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EJUSTCO:Monte Carlo radiation transport code hybrid with ANN model for gamma-ray shielding simulation

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Nuclear Science and Techniques 2023年第9期34卷 155-176页

作者： Joseph Konadu Boahen Ahmed S.G.Khalil Mohsen A.Hassan Samir A.Elsagheer Mohamed Materials Science and Engineering Department School of Innovative Design EngineeringEgypt-Japan University of Science and Technology(E-JUST)179New Borg El-Arab CityEgypt Physics Department Environmental and Smart Technology GroupFaculty of ScienceFayoum UniversityFayoum 63514Egypt Faculty of Engineering Aswan UniversityAswanEgypt

Gamma ray shielding is essential to ensure the safety of personnel and equipment in facilities and environments where radiation exists.The Monte Carlo technique is vital for analyzing the gamma-ray shielding capabilities of materials.In this study,a simple Monte Carlo code,EJUSTCO,is developed to cd simulate gamma radiation transport in shielding materials for academic purposes.The code considers the photoelectric effect,Compton(incoherent)scattering,pair production,and photon annihilation as the dominant interaction mechanisms in the gamma radiation shielding problem.Variance reduction techniques,such as the Russian roulette,survival weighting,and exponential transformation,are incorporated into the code to improve computational efficiency.Predicting the exponential transformation parameter typically requires trial and error as well as expertise.Herein,a deep learning neural network is proposed as a viable method for predicting this parameter for the first time.The model achieves an MSE of 0.00076752 and an R-value of 0.99998.The exposure buildup factors and radiation dose rates due to the passage of gamma radiation with different source energies and varying thicknesses of lead,water,iron,concrete,and aluminum in single-,double-,and triple-layer material systems are validated by comparing the results with those of MCNP,ESG,ANS-6.4.3,MCBLD,monteREY MARK(M),PENELOPE,and experiments.Average errors of 5.6%,2.75%,and 10%are achieved for the exposure buildup factor in single-,double-,and triple-layer materials,respectively.A significant parameter that is not considered in similar studies is the gamma ray albedo.In the EJUSTCO code,the total number and energy albedos have been computed.The results are compared with those of MCNP,FOTELP,and PENELOPE.In general,the EJUSTCO-developed code can be employed to assess the performance of radiation shielding materials because the validation results are consistent with theoretical,experimental,and literary results.

关键词： Monte Carlo Gamma rays Shielding Artificial neural network Simulation

THUDosePD:a three-dimensional Monte Carlo platform for phantom dose assessment

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Nuclear Science and Techniques 2023年第11期34卷 40-50页

作者： Xi‑Yu Luo Rui Qiu Zhen Wu Shu‑Chang Yan Zi‑Yi Hu Hui Zhang Jun‑Li Li Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging Tsinghua UniversityMinistry of EducationBeijing 100084China Nuctech Company Limited Beijing 100084China

Monte Carlo simulations are frequently utilized in radiation dose assessments.However,many researchers find the prevailing computing platforms to be intricate.This highlights a pressing need for a specialized framework for phantom dose evalua-tion.To address this gap,we developed a user-friendly radiation dose assessment platform using the Monte Carlo toolkit,Geant4.The Tsinghua University Phantom Dose(THUDosePD)augments the flexibility of Monte Carlo simulations in dosi-metric research.Originating from THUDose,a code with generic,functional,and application layers,THUDosePD focuses predominantly on anatomical phantom dose assessment.Additionally,it enables medical exposure simulation,intricate geometry creation,and supports both three-dimensional radiation dose analysis and phantom format transformations.The system operates on a multi-threaded parallel CPU architecture,with some modules enhanced for GPU parallel computing.Benchmark tests on the ICRP reference male illustrated the capabilities of THUDosePD in phantom dose assessment,covering the effective dose,three-dimensional dose distribution,and three-dimensional organ dose.We also conducted a voxelization conversion on the polygon mesh phantom,demonstrating the method’s efficiency and consistency.Extended applications based on THUDosePD further underline its broad adaptability.This intuitive,three-dimensional platform stands out as a valuable tool for phantom radiation dosimetry research.

