Neutron flux determination method and device applied to samarium-neodymium isotope system dating

Abstract

The embodiment of the specification provides a neutron flux determination method and device applied to samarium-neodymium isotope system dating, wherein the neutron flux determination method applied to the samarium-neodymium isotope system dating comprises the following steps: performing isotope measurement on a sample to determine isotope measurement data of the sample; performing simulation on a neutron irradiation effect of the sample to determine neutron irradiation model data; comparing the isotope measurement data and the neutron irradiation model data to determine a comparison result; and determining the epithermal neutron flux based on the comparison result. The size of the epithermal neutron flux is obtained by simulating the isotope data of the sample, the method is widely applicable, and can be used for drilling samples, return samples, meteorite samples and the like, thereby improving the accuracy of the dating results of isotope systems at different depths and providing a reliable basis for studying the drilling lunar soil sample turnover rate.

Description

TECHNICAL FIELD

[0001] Embodiments of the present specification relate to the technical field of space science, and in particular, to a neutron flux determination method applied to samarium-neodymium isotope system dating. BACKGROUND

[0002] The radioactive samarium-neodymium isotope system is widely used in geology research for geological tracing and dating, in which Sm and Nd represent samarium and neodymium elements respectively, and the dating results can be used to study the formation and evolution history of the earth, the moon and other solar system celestial bodies. Samarium 147 and samarium 146 are both long-lived radioactive isotopes, which can produce stable neodymium 143 and neodymium 142 through alpha decay: samarium 147-> neodymium 143+alpha, samarium 1476-> neodymium 143+alpha. The corresponding half-lives are 106Ga (1 billion years) and 103Ma (10 million years) respectively. 9 6

[0003] Because the half-lives of samarium 147 and samarium 146 are both above 1 billion years, the samarium-neodymium isotope dating system mainly analyzes samples that are more than 1 billion years old. Lunar soil samples will be subjected to long-term radiation of cosmic rays in such a long period of time, and some isotopes will undergo significant drift due to neutron capture.

[0004] Because the thermal neutron (less than 0.4 eV) capture cross section and the epithermal neutron (0.4 eV-0.5 MeV) resonance integral cross section are relatively large, the samarium-neodymium isotope system is greatly affected by thermal neutron and epithermal neutron capture. Therefore, the neutron capture effect correction is mainly to correct the influence of thermal neutron and epithermal neutron on the samarium-neodymium isotope system. The samarium 149 thermal neutron capture cross section is very large, reaching 71627 barns, and one thermal neutron is captured by a samarium 149 atom to become samarium 150, so the samarium 150 / samarium 149 isotope ratio of the lunar soil sample subjected to long-term neutron radiation will change significantly. The neutron capture cross section of neodymium 143 is also relatively large, with a thermal neutron capture cross section of 335 barns and an epithermal neutron resonance capture cross section of 132 barns. Neodymium 143 neutron capture will become neodymium 144, i.e., one neodymium 143 is reduced and one neodymium 144 is increased, which will affect the accuracy of samarium-neodymium isotope dating.

[0005] Currently, the estimation of epithermal neutron flux is based on the empirical value of the ratio of thermal neutron and epithermal neutron flux, and the estimation is made. However, the ratio of thermal neutron and epithermal neutron flux has a large variation range, so it is impossible to give an accurate epithermal neutron flux. Therefore, a better solution is urgently needed. SUMMARY

[0006] ​​Therefore, the embodiment of the present specification provides a neutron flux determination method applied to samarium-neodymium isotope system dating. One or more embodiments of the present specification also relate to a neutron flux determination device applied to samarium-neodymium isotope system dating, a computing device, a computer-readable storage medium, and a computer program to solve the technical defects in the prior art.

