AI 中文总结
该研究揭示月球尾迹电势的双尺度结构介导离子与电子的能量转换，其印记与ARTEMIS观测的速度分布特征相符，深化了对月球尾迹物理过程的认识。
AI 中文摘要
我们研究月球尾迹中电势的演化。尾迹电势呈现出两种不同的空间尺度：宏观尺度源于太阳风向真空中膨胀，其势长度尺度随与月球距离的增加而增长；微观尺度源于尾迹中心附近的离子声激波，其过渡层跨度为数十个局部德拜长度。这种双尺度电势在尾迹填充过程中介导离子与电子之间的能量转换：宏观尺度电势阻碍电子并将离子加速至超声速，将电子的热能转换为离子的动能；微观尺度电势随后将离子减速至亚声速并加热两种粒子，将离子的动能转换回热能。双尺度电势共同在速度分布上留下独特印记，包括离子束和电子平顶分布，与ARTEMIS观测结果一致。
英文摘要
We study the evolution of electric potentials in the lunar wake. The wake potential exhibits two distinct spatial scales. The macroscopic scale arises from solar wind expansion into the vacuum, with a potential length-scale growing with distance from the Moon; the microscopic scales arises from ion acoustic shocks near the wake center, with transition layers spanning tens of local Debye lengths. This two-scale potential mediates energy conversion between ions and electrons during wake refilling. The macroscale potential retards electrons and accelerates ions to supersonic velocities, converting electron thermal energy to ion kinetic energy. The microscale potential then decelerates ions to subsonic velocities and heats both species, converting ion kinetic energy back to thermal energy. Together, the two-scale potential imprints distinct signatures on velocity distributions, including ion beams and electron flat-top distributions, consistent with ARTEMIS observations.
