阅读说明：本技术 慢化体设计获取方法、装置、设备和介质 (Method, apparatus, device and medium for acquiring moderator design ) 是由 杨祎罡 张智 李玉兰 李元景 于 2021-07-12 设计创作，主要内容包括：本公开提供了一种慢化体设计获取方法、装置、设备和介质。其中,该方法包括：通过TRM方法获取对应初始慢化体种群的出射能谱；利用遗传目标函数针对出射能谱进行初始慢化体种群的每个初始慢化体设计的打分排序；以及对打分排序后的慢化体设计进行交叉变异以生成目标慢化体种群,其中目标慢化体种群包含多个目标慢化体设计。因此,相对于现有技术慢化体设计过程中的耗时长且缺乏全局遍历性的问题,实现了利用TRM方法的特征矩阵运算代替传统蒙特卡罗模拟的中子输运过程,节约了大量处理时间,同时采用遗传算法与TRM方法相结合,兼顾了运算时间与全局性遍历,能够实现针对BNCT一维平板慢化体以及其他慢中子应用场景下的慢化体设计的获取。(The present disclosure provides a moderator design acquisition method, apparatus, device, and medium. Wherein, the method comprises the following steps: acquiring an emergent energy spectrum corresponding to the initial moderator population by a TRM method; performing scoring ordering of each initial moderator design of the initial moderator population by using a genetic objective function aiming at the emergent energy spectrum; and performing cross variation on the scored and sorted moderator designs to generate a target moderator population, wherein the target moderator population comprises a plurality of target moderator designs. Therefore, compared with the problems of long time consumption and lack of global ergodicity in the design process of the slowing-down body in the prior art, the neutron transport process of the traditional Monte Carlo simulation is replaced by the characteristic matrix operation of the TRM method, a large amount of processing time is saved, meanwhile, the genetic algorithm and the TRM method are combined, the operation time and the global ergodicity are considered, and the design of the slowing-down body under the BNCT one-dimensional flat-plate slowing-down body and other slow neutrons application scenes can be obtained.)

1. A moderator design acquisition method comprising:

acquiring an emergent energy spectrum corresponding to the initial moderator population by a TRM method;

performing a scoring ranking of each initial moderator design of the initial moderator population for the outgoing energy spectrum using a genetic objective function; and

performing cross variation on the scored and sorted moderator designs to generate a target moderator population, wherein the target moderator population includes a plurality of target moderator designs.

2. The method of claim 1, wherein prior to said acquiring the outgoing spectrum for the initial population of moderators by the TRM method, further comprising:

generating the initial moderator population, the initial moderator population including a plurality of different initial moderator designs.

3. The method of claim 1, wherein the acquiring, by the TRM method, the outgoing energy spectrum corresponding to the initial population of moderators comprises:

obtaining a material matrix of the initial moderator population through response matrix operation;

and aiming at the input energy spectrum of the initial moderator population, obtaining the emergent energy spectrum by using the material matrix.

4. The method of claim 1, wherein in the scoring ordering of each initial moderator design of the population of initial moderators for the exit spectrum using a genetic objective function comprises:

scoring the emergent energy spectrum of each initial moderator design by using the genetic objective function to generate an energy spectrum score corresponding to each initial moderator design;

sequencing the initial moderator design of the initial moderator population according to the energy spectrum score to generate a sequenced moderator population; and

and performing sequencing screening on the sequencing moderator population to determine a reserved moderator population.

5. The method of claim 4, wherein the cross-mutating the scored and sorted moderator designs to generate a target moderator population comprises:

determining a parent moderator design according to the energy spectrum score of each moderator design of the reserved moderator population by using a roulette mode;

performing cross-mutation processing on the parent moderator design to generate the target moderator population.

6. The method of claim 1, further comprising:

judging the consistency of the designed quantity of the moderators in the target moderating body population and the initial moderating body population;

and updating the initial moderator population to the target moderator population according to the quantity consistency.

7. The method of claim 6, further comprising:

and carrying out cross variation on the moderator design of the target moderator population according to the quantity consistency.

8. A moderator design acquisition apparatus comprising:

the energy spectrum acquisition module is used for acquiring an emergent energy spectrum corresponding to the initial moderator population by a TRM method;

a scoring and sorting module for performing scoring and sorting of each initial moderator design of the initial moderator population for the outgoing energy spectrum using a genetic objective function; and

a cross variation module for cross varying the scored and sorted moderator designs to generate a target moderator population, wherein the target moderator population includes a plurality of target moderator designs.

9. An electronic device, comprising:

one or more processors;

a memory for storing one or more programs,

wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of any of claims 1-7.

10. A computer-readable storage medium storing computer-executable instructions for implementing the method of any one of claims 1 to 7 when executed.