[0007] According to a first aspect of the embodiment of the present specification, a neutron flux determination method applied to samarium-neodymium isotope system dating is provided, comprising:

[0008] Isotope measurement is performed on the sample to determine isotope measurement data of the sample;

[0009] Simulation of neutron irradiation effect is performed on the sample to determine neutron irradiation model data;

[0010] Comparison is performed based on the isotope measurement data and the neutron irradiation model data to determine a comparison result;

[0011] The epithermal neutron flux is determined based on the comparison result.

[0012] In a possible implementation, the isotope measurement is performed on the sample to determine the isotope measurement data of the sample, comprising:

[0013] A terrestrial standard substance is determined, and a mass spectrometer is calibrated based on the terrestrial standard substance;

[0014] The sample is subjected to an extraction operation to determine a sample to be measured;

[0015] The sample to be measured is measured by the mass spectrometer to determine an initial measurement result;

[0016] The initial measurement result is corrected to determine the isotope measurement data of the sample.

[0017] In a possible implementation, the simulation of the neutron irradiation effect is performed on the sample to determine the neutron irradiation model data, comprising:

[0018] A lunar standard substance composition is determined, and a simulation environment is determined based on the lunar standard substance composition;

[0019] A neutron flux intensity and a neutron energy spectrum are determined;

[0020] Cross-section information is determined based on the simulation environment, the neutron flux intensity, and the neutron energy spectrum;

[0021] The neutron irradiation model data is determined based on the cross-section information.

[0022] In a possible implementation, the comparison is performed based on the isotope measurement data and the neutron irradiation model data to determine the comparison result, comprising:

[0023] The residual error is calculated based on the isotope measurement data and the neutron irradiation model data, and the residual error calculation result is determined;

[0024] The comparison result is determined based on the residual error calculation result and the element type.

[0025] In a possible implementation, the epithermal neutron flux is determined based on the comparison result, including:

[0026] The initial epithermal neutron flux is adjusted by the least square method, and the comparison result is updated based on the initial epithermal neutron flux to obtain a target comparison result;

[0027] In a case where the target comparison result meets a preset variance condition, the epithermal neutron flux is determined.

[0028] In a possible implementation, the initial epithermal neutron flux is adjusted by the least square method, including:

[0029] The initial epithermal neutron flux is adjusted by the least square method using a gradient descent algorithm.

[0030] In a possible implementation, the earth standard substance includes:

[0031] The strontium element earth standard substance is SRM 987;

[0032] The neodymium element earth standard substance is Ames;

[0033] The hafnium element earth standard substance is JMC 475;

[0034] The lead standard substance is NBS 981.

[0035] According to a second aspect of an embodiment of the present specification, a neutron flux determination device applied to samarium-neodymium isotope system dating is provided, including:

[0036] The measurement data determination module is configured to perform isotope measurement on the sample, and determine isotope measurement data of the sample;

[0037] The neutron irradiation effect module is configured to simulate the neutron irradiation effect based on the sample, and determine neutron irradiation model data;

[0038] The data comparison module is configured to compare based on the isotope measurement data and the neutron irradiation model data, and determine a comparison result;

[0039] The neutron flux determination module is configured to determine the epithermal neutron flux based on the comparison result.

[0040] According to a third aspect of an embodiment of the present specification, a computing device is provided, including:

[0041] A memory and a processor;

[0042] The memory is configured to store computer executable instructions, and the processor is configured to execute the computer executable instructions, and the computer executable instructions, when executed by the processor, implement the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0043] According to a fourth aspect of the embodiments of the present specification, a computer readable storage medium is provided, which stores computer executable instructions, and the instructions, when executed by a processor, implement the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0044] According to a fifth aspect of the embodiments of the present specification, a computer program is provided, and when the computer program is executed in a computer, the computer program causes the computer to execute the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0045] The embodiments of the present specification provide a method and device for determining neutron flux applied to samarium-neodymium isotope system dating, wherein the method for determining neutron flux applied to samarium-neodymium isotope system dating comprises: performing isotope measurement on a sample to determine isotope measurement data of the sample; performing simulation of neutron irradiation effect based on the sample to determine neutron irradiation model data; comparing the isotope measurement data and the neutron irradiation model data to determine a comparison result; and determining epithermal neutron flux based on the comparison result. The size of the epithermal neutron flux is simulated by using the isotope data of the sample, which has a wide range of application and can be used for drilling samples, return samples, meteorite samples, etc., thereby improving the accuracy of dating results of isotope systems at different depths and providing a reliable basis for studying the refresh rate of drilling lunar soil samples. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a flowchart of a method for determining neutron flux applied to samarium-neodymium isotope system dating provided by an embodiment of the present specification;

