer of the carton and the generation of interference signals caused by mechanical operation on the innermost layer of the carton can be reduced
The paper samples can be cut into any shape, but shapes other than rectangular reduce the amount of sample loading and height control during the testing process; in the tests, the sample is generally crushed, but the experiment shows that the crushing mode can generate mechanical free radicals on the material, and the accuracy of the detection result is influenced. The control paper can be selected at only one site, and other sampling and preparation methods are the same as those of the paper to be tested. A sampling and preparation method of a control paper material comprises the following steps: selecting any position on paper to be extracted which is not irradiated or annealed, extracting a paper material sample from an interlayer of the inner wall of the paper at the position, cutting the paper material sample into a rectangle, weighing, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, and pushing the tube bottom to ensure that the sample height is in a test area. Furthermore, the side length of a rectangle cut by the paper material sample is 2-4cm, the weight of the rectangle is 0.100-0.300 g, and the height of the sample in a testing area of an ESR testing tube is not higher than 3 cm.
In the present invention, the paper samples to be tested (including the paper to be tested and the control paper) are tested in the ESR test tube within 15 days, preferably within 7 days.
When the paper to be tested selects the sites i and j, the calculation method of the product dose distribution and the unevenness thereof comprises the following steps: u ═ Di/Dj＝(Si-S0)/(Sj-S0) In which S isi、Sj、S0And D is irradiation absorption dose, and the product dose distribution is subjected to normalization treatment.
In the method, the measurement conditions of the ESR signal of the paper material to be measured are as follows: x wave band with power of 0.1-20 mW; a central magnetic field 348mT, and a scanning width +/-20 mT; the modulation frequency is 50 kHz-100 kHz, and the modulation amplitude is 0.1 mT-1.0 mT; a time constant of 40-200 ms, a scanning rate of 15mT/min, and a gain of 1.0 × 104～1.0×106。
The irradiation treatment of the invention is to adopt high-energy gamma rays, X rays or electron beams for irradiation, and the irradiation energy range is 0.1 MeV-28 MeV; the irradiation dose range of the product is 1.5-45 kGy.
The method is further obtained according to the result that ESR signals induced in paper materials by irradiation are in positive correlation with the irradiation dose of products, and the method is based on the following steps:
1. the material and the method are as follows: the actual radiation absorbed dose was measured by a dichromate dosimeter tracing for 4 replicates per group of 11 sets of paper samples, and was 0, 0.95kGy, 2.2kGy, 4.8kGy, 6.9kGy, 9.7kGy, 18.0kGy, 24.9kGy, 36.2kGy, 42.1kGy, and 55.4 kGy. And (3) extracting a paper material sample i and a paper material sample j from an interlayer on the inner wall of the paper material sample i after irradiation, cutting the paper material into a rectangle with the size of 2-4cm, weighing the rectangle to be about 0.100-0.300 g, curling the rectangle into a cylinder, kneading the cylinder, plugging an ESR test tube along the tube wall, pushing the ESR test tube into the tube bottom by using a special stainless steel shovel, and compacting the ESR test tube to ensure that the sample height is not higher than 3cm in a test area.
ESR measurement: the ESR spectrum was measured under the following conditions: the instrument Bruker Emx-p lus has an X wave band of 9.8GHz and power of 0.63 mW; a central magnetic field 348mT, and a scanning width +/-40 mT; the modulation frequency is 100kHz, and the modulation amplitude is 0.1 mT; time constant 80ms, scanning speed 2.0mT/min, gain 1.0 x 104；
3. Test results and calculation: after the paper material sample is irradiated, the main peak of ESR spectrum is strengthened, and an asymmetric splitting peak appears. And obtaining the integrated ESR signal intensity S by integrating the height of the ESR signal with the g value (g is 1.975-2.040).
In the range of 0-55.4 kGy, obtaining the following through linear regression: kS + m, … … (1),
wherein: k is a coefficient related to the paper composition.
Coefficient of determination R of this experiment2＝0.9805>0.98，k＝7.54×105Where m is-12.71, k and m are the slope and intercept, respectively, of the fitted line, quantities related to the properties of the paper itself.
