A method and system for testing a uniform density product depth dose

Abstract

The application discloses a method and system for testing the depth dose of a product with uniform density, which provides a single surface calibration depth dose of a product with specified density, and determines the depth dose of a product with uniform density to be measured through density conversion based on the single surface calibration depth dose, wherein the depth dose comprises a single surface irradiation depth dose and / or a double surface irradiation depth dose. The method has a small amount of calculation, does not need to perform a complex dose distribution, and can predict the dose at different depths of a certain uniform thickness material.

Description

Technical Field

[0001] This invention relates to the field of electron beam irradiation technology, and in particular to a method and system for testing the depth dose of a uniform density product. Background Technology

[0002] In the field of electron beam irradiation, obtaining and calculating the depth dose under 10MeV electron beam irradiation for uniform density products is a crucial foundation for irradiation process evaluation and dose uniformity assessment. Current mainstream techniques typically involve deploying dosimeters at different depths on the uniform density product, reading the absorbed dose at each depth after 10MeV electron beam irradiation, and then compiling this data to obtain the depth dose distribution and depth dose non-uniformity. Under bifacial irradiation conditions, the depth dose distribution is usually characterized by parameters such as incident depth, dose, depth dose, and non-uniformity.

[0003] While the above methods can directly reflect the internal dose status of a specific product, their implementation is limited by the product structure and dosimeter placement conditions. Specifically, if the product is a single piece and cannot be slotted, disassembled, or punctured, a dosimeter cannot be placed at a preset depth, resulting in the inability to obtain depth dose for that batch of products. If the available thickness at a certain depth is less than the thickness of the dosimeter, a dosimeter cannot be placed at that depth, causing a gap in the depth dose curve at a local depth, preventing the formation of a complete distribution.

[0004] Furthermore, existing methods typically require repeated deployment, irradiation, data reading, and data processing for each thickness or product specification, resulting in long measurement cycles and difficulty in generating unified data that can be directly accessed based on thickness. Simultaneously, depth dose and depth dose non-uniformity are often recorded scattered across individual measurement results, lacking a rapid query basis directly corresponding to product thickness, incident depth, and bi-sided irradiation conditions, making it difficult to quickly evaluate dose uniformity under bi-sided irradiation conditions. Summary of the Invention

[0005] To address some or all of the problems in existing technologies, and in order to reduce the need for actual placement measurements within products and quickly obtain the depth dose of products with uniform density, the first aspect of this invention provides a method for testing the depth dose of products with uniform density, comprising: Based on the single-sided calibrated depth dose of a product with a specified density, the depth dose of the uniform density product to be measured is determined by density conversion, wherein the depth dose includes single-sided irradiation depth dose and / or double-sided irradiation depth dose.

[0006] Further, determining the single-sided depth dose of the uniform density product to be measured includes: By converting density, the specified depth of the uniform density product to be measured is converted into the corresponding depth of the product with the specified density; The single-sided calibration depth dose of the specified density product at the corresponding depth is determined, which is the single-sided depth dose of the uniform density product to be measured. Further, determining the bi-sided depth dose of the uniform density product to be measured includes: By converting density, the specified depth of the uniform density product to be measured is converted into the corresponding depth of the product with the specified density; Determine the single-sided calibration depth dose of the specified density product at the corresponding depth from both sides inward; Adding the two together yields the bifacial calibrated absorbed dose at the corresponding depth of the product with the specified density, which is the electron beam bifacial irradiation depth dose at the specified depth of the uniform density product to be measured.

[0007] Furthermore, the absorbed dose of the specified density product at different depths is measured according to the following steps: Alternately place products of specified thickness and density with dose tablets to form a stack and place it directly below the titanium window; An electron beam is positioned above the titanium window to irradiate the stack with a specified dose; Measure the absorbed dose of each of the aforementioned dose tablets.

[0008] Furthermore, the thickness of the specified density product is 1 mm, and the thickness of the dosing tablet is less than R. p / 12, and / or the area of ​​the product with the specified density is not less than 3R p ×3R p And / or the thickness of the stack is greater than 1.5R p , where R p The expected actual electron range in a product of a specified density, which is determined based on the electron beam energy.

[0009] Furthermore, the specified density product is aluminum.