[0047] Figure 2 is a schematic diagram of neutron differential flow intensity of a method for determining neutron flux applied to samarium-neodymium isotope system dating provided by an embodiment of the present specification;

[0048] Figure 3 is a schematic diagram of the probability of reaction between neutrons and helium-3 of a method for determining neutron flux applied to samarium-neodymium isotope system dating provided by an embodiment of the present specification;

[0049] Figure 4 is a structural schematic diagram of a device for determining neutron flux applied to samarium-neodymium isotope system dating provided by an embodiment of the present specification;

[0050] Figure 5is a structural block diagram of a computing device provided by one embodiment of the present specification. DETAILED DESCRIPTION

[0051] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present specification. However, the present specification can be practiced without the specific details, other than in the examples described herein, and it is understood that the scope of the present specification is not limited to the details below.

[0052] The terminology used in one or more embodiments of the present specification is for the purpose of describing particular embodiments only and is not intended to be limiting of one or more embodiments of the present specification. As used in one or more embodiments of the present specification and the accompanying claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in one or more embodiments of the present specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0053] It will be understood that, although the terms first, second, etc. can be used herein to describe various information, these terms are not intended to denote a temporal or chronological order. These terms are used only to distinguish one from another. For example, without departing from the scope of one or more embodiments of the present specification, first can be termed second, and similarly, second can be termed first. Depending on the context, the word "if' as used herein can be interpreted as meaning "when" or "in response to determining."

[0054] In the present specification, a method for determining neutron flux applied to samarium-neodymium isotope system dating is provided, the present specification also relates to a device for determining neutron flux applied to samarium-neodymium isotope system dating, a computing device, and a computer readable storage medium, which are described in detail one by one in the following embodiments.

[0055] Referring to Figure 1 , Figure 1 A flowchart of a method for determining neutron flux applied to samarium-neodymium isotope system dating is shown according to one embodiment of the present specification, which specifically includes the following steps.

[0056] Step 101: Isotope measurement is performed on the sample to determine the isotope measurement data of the sample.

[0057] In a possible implementation, the isotope measurement is performed on the sample, and the isotope measurement data of the sample is determined, including: determining an earth standard substance, calibrating a mass spectrometer based on the earth standard substance; performing an extraction operation on the sample to determine a sample to be measured; performing measurement on the sample to be measured by the mass spectrometer to determine an initial measurement result; and correcting the initial measurement result to determine the isotope measurement data of the sample.

[0058] The earth standard substance includes: the strontium element earth standard substance is SRM 987; the neodymium element earth standard substance is Ames; the hafnium element earth standard substance is JMC 475; and the lead standard substance is NBS 981. The selection of the standard substance is based on the following consideration: the isotope ratio of SRM 987 has been accurately determined. Ames is an existing measured isotope standard substance. The isotope ratio of JMC 475 has been accurately determined and can be used to calibrate the accuracy and precision of the mass control analysis instrument. NBS 981 is an existing measured lead isotope standard substance.

