Measurement method and measurement structure for equivalent mass of 240Pu sample to be measured
By using multiple 240Pu standard sources of equivalent mass and pulse shape identification methods in the measurement structure, the relationship curve between counting rate and equivalent mass is established, and the problem of low measurement accuracy of 240Pu equivalent mass in the prior art is solved, and high-precision and fast measurement effects are achieved.
Patent Information
- Application Number
- CN202510296633.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-13
- Publication Date
- 2025-07-04
AI Technical Summary
In the prior art, the measurement accuracy of 240Pu equivalent mass is low, especially the thermal neutron measurement technology based on the 3He proportional counting tube has problems such as the time-related information being destroyed and accidental compliance during the fission of the nuclear material, resulting in low measurement accuracy.
The counting rate measurement is performed in the measurement structure using multiple 240Pu standard sources with different equivalent mass. The γ signal is separated by the pulse shape identification method, and the relationship curve between the counting rate and the equivalent mass is established. The equivalent mass is obtained by measuring the counting rate of the sample to be measured in 240Pu. The interference signal is shielded using polyethylene shell assembly and lead plate to optimize the door width to improve the accuracy of the counting rate.
The measurement accuracy of the equivalent mass of the 240Pu sample to be tested is improved, the measurement time is shortened, the measurement cost is reduced, and the impact of interfering signals on the measurement results is reduced, and the accuracy and efficiency of the measurement results are improved.
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Figure CN120254172A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of the measurement of nuclear material quality, and particularly relates to a 240 method and structure for measuring the equivalent mass of a Pu sample to be measured. Background Art
[0002] The measurement of nuclear material quality is one of the key focuses in the field of nuclear safeguards verification. Among them, the 240 measurement of the equivalent mass of Pu material has always been the focus of NDA (non-destructive analysis) measurement.
[0003] However, in the related technology, the accuracy of the measured 240 equivalent mass of Pu is relatively low. Summary of the Invention
[0004] In view of this, the main purpose of the embodiments of this application is to provide a method and structure for measuring the equivalent mass of a Pu sample to be measured with relatively high measurement accuracy. 240
[0005] To achieve the above purpose, the technical solution of the embodiments of this application is realized as follows:
[0006] On the one hand, the embodiments of this application provide a 240 method for measuring the equivalent mass of a Pu sample to be measured, and the measurement method includes the following steps:
[0007] Placing a plurality of Pu standard sources with different equivalent masses in the measurement structure in sequence to obtain the first counting rate of each 240 Pu standard source; 240
[0008] Obtaining a relationship curve according to the equivalent mass of each 240 Pu standard source and the first counting rate;
[0009] Measuring the second counting rate of the 240 Pu sample to be measured through the measurement structure;
[0010] Obtaining the equivalent mass of the 240 Pu sample to be measured according to the relationship curve and the second counting rate.
[0011] In an implementation manner, the obtaining of the first counting rate of each 240 Pu standard source specifically includes:
[0012] Discriminating the (n,γ) signal of the 240 Pu standard source received by the measurement structure through the pulse shape discrimination method to isolate the first γ signal;
[0013] Perform coincidence analysis on the first γ signal according to the first coincidence gate width to obtain the first count rate.
[0014] In one embodiment, the first coincidence gate width is greater than or equal to 20 ns and less than or equal to 40 ns.
