在核测井领域,蒙特卡罗方法应用于仪器开发设计到数据解释的各个环节。通用型多粒子输运程序(Monte Carlo N-Particle Transport Code,MCNP)作为领域内开展研究和解决问题的首要选择,其使用一直以来都受到许可限制,令研究人员面临挑战...在核测井领域,蒙特卡罗方法应用于仪器开发设计到数据解释的各个环节。通用型多粒子输运程序(Monte Carlo N-Particle Transport Code,MCNP)作为领域内开展研究和解决问题的首要选择,其使用一直以来都受到许可限制,令研究人员面临挑战。因此,FLUktuierende KAskade(FLUKA)具有开放使用权限的优势,利用FLUKA开展核测井基准模拟,对比分析FLUKA作为MCNP替代方案的可行性。利用FLUKA和MCNP分别构建具有代表性的核测井基准模型,涵盖伽马射线输运、中子输运以及伽马-中子耦合输运过程,获取了伽马能谱和密度、孔隙度等测井响应,用以评估FLUKA在低能辐射传输模拟中的表现。研究结果显示,对于低能伽马辐射输运,FLUKA获取的地层散射伽马能谱和MCNP响应之间的最大相对误差为5.37%,密度响应相对误差在3.75%以内。对于低能中子输运,二者孔隙度响应的相对误差不超过1%,并且中子诱发伽马射线能谱基本吻合。该研究通过对基准核测井问题的模拟分析,证明了可以使用FLUKA代替MCNP在核测井领域分析解决问题。展开更多
中国科学院高能物理研究所提出了ERL-FEL(Energy recovery linac-Free electron laser)"一机两用"的概念,通过同一直线加速器将能量回收加速器(Energy recovery linac,ERL)和自由电子激光(Free electron laser,FEL)结合到一...中国科学院高能物理研究所提出了ERL-FEL(Energy recovery linac-Free electron laser)"一机两用"的概念,通过同一直线加速器将能量回收加速器(Energy recovery linac,ERL)和自由电子激光(Free electron laser,FEL)结合到一起。本文讨论ERL-FEL两用实验装置主体屏蔽设计中,利用离散抽样的方法实现多个损失源项的整合,在同一FLUKA用户程序中实现多源抽样,并将蒙特卡罗计算结果与各源项独立处理的累积结果进行对比。计算表明,两者的结果吻合较好。基于束流损失源项整体建模的方法适用于其他小型直线加速器的整体屏蔽计算,可方便在其他装置上扩展应用。展开更多
The study of accelerator-driven subcritical reactor systems(ADSs) has been an important research topic in the field of nuclear energy for years. The main code applied in ADS research is MCNPX, which was developed by L...The study of accelerator-driven subcritical reactor systems(ADSs) has been an important research topic in the field of nuclear energy for years. The main code applied in ADS research is MCNPX, which was developed by Los Alamos National Laboratory. We studied the application of the open-source Monte Carlo codes FLUKA and OpenMC to a coupled ADS calculation. The FLUKA code was used to simulate the reaction of highenergy protons with the nucleus of the target material in the ADS, which produces spallation neutrons. Information on the spallation neutrons, such as their energy, position,direction, and weight, can be recorded by a user-defined routine called FLUSCW provided by FLUKA. Then, the information was stored in an external neutron source file in HDF5 format by using a conversion code, as required by the OpenMC calculation. Finally, the fixed-source calculation function of OpenMC was applied to simulate the transport of spallation neutrons and obtain the distribution of the neutron flux in the core region. In the coupled calculation, the high-energy cross-section library JENDL4.0/HE in ACE format produced by NJOY2016 was applied in the OpenMC transport simulation. The OECD–ADS benchmark problem was calculated, and the results were compared with those obtained using MCNPX. It was found that the flux calculations performed by FLUKA–OpenMC and MCNPX were in agreement, so the coupling calculation method for ADS is reasonable and feasible.展开更多
This work determined a new Monte Carlo code(FLUKA) that can be used to calculate the dosimetric characteristics of seed sources. Dosimetric parameters(dose rate constant, radial dose function, and anisotropy function)...This work determined a new Monte Carlo code(FLUKA) that can be used to calculate the dosimetric characteristics of seed sources. Dosimetric parameters(dose rate constant, radial dose function, and anisotropy function) of model 6711125 I seed source were calculated with FLUKA. The results were compared to the relative data recommended by AAPM TG43U1: dose rate constant with FLUKA was in agreement with 2.041%;radial dose functions with FLUKA for distances ranging from 0.5 cm to 10 cm, the deviation was less than 5%.Therefore the FLUKA code can be used to calculate the dosimetric characteristics of seed sources.展开更多
