Method and system for calculating response current of self-powered neutron detector, terminal equipment and storage medium

Abstract

The invention discloses a method and system for calculating response current of a self-powered neutron detector, terminal equipment and a storage medium, and belongs to the technical field of neutron detection. The method comprises the following steps: acquiring parameters to obtain the size of charge density in an insulating layer of the detector; obtaining the position of a zero electric field point in the insulating layer according to the charge density in the insulating layer of the detector; and obtaining a radiation surface current at the position of the zero electric field point, wherein the current is a total response current of the detector in a steady state. The method has the advantages that the total response current can be obtained only by obtaining the charge density distribution and the surface current once, and computing resources are greatly saved on the premise that high computing precision is kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of neutron detection, and in particular relates to a method, system, terminal equipment and storage medium for calculating the response current of a self-powered neutron detector. Background Art

[0002] Nuclear energy is a clean energy with great development potential. As the most extensive and basic way to utilize nuclear energy, the safety of nuclear reactors has always been the primary concern in the application process. During the operation of the reactor, the reactor neutron flux is the main basis for evaluating the operating status of the reactor. Self-powered neutron detectors are widely used in reactor neutron flux monitoring due to their advantages such as full solidification, high temperature resistance, and radiation resistance. The self-powered neutron detector is placed in the core. After being irradiated by reactor neutrons and photons, it will generate signal electrons through different pathways and then form a response current. The sensitivity of the self-powered neutron detector is its important characteristic parameter, which is the ratio of the response current to the neutron flux density. After the detector sensitivity is pre-calibrated, the neutron flux at the location of the detector can be obtained according to the detector's response current. Therefore, it is very critical and necessary to accurately and quickly calculate the detector's response current.

[0003] At present, many scholars at home and abroad have done a lot of research on the calculation of the response current of self-powered detectors, which can be mainly divided into two categories: analytical calculation method and numerical calculation method. The analytical calculation method mainly establishes a mathematical model to describe the reaction mechanism of the detector after being irradiated by the reactor mixed field, and finally gives the analytical form of the detection current. However, due to the complexity of the interaction between the detector and the particles in the reactor, it is difficult to establish a universal and accurate model to include all the effects that need to be considered in the formation of the response current.

[0004] With the gradual development of computer technology, high-performance Monte Carlo codes have been widely used in particle transport problems. Therefore, many scholars have begun to try to use the Monte Carlo method to study the response mechanism of self-powered detectors. In this process, the self-powered detector response current calculation method based on the Monte Carlo method has achieved fruitful results. However, there are some problems that need to be improved in the specific calculation method: 1) Most of the methods proposed in the literature include approximations of the charge density distribution of the insulating layer. For example, some methods believe that the charge density is uniformly distributed inside the insulating layer, which is contrary to the actual situation; 2) Most methods are based on the Goldstein current calculation model. The calculation of the response current requires the use of two surface currents, which will increase the consumption of computing resources and the process is complicated. Summary of the invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method, system, terminal device and storage medium for calculating the response current of a self-powered neutron detector, so as to solve the technical problems in the prior art that the charge density distribution does not conform to the actual situation, the computing resources are consumed greatly and the method is complicated.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for calculating a self-powered neutron detector response current comprises the following steps:

[0008] Obtain parameters to obtain the charge density at different radii of the detector;

[0009] According to the charge density at different radii of the detector, the position of the zero electric field point inside the insulating layer is obtained;

[0010] Obtain the radiation surface current at the zero electric field point, which is the total response current of the detector in the steady state;

[0011] Furthermore, the charge density of the detector at different radii is obtained by the Monte Carlo method:

[0012] The radiation field information at the location of the self-powered neutron detector and the parameters required for calculation are given as the input of the Monte Carlo program;

[0013] The Monte Carlo program simulates the interaction between the ray and the detector, and counts the charge density at different radii of the detector;

[0014] Furthermore, the radiation field information includes particle type, particle energy and momentum distribution, and radiation field flux density; the parameters required for the calculation include detector geometry, material, and steady-state electric field information.