[0010] Furthermore, the testing method also includes: The single-sided calibrated depth dose of the specified density product is converted to a density of 1 g / cm³. 3 The depth dose is used to form a lookup table, or a density of 1 g / cm³ is obtained by fitting. 3 The formula for calculating the product depth dose.

[0011] Furthermore, during electron beam irradiation, the scanning frequency is 19.1 Hz, the scanning current is 8.9 A, the pulse repetition frequency is 490 Hz, the peak electron beam current is 0.2 A, the electron beam current pulse width is 10.6 μs, and the speed of the conveyor belt under the beam is 10 mm / sec.

[0012] Furthermore, the testing method also includes: If the surface dose irradiation used to measure the depth dose of the uniform density product is different from the surface dose irradiation used to obtain the single-sided calibration depth dose of the specified density product, the final depth dose is determined based on the ratio of the surface dose irradiation used to measure the depth dose of the uniform density product to the surface dose irradiation used to obtain the single-sided calibration depth dose of the specified density product.

[0013] Based on the testing method described above, a second aspect of the present invention provides a testing system for depth dose of a uniform density product, comprising: A calibration depth dose module for a specified density product is used to store or calculate the calibration depth dose of a specified density product at a specified irradiation intensity. The calculation module is used to convert the specified depth of the uniform density product to be measured into the corresponding depth of the specified density product, and to determine the absorbed dose under other surface dose irradiation based on the absorbed dose under a specified surface dose irradiation. The lookup module is used to determine the calibration depth dose of the specified density product under a specified surface dose irradiation in the specified density product calibration depth dose module.

[0014] Furthermore, the specified density product calibration depth dose module includes a lookup table and / or a calculation module, wherein the lookup table includes a single-sided irradiation depth dose lookup table and a double-sided irradiation depth dose lookup table, wherein the single-sided irradiation depth dose lookup table is obtained through actual measurement, and the double-sided irradiation depth dose lookup table is calculated based on the single-sided irradiation depth dose lookup table.

[0015] This invention provides a method and system for testing depth dose in products with uniform density. It requires minimal computation and eliminates the need for complex dose distribution, enabling the prediction of dose at different depths for a material of uniform thickness. This provides a theoretical basis for optimal thickness design to control the maximum dose of uniform materials. Furthermore, the method and system can provide a theoretically calculated dose at a specific depth for products where dosimeters cannot be placed within the product itself, such as solid products or liquid products. Attached Figure Description

[0016] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the various embodiments of the present invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.

[0017] Figure 1 A flowchart illustrating a method for testing depth dose of a uniform density product according to an embodiment of the present invention is shown. Figure 2 This diagram illustrates a method for obtaining a single-sided calibrated depth dose of a product of a specified density according to an embodiment of the present invention. Figure 3 This diagram illustrates the structure of a uniform density product depth dose testing system according to an embodiment of the present invention. Detailed Implementation

[0018] In the following description, the invention is described with reference to various embodiments. However, those skilled in the art will recognize that the embodiments may be practiced without one or more specific details or with other alternatives and / or additional methods, materials, or components. In other instances, well-known structures, materials, or operations are not shown or described in detail so as not to obscure the inventive points of the invention. Similarly, for illustrative purposes, specific quantities, materials, and configurations are set forth to provide a comprehensive understanding of embodiments of the invention. However, the invention is not limited to these specific details. Furthermore, it should be understood that the embodiments shown in the drawings are illustrative representations and are not necessarily drawn to scale.

[0019] In this specification, references to "an embodiment" or "this embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. The phrase "in one embodiment" appearing throughout this specification does not necessarily refer to the same embodiment in all instances.

[0020] It should be noted that the embodiments of the present invention describe the process steps in a specific order; however, this is only for illustrating the specific embodiment and not for limiting the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to the process.