[0059] In actual application, first, the mass spectrometer is calibrated by using a standard substance, and the standard substance includes: the strontium element earth standard substance is SRM 987; the neodymium element earth standard substance is Ames; the hafnium element earth standard substance is JMC 475; and the lead standard substance is NBS 981. These standard substances are used to calibrate the measurement results of the mass spectrometry, to ensure that the current isotope content (such as strontium, neodymium, hafnium, lead, etc.) D1, N measurement results are correct, wherein D1 is the number of daughter nuclides produced by decay, and N is the content of the present decay parent. The sample that has been subjected to dissolution, chemical extraction and other operations can be measured by using a mass spectrometer including a mass spectrometer (MS-MS), an inductively coupled plasma mass spectrometer (ICP-MS) and the like, and the measurement results are processed and corrected to eliminate the influence of instrument drift or interference factors on the measurement results, to obtain the measurement value of the isotope composition in the sample.

[0060] For example, taking KREEP basalt sample 15386 as an example, the sample contains radioactive parent isotopes and their decay products (daughter isotopes). In order to accurately measure the isotope ratio, the sample is subjected to dissolution, chemical extraction and other operations to extract the isotopes to be measured. The mass ratio of different isotopes in the sample is measured by using an inductively coupled plasma mass spectrometer (ICP-MS) and the like. At the same time, the measurement results are processed and corrected to eliminate the influence of instrument drift and other interference factors on the measurement results.

[0061] The sample isotope data simulation in the embodiments of the present specification is used to obtain the size of the epithermal neutron flux, which has a wide range of applications and can be used for drilling samples, return samples, meteorite samples and the like.

[0062] Step 102: determining the neutron irradiation model data based on simulation of neutron irradiation effect on the sample.

[0063] In one possible implementation, the simulation of neutron irradiation effect on the sample is performed to determine the neutron irradiation model data, including: determining the composition of the lunar standard substance, determining the simulation environment based on the composition of the lunar standard substance; determining the neutron flux and the neutron energy spectrum; determining the cross-section information based on the simulation environment, the neutron flux and the neutron energy spectrum; and determining the neutron irradiation model data based on the cross-section information.

[0064] Specifically, referring to Table 1, the composition of the lunar standard substance can be obtained by referring to the composition of the substance in the range of 2 meters in depth on the lunar surface:

[0065] Table 1

[0066]

[0067] In actual application, first, the lunar standard substance composition (for example, the composition of the substance in the range of 2 meters in depth on the lunar surface) is used to verify the accuracy of the neutron flux, the neutron energy spectrum and the nuclear reaction probability obtained by the composition by comparing with the standard result (for example, the measured lunar neutron density). Second, the neutron flux and the neutron energy spectrum at different depths are determined; the cross-section information is determined based on the neutron flux and the neutron energy spectrum at different depths, and the number of daughter bodies D2 generated by neutron capture effect is calculated under the assumption of time T; the number of daughter bodies D1 generated by decay is calculated by the decay equation D1=N(e λT -1).

[0068] Further, the neutron flux and the neutron energy spectrum are obtained. Different energy neutrons and different modes of action of nuclides exist, and there is a significant difference in the neutron energy spectrum at different depths for the drilling sample. According to the scattering cross-section and the absorption cross-section of neutrons and nuclides of different energies and fluxes, the probability of nuclear reaction of elements and neutrons is calculated by using the nuclear reaction simulation software, and the concentration and composition of elements after neutron irradiation are obtained. The nuclear reaction simulation software can include Geant4.

[0069] Continuing with the above example, the composition before isotope irradiation is assumed to be consistent with chondritic uniform reservoir (CHUR). Then the calculation of neutron irradiation effect is carried out, first, the neutron flux and the neutron energy spectrum are determined. For the drilling sample, there is a significant difference in the neutron energy spectrum at different depths, and the neutron differential spectrum of the drilling at 0-10 meters in depth is as shown in Figure 2 According to the scattering cross-section and the absorption cross-section of neutrons and nuclides, referring to Figure 3 , the probability of nuclear reaction of elements and neutrons is calculated by using the nuclear reaction simulation software Geant4, and the concentration and composition of elements after neutron irradiation are obtained.

