To calculate nonlinear transport of space charge dominated beam in 6D phase spaces, a computer code package LEADS-v5 (Linear and Electrostatic Accelerator Dynamics Simulations) has been developed. The codes calculate ...To calculate nonlinear transport of space charge dominated beam in 6D phase spaces, a computer code package LEADS-v5 (Linear and Electrostatic Accelerator Dynamics Simulations) has been developed. The codes calculate particle motions in the beam transport systems consisting of electrostatic and magnetic focusing lenses, ion analyzers, multipoles and RF accelerating structures. The nonlinear forces of external electric/magnetic fields are analyzed by the Lie algebraic method, and the space charge forces are obtained by the particle in cell (PIC) scheme. In the codes, Uniform and Gaussian particle distributions can be chosen to generate randomly the particle initial coordinates. The optimization procedures are provided to make the beam optics designs reasonable and fast. Graphically displays of calculated results are provided.展开更多
Coupling with a three dimensional (3D) hydrodynamic model and a suspended solids model, a 3D model for the transport of Fe and Mn in Arha Reservoir, China, was developed. The 3D velocity fields for the flood season a...Coupling with a three dimensional (3D) hydrodynamic model and a suspended solids model, a 3D model for the transport of Fe and Mn in Arha Reservoir, China, was developed. The 3D velocity fields for the flood season are computed to drive the 3D model of Fe and Mn in which the processes of advection, diffusion, redox, sorption, desorption, deposition, and re suspension are included. The model has been calibrated by matching observed fluid, suspended solids, and total concentrations of Fe and Mn in the water column and in the sediment, successively. The model simulated both horizontal and vertical gradients of Fe and Mn in Arha Reservoir. It was found that Fe and especially Mn stratify in accordance with the stratification of DO during summer. The redox cycles across the water sediment interface has a principal role in the rise of Fe and Mn concentrations in the overlying water. It was also found that Fe and Mn loadings from the tributaries have a carryover effect on the water quality through a secondary contamination in the reservoir.展开更多
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
使用JMCT(J Monte Carlo Transport Code)对来自MIT的全堆芯pin-by-pin精细建模的国际基准模型BEAVRS的热零功率(HZP)状态进行了模拟计算,并与测试数据进行了对比和分析.比较的物理量包括临界本征值、控制棒价值、反应性温度系数、轴向...使用JMCT(J Monte Carlo Transport Code)对来自MIT的全堆芯pin-by-pin精细建模的国际基准模型BEAVRS的热零功率(HZP)状态进行了模拟计算,并与测试数据进行了对比和分析.比较的物理量包括临界本征值、控制棒价值、反应性温度系数、轴向积分的全堆探测器测量值和不同位置四个组件轴向相对功率密度分布.HZP状态下不同控制棒位置插入和硼浓度的临界本征值计算,JMCT结果与理论值1.000的误差小于0.2%,控制棒价值计算结果与测量值符合.JMCT对轴向积分的探测器径向相对功率分布和四个组件的轴向归一化的探测器的计算结果与测量值进行了比较和分析,计算结果与测量值一致,同时清晰地展示了模型增加格架后,轴向功率曲线在相应位置出现下凹的现象.此外,JMCT给出了轴向积分的组件径向相对功率密度分布和轴向相对功率最大处(Z轴位置)的pin径向相对功率密度分布,并与国际知名程序MC21结果进行了对比,两个图像都符合得非常好.随着计算机与并行计算的高速发展,蒙特卡罗程序开始从传统的反应堆校验工具向反应堆设计工具转变.展开更多
文摘To calculate nonlinear transport of space charge dominated beam in 6D phase spaces, a computer code package LEADS-v5 (Linear and Electrostatic Accelerator Dynamics Simulations) has been developed. The codes calculate particle motions in the beam transport systems consisting of electrostatic and magnetic focusing lenses, ion analyzers, multipoles and RF accelerating structures. The nonlinear forces of external electric/magnetic fields are analyzed by the Lie algebraic method, and the space charge forces are obtained by the particle in cell (PIC) scheme. In the codes, Uniform and Gaussian particle distributions can be chosen to generate randomly the particle initial coordinates. The optimization procedures are provided to make the beam optics designs reasonable and fast. Graphically displays of calculated results are provided.
文摘Coupling with a three dimensional (3D) hydrodynamic model and a suspended solids model, a 3D model for the transport of Fe and Mn in Arha Reservoir, China, was developed. The 3D velocity fields for the flood season are computed to drive the 3D model of Fe and Mn in which the processes of advection, diffusion, redox, sorption, desorption, deposition, and re suspension are included. The model has been calibrated by matching observed fluid, suspended solids, and total concentrations of Fe and Mn in the water column and in the sediment, successively. The model simulated both horizontal and vertical gradients of Fe and Mn in Arha Reservoir. It was found that Fe and especially Mn stratify in accordance with the stratification of DO during summer. The redox cycles across the water sediment interface has a principal role in the rise of Fe and Mn concentrations in the overlying water. It was also found that Fe and Mn loadings from the tributaries have a carryover effect on the water quality through a secondary contamination in the reservoir.
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。
文摘使用JMCT(J Monte Carlo Transport Code)对来自MIT的全堆芯pin-by-pin精细建模的国际基准模型BEAVRS的热零功率(HZP)状态进行了模拟计算,并与测试数据进行了对比和分析.比较的物理量包括临界本征值、控制棒价值、反应性温度系数、轴向积分的全堆探测器测量值和不同位置四个组件轴向相对功率密度分布.HZP状态下不同控制棒位置插入和硼浓度的临界本征值计算,JMCT结果与理论值1.000的误差小于0.2%,控制棒价值计算结果与测量值符合.JMCT对轴向积分的探测器径向相对功率分布和四个组件的轴向归一化的探测器的计算结果与测量值进行了比较和分析,计算结果与测量值一致,同时清晰地展示了模型增加格架后,轴向功率曲线在相应位置出现下凹的现象.此外,JMCT给出了轴向积分的组件径向相对功率密度分布和轴向相对功率最大处(Z轴位置)的pin径向相对功率密度分布,并与国际知名程序MC21结果进行了对比,两个图像都符合得非常好.随着计算机与并行计算的高速发展,蒙特卡罗程序开始从传统的反应堆校验工具向反应堆设计工具转变.