4. The product dose distribution and the unevenness calculation method thereof are as follows:
in the equation (1), k is not only related to the components of the paper material, but also related to storage time, irradiation temperature, environmental humidity and the like; when S is equal to S0I.e. when not irradiated, D is 0, kS0+m＝0,m＝-kS0Substituting (1) to obtain: D-kS0＝kS-kS0＝k(S-S0)。
But the same batch of paper samples had the same paper composition, storage time, irradiation temperature and ambient humidity, so k was the same. Thus, u ═ Di/Dj＝k(Si-S0)/k(Sj-S0)＝(Si-S0)/(Sj-S0)
When i is max (maximum irradiation dose corresponding site) and j is min (minimum irradiation dose corresponding site), U ═ Smax-S0)/(Smin-S0) I.e. dose non-uniformity of the product irradiation.
Thus, the calculation method of the product dose distribution and the unevenness thereof is obtained: u ═ Si-S0)/(Sj-S0)，Si、Sj、S0The integrated values of ESR signal height to g value (g is 1.965-2.040) of the irradiated dose monitoring site i, the irradiated dose monitoring site j and the non-irradiated paper sample respectively, and the product dose distribution can be obtained by normalization processing.
5.S0The indirect measurement method of (1) is as follows: and taking a sample to be detected, carrying out annealing treatment, namely drying in an oven at the temperature of 100 ℃ for 4 hours, removing a background signal, and then carrying out ESR (equivalent series resistance) measurement and calculation.
And (3) verification test:
TABLE 1 comparison of the u-values determined by the method with standard dosimeters
1. Compared with an alanine standard dosimeter, the u value measurement error is less than 7.98% in the dosage range of 1.5-45.0 kGy, and the u value measurement error is within the allowable range of 8% of irradiation processing dosage error.
2. Because the paper material sample is taken from the same batch of irradiated paper packaging boxes on the same day, the chemical components of the paper material sample, the standing time (within 7 days) before measurement, the irradiation temperature and the environmental humidity are consistent, and the k is the same, so that the measurement result of the u value is not influenced.
3. The ESR signal intensity of the paper sample is obviously attenuated after the paper sample is placed for more than 30 days. Because of the possible difference in the decay rate of ESR signal intensity under different irradiation doses, the ESR measurement in the method should be completed within 15 days, preferably 7 days.
The invention has the beneficial effects that:
1. the method is an innovation of the traditional dose measuring and tracking method, and can realize the tracking of the whole irradiation process of the product by sampling and detecting after the product is irradiated without arranging a dosimeter in advance.
2. Background signals are removed by heating for return, and blank control samples do not need to be reserved. Therefore, the spot check management of product production enterprises and supervision departments can be realized.
3. Samples are taken from the same product box for relative detection, and the actual dosage size does not need to be determined.
4. The method is suitable for the situation that dosimeters are not well laid, such as corners and smooth surfaces; the problem of breaking or losing the dosimeter cannot occur; the ESR signal can be measured at any point on the product box, and the dose distribution information at any point can be obtained.
5. The price is low. The dichromate or common organic glass dosimeter is at least 5 yuan/count, and the dosage sample of the invention is directly obtained from a product box without additional purchase and only needs to pay detection fee. For thousands of boxes of products, the labor and the financial resources are saved.
6. The method can avoid the disturbance phenomenon of the dosimeter placement on the original energy distribution of gamma or electron beam or X-ray irradiation. The electron beam irradiation can be used for determining the half dose depth and the effective range by measuring the vertical and continuous dose distribution on the carton, drawing a dose depth curve.
Drawings
FIG. 1 is an ESR spectrum and integration area induced by irradiation in a paper product bin; wherein the grey scale part represents the value range of g.
FIG. 2 is graph of integrated ESR signal intensity for paper material versus absorbed dose for irradiated product packaging.
Figure 3 is a schematic view of an irradiated product packaging container sampling site.
Detailed Description
The invention is further described below with reference to the figures and examples.
Example 1, measurement of unevenness of irradiation dose of dehydrated vegetables and red dates.