[0015] In one embodiment, the 240 Specifically, obtaining the relationship curve based on the equivalent mass of each
[0016] By 240 Fitting the equivalent mass of each
[0017] During the fitting process of the relationship curve, the weight of the smallest 240 Equivalent mass of the 240 Pu standard source and the weight of the largest 240 Equivalent mass of the
[0018] In one embodiment, the measurement by the measurement structure 240 Specifically, the second count rate of the
[0019] Pu sample to be measured includes: 240 Discriminate the (n,γ) signal of the
[0020] Pu sample to be measured received by the measurement structure through pulse shape discrimination to isolate the second γ signal;
[0021] In one embodiment, the 240 Measurement time of the
[0022] Pu sample to be measured is greater than or equal to 3 min and less than or equal to 50 min; and / or,
[0023] In one embodiment, the obtaining of the 240 Equivalent mass of the
[0024] Pu sample to be measured according to the relationship curve and the second count rate includes: 240 Substitute the second count rate into the relationship curve to obtain the
[0025] Another aspect of the embodiments of the present application provides a measurement structure for measuring the 240The equivalent mass of the Pu sample to be measured, and the measurement structure includes:
[0026] A housing assembly having a receiving cavity and a plurality of mounting seats, at least some of the mounting seats being arranged at intervals along the circumference of the housing assembly, the receiving cavity being for placing 240 a Pu standard source or 240 the Pu sample to be measured;
[0027] A plurality of detectors located within the mounting seats and arranged in one-to-one correspondence with the mounting seats.
[0028] In one embodiment, the material type of the housing assembly is polyethylene; and / or,
[0029] The measurement structure further includes a plurality of lead plates located on the side of the detector close to the receiving cavity and arranged in one-to-one correspondence with the detector.
[0030] In one embodiment, the housing assembly includes a first housing and a second housing. Along the height direction of the housing assembly, the first housing is located on the second housing;
[0031] The first housing has a regular hexagonal structure, and the mounting seats are provided on each side of the first housing. The distance between the relatively arranged mounting seats is greater than or equal to 30 cm and less than or equal to 50 cm; and / or,
[0032] The second housing has a regular hexagonal structure, and the mounting seats are provided on each side of the second housing. The distance between the relatively arranged mounting seats is greater than or equal to 30 cm and less than or equal to 50 cm.
[0033] The embodiment of the present application provides a 240 method and a measurement structure for measuring the equivalent mass of a Pu sample to be measured. The measurement method includes the following steps: placing a plurality of Pu standard sources with different equivalent masses 240 in the measurement structure in sequence to obtain the first counting rate of each 240 Pu standard source. Obtaining a relationship curve based on the equivalent mass and the first counting rate of each 240 Pu standard source. Measuring the second counting rate of the 240 Pu sample to be measured through the measurement structure. Obtaining the equivalent mass of the 240 Pu sample to be measured according to the relationship curve and the second counting rate. Thus, by using the relationship curve established with a plurality of Pu standard sources with different equivalent masses, the relationship between the equivalent mass and the first counting rate can be more accurately reflected, so that the result of the equivalent mass of the 240 Pu sample to be measured obtained through the relationship curve is more accurate. 240 Pu sample to be measured obtained through the relationship curve is more accurate. Description of the Drawings
[0034] Figure 1 This is a flowchart of a measurement method according to an embodiment of the present application;
[0035] Figure 2 This is a schematic structural diagram of a measurement structure according to another embodiment of the present application;
[0036] Figure 3 is Figure 2 a schematic structural diagram of another perspective of the measurement structure in;
[0037] Figure 4 In an embodiment of the present application 240 Fitting curve graph of the coincidence counting rate and equivalent mass of the Pu standard source.
[0038] Description of reference numerals
[0039] 10. Housing assembly; 10a. Accommodation cavity; 11. First housing; 12. Second housing; 13. Mounting base; 20. Detector. Detailed implementation manners
[0040] Referring to "embodiment" herein means that the specific features, structures or characteristics described in connection with the embodiment may be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.
[0041] In the description of the embodiments of the present application, unless otherwise clearly defined and limited, technical terms such as "installation", "connection", "connection", "fixation" and the like should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may also be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application may be understood according to specific situations.
[0042] In related technologies, 240 the equivalent mass of the Pu sample to be measured generally adopts a thermal neutron measurement technology based on 3 the He proportional counter. However, based on 3 the thermal neutron measurement technology of the He proportional counter, after the rays emitted during the fission process of nuclear materials are moderated, their time correlation information is destroyed, and there are too many accidental coincidences during time coincidence measurement, which limits the measurement accuracy. In addition, 3The He proportional counter tube can carry a relatively low counting rate. For some Pu materials (such as fluorides with more (α,n)), when the total counting rate reaches several thousand, the proportion of accidental coincidences in the collected coincidence signals will increase significantly, thus further reducing the measurement accuracy.