Technical Field

The present disclosure relates to the field of computer technologies, and in particular, to a method, an apparatus, a device, and a medium for acquiring a moderator design.

Background

Currently, Boron Neutron Capture Therapy (BNCT) is one of the popular research directions in the medical field, and mainly includes injecting Boron-containing drugs into human body to enrich the Boron-containing drugs in tumor cells, and since 10B has a high thermal Neutron absorption cross section 3836B @25.3meV, 10B atoms in tumor cells Capture thermal neutrons with low energy, and release two kinds of high-LET particles: 7Li and alpha particles. Wherein, the total range of the released 7Li and alpha particles in the cell is about 10 μm, which is smaller than the average size of a cell, and the energy is almost completely deposited in the tumor cell, so that the surrounding healthy cells can avoid the radiation damage caused by the neutron capture reaction generated in the tumor cells accumulating higher boron concentration, thereby killing the tumor cells without harming the adjacent healthy cells. The key factors for realizing boron neutron capture therapy are two: a boron-containing drug and a neutron source. In order to meet the requirements of BNCT on neutron beam, the neutron beam standard given by the international atomic energy organization is adopted, and because most neutrons directly generated by nuclear reaction are fast neutrons with energy in the MeV magnitude, the neutrons need to be moderated and decelerated to an interesting applicable energy area. In the neutron moderating process, the moderating body plays an important energy spectrum modulation role.

Disclosure of Invention

Technical problem to be solved

To solve at least one of the problems of the prior art in the design of a moderator, the present disclosure provides a moderator design acquisition method, a moderator design acquisition apparatus, a device, and a medium.

(II) technical scheme

One aspect of the present disclosure provides a moderator design acquisition method, including: acquiring an emergent energy spectrum corresponding to the initial moderator population by a TRM method; performing scoring ordering of each initial moderator design of the initial moderator population by using a genetic objective function aiming at the emergent energy spectrum; and performing cross variation on the scored and sorted moderator designs to generate a target moderator population, wherein the target moderator population comprises a plurality of target moderator designs.

According to the embodiment of the present disclosure, before the obtaining of the outgoing energy spectrum corresponding to the initial moderator population by the TRM method, the method further includes: an initial moderator population is generated, the initial moderator population including a plurality of different initial moderator designs.

According to the embodiment of the disclosure, the acquiring of the outgoing energy spectrum corresponding to the initial moderator population by the TRM method includes: obtaining a material matrix of the initial moderator population through response matrix operation; and aiming at the input energy spectrum of the initial moderator population, obtaining an emergent energy spectrum by using the material matrix.

According to an embodiment of the present disclosure, in the scoring and ordering of each initial moderator design of the initial moderator population for the exit energy spectrum using the genetic objective function, comprises: scoring the emergent energy spectrum of each initial moderator design by using a genetic objective function to generate an energy spectrum score corresponding to each initial moderator design; sequencing the initial moderator design of the initial moderator population according to the energy spectrum score to generate a sequenced moderator population; and performing sequencing screening on the sequencing moderator population to determine a reserved moderator population.

According to an embodiment of the disclosure, in cross-mutating the scored and sorted moderator designs to generate a target moderator population, the method comprises: determining a parent moderator design according to the energy spectrum score of each moderator design of the reserved moderator population by using a roulette mode; and carrying out cross variation processing on the parent moderator design to generate a target moderator population.

According to an embodiment of the disclosure, the method further comprises: judging the consistency of the designed quantity of the moderators in the target moderating body population and the initial moderating body population; and updating the initial moderator population into the target moderator population according to the quantity consistency.

According to an embodiment of the disclosure, the method further comprises: and carrying out cross variation on the moderator design of the target moderator population according to the quantity consistency.

Another aspect of the disclosure provides a moderator design acquisition apparatus comprising an energy spectrum acquisition module, a scoring and sorting module, and a cross-mutation module. The energy spectrum acquisition module is used for acquiring an emergent energy spectrum corresponding to the initial moderator population through a TRM method; the scoring and sorting module is used for carrying out scoring and sorting on each initial moderator design of the initial moderator population by utilizing a genetic objective function aiming at the emergent energy spectrum; and the cross variation module is used for carrying out cross variation on the slowers after the grading and sorting so as to generate a target slowers population, wherein the target slowers population comprises a plurality of target slowers.

Another aspect of the present disclosure provides an electronic device comprising one or more processors and memory; the memory is used for storing one or more programs, wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of the embodiments of the present disclosure.

Another aspect of the present disclosure provides a computer-readable storage medium storing computer-executable instructions that, when executed, implement the method of embodiments of the present disclosure.