[0070] Step 103: determining a comparison result based on the comparison between the isotope measurement data and the neutron irradiation model data.

[0071] In one possible implementation, the determining of the comparison result based on the comparison between the isotope measurement data and the neutron irradiation model data includes: performing residual calculation based on the isotope measurement data and the neutron irradiation model data to determine a residual calculation result; and determining the comparison result based on the residual calculation result and the element category.

[0072] In actual application, the calculated isotope composition is compared with the measured isotope composition, the residuals of the measured values are calculated, and the residuals are squared and summed to obtain a residual sum of squares. The residual sum of squares is divided by the number of element categories used to obtain the variance of the model values and the measured values.

[0073] In the above example, after obtaining the concentration and composition of the elements after neutron irradiation, the calculated isotope composition is compared with the measured isotope composition, and the variances of the two are calculated.

[0074] Step 104: determining the epithermal neutron flux based on the comparison result.

[0075] In one possible implementation, the determining of the epithermal neutron flux based on the comparison result includes: adjusting an initial epithermal neutron flux by using a least square method, updating the comparison result based on the initial epithermal neutron flux to obtain a target comparison result; and determining the epithermal neutron flux in a case where the target comparison result meets a preset variance condition.

[0076] In actual application, the least square method is used to determine the best fitting parameter of the epithermal neutron flux: the least square method is used to adjust the epithermal neutron flux assumption, and the epithermal neutron flux is adjusted so that the variance of the model values and the measured values of the element composition is minimized. The epithermal neutron flux that minimizes the variance of the model values and the measured values is found, which is the optimal epithermal neutron flux value, and is output.

[0077] In one possible implementation, the adjusting of the initial epithermal neutron flux by using the least square method includes: adjusting the initial epithermal neutron flux by using a gradient descent algorithm by using the least square method.

[0078] In actual application, the adjustment method of the epithermal neutron flux can be implemented by using an optimization algorithm such as gradient descent.

[0079] In the above example, the gradient descent optimization algorithm is used to adjust the epithermal neutron flux, and the epithermal neutron flux that minimizes the variance of the model values and the measured values is found, which is the optimal epithermal neutron flux value, and is output. The finally obtained optimal epithermal neutron flux is 4.05×10 16 n / cm2 .

[0080] Further, after determining the epithermal seed flux, a corrected age result of the neutron capture effect can be given.

[0081] Specifically, the basic formula of isotope geochronology is:

[0082] T = (1 / lambda)ln(D / N+1);

[0083] Wherein, lambda is the decay constant, D is the content of the daughter nuclide, N is the content of the parent nuclide, and T is the age, that is, the time experienced by the geological body since the formation of the closed system.

[0084] The content of the daughter nuclide will be affected by the neutron capture D2 in addition to the increase in age D1, and D = D1+D2. Especially when using the samarium-neodymium isotope system dating method. By determining the thermal and epithermal neutron flux, the effect of neutron capture can be corrected, and the accuracy of samarium-neodymium isotope system dating can be improved.

[0085] The embodiment of the present specification uses the optimal epithermal neutron flux value to obtain relatively accurate dating results of the samarium-neodymium isotope system at different depths, and provides a reliable basis for studying the refresh rate of lunar soil samples.

[0086] The embodiment of the present specification provides a neutron flux determination method and device applied to samarium-neodymium isotope system dating, wherein the neutron flux determination method applied to the samarium-neodymium isotope system dating comprises: performing isotope measurement on a sample to determine isotope measurement data of the sample; simulating neutron irradiation effect based on the sample to determine neutron irradiation model data; comparing the isotope measurement data and the neutron irradiation model data to determine a comparison result; and determining an epithermal neutron flux based on the comparison result. The size of the epithermal neutron flux is simulated by using the isotope data of the sample, which has a wide range of applications and can be used for drilling samples, return samples, meteorite samples, etc., thereby improving the accuracy of the dating results of the isotope system at different depths and providing a reliable basis for studying the refresh rate of lunar soil samples.