[0043] An embodiment of the present application provides a 240 method for measuring the equivalent mass of a Pu sample to be measured. Please refer to Figure 1 , and the measurement method includes the following steps:
[0044] Step S1: Place a plurality of Pu standard sources with different equivalent masses 240 in the measurement structure in turn to obtain the first counting rate of each 240 Pu standard source.
[0045] Step S2: Obtain a relationship curve based on the equivalent mass and the first counting rate of each 240 Pu standard source.
[0046] Step S3: Measure the second counting rate of the 240 Pu sample to be measured through the measurement structure.
[0047] Step S4: Obtain the equivalent mass of the 240 Pu sample to be measured according to the relationship curve and the second counting rate.
[0048] Specifically, 240 the Pu standard source refers to a sample whose 240 Pu equivalent mass is known.
[0049] The first counting rate refers to 240 the coincidence counting rate obtained by the detector 20 after the interference signals are eliminated when the Pu standard source is placed in the measurement structure.
[0050] The time for the measurement structure to measure the 240 Pu standard source is not limited.
[0051] For example, the time for the measurement structure to measure the 240 Pu standard source is determined according to the 240 equivalent mass of the Pu standard source.
[0052] The method for obtaining the first counting rate of each 240 Pu standard source is not limited.
[0053] Exemplarily, the (n,γ) signals of the Pu standard source received by the measurement structure are discriminated by the pulse shape discrimination method to isolate the first γ signal; 240
[0054] Coincidence analysis is performed on the first γ signal according to the first coincidence gate width to obtain the first counting rate.
[0055] Specifically, the signals emitted by the 240 Pu standard source collected by the measurement structure are processed to filter out the low-energy noise therein, and then the (n,γ) signals emitted by the 240 Pu standard source are separated by the pulse shape discrimination method.
[0056] The pulse shape discrimination method (Pulse Shape Discrimination, PSD) is a technique used to distinguish the pulse signals generated by different types of particles. Through the pulse shape discrimination method, the measurement structure can 240 separate the (n,γ) signals emitted by the Pu standard source, eliminate the neutron signals, and retain the first γ signals. Thus, the influence of interference signals on the measurement results can be eliminated, thereby improving the accuracy of the measurement results.
[0057] The first coincidence gate width refers to a time range set during coincidence analysis. This time range defines the time window for judging whether the first γ signals meet the measurement requirements. If two first γ signals arrive at different detectors 20 within the measurement structure within this time window, they are considered coincidence events.
[0058] The size of the first coincidence gate width is not limited.
[0059] Exemplarily, the first coincidence gate width is greater than or equal to 20 ns and less than or equal to 40 ns. For example, the first coincidence gate width is 20 ns, 30 ns, or 40 ns. Thus, the accuracy of obtaining the first counting rate can be improved, and further the accuracy of the measurement results is improved.
[0060] It should be noted that the first coincidence gate width is 30 ns. That is to say, when two first γ signals arrive at different detectors 20 at different positions within the measurement structure within 30 ns, it is considered that these two first γ signals meet the requirements of coincidence analysis.
[0061] The second counting rate refers to 240 the coincidence counting rate obtained by the detector 20 after the interference signals are eliminated when the Pu sample to be measured is placed in the measurement structure.
[0062] Multiple 240 Pu standard sources with known equivalent masses are sequentially placed in the measurement structure for measurement to obtain multiple groups of equivalent masses and the corresponding first counting rates with interference signals eliminated. Data processing is performed on the multiple groups of equivalent masses and first counting rates to obtain a relationship curve that can describe the relationship between the equivalent mass and the counting rate. Subsequently, 240 the Pu sample to be measured is placed in the measurement structure, and in the same way as measuring the 240 Pu standard source, 240The second counting rate of the Pu sample to be measured, from which the interference signal has been removed. The measured second counting rate is substituted into the relationship curve, and according to the relationship between the equivalent mass and the counting rate described by the relationship curve, the 240 equivalent mass of the Pu sample to be measured is calculated.