Another aspect of the present disclosure provides a computer program comprising computer executable instructions that when executed perform the method of embodiments of the present disclosure.

(III) advantageous effects

The present disclosure provides a moderator design acquisition method, apparatus, device, and medium. Wherein, the method comprises the following steps: acquiring an emergent energy spectrum corresponding to the initial moderator population by a TRM method; performing scoring ordering of each initial moderator design of the initial moderator population by using a genetic objective function aiming at the emergent energy spectrum; and performing cross variation on the scored and sorted moderator designs to generate a target moderator population, wherein the target moderator population comprises a plurality of target moderator designs. Therefore, compared with the problems of long time consumption and lack of global ergodicity in the design process of the slowing-down body in the prior art, the neutron transport process of the traditional Monte Carlo simulation is replaced by the characteristic matrix operation of the TRM method, a large amount of processing time is saved, meanwhile, the genetic algorithm and the TRM method are combined, the operation time and the global ergodicity are considered, and the design of the slowing-down body under the BNCT one-dimensional flat-plate slowing-down body and other slow neutrons application scenes can be obtained.

Drawings

FIG. 1 schematically illustrates a flow diagram of a moderator design acquisition method in accordance with an embodiment of the present disclosure;

FIG. 2 schematically illustrates another flow diagram of a moderator design acquisition method according to an embodiment of the present disclosure;

FIG. 3 schematically illustrates a schematic diagram of neutron extraction spectrum estimation using a TRM method according to an embodiment of the disclosure;

fig. 4 schematically illustrates another schematic diagram of neutron extraction spectrum estimation using the TRM method according to an embodiment of the disclosure;

FIG. 5 schematically illustrates a schematic diagram of a cross-mutation acquire children process, according to an embodiment of the present disclosure;

FIG. 6 schematically shows a composition diagram of a moderator design acquisition apparatus according to an embodiment of the present disclosure; and

FIG. 7 schematically shows an architecture diagram of an electronic device to which the above-described moderator design acquisition method can be applied, according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.

It is to be noted that, in the attached drawings or in the description, the implementation modes not shown or described are all the modes known by the ordinary skilled person in the field of technology, and are not described in detail. Further, the above definitions of the various elements and methods are not limited to the various specific structures, shapes or arrangements of parts mentioned in the examples, which may be easily modified or substituted by those of ordinary skill in the art.

It should also be noted that directional terms, such as "upper", "lower", "front", "rear", "left", "right", and the like, used in the embodiments are only directions referring to the drawings, and are not intended to limit the scope of the present disclosure. Throughout the drawings, like elements are represented by like or similar reference numerals. Conventional structures or constructions will be omitted when they may obscure the understanding of the present disclosure.

And the shapes and sizes of the respective components in the drawings do not reflect actual sizes and proportions, but merely illustrate the contents of the embodiments of the present disclosure. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The use of ordinal numbers such as "first," "second," "third," etc., in the specification and in the claims to modify a corresponding element does not by itself connote any ordinal number of the element or any ordering of one element from another or the order of manufacture, and the use of the ordinal numbers is only used to distinguish one element having a certain name from another element having a same name.

Those skilled in the art will appreciate that the modules in the device of an embodiment may be adaptively changed and placed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Also in the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various disclosed aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that is, the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, disclosed aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this disclosure.

The conventional method for obtaining the design of the slowing-down body mainly comprises the steps of determining a slowing-down material (such as polyethylene and the like) to be used according to priori knowledge, estimating the thickness dimension of the slowing-down body, modeling, carrying out Monte Carlo simulation analysis, and selecting the design of the slowing-down body under the condition of being most beneficial. In short, the design of the slowing-down body in the prior art is based on the empirical design, and the parameter scanning is locally carried out to select the optimal value in the limited body.

Thus, the problems in the acquisition of conventional moderator design are mainly two-fold:

(1) it takes a long time. For Monte Care simulation, the statistical error of the obtained result is related to the particle count, that is, the statistical error follows 1/N1/2 law, and in the scene of strong shielding deep penetration and the like, the initial incident particle number must be increased, that is, the simulation time must be increased, in order to obtain a result with smaller statistical error without considering the variance reduction technique.

(2) Global traversability is lacking. Due to the time-consuming nature of the simulation calculations, it is not practical to perform a global search within the entire parameter space (the parameter space consisting of the type of moderator material, the order of arrangement, moderator thickness, shape, etc.).

In order to solve at least one of the problems of the prior art in the design of a moderator applied to BNCT, such as at least one of time consumption in the design process of the moderator and lack of global ergodicity, the disclosure provides a moderator design obtaining method, a device, equipment and a medium, and provides a technical scheme capable of rapidly predicting the structure of the moderator and the neutron emergent energy spectrum.