文摘在核测井领域,蒙特卡罗方法应用于仪器开发设计到数据解释的各个环节。通用型多粒子输运程序(Monte Carlo N-Particle Transport Code,MCNP)作为领域内开展研究和解决问题的首要选择,其使用一直以来都受到许可限制,令研究人员面临挑战。因此,FLUktuierende KAskade(FLUKA)具有开放使用权限的优势,利用FLUKA开展核测井基准模拟,对比分析FLUKA作为MCNP替代方案的可行性。利用FLUKA和MCNP分别构建具有代表性的核测井基准模型,涵盖伽马射线输运、中子输运以及伽马-中子耦合输运过程,获取了伽马能谱和密度、孔隙度等测井响应,用以评估FLUKA在低能辐射传输模拟中的表现。研究结果显示,对于低能伽马辐射输运,FLUKA获取的地层散射伽马能谱和MCNP响应之间的最大相对误差为5.37%,密度响应相对误差在3.75%以内。对于低能中子输运,二者孔隙度响应的相对误差不超过1%,并且中子诱发伽马射线能谱基本吻合。该研究通过对基准核测井问题的模拟分析,证明了可以使用FLUKA代替MCNP在核测井领域分析解决问题。
文摘中国科学院高能物理研究所提出了ERL-FEL(Energy recovery linac-Free electron laser)"一机两用"的概念,通过同一直线加速器将能量回收加速器(Energy recovery linac,ERL)和自由电子激光(Free electron laser,FEL)结合到一起。本文讨论ERL-FEL两用实验装置主体屏蔽设计中,利用离散抽样的方法实现多个损失源项的整合,在同一FLUKA用户程序中实现多源抽样,并将蒙特卡罗计算结果与各源项独立处理的累积结果进行对比。计算表明,两者的结果吻合较好。基于束流损失源项整体建模的方法适用于其他小型直线加速器的整体屏蔽计算,可方便在其他装置上扩展应用。
基金supported by the ‘‘Strategic Priority Research Program’’ of the Chinese Academy of Sciences(No.XDA03030102)
文摘The study of accelerator-driven subcritical reactor systems(ADSs) has been an important research topic in the field of nuclear energy for years. The main code applied in ADS research is MCNPX, which was developed by Los Alamos National Laboratory. We studied the application of the open-source Monte Carlo codes FLUKA and OpenMC to a coupled ADS calculation. The FLUKA code was used to simulate the reaction of highenergy protons with the nucleus of the target material in the ADS, which produces spallation neutrons. Information on the spallation neutrons, such as their energy, position,direction, and weight, can be recorded by a user-defined routine called FLUSCW provided by FLUKA. Then, the information was stored in an external neutron source file in HDF5 format by using a conversion code, as required by the OpenMC calculation. Finally, the fixed-source calculation function of OpenMC was applied to simulate the transport of spallation neutrons and obtain the distribution of the neutron flux in the core region. In the coupled calculation, the high-energy cross-section library JENDL4.0/HE in ACE format produced by NJOY2016 was applied in the OpenMC transport simulation. The OECD–ADS benchmark problem was calculated, and the results were compared with those obtained using MCNPX. It was found that the flux calculations performed by FLUKA–OpenMC and MCNPX were in agreement, so the coupling calculation method for ADS is reasonable and feasible.
基金Supported by the National Natural Science Foundation of China （Nos. 11105081, 11275110 and 11375103） and the National Energy Application Project For Research and Demonstration （No. 20131660315）.
基金Supported by Hunan Province Key Laboratory of special projects(No.2008TP4009-2)
文摘This work determined a new Monte Carlo code(FLUKA) that can be used to calculate the dosimetric characteristics of seed sources. Dosimetric parameters(dose rate constant, radial dose function, and anisotropy function) of model 6711125 I seed source were calculated with FLUKA. The results were compared to the relative data recommended by AAPM TG43U1: dose rate constant with FLUKA was in agreement with 2.041%;radial dose functions with FLUKA for distances ranging from 0.5 cm to 10 cm, the deviation was less than 5%.Therefore the FLUKA code can be used to calculate the dosimetric characteristics of seed sources.