[0015] Furthermore, the zero electric field point position r c is the radius of the cylindrical surface where the electric field inside the detector insulation layer is zero.

[0016] Furthermore, the total response current at any radial position of the detector includes the radiation current at the position and the conduction current at the position, as shown in the following formula:

[0017] I(r)=I r (r)+I c (r)

[0018] Where r is the radius, I(r) is the total response current at the radius r, and I r (r) represents the radiation current at radius r, I c (r) represents the conduction current at radius r.

[0019] The conduction current I at r c The relationship between (r) and the electric field E(r) is shown in the following equation:

[0020] I c (r)=σE(r)A(r)

[0021] Where σ is the conductivity of the detector insulation material and A(r) is the area of ​​the cylinder with radius r.

[0022] Furthermore, the total response current of the detector is equal at different radii under steady-state conditions, and the derivation process is:

[0023] Since the structure of the self-powered detector is a coaxial cylinder and the length of the detector is much larger than the radius, the detector can be equivalent to an infinitely long axis of symmetry, so that its charge, electric field and current distribution are considered to be only related to r. In cylindrical coordinates, according to the law of conservation of charge, when the detector reaches a steady state, the charge density at different radii no longer changes, and we have:

[0024]

[0025] The expression for the total current density can be derived:

[0026]

[0027] Then the total response current of the detector is:

[0028] I(r)=J(r)S(r)=2πrlC=I

[0029] Where J(r) is the total current density, J r (r) is the axial component of the total current density in cylindrical coordinates, ρ(r,t) is the time-varying charge density distribution, C is an undetermined constant, and I is the total steady-state detector response current.

[0030] It can be seen that under steady-state conditions, the total response current of the self-powered detector is equal at different radii, and the total response current at any position is the sum of the radiation current and the conduction current at that position. Therefore, under steady-state conditions, the total response current at the zero electric field point in the insulating layer of the detector is the total response current of the detector.

[0031] Furthermore, the zero electric field point r c The radiation surface current at the position is the total response current of the detector in the steady state, and its calculation process is:

[0032] According to the zero electric field point r c The locations are:

[0033] E(r c)=0

[0034] Then the conduction current I at the zero electric field point is c (r c ):

[0035] I c (r c )=σE(r c )A(r c )=0

[0036] Then the total response current of the detector with zero field point is

[0037] I(r c )=I r (r c )+I c (r c )=I r (r c )=I

[0038] Among them, E(r c ) is the electric field at the zero electric field point, I r (r c ) is the radiation surface current at the zero electric field point;

[0039] Furthermore, the zero electric field point position r c The radiation surface current I r (r c ) is obtained by Monte Carlo method:

[0040] The radiation field information at the location of the self-powered neutron detector and the parameters required for calculation are given as the input of the Monte Carlo program;

[0041] The Monte Carlo program simulates the interaction between the ray and the detector, and counts the detector at the zero electric field point r c The surface current I r (r c )size;

[0042] Furthermore, the radiation field information includes particle type, particle energy and momentum distribution, and radiation field flux density; the parameters required for the calculation include detector geometry, material, and steady-state electric field information.

[0043] The present invention also discloses a system for calculating the response current of a self-powered neutron detector, based on the above method for calculating the response current of a self-powered neutron detector, comprising:

[0044] A charge density acquisition module is used to obtain the charge density at different radii of the detector by using the Monte Carlo method according to the acquired parameters;

[0045] A zero electric field position determination module is used to obtain the position of the zero electric field point inside the insulating layer according to the charge density at different radii of the detector;

[0046] The total response current calculation module is used to calculate the radiation surface current at the position according to the acquired zero electric field point position, so as to obtain the total response current of the detector in the steady state.

[0047] The present invention also discloses a terminal device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0048] The present invention also discloses a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention provides a method for calculating the response current of a self-powered neutron detector, which takes into account the real non-uniform charge density distribution and reduces the approximation compared with the traditional uniform charge density distribution. According to the charge conservation law and the total response current component of the detector, it is proposed to use the radiation surface current at the location of the zero-point field point to calculate the steady-state total response current of the detector, which only involves the calculation of one surface current, simplifies the calculation process, and thus realizes the efficient and high-precision calculation of the response current of the self-powered neutron detector.