One aspect of the present disclosure provides a moderator design acquisition method including steps S101-S103.

In step S101, an outgoing energy spectrum corresponding to the initial moderator population is obtained by a TRM method;

in step S102, a genetic objective function is used to perform a scoring ranking of each initial moderator design of the initial moderator population for the outgoing energy spectrum; and

in step S103, cross-variation is performed on the scored and sorted moderator designs to generate a target moderator population, wherein the target moderator population includes a plurality of target moderator designs.

The initial moderator population includes a plurality of initial moderator designs, which are data sets formed by a plurality of original moderator design data without screening processing. The target moderator population includes a plurality of corresponding target moderator designs, and is a data set formed by a plurality of final moderator design data formed after being screened by the method of the steps S101-S103.

A Transmission and Reflection Matrix (TRM) method is an emergent neutron energy spectrum estimation method based on Monte Carlo simulation calculation and neutron moderator response matrixes (namely a Transmission matrix T and a Reflection matrix R). The response matrixes of monoenergetic neutrons with different energies and incidence directions passing through flat moderator made of different materials are calculated by mainly utilizing Monte Carlo simulation, and then the neutron energy spectrum modulated by the moderator is estimated by replacing the transportation process of the neutrons in the moderator through matrix operation.

Each row in the response matrix is the energy and angle distribution of the transmission neutrons or the reflection neutrons of a unit neutron source with certain fixed energy and angle incidence after passing through a layer of moderating material. The row vectors are shown below:

wherein, the superscripts "out" and "in" of the energy E represent input and output, respectively; the numbers of the subscripts of energy E and direction Dir represent the several energy intervals and direction intervals, E_binAnd Dir_binRepresenting the number of division intervals in energy and angular direction. In addition, the lower corner mark of the row vector represents the information of the incident neutron, and the incident neutron traverses all the energy and direction intervals to obtain E_bin×Dir_binAnd the number of the row vectors is the same as that of the elements of the row vectors, and the row vectors are spliced to obtain the square matrix T or R.

Based on the above, the TRM method has the following features: (1) the calculation of the response matrix of the slowing-down body can be made into a database, so that the effect of 'once and for all' is achieved; (2) the operation of the response matrix can replace the transportation process of neutrons in the moderating body, so that the operation time is saved; (3) can flexibly adapt to different input neutron energy spectrums and output neutron energy spectrum requirements. That is, the TRM method can effectively solve the problem that the conventional monte carlo simulation computation is time-consuming.

To traverse the entire moderator parameter space, further reducing the number of computations, making the total computation cost smaller to find the globally optimal solution, in embodiments of the present disclosure, a GAM method, i.e., a Genetic Algorithm with Matrices method, is constructed by combining the Genetic Algorithm with the TRM method and applied in moderator design such as BNCT.

Specifically, original moderator design individuals can be randomly selected through a genetic algorithm to form an initial moderator design population, the individuals are scored by using genetic objective functions such as scoring functions and the like, the individuals are ranked according to the scores, and the individuals are ranked to be superior or inferior, so that the individuals can gradually converge to the same kind of design through multiple iterations. The genetic objective function in the design of the moderator is composed of interesting parameters in an emergent neutron energy spectrum (namely the emergent neutron energy spectrum), such as fluence rate, time and the like, and the estimation of the emergent neutron energy spectrum of each moderator is completed by a TRM method, so that the condition that a Monte Carlo input file needs to be regenerated for particle simulation every iteration is avoided. Therefore, the GAM method can improve the calculation speed of the acquisition process of the moderator design and can better realize the search of the global optimal solution.

Finally, the moderator designs after the scoring and sorting are subjected to cross variation processing, so that the generated target moderator population can contain a plurality of required moderator designs, namely the target moderator designs. In the genetic algorithm, the cross (crossbar) is a data processing method for exchanging respective partial data of a parent generation and a parent generation based on binary coding to form a new individual; mutation (Mutation) is generally a data processing method in which a new individual is generated based on a certain Mutation probability.

Therefore, compared with the problems of long time consumption and lack of global ergodicity in the design process of the slowing-down body in the prior art, the neutron transport process of the traditional Monte Carlo simulation is replaced by the characteristic matrix operation of the TRM method, a large amount of processing time is saved, meanwhile, the genetic algorithm and the TRM method are combined, the operation time and the global ergodicity are considered, and the design of the slowing-down body under the BNCT one-dimensional flat-plate slowing-down body and other slow neutrons application scenes can be obtained.

As shown in fig. 1 and fig. 2, according to the embodiment of the present disclosure, before acquiring the outgoing energy spectrum corresponding to the initial moderator population by the TRM method in step S101, the method further includes:

an initial moderator population is generated, the initial moderator population including a plurality of different initial moderator designs.