[0063] In the embodiment of the present application, 240 the method for measuring the equivalent mass of the Pu sample to be measured includes placing a plurality of Pu standard sources with different equivalent masses in the measurement structure in sequence to obtain the 240 first counting rate of each Pu standard source. According to the equivalent mass and the first counting rate of each 240 Pu standard source, a relationship curve is obtained. The second counting rate of the 240 Pu sample to be measured is measured through the measurement structure. According to the relationship curve and the second counting rate, the 240 equivalent mass of the Pu sample to be measured is obtained. Thus, by using the relationship curve established with a plurality of Pu standard sources with different equivalent masses, the relationship between the equivalent mass and the first counting rate can be reflected more accurately, so that the result of the 240 equivalent mass of the Pu sample to be measured obtained through the relationship curve is more accurate. 240 equivalent mass of the Pu sample to be measured obtained through the relationship curve is more accurate. 240 equivalent mass of the Pu sample to be measured is more precise.
[0064] In one embodiment, please refer to Figure 4 and obtaining the relationship curve according to the equivalent mass and the first counting rate of each 240 Pu standard source specifically includes:
[0065] By fitting the equivalent mass of each 240 Pu standard source and its corresponding first counting rate, a relationship curve is obtained.
[0066] During the process of fitting the relationship curve, the weight of the smallest 240 equivalent mass of the Pu standard source and the weight of the largest 240 equivalent mass of the Pu standard source are greater than the weights of the equivalent masses of the remaining 240 Pu standard sources. Thus, the accuracy of fitting the relationship curve is improved.
[0067] Specifically, the relationship curve refers to a curve that describes the 240 corresponding relationship between the equivalent mass of the Pu standard source and the first counting rate. By measuring the 240 counting rate of the Pu sample to be measured and substituting it into the relationship curve, the 240 equivalent mass of the Pu sample to be measured can be obtained.
[0068] The weight refers to an index used to represent the relative importance of a data point during the fitting process.
[0069] In one embodiment, through the measurement structure, the240 The second counting rate of the Pu sample to be tested specifically includes:
[0070] The pulse shape discrimination method is used to identify the pulses received by the measurement structure. 240 The (n, γ) signal of the Pu sample to be tested is used to separate the second γ signal.
[0071] A coincidence analysis is performed on the second gamma signal according to a second coincidence gate width to obtain a second count rate.
[0072] Specifically, the data collected from the measurement structure 240 The signal from the Pu sample to be tested is processed to filter out the low-energy noise, and then separated by pulse shape discrimination to make the measurement structure 240 The (n,γ) signal emitted by the Pu sample to be tested is separated, the neutron signal is eliminated, and the second γ signal is retained. In this way, the influence of the interference signal on the measurement result can be eliminated, thereby improving the accuracy of the measurement result.
[0073] Second, there is no limit to the door width.
[0074] Exemplarily, the second coincidence gate width is greater than or equal to 20ns and less than or equal to 40ns. For example, the first coincidence gate width is 20ns, 30ns or 40ns. Thus, the accuracy of obtaining the second count rate can be improved, thereby improving the accuracy of the measurement result.
[0075] Measurement Structure Measurement 240 There is no limit on the time of the sample to be tested.
[0076] For example, 240 The measurement time of the Pu sample to be tested is greater than or equal to 3 minutes and less than or equal to 50 minutes. For example, 240 The measurement time of Pu test sample is 3min, 6min, 15min, 24min, 48min or 50min.
[0077] In the related art, according to 240 Initial temperature, thermal conductivity, mass and specific heat capacity of the Pu sample to be tested 240 However, this measurement method 240 The measurement time of the Pu sample to be tested is 4-8 hours, and the measurement cycle is relatively long. 240 The measurement time of the Pu sample to be tested is greater than or equal to 3 minutes and less than or equal to 50 minutes. 240 The Pu sample measurement time and cycle are short.