[0051] Furthermore, since the structure of the self-powered detector is a coaxial cylinder and the length of the detector is much larger than the radius, the detector can be equivalent to an infinitely long axis of symmetry, so that its charge, electric field and current distribution are considered to be only related to r.

[0052] Furthermore, under steady-state conditions, the total response current of the self-powered detector is equal at different radii, and the total response current at any position is the sum of the radiation current and the conduction current at that position. Therefore, under steady-state conditions, the total response current at the zero electric field point in the insulating layer of the detector is the total response current of the detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a schematic diagram of the process of the present invention.

[0054] Figure 2 The distribution of radiation current, conduction current and total current inside the insulation layer when the detector is in steady state.

[0055] Figure 3 This is a structural diagram of the rhodium self-powered detector used in a specific embodiment.

[0056] Figure 4 The neutron energy spectrum used in the specific embodiment.

[0057] Figure 5 It is the charge density distribution result in the insulating layer of the rhodium self-powered detector in a specific embodiment.

[0058] Figure 6 This is the electric field distribution result inside the insulating layer of the rhodium self-powered detector in a specific embodiment.

[0059] Figure 7 It is the electric field fitting result in the insulating layer of the rhodium self-powered detector in a specific embodiment. DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0061] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0062] It should be noted that the terminals involved in the embodiments of the present application may include but are not limited to mobile phones, personal digital assistants (PDAs), wireless handheld devices, tablet computers, personal computers (PCs), MP3 players, MP4 players, wearable devices (for example, smart glasses, smart watches, smart bracelets, etc.), smart home devices and other smart devices.

[0063] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0064] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0065] See also Figure 1 The present invention provides a method, system, terminal device and storage medium for calculating the response current of a self-powered neutron detector, comprising the following steps:

[0066] Step 1: Calculate the steady-state charge density at different radii of the detector. The steady-state charge density is calculated by Monte Carlo simulation software, that is, the radiation field information (including particle type, particle energy and momentum distribution, radiation field flux density, etc.) and the parameters required for calculation (detector geometry, material and steady-state electric field information, etc.) at the location of the given self-powered neutron detector are used as input to the Monte Carlo program; the Monte Carlo program simulates the interaction between the rays and the detector, and counts the charge density at different radii of the detector. The statistical method for the steady-state charge density at different radii can be selected according to the Monte Carlo software used for the research problem:

[0067] (1) If Monte Carlo software that supports particle tracking is used, the detector is designed in layers, the detector insulation layer is divided into m layers, and the number of electron depositions in each layer is counted. In the simulation calculation, the number of simulated neutron events is set to M. Then the charge deposition amount caused by M simulated events in the nth layer is:

[0068] Q ns =N en e

[0069] The simulation needs to be converted to reality, so we need to obtain the real number of neutrons. Since the real neutron information we obtain is the neutron flux of the emitter, the real number of neutrons can be obtained by the ratio of the simulated neutron flux to the real neutron flux, and then the simulation is converted to reality. In the Monte Carlo software that supports particle tracking, the simulated neutron flux is considered to be the ratio of the cumulative track length of M simulation cases in the emitter to the volume of the emitter:

[0070]

[0071] The actual charge deposition can then be written as:

[0072]

[0073] Then the charge density of the nth insulating layer can be calculated:

[0074]

[0075] in:

[0076] m is the number of layers of the detector insulation layer;

[0077] n is the serial number of each layer after the detector insulation layer is layered, n = 1, 2, 3...m;

[0078] M is the number of cases used in the simulation calculation;

[0079] V is the detector emitter volume;

[0080] λ ni is the length of the motion track of the i-th neutron inside the emitter;

[0081] is the total emitter neutron flux caused by N simulated neutron events;

[0082] Φ n is the emitter neutron flux in the actual environment of the detector; N en is the number of electrons deposited in the nth layer of the detector insulation layer;

[0083] e is the elementary charge, and its value can be 1.60217×10 -19 Cullen;