The initial moderator design is formed by parameters such as moderator material, thickness, etc., and a collection of multiple different initial moderator designs forms an initial moderator population, as described with reference to step S201 of fig. 2.

As shown in fig. 1 and 2, according to the embodiment of the present disclosure, in acquiring the outgoing energy spectrum corresponding to the initial moderator population by the TRM method in step S101, the method includes:

obtaining a material matrix of the initial moderator population through response matrix operation;

and aiming at the input energy spectrum of the initial moderator population, obtaining an emergent energy spectrum by using the material matrix.

For any known input spectrum S_iThe material matrix of the (n +1) -layer moderator can be obtained by response matrix operation, such as the transmission matrix T_n+1And a reflection matrix R_n+1The method comprises the following steps:

in which, as shown in fig. 3 and 4, for n layers of moderators (corresponding to the transmission matrix T)_n) And a moderator of the (n +1) th layer (corresponding to the transmission matrix T)_n+1) The condition that the neutrons are reflected by the nth layer of slowing-down body in the process of emitting the neutrons exists, different transmission matrixes T are determined according to different reflection times_n+1. Similarly, for a moderator for n layers (corresponding to the reflection matrix R)_n) And a moderator of the (n +1) th layer (corresponding to the reflection matrix R)_n+1) When the neutron is reflected by the n-th layer of slowing-down body in the process of emitting the neutron, different reflection matrixes R are determined according to different reflection times_n+1。

Aiming at the input energy spectrum S through response matrix operation according to the formulas (1) and (2)_iFurther, the emission energy spectrum S corresponding to the initial moderator population can be obtained by multiplying the material matrix by a TRM method_pThe method comprises the following steps:

S_p＝S_i·T_n+1 (3)

based on the scheme of data processing, compared with the Monte Carlo simulation calculation method in the prior art, the TRM method disclosed by the embodiment of the disclosure can accelerate the acquisition of the emergent energy spectrum of a single moderator design and save the operation time. Specifically, experiments show that, in the case of achieving the same statistical error, the monte carlo simulation method in the prior art, in the case of employing the grid weight card and the energy splitting card minus the variance, it takes 240 minutes to calculate the statistical error that the neutron transport of the 60cm thick moderator reaches about 0.2%, whereas the operation processing method of the above-mentioned response matrix of the TRM method of the embodiment of the present disclosure only needs 30 seconds, which saves about 480 times of time consumption, which is actually beyond the expectation of those skilled in the art, and belongs to a great technical advance in the art. In addition, compared with Monte Carlo simulation calculation, because each calculation needs to be modeled again, a large number of incident neutrons are needed to reduce statistical errors caused by simulation, the TRM method of the embodiment of the disclosure only needs to prepare a database of transmission matrixes and reflection matrixes of neutrons passing through different materials in advance, the statistical errors are reduced as much as possible when the database is calculated, and each calculation can realize the estimation of the neutron emission energy spectrum only through the operation of the matrixes. Thus, the above-described method of the embodiments of the present disclosure may greatly reduce time consumption.

As shown in fig. 1 and 2, in the scoring and sorting of each initial moderator design of the initial moderator population for the exit energy spectrum using the genetic objective function in step S102 according to the embodiment of the present disclosure, the method includes:

scoring the emergent energy spectrum of each initial moderator design by using a genetic objective function to generate an energy spectrum score corresponding to each initial moderator design;

sequencing the initial moderator design of the initial moderator population according to the energy spectrum score to generate a sequenced moderator population; and

the ranked moderator populations are ranked and screened to determine the retention moderator populations.

For each moderator design in the randomly acquired initial moderator population, after the emergent energy spectrum is acquired in a targeted manner, a scoring operation may be performed on each initial moderator design with respect to the emergent energy spectrum, and the specific scoring operation may be a genetic objective function based on a genetic algorithm, which is a scoring function, and is not limited in particular. Through the genetic objective function, the determination of the energy spectrum score of the emergent energy spectrum designed by each initial slowing-down body can be realized, and the energy spectrum score can be used for reflecting the quality of the emergent energy spectrum designed by a corresponding slowing-down body.

And sequencing the initial moderator design with the emergent energy spectrum according to the magnitude relation of the energy spectrum scores to generate a sequenced moderator population.

And finally, screening specific moderator designs in the sequencing moderator population, and selecting the moderator designs to be superior or inferior, wherein the moderator designs with excellent energy spectrum scores of the first 5 percent of the population can be directly reserved to the next generation to form a reserved moderator population. The above can refer to steps S202-S203 shown in fig. 2, which are not described herein. The scoring function in the GAM method is actually extracted for some interesting parameters in the emergent energy spectrum estimated by the TRM method.