[0087] Corresponding to the above method embodiment, the present specification also provides a neutron flux determination device embodiment applied to samarium-neodymium isotope system dating, Figure 4 Fig. 1 shows a structure schematic diagram of a neutron flux determination device applied to samarium-neodymium isotope system dating according to an embodiment of the present specification. As shown in Figure 4 The device comprises:

[0088] The measurement data determination module 401 is configured to perform isotope measurement on a sample to determine isotope measurement data of the sample;

[0089] The neutron irradiation effect module 402 is configured to determine neutron irradiation model data based on simulation of neutron irradiation effect on the sample;

[0090] The data comparison module 403 is configured to determine a comparison result based on comparison of the isotope measurement data and the neutron irradiation model data;

[0091] The neutron flux determination module 404 is configured to determine the epithermal neutron flux based on the comparison result.

[0092] In a possible implementation, the isotope measurement on the sample is performed to determine the isotope measurement data of the sample, including:

[0093] The earth standard substance is determined, and the mass spectrometer is calibrated based on the earth standard substance;

[0094] The sample is subjected to an extraction operation to determine the sample to be measured;

[0095] The sample to be measured is measured by the mass spectrometer to determine an initial measurement result;

[0096] The initial measurement result is corrected to determine the isotope measurement data of the sample.

[0097] In a possible implementation, the neutron irradiation model data is determined based on simulation of neutron irradiation effect on the sample, including:

[0098] The lunar standard substance composition is determined, and the simulation environment is determined based on the lunar standard substance composition;

[0099] The neutron flux intensity and the neutron energy spectrum are determined;

[0100] The cross-section information is determined based on the simulation environment, the neutron flux intensity, and the neutron energy spectrum; and the neutron irradiation model data is determined based on the cross-section information.

[0101] In a possible implementation, the comparison result is determined based on comparison of the isotope measurement data and the neutron irradiation model data, including:

[0102] Residual calculation is performed based on the isotope measurement data and the neutron irradiation model data to determine a residual calculation result;

[0103] The comparison result is determined based on the residual calculation result and the element type.

[0104] In a possible implementation, the epithermal neutron flux is determined based on the comparison result, including:

[0105] The initial epithermal neutron flux is adjusted by a least square method, the comparison result is updated based on the initial epithermal neutron flux to obtain a target comparison result;

[0106] In a case where the target comparison result meets a preset variance condition, the epithermal neutron flux is determined.

[0107] In a possible implementation, the initial epithermal neutron flux is adjusted by a least square method, including:

[0108] The initial epithermal neutron flux is adjusted by a gradient descent algorithm through the least square method.

[0109] In a possible implementation, the earth standard substance includes:

[0110] The strontium element earth standard substance is SRM 987;

[0111] The neodymium element earth standard substance is Ames;

[0112] The hafnium element earth standard substance is JMC 475;

[0113] The lead standard substance is NBS 981.

[0114] The embodiment of the present specification provides a neutron flux determination method and device applied to samarium-neodymium isotope system dating, wherein the neutron flux determination device applied to the samarium-neodymium isotope system dating includes: performing isotope measurement on a sample to determine isotope measurement data of the sample; performing simulation of a neutron irradiation effect based on the sample to determine neutron irradiation model data; comparing the isotope measurement data and the neutron irradiation model data to determine a comparison result; and determining an epithermal neutron flux based on the comparison result. The size of the epithermal neutron flux is obtained by simulating the isotope composition of the sample, which has a wide range of applications and can be used for drilling samples, return samples, meteorite samples, etc., thereby improving the accuracy of the dating results of isotope systems at different depths and providing a reliable basis for studying the refresh rate of drilling lunar soil samples.

