Boris push with spatial stepping
Boris push with spatial stepping
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DOI：
10.1088/0954-3899/29/8/337
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发表时间：
2003-07
期刊：
影响因子：
--
通讯作者：
G. Penn;P. Stoltz;J. Cary;J. Wurtele
中科院分区：
文献类型：
--
作者：
G. Penn;P. Stoltz;J. Cary;J. Wurtele
鲍里斯推力因其速度和稳定性而常用于等离子体物理模拟。它具有二阶精度，每个时间步仅需要一次场评估，并且具有良好的守恒特性。然而，对于加速器模拟来说，沿变化的光束线传播 z 轴上的粒子是很方便的。已经开发了一种“空间鲍里斯推送”算法，该算法与鲍里斯推送类似，但使用空间坐标作为自变量，而不是时间。该方案与四阶龙格-库塔算法进行比较，针对两个简化的μ子束晶格：均匀的螺线管场和“FOFO”晶格，其中螺线管场沿轴正弦变化。对轴对称系统中应守恒的正则角动量的检查表明，空间鲍里斯推力提高了长距离的精度。
The Boris push is commonly used in plasma physics simulations because of its speed and stability. It is second-order accurate, requires only one field evaluation per time step, and has good conservation properties. However, for accelerator simulations it is convenient to propagate particles in z down a changing beamline. A 'spatial Boris push' algorithm has been developed which is similar to the Boris push but uses a spatial coordinate as the independent variable, instead of time. This scheme is compared to the fourth-order Runge–Kutta algorithm, for two simplified muon beam lattices: a uniform solenoid field, and a 'FOFO' lattice where the solenoid field varies sinusoidally along the axis. Examination of the canonical angular momentum, which should be conserved in axisymmetric systems, shows that the spatial Boris push improves accuracy over long distances.