The moon Dione orbits Saturn at 6.2 Saturn radii R _S deep in the Kronian magnetosphere. In situ studies of the moon‐magnetosphere interaction processes near Dione were possible with the Cassini/Huygens mission which flew by close to Dione five times at distances between 99 and 516 km. In addition, Cassini crossed Dione's L‐shell more than 400 times between 2004 and 2017 and documented the variability of Saturn's magnetosphere. Different flyby geometries allowed to study the interaction processes upstream, in the low‐energy wake, and above the north pole of Dione. We describe here the energetic particle measurements from the Low Energy Magnetospheric Measurement System (LEMMS), part of the Magnetosphere Imaging Instrument (MIMI) onboard Cassini. We also use hybrid simulation results from “A.I.K.E.F.” to interpret the signatures in the particle fluxes. This paper is a continuation of Krupp et al. (2013, https://doi.org/10.1016/j.icarus.2013.06.007) and Kotova et al. (2015, https://doi.org/10.1016/j.icarus.2015.06.031). The key results are as follows: (1) Saturn's magnetosphere at Dione's orbit is highly variable with changes in energetic charged particle fluxes by 1–2 orders of magnitude. (2) The dropout signatures near Dione are basically consistent with a fully absorbing obstacle, but some features point to more complex interaction processes than plasma and energetic particle absorption. (3) Absorption signatures are found to be asymmetric with respect to the orientation of the moon, indicative of the presence of radial drift components for electrons. (4) The deepest absorption signatures were observed at the edge of the low‐energy wake pointing to gradient‐B drifts strongest in that part of the interaction region.

中文翻译：

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土星“月亮二烯”的磁层相互作用（2005–2015）

Dione卫星以6.2土星半径R _S绕土星运行在克朗磁层深处。卡西尼/惠更斯号任务可能在迪奥尼附近进行月球-磁气圈相互作用过程的原位研究，该任务在99至516公里之间飞近迪奥尼五次。此外，卡西尼号（Cassini）在2004年至2017年期间越过Dione的L壳400次，并记录了土星磁层的变化性。通过不同的飞越几何形状，可以研究下游，低能尾流以及Dione北极上方的相互作用过程。我们在这里描述低能量磁层测量系统（LEMMS）的高能粒子测量，该系统是卡西尼号上磁层成像仪（MIMI）的一部分。我们还使用来自“ AIKEF”的混合仿真结果来解释粒子通量中的特征。本文是克虏伯等人的继续。（2013，https://doi.org/10.1016/j.icarus.2013.06.007）和Kotova等人。（2015年，https：//doi.org/10.1016/j.icarus.2015.06.031）。主要结果如下：（1）迪翁轨道的土星磁层随着高能带电粒子通量变化1-2个数量级而变化很大。（2）Dione附近的滴落信号基本上与完全吸收的障碍物一致，但是某些特征表明，与等离子体和高能粒子吸收相比，相互作用过程更为复杂。（3）发现吸收特征相对于月球的方向是不对称的，表明存在电子的径向漂移成分。