关键词： Monte Carlo Phantom Dose assessment Voxelization Three dimensional

Monte Carlo simulation for performance evaluation of detector model with a monolithic LaBr_(3)(Ce)crystal and SiPM array forγradiation imaging

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Nuclear Science and Techniques 2022年第8期33卷 163-174页

作者： Wei Lu Lei Wang Yong Yuan Ting Zhang Ge Tang Ming-Zhe Liu Xian-Guo Tuo Jing Ning Chengdu University of Technology Chengdu 610059China Sichuan University of Science and Engineering Zigong 643000China Beijing Institute of Radiation Medicine Beijing 100850China

In recent years,LaBr_(3)(Ce)crystals and silicon photomultipliers(SiPMs)have been increasingly used in radiation imaging.This study involved the establishment of a detector model with a monolithic LaBr_(3)(Ce)crystal and SiPM array forγ-radiation imaging on the GEANT4 platform.The optical process included in the detector model was defined by key parameters,such as the emission spectrum,scintillation yield,and intrinsic resolution of the LaBr_(3):5%Ce crystal,as well as the detection efficiency of the SiPM array.The response of the detector model to^(57)Co flooded field irradiation was simulated and evaluated.The radiation images generated by the detector model exhibited a compression effect that was very close to that on images acquired by the physical detector.The spatial resolution of the simulated detector closely approximates that of the physical experiment.A detector model without the optical process was also established for comparison with a detector using the optical process.Both were used in a near-field modified uniform redundant array(MURA)imaging system to acquire images of a point source and a ring source of^(57)Co at the center of the field-of-view of the imaging system.The spatial resolution and signal-to-noise ratio of the images that were reconstructed using the two detector models were determined and compared.Compared with the detector model without optical processes,although the images from the proposed detector model have slightly inferior signal-to-noise ratios and more artifacts,they are more consistent with the reconstructed versions of images acquired in real physical experiments.The results confirm that the detector model can be used to design aγ-radiation imaging detector and to develop an imaging algorithm that can significantly shorten the development time and reduce the cost.

关键词： Scintillation photons Monte Carlo SiPM array Spatial resolution Monolithic LaBr_(3)(Ce)crystal

Design and optimization of graphene quantum dot-based luminescent solar concentrator using monte-carlo simulation

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Energy and Built Environment

Energy and Built Environment 2023年第2期4卷 140-147页

作者： Milad Rastkar Mirzaei Ali Rostami Samiye Matloub Masoumeh Nazari ECE Department University of OklahomaNormanOklahoma73019United States Photonics and Nanocrystals Research Lab(PNRL) University of TabrizTabriz***Iran SP-EPT Lab ASEPE CompanyIndustrial Park of Advanced TechnologiesTabrizIran Quantum Photonics Research Lab(QPRL) University of TabrizTabriz***Iran

The demand for green energy is growing these days as a result of the world energy crisis,as well as global warm-ing.Solar cells are in great interest due to the fact that solar energy can be easily converted to electricity,if the photovoltaic cell’s cost can be lowered.One of the methods to make low-cost energy is using Luminescent solar concentrators.They have the advantage of directly integrating solar cells to dense urban areas as well as skyscrapers.Different materials and waveguide sizes have been investigated for use in luminescent solar concen-trators.However,the optimized waveguide geometry and quantum dots concentrators have not been thoroughly studied.In this paper,we have simulated graphene quantum dots using density function theory.A monte-carlo ray-tracing simulation was developed to model our device.We have optimized the luminescent solar concentrator geometry by monte-carlo simulation.The optimization results show a 99%enhancement in the energy flux gain of the final device.Besides,we have calculated and analyzed the fate of all photons.