[0115] The above is a schematic scheme of a neutron flux determination device applied to samarium-neodymium isotope system dating according to an embodiment of the present specification. It should be noted that the technical scheme of the neutron flux determination device applied to the samarium-neodymium isotope system dating belongs to the same concept as the technical scheme of the neutron flux determination method applied to the samarium-neodymium isotope system dating described above, and the technical scheme of the neutron flux determination device applied to the samarium-neodymium isotope system dating which is not described in detail can be referred to the description of the technical scheme of the neutron flux determination method applied to the samarium-neodymium isotope system dating described above.

[0116] Figure 4 A structural block diagram of a computing device 400 is shown according to an embodiment of the present specification. The components of the computing device 400 include but are not limited to a memory 410 and a processor 420. The processor 420 is connected with the memory 410 through a bus 430, and a database 450 is used to save data.

[0117] The computing device 400 also includes an access device 440 that enables the computing device 400 to communicate via one or more networks 460. Examples of these networks include a public switched telephone network (PSTN), a local area network (LAN), a wide area network (WAN), a personal area network (PAN), or combinations of these and / or other types of networks such as the Internet. The access device 440 can include one or more of any type of network interface (for example, a network interface card (NIC)), such as an IEEE 802.11 wireless local area network (WLAN) wireless interface, a Worldwide Interoperability for Microwave Access (Wi-MAX) interface, an Ethernet interface, a Universal Serial Bus (USB) interface, a cellular network interface, a Bluetooth interface, Near Field Communication (NFC).

[0118] In one embodiment of the present specification, the above-mentioned components of the computing device 400 and other components not shown in the Figure 4 may be connected to each other, for example, through a bus. It should be understood that Figure 4 The computing device structure diagram shown is for the purpose of example only, and is not a limitation on the scope of the present specification. Other components can be added or replaced as needed by those skilled in the art.

[0119] The computing device 400 can be any type of stationary or mobile computing device, including a mobile computer or mobile computing device (for example, a tablet computer, a personal digital assistant, a laptop computer, a notebook computer, a netbook, and the like), a mobile phone (for example, a smartphone), a wearable computing device (for example, a smartwatch, smart glasses, and the like), or other types of mobile devices, or a stationary computing device such as a desktop computer or a personal computer (PC). The computing device 400 can also be a mobile or stationary server.

[0120] The processor 420 is configured to execute computer-executable instructions to implement the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating. The above describes a schematic solution of the computing device of the embodiment. It should be noted that the technical solution of the computing device and the technical solution of the method for determining neutron flux applied to samarium-neodymium isotope system dating belong to the same concept, and the details of the technical solution of the computing device not described in detail can be referred to the description of the technical solution of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0121] The embodiment of the present specification also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0122] The above describes a schematic solution of the computer-readable storage medium of the embodiment. It should be noted that the technical solution of the storage medium and the technical solution of the method for determining neutron flux applied to samarium-neodymium isotope system dating belong to the same concept, and the details of the technical solution of the storage medium not described in detail can be referred to the description of the technical solution of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0123] The embodiment of the present specification also provides a computer program, which, when executed in a computer, causes the computer to perform the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0124] The above describes a schematic solution of the computer program of the embodiment. It should be noted that the technical solution of the computer program and the technical solution of the method for determining neutron flux applied to samarium-neodymium isotope system dating belong to the same concept, and the details of the technical solution of the computer program not described in detail can be referred to the description of the technical solution of the method for determining neutron flux applied to samarium-neodymium isotope system dating.

[0125] The specific embodiments of the present specification are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order and still achieve desirable results. Additionally, the process depicted in the figures does not necessarily require the particular order shown, or sequential order to achieve desirable results. In certain implementations, multitasking and parallel processing can be advantageous.

[0126] The computer readable medium can include any entity or apparatus capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, software distribution medium, etc. It should be noted that the computer readable medium can include appropriate additions or subtractions according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0127] It should be noted that for the foregoing method embodiments, the descriptions are each simply a combination of a series of acts for the sake of brevity, but those skilled in the art should know that the present application is not limited by the order of the acts described, because some steps can be performed in other orders or at the same time in accordance with the present application. In addition, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the acts and modules involved are not necessarily essential to the present application.