The specifications of the dehydrated vegetables and red dates packing cartons are respectively 30 multiplied by 25 multiplied by 20cm3、25×25×20cm3，Co60Gamma irradiation, dynamic suspension mode, 55X 85X 160cm sling3The predetermined irradiation dose is 6kGy, 2 kGy. 2 sites are respectively selected in the lifting appliance filled with dehydrated vegetables and red dates: top site min (minimum dose), front 3/4 site max (maximum dose), and marking on the outer surface of the carton (both before and after irradiation), samples were taken within 2 days after irradiation. Tearing the paper box, and cutting 2.5 × 4cm from the interlayer of the inner wall of the paper box at the mark2Weighing 0.135g of paper, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, pushing the ESR test tube into the bottom of the tube by using a special stainless steel shovel, and compacting to ensure that the height of a sample is between 2.5 and 2.8 cm.
Separately, 2 samples were taken from the dehydrated vegetables and red dates in the packaging cartons, and dried in an oven at 100 ℃ for 4 hours as a control CK.
After 24 hours, a total of 4X 2 samples were examined with an ESR spectrometer. The measurement conditions were: microwave frequency: x wave band with power of 0.63 mW; magnetic field: a central magnetic field 348mT, and a scanning width +/-10 mT; signal path: modulation frequency of 100kHz, modulation amplitude of 0.1mT, time constant of 40ms, scan rate of 15mT/min, gain of 5.0 × 104。
The product radiation dose non-uniformity was calculated as follows:
Smax、Smin、S0the integral value (g is 1.965-2.04) of ESR signal intensity to g value of the paper material samples of the positions max, min and CK respectively, the dose unevenness of the dehydrated vegetables and red dates is 1.5 and 1.7 respectively, U is less than 2, the requirement of irradiation processing is met, and compared with the actual measurement error of a dichromate standard dosimeter, the dose unevenness of the dehydrated vegetables and red dates is less than 5%, and therefore, the method can be used as an alternative method for measuring the dose unevenness of products.
Example 2, e-beam irradiation dressing and film dosage unevenness determination.
The specifications of the dressing and the facial film packaging carton are respectively 60 multiplied by 28 multiplied by 35cm3、30×25×27cm3And electron beam irradiation (10MeV), plate chain conveying is adopted for conveying under the beam, and the preset irradiation dose is 10 and 15 kGy. 2 sites were respectively selected on the flat side and at the edge of the dressing and mask packaging cartons: min (minimum dose), max (maximum dose) at the edge, and marking (both before and after irradiation) on the outer surface of the carton, and sampling within 7 days after irradiation. Tearing the paper box, and cutting 2.5 × 4cm from the interlayer of the inner wall of the paper box at the mark2Weighing 0.150g of paper, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, pushing the ESR test tube into the tube bottom by using a special stainless steel shovel, and compacting to ensure that the height of a sample is between 2.8 and 3.0 cm.
Another 2 samples were taken from each of the dressing and the face film packaging cartons as control points CK and dried in an oven at 100 ℃ for 4 hours.
After 24 hours, a total of 4X 2 samples were examined with an ESR spectrometer. The measurement conditions were: microwave frequency: x wave band with power of 1.18 mW; magnetic field: a central magnetic field 348mT, and a scanning width +/-10 mT; signal path: modulation frequency of 100kHz, modulation amplitude of 0.4mT, time constant of 80ms, scan rate of 15mT/min, gain of 5.0 × 105。
Smax、Smin、S0The integral value (g is 1.965-2.04) of ESR signal intensity to g value of paper samples of positions max, min and CK respectively, the dosage unevenness of the dressing and the coating agent is 1.3 and 1.3 respectively, U is less than 2, the requirement of irradiation processing is met, and compared with the actual measurement error of an alanine standard dosimeter, the dosage unevenness is less than 5%, and therefore the method can be used as an alternative method for measuring the dosage unevenness of products.
Example 3, X-ray irradiation blood collection needle and glove dose unevenness measurement.