关键词： Luminescent solar concentrator Solar cell Quantum dot Graphene Energy-efficient building Monte Carlo

THUBrachy:fast Monte Carlo dose calculation tool accelerated by heterogeneous hardware for high-dose-rate brachytherapy

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Nuclear Science and Techniques 2021年第3期32卷 107-119页

作者： An-Kang Hu Rui Qiu Huan Liu Zhen Wu Chun-Yan Li Hui Zhang Jun-Li Li Rui-Jie Yang Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging Tsinghua UniversityMinistry of EducationBeijing 100084China Nuctech Company Limited Beijing 100084China Department of Radiation Oncology Peking University Third HospitalBeijing 100191China

The Monte Carlo(MC)simulation is regarded as the gold standard for dose calculation in brachytherapy,but it consumes a large amount of computing resources.The development of heterogeneous computing makes it possible to substantially accelerate calculations with hardware accelerators.Accordingly,this study develops a fast MC tool,called THUBrachy,which can be accelerated by several types of hardware accelerators.THUBrachy can simulate photons with energy less than 3 MeV and considers all photon interactions in the energy range.It was benchmarked against the American Association of Physicists in Medicine Task Group No.43 Report using a water phantom and validated with Geant4 using a clinical case.A performance test was conducted using the clinical case,showing that a multicore central processing unit,Intel Xeon Phi,and graphics processing unit(GPU)can efficiently accelerate the simulation.GPU-accelerated THUBrachy is the fastest version,which is 200 times faster than the serial version and approximately 500 times faster than Geant4.The proposed tool shows great potential for fast and accurate dose calculations in clinical applications.

关键词： High-dose-rate brachytherapy Monte Carlo Heterogeneous computing Hardware accelerators

Monte Carlo performance study of virtual high performance computing cluster over cloud

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Radiation Medicine and Protection 2022年第3期3卷 108-114页

作者： Libing Zhu Ze Xi Peng Cong Gongyi Yu Yuan Liu Xincheng Xiang Wei Xu Xiangang Wang Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Institute for Interdisciplinary Information Sciences Tsinghua UniversityBeijing 100084China

Objective:As a high computation cost discipline,nuclear science and engineering still relies heavily on traditional high performance computing(HPC)clusters.However,the usage of traditional HPC for nuclear science and engineering has been limited due to the poor flexibility,the software compatibility and the poor user interfaces.Virtualized/virtual HPC(vHPC)can mimic an HPC by using a cloud computing platform.In this work,we designed and developed a vHPC system for employment in nuclear engineering.Methods:The system is tested using the computation of the numberπby Monte Carlo and an X-ray digital imaging system simulation.The performance of the vHPC system is compared with that of the traditional HPCs.Results:As the number of the simulated particles increases,the virtual cluster computing time grows propor-tionally.The time used for the simulation of the X-ray imaging was about 21.1 h over a 12 kernels virtual server.Experimental results show that the performance of virtual cluster computing and the actual physical machine is almost the same.Conclusions:From these tests,it is concluded that vHPC is a good alternative for employing in nuclear engineering.The proposed vHPC in this paper will make HPC flexible and easy to deploy.

关键词： Cloud computing Virtualization High performance computing(HPC) Virtual HPC Monte Carlo

Implementation of Monte Carlo based PET verification of ion beam delivery into a TPS

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Radiation Medicine and Protection 2022年第3期3卷 131-138页

作者： Pablo Yepes Zhuangming Shen Michael F.Moyers Qianxia Wang Hongliang Chen Jie Li Yongqiang Li James Lin Rice University HoustonTX77005USA Shanghai Proton and Heavy Ion Center Shanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghai 201315China

Objective:To develop and implement an ion beam teletherapy verification system based upon simulations of induced radioactivity and comparison with patient positron emission tomography(PET)scans.Methods:A Monte Carlo algorithm was integrated into an in-house built treatment,information,management,and planning system(TIMPS■)to calculate distributions of positron emitters induced by ion beams.These distribu-tions are processed to simulate PET images taking into account positron diffusion,radioactive decay,biological washout,and detector blurring.Additional tools were developed to register simulated PET images with planning CT images and perform comparisons of measured and simulated PET images.Results:Production cross-sections were generated for various isotopes and materials.Treatment plans for several different body sites were used to verify the functioning and utility of the new tools for both proton and carbon ion beams.Conclusions:Several tools have been developed to simulate PET scans of patients irradiated with ion beams and compare the simulated images to measurements.After commissioning and implementation into the clinic,the appropriate sizes for margins that account for uncertainties may be investigated.