[0128] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0129] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The alternative embodiments do not describe all the details and limit the present application to the specific embodiments described. Obviously, according to the content of the present application, many modifications and changes can be made. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and use the present application. The present application is limited only by the claims and their full scope and equivalents.

Claims

1. A method for determining the neutron flux applied in the dating of samarium-neodymium isotope systems, characterized in that, The method comprises the following steps: isotope measurement is performed on a sample to determine isotope measurement data of the sample; simulation of neutron irradiation effect is performed based on the sample to determine neutron irradiation model data; comparison is performed based on the isotope measurement data and the neutron irradiation model data to determine a comparison result; epithermal neutron flux is determined based on the comparison result. The isotope measurement performed on the sample to determine the isotope measurement data of the sample comprises the following steps: a terrestrial standard substance is determined, and a mass spectrometer is calibrated based on the terrestrial standard substance; an extraction operation is performed on the sample to determine a sample to be measured; the sample to be measured is measured by the mass spectrometer to determine an initial measurement result; the initial measurement result is corrected to determine the isotope measurement data of the sample; The simulation of neutron irradiation effect performed based on the sample to determine the neutron irradiation model data comprises the following steps: a lunar standard substance composition is determined, and a simulation environment is determined based on the lunar standard substance composition; a neutron flux intensity and a neutron energy spectrum are determined; cross-section information is determined based on the simulation environment, the neutron flux intensity and the neutron energy spectrum; neutron irradiation model data is determined based on the cross-section information.

2. The method of claim 1, wherein, The comparison performed based on the isotope measurement data and the neutron irradiation model data to determine the comparison result comprises the following steps: residual calculation is performed based on the isotope measurement data and the neutron irradiation model data to determine a residual calculation result; the comparison result is determined based on the residual calculation result and an element type.

3. The method of claim 1, wherein, The determination of the epithermal neutron flux based on the comparison result comprises the following steps: an initial epithermal neutron flux is adjusted by a least square method, the comparison result is updated based on the initial epithermal neutron flux to obtain a target comparison result; in a case where the target comparison result meets a preset variance condition, the epithermal neutron flux is determined.

4. The method of claim 3, wherein, The adjustment of the initial epithermal neutron flux by the least square method comprises the following steps: the initial epithermal neutron flux is adjusted by a gradient descent algorithm by the least square method.

5. The method of claim 1, wherein, The terrestrial standard substance comprises: a strontium element terrestrial standard substance is SRM 987; a neodymium element terrestrial standard substance is Ames; a hafnium element terrestrial standard substance is JMC 475; a lead standard substance is NBS 981.

6. A neutron flux determining device for use in samarium-neodymium isotope system dating, characterized by The steps for implementing the method for determining neutron flux applied to samarium-neodymium isotope dating according to any one of claims 1 to 5 comprise: a measurement data determination module configured to perform isotope measurement on a sample to determine isotope measurement data of the sample; a neutron irradiation effect module configured to perform simulation of neutron irradiation effect based on the sample to determine neutron irradiation model data; a data comparison module configured to perform comparison based on the isotope measurement data and the neutron irradiation model data to determine a comparison result; a neutron flux determination module configured to determine epithermal neutron flux based on the comparison result.

7. A computing device, comprising: The method comprises the following steps: a memory and a processor; The memory is configured to store computer executable instructions, and the processor is configured to execute the computer executable instructions, and the computer executable instructions, when executed by the processor, implement the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating according to any one of claims 1 to 5. 8.A computer readable storage medium storing computer executable instructions, and the computer executable instructions, when executed by a processor, implement the steps of the method for determining neutron flux applied to samarium-neodymium isotope system dating according to any one of claims 1 to 5.

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