The spatial and temporal characterization of trapped charged particle trajectories in magnetospheres has been extensively studied in dipole magnetic field structures. Such studies have allowed the calculation of spatial quantities, such as equatorial loss cone size as a function of radial distance, the location of the mirror points along particular field lines (L ‐shells) as a function of the particle's equatorial pitch angle, and temporal quantities such as the bounce period and drift period as a function of the radial distance and the particle's pitch angle at the equator. In this study, we present analogous calculations for the disk‐like field structure associated with the giant rotation‐dominated magnetospheres of Jupiter and Saturn as described by the University College London/Achilleos‐Guio‐Arridge (UCL/AGA) magnetodisk model. We discuss the effect of the magnetodisk field on various particle parameters and make a comparison with the analogous motion in a dipole field. The bounce period in a magnetodisk field is in general smaller the larger the equatorial distance and pitch angle, by a factor as large as ∼8 for Jupiter and ∼2.5 for Saturn. Similarly, the drift period is generally smaller, by a factor as large as ∼2.2 for equatorial distances ∼20–24 R _J at Jupiter and ∼1.5 for equatorial distances ∼7–11 R _S at Saturn.

中文翻译：

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磁盘磁场中的被困粒子运动

在偶极子磁场结构中，已经广泛研究了磁层中捕获的带电粒子轨迹的时空特征。这样的研究可以计算空间量，例如赤道损耗锥的大小与径向距离的关系，镜点沿特定视场线的位置（L-壳）是粒子赤道俯仰角的函数，而时间量（例如反弹周期和漂移周期）是径向距离和赤道处粒子的俯仰角的函数。在这项研究中，我们提供了与伦敦大学/阿奇里奥斯-吉奥-里奇大学（UCL / AGA）磁磁盘模型所描述的与木星和土星的巨大旋转为主的磁层相关的盘状场结构的类似计算。我们讨论了磁盘场对各种粒子参数的影响，并与偶极子场中的类似运动进行了比较。赤道距离和俯仰角越大，磁盘磁场的弹跳周期通常就越小，木星的弹跳周期大约为8，土星的弹跳周期大约为2.5。同样，漂移周期通常较小， 在木星上的R _J和在赤道距离上的约1.5的R _J约为土星的7-11  R _S。