[0084] Q ns is the charge deposition amount on the detector insulation layer at layer n by N simulated neutron events;

[0085] Q n is the charge deposition of the nth layer of the detector insulation layer under the real neutron flux of the environment;

[0086] V n is the volume of the nth layer of the detector insulation layer;

[0087] ρ n is the charge density of the nth layer of the detector insulation layer;

[0088] (2) If Monte Carlo software with a fixed computing card is used, the detector is designed in layers, the insulating layer is divided into m layers, and the number of deposited electrons in each layer is counted, that is, N en , and also requires the emitter neutron flux of the statistical simulation The remaining calculation steps are the same as those using Monte Carlo software that supports particle tracking, and will not be described here;

[0089] The statistics of charge density can be selected according to the needs of the research problem: 1) If the influence of the real steady-state electric field is concerned, the iterative method is used to calculate the accumulated charge density distribution under the real steady-state electric field. 2) If the steady-state spatial electric field is considered to be small, the shape of the real steady-state spatial charge density distribution can be considered to be similar to the shape of the charge density distribution calculated by the charge deposition rate when there is no electric field, so the charge density distribution when there is no electric field is used to save calculation time. 3) In order to save computing resources, the spatial charge density distribution is directly considered as a constant, that is, the charge density at different positions in the insulating layer is equal.

[0090] Step 2: Obtain the position of the zero electric field point inside the insulating layer according to the charge density distribution in the insulating layer. The acquisition of the zero electric field point can be selected according to the acquisition of the charge density distribution in step 1, and the zero electric field point acquisition method includes but is not limited to the following two methods:

[0091] (1) When non-uniform charge density is used, the Poisson equation is shown below:

[0092]

[0093] According to the boundary conditions:

[0094] V(r i )=V(r o )=0

[0095] Solve the electric field expression obtained by the non-uniform charge density ρ(r):

[0096]

[0097] Discretize it for use in the next step:

[0098]

[0099] Where:

[0100]

[0101] in:

[0102] r is the radius;

[0103] r i is the inner radius of the entire insulation layer;

[0104] r o is the outer radius of the entire insulation layer;

[0105] V(r) is the potential distribution in the insulating layer;

[0106] ∈ is the dielectric constant of the insulating layer material;

[0107] ρ(r) is the charge density distribution in the insulating layer;

[0108] E(r) is the electric field distribution in the insulating layer;

[0109] E(r k ) is the discrete electric field distribution under steady-state electric field;

[0110] k is the number of the radius position, k = 1, 2, 3...m+1;

[0111] r n is the average radius of the nth insulating layer;

[0112] Δr k Layer thickness for layering insulation;

[0113] Combining the obtained discrete electric field distribution with the polynomial fitting method, we can sort out the fitting relationship between the distribution of the electric field and the insulation layer radius:

[0114] E(r)=a n ·r n +a n-1 ·r n-1 +…+a1·r+a0

[0115] According to the characteristics of the zero electric field point:

[0116] E(r c )=0

[0117] in:

[0118] a n is the coefficient of the n-order term in the polynomial fitting;

[0119] r c Satisfy i ≤r c ≤r o For low-order polynomials, r can be obtained by the root-finding formula c For high-order polynomials, the zero electric field point r can be obtained by root-finding methods (bisection method, etc.) combined with computer programs. c location.

[0120] (2) When the charge density distribution is considered to be uniform, the Poisson equation is shown below:

[0121]

[0122] The expression of electric potential V(r) can be written as:

[0123]

[0124] According to the boundary conditions:

[0125]

[0126] And the charge is evenly distributed:

[0127] ρ(r o )=ρ(r i )=ρ

[0128] The expression of coefficient A can be obtained:

[0129]

[0130] According to the relationship between electric potential and electric field, the expression of electric field E(r) can be written as:

[0131]

[0132] Combining the expression of coefficient A and the uniform distribution of charge, the expression of the electric field can be written as:

[0133]

[0134] According to the characteristics of the zero electric field point:

[0135] E(r c )=0

[0136] The explicit expression for the zero electric field point can be solved directly:

[0137]

[0138] in:

[0139] V(r) is the potential at point r in the insulating layer;

[0140] A is the coefficient;

[0141] B is the coefficient;

[0142] ρ is the uniformly distributed charge density;

[0143] Step 3: Obtain the radiation surface current at the zero electric field point, which is the total response current of the detector in a steady state;

[0144] The total response current of the detector includes radiation current and conduction current, as shown in the following formula:

[0145] I(r)=I r (r)+I c (r)

[0146] Where r is the radius, I(r) is the total response current at the radius r, and I r (r) represents the radiation current at radius r, I c(r) represents the conduction current at radius r.