Therefore, the GAM method provided by the embodiment of the disclosure has the capability of finding a global optimal solution due to the addition of the genetic algorithm, so that the problems of time consumption and lack of global property in the slowing-down body optimization process can be better solved.

As shown in fig. 1 and 2, according to an embodiment of the present disclosure, cross-mutating the scored and sorted moderator designs in step S103 to generate a target moderator population includes:

determining a parent moderator design according to the energy spectrum score of each moderator design of the reserved moderator population by using a roulette mode;

and carrying out cross variation processing on the parent moderator design to generate a target moderator population.

The obtained population of retained moderator is sorted and screened for the above scoring, and each moderator design can be further analyzed for energy spectrum score by roulette to determine the parent moderator design, as shown in step S204 of fig. 2.

For the obtained parent moderator designs, different offspring moderator designs can be formed through the processing procedure of cross variation as shown in fig. 5, and a plurality of different offspring moderator designs (also referred to as offspring moderators) form a new moderator design population, i.e., a target moderator population, specifically referring to steps S205-S206 shown in fig. 2. Namely, the offspring moderators generated by the cross variation between the excellent parent individuals are designed to form a new target moderator population, and the iterative calculation is repeated until convergence.

Specifically, for example, for the design of BNCT moderators, as shown in fig. 2, the GAM method is used for the design:

first, 50 moderator individuals of a row vector of length 60 were randomly generated to form an initial moderator design population. Wherein each data in the row vector represents a one-dimensional plate moderator having a thickness of 1cm, and each data size represents a material number corresponding to each material, as shown in step S201 of fig. 2. Then, the emission spectrum S is estimated for each moderator by the TRM method using the above equations (1) to (3)_pThe result calculated by the TRM method is scored according to a preset genetic objective function, as shown in step S202 of fig. 2. Then, for the design of the moderator with high score, it will be more likely to remain or become the parent, and new moderator will be generated by genetic variation to form a new population, as shown in steps S203-S206 of fig. 2. Finally, this is iterated until convergence.

As mentioned above, the epithermal neutron fluence rate φ of the emitted neutron beam is required_epi≥5×10⁸n/cm²The high epithermal neutron fluence rate can reduce the treatment time of the patient and reduce the risks of other unnecessary metering irradiation; meanwhile, fast neutrons and photons cannot pass through¹⁰B distinguishes between tumor and healthy cells and adds extra to the patient's killing of tumor cells, and therefore, this also for fast neutron dose rate D_fastAnd photon dose rate D_γThe following requirements are proposed:

φ_epi/D_fast≤2×10^-13Gy·n/cm² (4)

φ_epi/D_γ≤2×10^-13Gy·n/cm² (5)

to satisfy the above equations (4) and (5), in the above GAM method according to the embodiment of the present disclosure, the set target scoring function should include the above related three parameters of interest, which are specifically as follows:

wherein x is_i(i is 1, 2, 3) is phi_epi/φ₀、(φ_epi/D_fast)/(φ₀/D_fast0) And (phi)_epi/D_γ)/(φ₀/D_γ0)；φ₀、D_fast0And D_γ0Respectively setting a preset epithermal neutron fluence rate and a fast neutron and gamma photon fluence rate standard (such as standard parameters recommended by international atomic energy agency IAEA); g (x)_i) As a scoring function in the GAM method, f (x)_i) To relate to x_iK is the step intercept.

Therefore, as can be seen from the above equation (7), when the index to be optimized is smaller than the target value (x)_iWhen the value is less than 1), the optimized slope is a; when the index to be optimized is greater than or equal to the target value (x)_iAnd when the slope is more than or equal to 1), the optimized slope is b. Wherein a step intercept k is added so that the already optimized parameters do not slip down to x_iThe area less than 1 achieves the effect of phase holding. The three parameters can be classified into two categories for the setting of the slope: (1) the fast neutron and photon dosage rate is the parameter which can be reduced below the IAEA standard, namely the parameter which can reach the standard, when x is₂，x₃At ≧ 1, the slope after the step hold may decrease, for example, to 1% of the original, i.e., b ═ a × 1%; (2) the greater the epithermal neutron fluence rate, the better, hence at x₁After the value is more than or equal to 1, besides the step protection step winning achievement, a larger optimization slope is needed, such as keeping b-a.