[0021] To rapidly calculate the depth dose of products with uniform density, especially solid or liquid products, this invention provides a method and system for testing the depth dose of products with uniform density. Through density conversion, it obtains the absorbed dose of a substance of a certain density at different depths based on a single-sided calibrated depth dose of a product with a specified density. The overall calculation is simple and does not require dose distribution analysis. This method provides a theoretical basis for optimal thickness design to control the maximum dose of uniform substances. For example, polyethylene sheets can be modified by irradiation crosslinking to improve the physical properties of the product, and then used to manufacture artificial joints. However, to control the irradiation dose to not exceed the upper limit to ensure the quality of the artificial joint, the method and system provided by this invention can quickly determine the absorbed dose of the polyethylene sheet at different depths, thereby determining the optimal dose and thickness. Designing the irradiation thickness of the sheet according to this thickness ensures the optimal dose required for the product's irradiation modification, thus guaranteeing optimal product quality.

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings of the embodiments.

[0023] Figure 1 This diagram illustrates a flow chart of a method for testing the depth dose of a uniform density product according to an embodiment of the present invention. As previously described, a method for testing the depth dose of a uniform density product involves determining the depth dose of the uniform density product to be measured by density conversion based on a single-sided calibrated depth dose of a product with a specified density. The depth dose includes single-sided irradiation depth dose and / or double-sided irradiation depth dose. Figure 1 As shown, the test method includes: First, in step 101, density conversion. Through density conversion, the specified depth of the uniform density product to be measured is converted to the corresponding depth of the product with the specified density. : , in, The density of the uniform density product to be measured. The density of the product with the specified density. For a specified depth; Next, in step 102, the corresponding single-sided calibration depth dose is determined. The single-sided calibration depth dose for the specified density product at the corresponding depth is determined. In one embodiment of the invention, the single-sided calibration depth dose for the specified density product at the corresponding depth is determined by looking up a table. In another embodiment of the invention, the single-sided calibration depth dose for the specified density product at the corresponding depth is calculated according to a formula. Both the lookup table and the calculation formula are based on actual measured values. Specifically, in one embodiment of the invention, a specified density product of a specified thickness is alternately placed with a dose sheet to form a stack placed directly below a titanium window. Then, an electron beam is placed above the titanium window, and the stack is irradiated with a specified dose. The absorbed dose of each dose sheet is measured, and a lookup table is formed, or a calculation formula is obtained by fitting. The thickness of the specified density product is 1 mm, and the thickness of the dose sheet is less than R. p / 12, to ensure sufficient data points for plotting depth-dose distribution curves. The area of ​​the specified density product is not less than 3R. p ×3R p To avoid the influence of edge effects on the dosimeter, the thickness of the stack is greater than 1.5R. p , where R pThe expected actual electron range (line range) in a product with a specified density is determined based on the electron beam energy. In one embodiment of the invention, an electron beam with an energy of 10 MeV is used for irradiation. During irradiation, the scanning frequency is 19.1 Hz, the scanning current is 8.9 A, the pulse repetition frequency is 490 Hz, the peak electron beam current is 0.2 A, the electron beam current pulse width is 10.6 μs, and the under-beam conveyor belt speed is 10 mm / sec.

[0024] For faster calculation, in one embodiment of the present invention, the measured absorbed dose can also be converted to a density of 1 g / cm³. 3 The depth dose is then determined, and a lookup table or calculation formula is formed. To better illustrate the formation of the lookup table or calculation formula, the specific process is explained in detail below using an aluminum block as an example. Figure 2 As shown, approximately 470 mm directly below the titanium window, alternating layers of aluminum plates and CTA dosimeters were placed for electron beam irradiation. The CTA dosimeters were 118 micrometers thick, and the aluminum plates were 1 millimeter thick, totaling 25 sets. Several additional aluminum plates were placed at the bottom, and the overall thickness of the stack was greater than 1.5R. p The lateral dimension of the stack is not less than 3R p ×3R p , where R p Approximately 2 cm in diameter, the sample was irradiated with a 10 MeV electron beam at a scanning frequency of 19.1 Hz, a scanning current of 8.9 A, a pulse repetition frequency of 490 Hz, a peak electron current of 0.2 A, a pulse width of 10.6 μs, and a conveyor belt speed of 10 mm / sec. The absorbed dose of the CTA dosimeters attached to each aluminum plate was measured using a Shimadzu 1240 UV spectrophotometer and converted to a density of 1 g / cm³. 3 The depth dose is shown in Table 1. The CTA dosimeter density is approximately 1.29 g / cm³. 3 The density of the aluminum plate is 2.69 g / cm³. 3 Using the dose at the center of the CTA dosimeter as the measured value, the converted incident depth of the first CTA dosimeter is (0.0118 / 2) * 1.29 = 0.007611, and the converted incident depth of the second CTA dosimeter is (0.0118 / 2) * 1.29 + 0.0118 * 1.29 + 0.1 * 2.69 = 0.291833, and so on. This allows us to obtain a density of 1 g / cm³. 3 The product's depth dose at different incident depths is used to form a lookup table, or a calculation formula is further fitted based on the lookup table, wherein the absorbed dose of the first CTA dosimeter is regarded as the surface incident dose.