[0078] In one embodiment, the relationship curve and the second count rate are obtained. 240The equivalent mass of the Pu sample to be measured specifically includes:
[0079] Substitute the second counting rate into the relationship curve to obtain 240 the equivalent mass of the Pu sample to be measured. Thus, by substituting the second counting rate into the relationship curve, the equivalent mass of the 240 Pu sample to be measured can be quickly obtained, simplifying the measurement and calculation processes and improving the measurement efficiency.
[0080] Another embodiment of the present application provides a measurement structure. Please refer to Figure 2 and Figure 3 , for measuring 240 the equivalent mass of the Pu sample to be measured. The measurement structure includes a housing assembly 10 and a plurality of detectors 20.
[0081] The housing assembly 10 has a receiving cavity 10a and a plurality of mounting seats 13. At least part of the mounting seats 13 are arranged at intervals along the circumference of the housing assembly 10. The receiving cavity 10a is used to place 240 the Pu standard source or 240 the Pu sample to be measured.
[0082] The detectors 20 are located within the mounting seats 13 and are arranged in one-to-one correspondence with the mounting seats 13.
[0083] Thus, on the one hand, the measurement structure is simplified and the measurement cost is reduced. On the other hand, by providing a plurality of detectors 20, the measurement efficiency and measurement accuracy are improved.
[0084] Specifically, the receiving cavity 10a refers to the internal space of the housing assembly 10, which is used to place 240 the Pu standard source or 240 the Pu sample to be measured.
[0085] The mounting seat 13 refers to the component on the housing assembly 10 for mounting the detector 20.
[0086] The structural type of the mounting seat 13 is not limited.
[0087] For example, the mounting seat 13 is a hole-like structure on the housing assembly 10, and the detector 20 is inserted into the mounting seat 13.
[0088] Of course, the mounting seat 13 can also be in other structural forms as long as it can be used to mount the detector 20.
[0089] The detector 20 refers to the component for receiving 240 the signal emitted by the Pu standard source or 240 the Pu sample to be measured.
[0090] The material type of the housing assembly 10 is not limited.
[0091] For example, the material type of the housing assembly 10 is polyethylene. Thus, interference signals can be shielded, and the accuracy of the measurement results can be improved.
[0092] In one embodiment, the measurement structure further includes a plurality of lead plates. The lead plates are located on the side of the detector 20 close to the accommodation cavity 10a and are arranged in one-to-one correspondence with the detector 20. Thus, the influence of stray rays on the measurement results of the detector 20 can be effectively reduced, and the accuracy of the measurement results can be further improved.
[0093] Specifically, the thickness of the lead plate is not limited.
[0094] Exemplarily, the thickness of the lead plate is less than or equal to 5 mm. The thickness of the lead plate is 2 mm, 3 mm, 4 mm, or 5 mm. Thus, while the lead plate can have a good shielding effect, the manufacturing cost of the measurement structure is saved.
[0095] In one embodiment, please refer to Figure 2 and Figure 3 , the housing assembly 10 includes a first housing 11 and a second housing 12. Along the height direction of the housing assembly 10, the first housing 11 is located on the second housing 12.
[0096] The first housing 11 has a regular hexagon structure. Mounting seats 13 are provided on each side of the first housing 11. The distance between the oppositely arranged mounting seats 13 is greater than or equal to 30 cm and less than or equal to 50 cm. For example, the distance between the oppositely arranged mounting seats 13 is 30 cm, 40 cm, or 50 cm. Thus, the detection blind area of the detector 20 can be reduced, the capture rate of rays can be increased, and the accuracy of the measurement results can be improved.
[0097] In one embodiment, please refer to Figure 2 and Figure 3 , the housing assembly 10 includes a first housing 11 and a second housing 12. Along the height direction of the housing assembly 10, the first housing 11 is located on the second housing 12.