The input of the GAM method of the embodiment of the disclosure can be selected as the uncancelled neutron energy spectrum directly generated by a 25MeV photon source, and after iteration, the epithermal neutron fluence rate generated per kW after GAM optimization is 3.04 × 10⁷n/cm²S, current ofThe results in the prior art are improved by about 80%, and the fast neutron and photon dose rates reach the standard, which is actually greatly beyond the expectation of the skilled person, and belongs to the great progress recognized in the field. In addition, in order to achieve the epithermal neutron fluence rate recommended by IAEA for BNCT treatment, the power of the photoneutron source used in the prior art needs to reach 59kW, while the power of the photoneutron source based on GAM design of the embodiment of the present disclosure only needs 33kW, so that the same epithermal neutron fluence rate can be achieved, the burden of the heat dissipation problem of the electronic target is further reduced, the globality of the GAM method optimization problem is reflected, and a better result can be obtained.

As shown in fig. 2, according to an embodiment of the present disclosure, the method further comprises:

judging the consistency of the designed quantity of the moderators in the target moderating body population and the initial moderating body population;

and updating the initial moderator population into the target moderator population according to the quantity consistency.

According to an embodiment of the disclosure, the method further comprises:

and carrying out cross variation on the moderator design of the target moderator population according to the quantity consistency.

Comparing the number of the design of the moderator in the target moderator population with the number of the design of the moderator in the initial moderator population, when the numbers of the design of the moderator in the target moderator population and the number of the design of the moderator in the initial moderator population are consistent, determining that the target moderator population is the final obtained result of the method of the embodiment of the disclosure, and replacing the initial moderator population of the current population with the target moderator population, as shown in steps S207-S208 of fig. 2. Otherwise, when the numbers of the two are inconsistent, it is indicated that the target moderator population has not completed iteration, further iterative computation needs to be repeated, and the cross mutation operation is performed in a loop until convergence, as shown in steps S207-S206 of fig. 2.

The GAM method of the disclosed embodiments may be equally adaptable for different inputs. The calculation of the characteristic matrix is obtained by unit source simulation, so different unit sources only need to obtain non-moderated neutron energy spectrums, matrix multiplication and addition are carried out according to the TRM methods of the formulas (1) and (2), and only the output in the formula (3) needs to be replacedEnergy spectrum S_iThat is, the rest of the optimization process is consistent with the method shown in fig. 1-2, and the optimized result can be obtained finally. For different input requirements, the processing procedure of the TRM method in the embodiment of the present disclosure does not need to be changed, and only the form of the objective function needs to be changed, for example, the energy of the neutron in the energy region of interest is changed, and other optimization ideas and procedures remain unchanged.

Similarly, if the design of the slowing-down body is in other application scenes, the interested parameters can be extracted and merged into the scoring function. For example, in thermal neutron imaging, the parameter of interest is the thermal neutron count after passing through the moderating body, and then the target scoring function needs to be a function related to the thermal neutron count, that is, the parameter of interest can be continuously optimized in the process of maximizing the target function.

Therefore, based on the above description, the method of the embodiment of the present disclosure has at least the following technical effects:

(1) the neutron transport process of the Monte Carlo simulation is replaced by the operation of the characteristic matrix (the transmission matrix T and the reflection matrix R) (namely, the subsequent matrix operation does not need the Monte Carlo simulation, as shown in formulas (1) to (3)), the modulated emergent neutron energy spectrum can be estimated by matrix multiplication and addition, the emergent neutron energy spectrum does not need to be estimated by the calculation of the Monte Carlo simulation, and the calculation time is saved. Specifically, taking the BNCT moderator design as an example, under the condition that the statistical error of the epithermal neutrons emitted from the moderator with the thickness of 60cm is 0.2%, the time used by the TRM method of the embodiment of the disclosure can be reduced by 2 orders of magnitude compared with the traditional monte carlo simulation.

(2) The GAM method of the embodiment of the disclosure is utilized to carry out optimization design on a BNCT one-dimensional plate moderator and the like, and calculation time and traversal globality are considered by combining a genetic algorithm and a TRM.

(3) The method disclosed by the embodiment of the disclosure can adapt to different input energy spectrums and output requirements, is not only applied to BNCT moderators, but also can adapt to moderators in other slow neutron application scenes, such as the design of thermal neutron imaging moderators, and is wider in application range.

Another aspect of the disclosure provides a moderator design acquisition apparatus 600 that includes an energy spectrum acquisition module 610, a scoring ordering module 620, and a cross-mutation module 630. The energy spectrum acquisition module 610 is used for acquiring an emergent energy spectrum corresponding to the initial moderator population by a TRM method; the scoring and sorting module 620 is configured to perform scoring and sorting of each initial moderator design of the initial moderator population for the outgoing energy spectrum using the genetic objective function; and a cross-mutation module 630 for cross-mutating the scored and sorted moderator designs to generate a target moderator population, wherein the target moderator population includes a plurality of target moderator designs.