[0025] Table 1 Finally, in step 103, the depth dose is determined. The single-sided calibration depth dose obtained based on a depth lookup table or calculation after conversion is the single-sided depth dose of the uniform density product to be measured. If the double-sided depth dose of the uniform density product to be measured is required, the single-sided calibration depth dose at the corresponding depth from both sides of the specified density product needs to be determined. Then, the two are added together to obtain the double-sided calibration absorbed dose at the corresponding depth of the specified density product, which is the electron beam double-sided irradiation depth dose of the uniform density product to be measured at the specified depth. For faster calculation, in one embodiment of the invention, a double-sided calibration depth dose lookup table or calculation formula can be constructed based on the single-sided calibration depth dose. Taking the data in Table 1 as an example, a double-sided calibration depth dose lookup table for products of several thicknesses can be constructed, where the density is 1.00 g / cm³. 3 In the dose distribution table for double-sided irradiation depth of a product with a thickness of 9.671159 cm, the double-sided irradiation depth dose at an incident depth of 0.007611 is equal to the single-sided irradiation depth dose at an incident depth of 0.007611 plus the single-sided irradiation depth dose at an incident depth of 9.671159; the double-sided irradiation depth dose at an incident depth of 0.291833 is equal to the single-sided irradiation depth dose at an incident depth of 0.291833 plus the single-sided irradiation depth dose at an incident depth of 9.386937, and so on. If the density is 1.00 g / cm³... 3 In the product thickness of 1.997165cm, the double-sided irradiation depth dose distribution table shows that the double-sided irradiation depth dose at an incident depth of 0.007611 is equal to the single-sided irradiation depth dose at an incident depth of 0.007611 plus the single-sided irradiation depth dose at an incident depth of 1.997165. Similarly, the double-sided irradiation depth dose at an incident depth of 0.291833 is equal to the single-sided irradiation depth dose at an incident depth of 0.291833 plus the single-sided irradiation depth dose at an incident depth of 1.712943, and so on.

[0026] In one embodiment of the present invention, if the surface dose irradiation of the depth dose of the uniform density product to be measured is different from the surface dose irradiation used when obtaining the single-sided calibration depth dose of the specified density product, the final depth dose is determined based on the ratio of the surface dose irradiation of the depth dose of the uniform density product to be measured to the surface dose irradiation used when obtaining the single-sided calibration depth dose of the specified density product. Specifically, the value obtained by looking up a table or by calculation is multiplied by the ratio of the surface dose irradiation of the depth dose of the uniform density product to be measured to the surface dose irradiation used when obtaining the single-sided calibration depth dose of the specified density product.

[0027] Based on the testing methods described above Figure 3 This diagram illustrates the structure of a uniform density product depth dose testing system according to an embodiment of the present invention. Figure 3 As shown, a testing system for depth dose of a uniform density product includes a specified density product calibration depth dose module 301, a first calculation module 302, and a lookup module 303. The specified density product calibration depth dose module 301 is used to store or calculate the calibration depth dose of the specified density product under a specified irradiation intensity. The calculation module 302 is used to convert the specified depth of the uniform density product to be measured into the corresponding depth of the specified density product, and to determine the absorbed dose under other surface dose irradiations based on the absorbed dose under a specified surface dose irradiation. The lookup module 303 is used to determine the calibration depth dose of the specified density product under a specified surface dose irradiation in the specified density product calibration depth dose module.

[0028] In one embodiment of the present invention, the specified density product calibration depth dose module 301 includes a lookup table and / or a second calculation module, wherein the lookup table includes a single-sided irradiation depth dose lookup table and a double-sided irradiation depth dose lookup table, wherein the single-sided irradiation depth dose lookup table is obtained through actual measurement, and the double-sided irradiation depth dose lookup table is calculated based on the single-sided irradiation depth dose lookup table.