The specifications of the blood taking needle and the glove packing carton are respectively 65 multiplied by 38 multiplied by 35cm3、40×35×67cm3X-ray irradiation (5MeV), conveying under the beam by adopting a crawler belt conveying mode, and presetting irradiation dose to be 25 and 35 kGy. Respectively select 2 loci respectively with the edge on the flat surface of blood taking needle and gloves packing carton: min (minimum dose), max (maximum dose) at the edge, and marking (both before and after irradiation) on the outer surface of the carton, and sampling within 15 days after irradiation. Tearing the paper box, and cutting 2.5 × 4cm from the interlayer of the inner wall of the paper box at the mark2Weighing 0.150g of paper, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, pushing the ESR test tube into the tube bottom by using a special stainless steel shovel, and compacting to ensure that the height of a sample is between 2.8 and 3.0 cm.
In addition, 2 samples were taken from the same batch of packaging cartons without irradiation of the dressing and mask as control points CK.
After 24 hours, a total of 4X 2 samples were examined with an ESR spectrometer. The measurement conditions were: microwave frequency: x wave band with power of 20 mW; magnetic field: central magnetic field 348mT, scanning width +/-10 mT; signal path: modulation frequency of 50kHz, modulation amplitude of 1.0mT, time constant of 100ms, scan rate of 15mT/min, gain of 5.0 × 105。
The product radiation dose non-uniformity was calculated as follows:
Smax、Smin、S0the integral value (g is 1.965-2.04) of ESR signal intensity to g value of paper samples of the positions max, min and CK respectively, the dose unevenness of the blood taking needle and the glove is 1.5 and 1.5 respectively, U is less than 2, the requirement of irradiation processing is met, and compared with the actual measurement error of an alanine standard dosimeter, the measurement error is less than 6%, and therefore the method can be used as an alternative method for measuring the dose unevenness of products.
Example 4, gamma radiation source reference surface dose distribution determination.
The reference surface dose distribution was measured using a simulated product, which was packed in cartons and irradiated using a gamma irradiation source (1.25 MeV). Stacking area of 200X 200cm at 1 meter with cartons filled with simulated product2The reference plane of (1). The preset irradiation dose is 7-10 kGy. At intervals of 30X 40cm2And arranging a dosimeter dot matrix, marking the outer surface of the carton, and sampling within 7 days after irradiation. Tearing the paper box, and cutting 2.5 × 4cm from the interlayer of the inner wall of the paper box at the mark2Weighing 0.150g of paper, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, pushing the ESR test tube into the tube bottom by using a special stainless steel shovel, and compacting to ensure that the height of a sample is between 2.8 and 3.0 cm.
Another 2 samples were taken from the unirradiated batch of packaging cartons each as control points CK.
After 24 hours, a total of 4X 2 samples were examined with an ESR spectrometer. The measurement conditions were: microwave frequency: x wave band with power of 0.63 mW; magnetic field: a central magnetic field 348mT, and a scanning width +/-10 mT; signal path: modulation frequency of 100kHz, modulation amplitude of 1.0mT, time constant of 200ms, scan rate of 15mT/min, gain of 5.0 × 106。
The product radiation dose distribution is calculated as follows:
TABLE 2 integral of ESR signal intensity vs. g value for paper
TABLE 3 reference surface dose distribution determination (normalization treatment)
After the alanine standard dosimeter measurement and the reference surface dose distribution normalization treatment, the maximum and minimum relative dose distributions are 1.42 and 0.95 respectively, and the measurement result of the method is 1.52 and 0.92, and the relative error of the maximum and minimum relative dose distributions is 8.29 percent and less than 10 percent, so the method can be used as an alternative method for measuring the product irradiation dose distribution.
The parts not involved in the present invention are the same as or can be implemented using the prior art.