[0098] The second housing 12 has a regular hexagon structure. Mounting seats 13 are provided on each side of the second housing 12. The distance between the oppositely arranged mounting seats 13 is greater than or equal to 30 cm and less than or equal to 50 cm. For example, the distance between the oppositely arranged mounting seats 13 is 30 cm, 40 cm, or 50 cm. Thus, the detection blind area of the detector 20 can be reduced, the capture rate of rays can be increased, and the accuracy of the measurement results can be improved.
[0099] Specifically, in the projection plane perpendicular to the height direction of the housing assembly 10, the projection range of the first housing 11 coincides with the projection range of the second housing 12. The detectors 20 located on the first housing 11 coincide with the detectors 20 located on the second housing 12 in the projection plane.
[0100] In one embodiment, the equivalent mass of the Pu sample to be measured is measured through a measurement structure, specifically including the following steps: 240 Place four Pu standard sources with known equivalent masses at the center position of the accommodation cavity 10a of the measurement structure in sequence. Among them,
[0101] the equivalent masses of the Pu standard sources are 0.11 g, 2.72 g, 13.36 g, and 27.22 g respectively, and the measurement times of each Pu standard source are 48 min, 24 min, 6 min, and 3 min respectively. 240 The equivalent masses of the Pu standard sources are 0.11 g, 2.72 g, 13.36 g, and 27.22 g respectively, and the measurement times of each Pu standard source are 48 min, 24 min, 6 min, and 3 min respectively. 240 Perform (n,γ) discrimination on the signals measured by the detector 20, and use the pulse shape discrimination method to separate the neutron signals and γ signals measured by the detector 20. 240 Set the coincidence gate width to 30 ns, perform coincidence analysis on the separated γ signals, obtain the coincidence count rate of each Pu standard source, and combine the equivalent mass of the Pu standard source to fit the relationship curve between the coincidence count rate and the equivalent mass.
[0102] Place the Pu sample to be measured at the center position of the accommodation cavity 10a of the measurement structure. According to the mass of the Pu sample to be measured, after measuring for 3 - 50 min, obtain the coincidence count rate of the Pu sample to be measured, and obtain the equivalent mass of the Pu sample to be measured from the relationship curve of the coincidence count rate of the Pu sample to be measured.
[0103] The measurement results of the Pu sample to be measured are shown in Table 1. 240 As can be seen from Table 1, the relative deviation between the measured value of the equivalent mass of the Pu sample to be measured by this measurement method and the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy. 240 The measurement results of the Pu sample to be measured are shown in Table 1.
[0104] Table 1 240 The measurement results of the Pu sample to be measured 240 As can be seen from Table 1, the relative deviation between the measured value of the equivalent mass of the Pu sample to be measured by this measurement method and the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy. 240 As can be seen from Table 1, the relative deviation between the measured value of the equivalent mass of the Pu sample to be measured by this measurement method and the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy. 240 As can be seen from Table 1, the relative deviation between the measured value of the equivalent mass of the Pu sample to be measured by this measurement method and the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy. 240 As can be seen from Table 1, the relative deviation between the measured value of the equivalent mass of the Pu sample to be measured by this measurement method and the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy. 240 As can be seen from Table 1, the relative deviation between the measured value of the equivalent mass of the Pu sample to be measured by this measurement method and the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy.
[0105] Table 1 240 The measurement results of the Pu sample to be measured
[0106]
[0107] As can be seen from Table 1, the relative deviation between the measured value of the equivalent mass of the Pu sample to be measured by this measurement method and the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy. 240 the measured value of the equivalent mass of the Pu sample to be measured 240 and 240 the nominal value of the equivalent mass of the Pu sample to be measured is small, and the measurement method of the equivalent mass of the Pu sample to be measured in this application has high accuracy.
[0108] In the description of the present application, the descriptions with reference to terms such as "in one embodiment", "in some embodiments", "in a specific embodiment", or "exemplary" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine the different embodiments or examples described in the present application and the features of different embodiments or examples.