[0029] Although various embodiments of the invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A method for testing depth dosage of a uniform density product, characterized in that, include: Provides single-sided calibrated depth dose for products of specified density; as well as Based on the single-sided calibrated depth dose, the depth dose of the uniform density product to be measured is determined by density conversion, wherein the depth dose includes single-sided irradiation depth dose and / or double-sided irradiation depth dose.

2. The test method as described in claim 1, characterized in that, Determining the single-sided depth dose of the uniform density product to be measured includes: By converting density, the specified depth of the uniform density product to be measured is converted into the corresponding depth of the product with the specified density; The single-sided calibration depth dose of the specified density product at the corresponding depth is determined, which is the single-sided depth dose of the uniform density product to be measured.

3. The test method as described in claim 1, characterized in that, Determining the bi-sided depth dose of the uniform density product to be measured includes: By converting density, the specified depth of the uniform density product to be measured is converted into the corresponding depth of the product with the specified density; Determine the single-sided calibration depth dose of the specified density product at the corresponding depth from both sides inward; The single-sided calibration depth doses at corresponding depths from both sides of the product of specified density are added together to obtain the double-sided calibration absorbed dose at the corresponding depth of the product of specified density, which is the electron beam double-sided irradiation depth dose at the specified depth of the uniform density product to be measured.

4. The test method as described in claim 1, characterized in that, The single-sided calibrated depth dose for providing a product with a specified density includes: Alternately place products of specified thickness and density with dose tablets to form a stack and place it directly below the titanium window; An electron beam is positioned above the titanium window to irradiate the stack with a specified dose; The absorbed dose of each of the aforementioned dose tablets is measured to obtain the single-sided calibrated depth dose.

5. The test method as described in claim 4, characterized in that, The thickness of the specified density product is 1 mm, and the thickness of the dosing tablet is less than R. p / 12, and / or the area of ​​the product with the specified density is not less than 3R p ×3R p And / or the thickness of the stack is greater than 1.5R p , where R p The expected actual electron range in a product of a specified density, which is determined based on the electron beam energy.

6. The test method as described in claim 4, characterized in that, During electron beam irradiation, the scanning frequency is 19.1 Hz, the scanning current is 8.9 A, the pulse repetition frequency is 490 Hz, the peak electron beam current is 0.2 A, the electron beam current pulse width is 10.6 μs, and the speed of the conveyor belt under the beam is 10 mm / sec.

7. The test method as described in claim 1, characterized in that, Also includes: The single-sided calibrated depth dose of the specified density product is converted to a density of 1 g / cm³. 3 The depth dose is used to form a lookup table, or a density of 1 g / cm³ is obtained by fitting. 3 The formula for calculating the product depth dose.

8. The test method as described in claim 1, characterized in that, Also includes: If the surface dose irradiation used to measure the depth dose of the uniform density product is different from the surface dose irradiation used to obtain the single-sided calibration depth dose of the specified density product, the final depth dose is determined based on the ratio of the surface dose irradiation used to measure the depth dose of the uniform density product to the surface dose irradiation used to obtain the single-sided calibration depth dose of the specified density product.

9. A testing system for depth dosage of a uniform density product, characterized in that, include: A calibration depth dose module for a specified density product is configured to store or calculate the calibration depth dose of a specified density product at a specified irradiation intensity. The first calculation module is configured to convert a specified depth of the uniform density product to be measured into the corresponding depth of the specified density product, and to determine the absorbed dose under other surface dose irradiation based on the absorbed dose under a specified surface dose irradiation. The lookup module is configured to determine the calibration depth dose of the specified density product under a specified surface dose irradiation in the specified density product calibration depth dose module.

10. The testing system as described in claim 9, characterized in that, The specified density product calibration depth dose module includes a lookup table and / or a second calculation module, wherein the lookup table includes a single-sided irradiation depth dose lookup table and a double-sided irradiation depth dose lookup table, wherein the single-sided irradiation depth dose lookup table is obtained through actual measurement, and the double-sided irradiation depth dose lookup table is calculated based on the single-sided irradiation depth dose lookup table.

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