[0147] The conduction current I at r c The relationship between (r) and the electric field E(r) is shown in the following equation:

[0148] I c (r)=σE(r)A(r)

[0149] Where σ is the conductivity of the detector insulation material and A(r) is the area of ​​the cylinder with radius r.

[0150] Since the structure of the self-powered detector is a coaxial cylinder and the length of the detector is much larger than the radius, the detector can be equivalent to an infinitely long axis of symmetry, so that its charge, electric field and current distribution are considered to be only related to r. In cylindrical coordinates, according to the law of conservation of charge, when the detector reaches a steady state, the charge density at different radii no longer changes, and we have:

[0151]

[0152] The expression for the total current density can be derived:

[0153]

[0154] Then the total response current of the detector is:

[0155] I(r)=K(r)S(r)=2πrlC=I

[0156] Where J(r) is the total current density, J r (r) is the axial component of the total current density in cylindrical coordinates, ρ(r,t) is the time-varying charge density distribution, C is an undetermined constant, and I is the total steady-state detector response current.

[0157] When the detector is in steady state, the radiation current, conduction current and total current inside the insulation layer are shown in the attached figure. Figure 2 As shown, it is known that the response current of the detector at different radial positions is the same in the steady state, so the zero electric field point r c The radiation surface current at the position is the total response current of the detector in steady state. The response current at the zero electric field point is calculated as follows:

[0158] According to the zero electric field point r c The locations are:

[0159] E(r c )=0

[0160] Then the conduction current I at the zero electric field point is c (r c ):

[0161] I c (r c )=σE(r c )S(r c )=0

[0162] Then the total response current I of the detector with zero field point is:

[0163] I=I(r c )=I r (r c )+I c (r c )=I r (r c )

[0164] Among them, E(r c ) is the electric field at the zero electric field point, I r (r c ) is the radiation surface current at the zero electric field point; that is, the radiation surface current at the location of the zero electric field point is equal to the total response current of the detector.

[0165] Among them, the radiation surface current I r (r c ) is calculated by Monte Carlo simulation software, that is, the radiation field information (including particle type, particle energy and momentum distribution, radiation field flux density, etc.) at the location of the self-powered neutron detector and the parameters required for calculation (detector geometry, material and steady-state electric field information, etc.) are given as the input of the Monte Carlo program; the Monte Carlo program simulates the interaction between the ray and the detector, and the radiation surface current I at the zero electric field point of the detector is counted. r (r c ). Radiation surface current I r (r c ) can be selected based on the Monte Carlo software used for the research question:

[0166] (1) If Monte Carlo software that supports particle tracking is used, the forward and reverse crossings r c The number of electrons on the surface can be obtained by the following formula: c The net number of electrons on the surface. In the simulation calculation, the number of simulated neutron events is set to M. Then M simulated events are c The net number of electrons caused by the surface is:

[0167] N e =N e+ -N e-

[0168] The simulation needs to be converted to reality, so we need to obtain the real number of neutrons. Since the real neutron information we obtain is the neutron flux of the emitter, the real number of neutrons can be obtained by the ratio of the simulated neutron flux to the real neutron flux, and then the simulation is converted to reality. In the Monte Carlo software that supports particle tracking, the simulated neutron flux is considered to be the ratio of the cumulative track length of M simulation cases in the emitter to the volume of the emitter:

[0169]

[0170] Then we can use the real situation r c The radiating surface current at the position is written as:

[0171]

[0172] in:

[0173] N e+ For M simulated neutron events in r c The number of positive electrons caused by the surface;

[0174] N e- For M simulated neutron events in r c The number of reverse electrons caused by the surface;

[0175] N e For M simulated neutron events in r c The net number of electrons caused by the surface;

[0176] (2) If Monte Carlo software with a fixed computing card is used, it is necessary to count the number of times r is crossed. c Net number of electrons on the surface N e , and statistically simulated emitter neutron flux Φ n , the remaining calculation steps can be calculated using Monte Carlo software that supports particle tracking;

[0177] Example 1

[0178] This embodiment uses a typical rhodium self-powered detector, and its detector size and material parameters are as shown in the attached Figure 3 As shown, the radiation source is a cylindrical isotropic neutron surface source, and the energy spectrum is as shown in the attached Figure 4 As shown, it is located on the outer surface of the guide tube. The real charge density distribution is used, and the results are shown in the attached Figure 5 As shown in the figure, the critical radius is obtained by polynomial fitting of the electric field. The electric field calculated by the real charge density distribution is shown in the figure. Figure 6 As shown, the determination coefficient of the fitting is 0.998, and the effect of the fitting is shown in the attached Figure 7 , and finally the zero electric field point r is obtained c=0.038198cm. Monte Carlo software was used to obtain I r (r c ) is 2.015μA, that is, the total response current of the detector is 2.015μA.

[0179] Example 2

[0180] This embodiment uses a typical rhodium self-powered detector, and its detector size and material parameters are as shown in the attached Figure 2 As shown, the radiation source is a cylindrical isotropic neutron surface source, and the energy spectrum is as shown in the attached Figure 4 As shown, it is located on the outer surface of the guide tube. A uniform charge density distribution is adopted, and the zero electric field point r is finally solved by an explicit solution method. c =0.039012cm. Monte Carlo software was used to obtain I r (r c ) is 2.001μA, that is, the total response current of the detector is 2.001μA.

[0181] Example 3

[0182] This embodiment uses a typical rhodium self-powered detector, and its detector size and material parameters are as shown in the attached Figure 2 As shown, the radiation source is a cylindrical isotropic neutron surface source, and the energy spectrum is as shown in the attached Figure 4 As shown, it is located on the outer surface of the guide tube. The non-uniform charge density distribution calculated by the charge deposition rate in the absence of an electric field was used, and the critical radius was obtained by polynomial fitting of the electric field. The determination coefficient of the fitting was 0.998, and the zero electric field point r was finally solved. c =0.038245cm. Monte Carlo software was used to obtain I r (r c ) is 2.018μA, that is, the total response current of the detector is 2.018μA.

[0183] The above three embodiments are all specific implementations of a method, system, terminal device and storage medium for calculating the response current of a self-powered neutron detector provided by the present invention. Among them, Example 1 adopts the most accurate and realistic charge density distribution and the surface current of the charge under the influence of a real electric field, so it is the most accurate and computationally expensive implementation method, which is suitable for scenarios that require high-precision results, but the cost is large and may be limited by resource conditions. Example 2 adopts the approximation of uniform charge distribution and its surface current under the condition of no electric field. It is the implementation method with the lowest computational cost and is suitable for scenarios with high requirements for speed and cost. Example 3 adopts the approximation of non-uniform charge distribution under the condition of no electric field and its surface current under the condition of no electric field. It is an implementation method with moderate computational cost, which achieves a balance between accuracy and cost and is suitable for most practical scenarios.

[0184] The computational resource overheads of Example 1, Example 2, and Example 3 are different, but their results are relatively close, indicating that the method, system, terminal device, and storage medium for calculating the response current of a self-powered neutron detector provided by the present invention have good robustness and versatility in practical applications. The method, system, terminal device, and storage medium for calculating the response current of a self-powered neutron detector provided by the present invention provide a variety of solutions from precise to approximate to meet different application requirements. Regardless of which implementation method is selected, the method can provide a reasonable solution path for practical problems and support optimization selection based on resource conditions.