Claims (3)
1. A method for measuring the radiation dose distribution and the unevenness of the radiation dose distribution of a product is characterized by comprising the following steps:
1) after the product is subjected to irradiation treatment, taking a packaging paper box or measuring paper which is inside or outside the product and is subjected to irradiation treatment together with the product, and respectively extracting paper materials to be measured from at least two sites of the packaging paper box or the measuring paper;
the sampling and preparation method of the paper material to be tested comprises the following steps: selecting irradiation dose monitoring sites i and j on paper to be extracted, extracting a paper material sample i and a paper material sample j from an interlayer of the inner walls of the paper at the sites i and j, cutting the paper material sample into a rectangle, weighing, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, and pushing the tube bottom to ensure that the sample height is in a test area; the side length of the rectangle is 2-4cm, the weight of the rectangle is 0.100-0.300 g, and the height of a sample in a test area of an ESR test tube is not higher than 3 cm;
the source of the packaging paper box or the measuring paper is the same batch of processed products with consistent chemical components, or the same batch of processed products in an accelerator transmission line or a cobalt source irradiation hanging box;
2) taking the same batch of packaging cartons or determination paper which is not subjected to irradiation treatment as a comparison to-be-detected sample and extracting comparison paper materials, or taking the packaging cartons or the determination paper which are subjected to irradiation treatment together as a comparison to-be-detected sample and extracting the comparison paper materials after annealing treatment;
the sampling and preparation method of the control paper comprises the following steps: selecting any position on paper which is not irradiated or annealed and is to be extracted, extracting a paper material sample from an interlayer of the inner wall of the paper at the position, cutting the paper material sample into a rectangle, weighing, curling into a cylinder, kneading, plugging an ESR test tube along the tube wall, and pushing the tube bottom to ensure that the sample height is in a test area; the side length of the rectangle is 2-4cm, the weight of the rectangle is 0.100-0.300 g, and the height of the sample in a test area of an ESR test tube is not higher than 3 cm;
the annealing treatment is to dry the paper at 90-110 ℃ for 2-6 hours and remove background signals;
3) measuring the ESR signals of the paper to be measured and the control paper within 15 days, and calculating the irradiation dose distribution and the unevenness of the product according to the ESR signal intensity of each paper;
the method for calculating the product dose distribution and the unevenness thereof comprises the following steps: u ═ Si-S0)/(Sj-S0) In which S isi、Sj、S0Respectively integrating the ESR signal intensity of paper samples i, j and comparison paper with g value of 1.965-2.040, and carrying out normalization treatment on the product dose distribution;
the measurement conditions of the ESR signal are as follows: x wave band with power of 0.1-20 mW; a central magnetic field 348mT, and a scanning width +/-20 mT; the modulation frequency is 50 kHz-100 kHz, and the modulation amplitude is 0.1 mT-1.0 mT; a time constant of 40-200 ms, a scanning rate of 15mT/min, and a gain of 1.0 × 104～1.0×106。
2. The method of testing according to claim 1, wherein the paper sample to be tested is tested in an ESR test tube within 7 days.
3. The method according to claim 1, wherein the irradiation treatment is carried out by irradiation with a high-energy gamma ray, an X-ray or an electron beam, and the irradiation energy is in the range of 0.1MeV to 28 MeV; the irradiation dose range of the product is 1.5-45 kGy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611063368.8A CN106772528B (en) | 2016-11-28 | 2016-11-28 | Method for measuring radiation dose distribution and nonuniformity of product |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611063368.8A CN106772528B (en) | 2016-11-28 | 2016-11-28 | Method for measuring radiation dose distribution and nonuniformity of product |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106772528A CN106772528A (en) | 2017-05-31 |
| CN106772528B true CN106772528B (en) | 2020-04-14 |
Family