关键词： ion beam PET Monte Carlo

Comparison of pencil beam and Monte Carlo calculations with ion chamber array measurements for patient-specific quality assurance

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Radiation Medicine and Protection 2022年第3期3卷 115-122页

作者： Yu Deng Zhi Chen Qianxia Wang Pablo Yepes Zhuangming Shen Hongliang Chen Jie Li Michael F.Moyers Shanghai Proton and Heavy Ion Center Shanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghai 201315China Rice University HoustonTX77005USA

Objective:To determine under what conditions and criteria comparisons between calculations made with the current clinical treatment planning system(Syngo)and an in-house built TPS(TIMPS)would allow skipping of in-beam portal-specific measurements.Methods:Measurements were made with an array of 24 ion chambers in a water phantom for 227 proton and 313 carbon ion portals with and without a range shifter(RS).These measurements were compared with calculations performed with Syngo and TIMPS using metrics of average dose difference and Gamma index.Results:For proton portals without RS,if a Gamma comparison between TIMPS and Syngo passed using criteria of 90%of tested points being within 3%and 3 mm,then 74%of measurements would agree with both TIMPS and Syngo.For proton portals with RS,more than 80%of measurements would agree with both calculations using the same criteria.For carbon ion portals without RS,if a Gamma evaluation between TIMPS and Syngo passed with criteria of 90%of tested points being within 2%and 2 mm,85%of measurements would agree with both cal-culations.For carbon ion portals with RS,if a Gamma evaluation between TIMPS and Syngo passed with criteria of 90%of tested points being within 3%and 3 mm,60%of measurements would agree with both calculations.Conclusions:Both the pencil beam algorithm in Syngo and the FDC algorithm in TIMPS can provide accurate dose calculations in water for most clinical portals.For about 75%of portals,physicists can perform comparisons of calculations instead of phantom measurements to verify Syngo calculations thereby saving a large amount of beam time.There are some portals,however,such as for low-energy protons without RS and high-energy carbon ions,where agreement between the two calculations and measurements are not yet satisfactory to allow the elimination of all measurements.

关键词： Ion beam Quality assurance Monte Carlo Pencil beam

Monte Carlo calculations of the incineration of plutonium and minor actinides of laser fusion inertial confinement fusion fission energy (LIFE) engine

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Plasma Science and Technology 2018年第7期20卷 159-165页

作者： adem acir esref baysal gazi university faculty of technologydepartment of energy systems engineeringTeknikokullarAnkaraTurkey manisa celal bayarüniversitesi hasan ferdi turgutlu faculty of technology department of energy systems engineeringManisaTurkey

In this paper, neutronic analysis in a laser fusion inertial confinement fusion fission energy （LIFE） engine fuelled plutonium and minor actinides using a MCNP codes was investigated. LIFE engine fuel zone contained 10 vol% TRISO particles and 90 vol% natural lithium coolant mixture. TRISO fuel compositions have Mod①： reactor grade plutonium （RG-Pu）, Mod②： weapon grade plutonium （WG-Pu） and Mod③： minor actinides （MAs）. Tritium breeding ratios （TBR） were computed as 1.52, 1.62 and 1.46 for Mod（D, Mod② and Mod③, respectively. The operation period was computed as ~21 years when the reference TBR 〉 1.05 for a self- sustained reactor for all investigated cases. Blanket energy multiplication values （M） were calculated as 4.18, 4.95 and 3.75 for Mod①, Mod② and Mod③, respectively. The bumup （BU） values were obtained as ~1230, ~1550 and ~1060 GWd tM-1, respectively. As a result, the higher BU were provided with using TRISO particles for all cases in LIFE engine.

关键词： fusion nuclear Monte Carlo