Extensions of guiding center motion to higher order. [for plasma in static magnetic field
Extensions of guiding center motion to higher order. [for plasma in static magnetic field
复制标题
引导中心运动向更高阶的扩展。
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
J. Rome
中科院分区：
文献类型：
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作者：
T. Northrop;J. Rome
在静磁场中，一些著名的导引中心方程在回转半径中扩展到下一阶时保持其形式。在这些情况下，只需要在磁矩序列中包括下一阶项。给出了导引中心运动的微分方程，该方程正确地描述了回转半径内一阶的平行速度和垂直速度。本文提出并讨论了如何用二阶导数确定导引中心位置的问题，并导出了一种常用定义的二阶导数。利用一阶修正的导引中心速度，证明了轴对称场中导引中心的环向正则角动量Pφ是守恒的。当包含二阶运动时，Pφ不再是常数。对导引中心理论的上述推广，有助于解决用导引中心运动方程或用Pφ守恒得到的不同托卡马克轨道。
In a static magnetic field, some well‐known guiding center equations maintain their form when extended to next order in gyroradius. In these cases, it is only necessary to include the next order term in the magnetic moment series. The differential equation for guiding center motion which describes both the parallel and perpendicular velocities correctly through first order in gyroradius is given. The question of how to define the guiding center position through second order arises and is discussed, and second order drifts are derived for one usual definition. The toroidal canonical angular momentum, Pφ, of the guiding center in an axisymmetric field is shown to be conserved using the guiding center velocity correct through first order. When second‐order motion is included, Pφ is no longer a constant. The above extensions of guiding center theory help to resolve the different tokamak orbits obtained either by using the guiding center equations of motion or by using conservation of Pφ.