[0185] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0186] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0187] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0188] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0189] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for calculating the response current of a self-powered neutron detector, characterized in that: include: Obtain parameters and obtain the charge density at different radii of the detector through the Monte Carlo method; According to the charge density at different radii of the detector, the position of the zero electric field point inside the insulating layer is obtained; The radiation surface current at the zero electric field point is obtained by the Monte Carlo method, that is, the total response current of the detector in the steady state is obtained.

2. The method for calculating the response current of the self-powered neutron detector according to claim 1, characterized in that: The Monte Carlo method is used to obtain the charge density at different detector radii, including: The radiation field information at the location of the self-powered neutron detector and the parameters required for calculation are given as the input data of the Monte Carlo program; the Monte Carlo program then simulates the interaction between the rays and the detector, and counts the charge density at different radii of the detector; where: The radiation field information includes particle types, particle energy and momentum distribution, and radiation field flux density; the parameters required for the calculation include detector geometry, materials, and steady-state electric field information.

3. The method for calculating the response current of the self-powered neutron detector according to claim 1, characterized in that: The position of the zero electric field point is the radial position of the cylindrical surface where the electric field inside the detector insulation layer is zero.

4. The method for calculating the response current of the self-powered neutron detector according to claim 1, characterized in that: The total response current at any radial position of the detector includes the radiation current at that position and the conduction current at that position, as shown in the following formula: I(r)=I r (r)+I c (r) Where r is the radius, I(r) is the total response current at the radius r, and I r (r) represents the radiation current at radius r, I c (r) represents the conduction current at radius r; The conduction current I at r c The relationship between (r) and the electric field E(r) is shown in the following equation: I c (r)=σE(r)A(r) Where σ is the conductivity of the detector insulation material and A(r) is the area of ​​the cylinder with radius r.

5. The method for calculating the response current of the self-powered neutron detector according to claim 4, characterized in that: The total response current of the detector is equal at different radii under steady-state conditions; In cylindrical coordinates, according to the law of conservation of charge, when the detector reaches a steady state, the charge density at different radii no longer changes, and we have: The expression for the total current density is derived: Then the total response current of the detector is: I(r)=J(r)S(r)=2πrlC=I Where J(r) is the total current density, J r (r) is the axial component of the total current density in cylindrical coordinates, ρ(r,t) is the charge density distribution that varies with time t, C is an undetermined constant, and I is the total steady-state detector response current.

6. The method for calculating the response current of the self-powered neutron detector according to claim 5, characterized in that: Zero electric field point r c The radiation surface current at the position is the total response current of the detector in the steady state, and its calculation process is: According to the zero electric field point r c The locations are: E(r c )＝0 Then the conduction current I at the zero electric field point is c (r c ): I c (r c )=σE(r c )A(r c )=0 Then the total response current of the detector with zero field point is I(r c )=I r (r c )+I c (r c )=I r (r c )=I Among them, E(r c ) is the electric field at the zero electric field point, I r (r c ) is the radiation surface current at the zero electric field point.

7. The method for calculating the response current of the self-powered neutron detector according to claim 6, characterized in that: Zero electric field point position r c The radiation surface current I r (r c ) is obtained by Monte Carlo method: Given the radiation field information at the location of the self-powered neutron detector and the parameters required for calculation, they are used as the input of the Monte Carlo program; the Monte Carlo program then simulates the interaction between the radiation and the detector, and counts the detector at the zero electric field point r c The surface current I r (r c ) size; where: The radiation field information includes particle types, particle energy and momentum distribution, and radiation field flux density; the parameters required for the calculation include detector geometry, materials, and steady-state electric field information.

8. A system for calculating the response current of a self-powered neutron detector, based on the method for calculating the response current of a self-powered neutron detector according to any one of claims 1 to 7, characterized in that: include: A charge density acquisition module is used to obtain the charge density at different radii of the detector by using the Monte Carlo method according to the acquired parameters; A zero electric field position determination module is used to obtain the position of the zero electric field point inside the insulating layer according to the charge density at different radii of the detector; The total response current calculation module is used to calculate the radiation surface current at the position according to the acquired zero electric field point position, so as to obtain the total response current of the detector in the steady state.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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