ID=58904534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611063368.8A Active CN106772528B (en) | 2016-11-28 | 2016-11-28 | Method for measuring radiation dose distribution and nonuniformity of product |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106772528B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107229064B (en) * | 2017-08-03 | 2019-03-12 | 湖南省核农学与航天育种研究所 | A kind of comparison mould device and measurement method measuring irradiation dose |
| WO2020259368A1 (en) * | 2019-06-27 | 2020-12-30 | 清华大学 | Article dose distribution measurement method and apparatus |
| CN112146601B (en) * | 2019-06-27 | 2021-07-16 | 清华大学 | Radiation imaging method and device based on dose field detection |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101241089A (en) * | 2008-03-11 | 2008-08-13 | 江苏省农业科学院 | Irradiation products discrimination method based on ESR method |
| CN102608146A (en) * | 2011-12-12 | 2012-07-25 | 中华人民共和国上海出入境检验检疫局 | Egg irradiation detection method |
| CN203519520U (en) * | 2013-10-15 | 2014-04-02 | 江苏省农业科学院 | EPR (electron paramagnetic resonance) testing tube component with opening |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007187641A (en) * | 2006-01-13 | 2007-07-26 | Keycom Corp | Method and device for inspecting irradiated food |
| JP6240211B2 (en) * | 2012-12-03 | 2017-11-29 | テトラ ラバル ホールディングス アンド ファイナンス エス エイ | Apparatus and method for irradiating a packaging container with an electron beam |
-
2016
- 2016-11-28 CN CN201611063368.8A patent/CN106772528B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101241089A (en) * | 2008-03-11 | 2008-08-13 | 江苏省农业科学院 | Irradiation products discrimination method based on ESR method |
| CN102608146A (en) * | 2011-12-12 | 2012-07-25 | 中华人民共和国上海出入境检验检疫局 | Egg irradiation detection method |
| CN203519520U (en) * | 2013-10-15 | 2014-04-02 | 江苏省农业科学院 | EPR (electron paramagnetic resonance) testing tube component with opening |
Non-Patent Citations (1)
| Title |
|---|
| 丙氨酸-ESR剂量计用于测量产品箱内剂量分布的研究;张荫芬等;《核农学报》;19921231;第6卷(第2期);第87-91页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106772528A (en) | 2017-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106772528B (en) | Method for measuring radiation dose distribution and nonuniformity of product | |
| CN103206931B (en) | A kind of X-ray ga(u)ging method and device | |
| Kim et al. | Simulation of pathogen inactivation in whole and fresh-cut cantaloupe (Cucumis melo) using electron beam treatment | |
| JP6253096B2 (en) | Electromagnetic wave characteristic evaluation equipment | |
| EP0795181A1 (en) | A method for monitoring absorbed dose in an electron beam | |
| Vadrucci et al. | Parchment processing and analysis: ionizing radiation treatment by the REX source and multidisciplinary approach characterization | |
| Song et al. | Identification of red pepper powder irradiated with different types of radiation using luminescence methods: A comparative study | |
| CN106597515B (en) | A kind of assay method of irradiation of product dosage | |
| Rushdi et al. | Radiation-induced defects in strontium carbonate rod for EPR dosimetry applications | |
| Rizzoni et al. | Micronucleus induction by low doses of X-rays in Vicia faba root tips | |
| Abdel-Fattah | Identification and dose assessment of irradiated cumin by EPR spectrometry | |
| JP2006242870A (en) | Inspection method for food irradiated with radiation | |
| Vazirov et al. | EPR measurement of radiation-treated chicken eggs | |
| Mierzwinska et al. | Alanine/EPR dosimetry as a potential tool for quality assurance in proton beam radiotherapy | |
| Beshir | Identification and dose assessment of irradiated cardamom and cloves by EPR spectrometry | |
| Kuntz et al. | Dosimeters for Gamma, E-beam, and X-ray Food Irradiation | |
| Ziaie et al. | Bone powder as EPR dosimetry system for electron and gamma radiation | |
| Miller et al. | Dosimetry for industrial radiation processing. | |
| Aydın | Detection and original dose assessment of egg powders subjected to gamma irradiation by using ESR technique | |
| Yusof et al. | Good radiation practices for sterilisation of allografts | |
| Mehta et al. | Dosimetry for food processing and research applications | |
| Benny et al. | Double sided irradiation on homogenous products of different densities at an industrial EB accelerator of 2 MeV energy | |
| Kovács et al. | Applicability of the Sunna dosimeter for food irradiation control | |
| Malek et al. | CO2 diffusion from X-ray and γ-ray irradiated CR-39 plastic | |
| Ziaie et al. | Effect of high-dose electron irradiation on specific heat capacity of high-impact polystyrene |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |