Explicit structure-preserving geometric particle-in-cell algorithm in curvilinear orthogonal coordinate systems and its applications to whole-device 6D kinetic simulations of tokamak physics
Explicit structure-preserving geometric particle-in-cell algorithm in curvilinear orthogonal coordinate systems and its applications to whole-device 6D kinetic simulations of tokamak physics
复制标题
曲线正交坐标系中显式保结构几何粒子内算法及其在托卡马克物理全装置6D动力学模拟中的应用
DOI：
10.1088/2058-6272/abf125
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发表时间：
2020-04
影响因子：
1.7
通讯作者：
Qin Hong
中科院分区：
文献类型：
--
作者：
Xiao Jianyuan;Qin Hong
提出了曲线直角坐标系下的显式保结构几何质点(PIC)算法。该算法是对保结构几何PIC算法的进一步发展，达到了在磁聚变研究中的实际应用目的。该算法是通过对带电粒子和电磁场系统的场论采用Whitney形式、离散外积分和显式非正则辛积分进行离散化而构造的。除了截断无限维辛结构外，该算法还保持了许多重要的物理对称性和守恒定律，如局部能量守恒、规范对称性和相应的局部电荷守恒。结果表明，该算法具有较高的计算精度和较高的计算精度该算法具有基于第一性原理的多尺度托卡马克物理模拟所需的长期精度和保真度。该算法已在为现代集群中高效大规模并行PIC模拟而设计的SymPIC程序中实现。该程序已被用于托卡马克物理的全装置6维动力学模拟研究。在以对角和各向异性压强为主的情况下，数值计算发现托卡马克几何结构中聚变等离子体的自洽运动定态。该状态还允许在10 km-1范围内的稳态亚音速离子流，对自洽动力学定态下的动力学气球不稳定性进行了模拟，结果表明，高n气球模的增长率大于低n全局模的增长率，在非线性阶段，由于不稳定性产生的E×B流，气球模在大约5个离子渡越时间内饱和。这些结果与早期和最近的电磁陀螺动力学模拟是一致的。
Explicit structure-preserving geometric particle-in-cell(PIC)algorithm in curvilinear orthogonal coordinate systems is developed.The work reported represents a further development of the structure-preserving geometric PIC algorithm achieving the goal of practical applications in magnetic fusion research.The algorithm is constructed by discretizing the field theory for the system of charged particles and electromagnetic field using Whitney forms,discrete exterior calculus,and explicit non-canonical symplectic integration.In addition to the truncated infinitely dimensional symplectic structure,the algorithm preserves exactly many important physical symmetries and conservation laws,such as local energy conservation,gauge symmetry and the corresponding local charge conservation.As a result,the algorithm possesses the long-term accuracy and fidelity required for first-principles-based simulations of the multiscale tokamak physics.The algorithm has been implemented in the SymPIC code,which is designed for highefficiency massively-parallel PIC simulations in modern clusters.The code has been applied to carry out whole-device 6D kinetic simulation studies of tokamak physics.A self-consistent kinetic steady state for fusion plasma in the tokamak geometry is numerically found with a predominately diagonal and anisotropic pressure tensor.The state also admits a steady-state subsonic ion flow in the range of 10 km s–1,agreeing with experimental observations and analytical calculations Kinetic ballooning instability in the self-consistent kinetic steady state is simulated.It is shown that high-n ballooning modes have larger growth rates than low-n global modes,and in the nonlinear phase the modes saturate approximately in 5 ion transit times at the 2% level by the E×B flow generated by the instability.These results are consistent with early and recent electromagnetic gyrokinetic simulations.
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影响因子：
4.1
作者：
Yang Chen;S. Parker
通讯作者：
Yang Chen;S. Parker
理想二流体系统的显式高阶非正则辛算法
影响因子：
2.2
作者：
Xiao Jianyuan;Qin Hong;Morrison Philip J;Liu Jian;Yu Zhi;Zhang Ruili;He Yang
通讯作者：
He Yang
影响因子：
4.1
作者：
J. Cary;I. Doxas
通讯作者：
J. Cary;I. Doxas
DOI：
--
发表时间：
2019-04
期刊：
arXiv: Plasma Physics
影响因子：
--
作者：
Jianyuan Xiao;H. Qin
通讯作者：
Jianyuan Xiao;H. Qin
影响因子：
2.2
作者：
H. Qin;W. Tang;W. Lee
通讯作者：
H. Qin;W. Tang;W. Lee