[0109] The foregoing is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are all included within the protection scope of the present application.
Claims
1. A 240 method for measuring the equivalent mass of a Pu sample to be measured, characterized in that The measurement method includes the following steps: Place multiple Pu standard sources with different equivalent masses in sequence within the measurement structure to obtain the first counting rate of each of the 240 Pu standard sources; 240 Pu standard source. According to each of the 240 equivalent mass of the Pu standard source and the first counting rate, obtain a relationship curve; Measure the second count rate of the 240 Pu sample to be measured; Obtain the 240 equivalent mass of the Pu sample to be measured according to the relationship curve and the second counting rate.
2. The measuring method according to claim 1, characterized in that The obtaining of each of the 240 first counting rates of the Pu standard sources specifically includes: The pulse shape discrimination method is used to discriminate the pulses received by the measurement structure. 240 The (n,γ) signal of the Pu standard source is used to separate the first γ signal; Performing coincidence analysis on the first γ signal according to the first coincidence gate width to obtain the first count rate.
3. The measurement method according to claim 2, characterized in that, The first coincidence gate width is greater than or equal to 20 ns and less than or equal to 40 ns.
4. The measurement method according to claim 1, characterized in that, The described according to each of the 240 Obtaining the relationship curve based on the equivalent mass of the Pu standard source and the first counting rate specifically includes: By fitting the equivalent mass of each of the 240 Pu standard sources and the corresponding first counting rate thereof, the relationship curve is obtained; During the fitting process of the relationship curve, the weight of the equivalent mass of the smallest 240 Pu standard source and the weight of the equivalent mass of the largest 240 Pu standard source are greater than the weights of the equivalent masses of the remaining 240 Pu standard sources.
5. The measurement method according to claim 1, characterized in that, The measurement by the measurement structure 240 The second count rate of the Pu sample to be measured specifically includes: The pulse shape discrimination method is used to discriminate the pulses received by the measurement structure. 240 The (n, γ) signal of the Pu sample to be tested is used to separate the second γ signal; Performing coincidence analysis on the second γ signal according to the second coincidence gate width to obtain the second count rate.
6. The measuring method according to claim 5, characterized in that, The 240 measurement time of the Pu test sample is greater than or equal to 3 min and less than or equal to 50 min; and / or, The second coincidence gate width is greater than or equal to 20 ns and less than or equal to 40 ns.
7. The measurement method according to claim 1, characterized in that Obtaining the 240 equivalent mass of the Pu sample to be measured specifically includes: Substitute the second counting rate into the relationship curve to obtain the 240 equivalent mass of the Pu sample to be measured.
8. A measuring structure for measuring the 240 equivalent mass of the Pu sample to be measured, characterized in that The measurement structure includes: A housing assembly, the housing assembly having a receiving cavity and a plurality of mounting seats, at least some of the mounting seats being arranged at intervals along the circumferential direction of the housing assembly, the receiving cavity being used for placing 240 a Pu standard source or 240 a Pu sample to be measured; A plurality of detectors, which are located in the mounting base and are arranged in one-to-one correspondence with the mounting base.
9. The measurement structure according to claim 8, wherein, The material type of the housing assembly is polyethylene; and / or, The measurement structure further includes a plurality of lead plates, which are located on the side of the detector close to the accommodation cavity and are arranged in one-to-one correspondence with the detector.
10. The measurement structure according to claim 8 or 9, characterized in that, The housing assembly includes a first housing and a second housing. Along the height direction of the housing assembly, the first housing is located on the second housing; The first housing has a regular hexagon structure, and mounting bases are provided on each side of the first housing. The distance between the oppositely arranged mounting bases is greater than or equal to 30 cm and less than or equal to 50 cm; and / or, The second housing has a regular hexagon structure, and mounting bases are provided on each side of the second housing. The distance between the oppositely arranged mounting bases is greater than or equal to 30 cm and less than or equal to 50 cm.