It should be noted that the embodiment of the portion of the moderator design acquisition apparatus 600 shown in fig. 6 is similar to the embodiment of the moderator design acquisition method portion, and the achieved technical effects are also similar, which are not described herein again.

Fig. 7 schematically shows a block diagram of an electronic device according to an embodiment of the disclosure.

Another aspect of the present disclosure provides an electronic device comprising one or more processors and memory; the memory is used for storing one or more programs, wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of the embodiments of the present disclosure.

Fig. 7 schematically shows a block diagram of an electronic device according to an embodiment of the disclosure. The electronic device shown in fig. 7 is only an example, and should not bring any limitation to the functions and the scope of use of the embodiments of the present disclosure.

As shown in fig. 7, a computer system 700 according to an embodiment of the present disclosure includes a processor 701, which can perform various appropriate actions and processes according to a program stored in a Read Only Memory (ROM)702 or a program loaded from a storage section 708 into a Random Access Memory (RAM) 703. The processor 701 may include, for example, a general purpose microprocessor (e.g., a CPU), an instruction set processor and/or associated chipset, and/or a special purpose microprocessor (e.g., an Application Specific Integrated Circuit (ASIC)), among others. The processor 701 may also include on-board memory for caching purposes. The processor 701 may comprise a single processing unit or a plurality of processing units for performing the different actions of the method flows according to embodiments of the present disclosure.

In the RAM 703, various programs and data necessary for the operation of the system 700 are stored. The processor 701, the ROM 702, and the RAM 703 are connected to each other by a bus 704. The processor 701 performs various operations of the method flows according to the embodiments of the present disclosure by executing programs in the ROM 702 and/or the RAM 703. It is noted that the programs may also be stored in one or more memories other than the ROM 702 and RAM 703. The processor 701 may also perform various operations of method flows according to embodiments of the present disclosure by executing programs stored in the one or more memories.

According to an embodiment of the present disclosure, the system 700 may also include an input/output (I/O) interface 705, the input/output (I/O) interface 705 also being connected to the bus 704. The system 700 may also include one or more of the following components connected to the I/O interface 705: an input portion 706 including a keyboard, a mouse, and the like; an output section 707 including a display such as a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), and the like, and a speaker; a storage section 708 including a hard disk and the like; and a communication section 709 including a network interface card such as a LAN card, a modem, or the like. The communication section 709 performs communication processing via a network such as the internet. A drive 710 is also connected to the I/O interface 708 as needed. A removable medium 711 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is mounted on the drive 710 as necessary, so that a computer program read out therefrom is mounted into the storage section 708 as necessary.

According to embodiments of the present disclosure, method flows according to embodiments of the present disclosure may be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product comprising a computer program embodied on a computer readable storage medium, the computer program containing program code for performing the method illustrated by the flow chart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication section 709, and/or installed from the removable medium 711. The computer program, when executed by the processor 701, performs the above-described functions defined in the system of the embodiment of the present disclosure. The systems, devices, apparatuses, modules, units, etc. described above may be implemented by computer program modules according to embodiments of the present disclosure.

The present disclosure also provides a computer-readable storage medium, which may be contained in the apparatus/device/system described in the above embodiments; or may exist separately and not be assembled into the device/apparatus/system. The computer-readable storage medium carries one or more programs which, when executed, implement the method according to an embodiment of the disclosure.

According to embodiments of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium, which may include, for example but is not limited to: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present disclosure, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. For example, according to embodiments of the present disclosure, a computer-readable storage medium may include the ROM 702 and/or the RAM 703 and/or one or more memories other than the ROM 702 and the RAM 703 described above.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams or flowchart illustration, and combinations of blocks in the block diagrams or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Another aspect of the present disclosure provides a computer-readable storage medium storing computer-executable instructions that, when executed, implement the method of embodiments of the present disclosure.

Specifically, the computer-readable storage medium may be contained in the apparatus/device/system described in the above embodiments; or may exist separately and not be assembled into the device/apparatus/system. The above-described computer-readable storage medium carries one or more programs which, when executed, implement a moderator design acquisition method according to an embodiment of the present disclosure.

Alternatively, the computer-readable storage medium may be included in the apparatus/device/system described in the above embodiments; or may exist separately and not be assembled into the device/apparatus/system. The computer-readable storage medium carries one or more programs which, when executed, implement the method according to an embodiment of the disclosure.

Another aspect of the present disclosure provides a computer program comprising computer-executable instructions that, when executed, are configured to implement a method for slowdown design acquisition according to an embodiment of the present disclosure.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams or flowchart illustration, and combinations of blocks in the block diagrams or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

It will be understood by those skilled in the art that while the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Accordingly, the scope of the present disclosure should not be limited to the above-described embodiments, but should be defined not only by the appended claims, but also by equivalents thereof.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.