Abstract An active mapping mission is described that unambiguously connects measurements in the Earth's magnetosphere to visible aurora in the atmosphere. The core of the mission is an electron-beam source operated on a spacecraft in the equatorial magnetosphere, with the electron beam traveling along the Earth's magnetic-field lines to the atmosphere, depositing its energy to create an optical beam-spot in the atmosphere at the footpoint of the spacecraft's magnetic-field line. This optical spot can be imaged by ground-based cameras, putting the location of the spacecraft's magnetic footpoint into the context of the optical aurora. Scientific instruments carried on the spacecraft make critical measurements of the properties of the magnetosphere at the locations where the magnetosphere powers the aurora, allowing the determination of the plasma-physics mechanisms by which the magnetosphere drives the aurora, in particular answering the outstanding question of how the magnetosphere drives low-latitude auroral arcs. Long-standing questions in magnetosphere-ionosphere coupling that have not been answered because we could not unambiguously connect locations in the magnetosphere with their image in the ionosphere will finally be addressed. In this paper the properties of a “standard” growth-phase auroral arc are collected, theories of the magnetospheric generation of auroral arcs are reviewed, and critical magnetospheric measurements to discern the mechanisms that drive auroral arcs are determined. Further, the plasma physics of the experiment is investigated, including spacecraft-charging mitigation, beam stability, beam scattering, and electron orbit theory. Tradeoffs (keV versus MeV) concerning the energy of the electron beam are enumerated.

中文翻译：

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通过使用电子束将关键磁层测量结果明确地连接到极光图像来解决极光-弧光发生器问题

摘要 描述了一项主动测绘任务，该任务明确地将地球磁层中的测量结果与大气中的可见极光联系起来。该任务的核心是在赤道磁层中的航天器上运行的电子束源，电子束沿着地球的磁场线传播到大气层，将其能量沉积在大气层中，在航天器磁场线的立足点。这个光斑可以通过地面相机成像，将航天器磁脚点的位置放入光学极光的背景中。航天器上携带的科学仪器对磁层为极光提供动力的位置的磁层特性进行重要测量，允许确定磁层驱动极光的等离子体物理机制，特别是回答磁层如何驱动低纬度极光弧的悬而未决的问题。由于我们无法明确地将磁层中的位置与其在电离层中的图像联系起来，因此磁层-电离层耦合中长期存在的问题尚未得到解答，最终将得到解决。在本文中，收集了“标准”生长阶段极光弧的特性，回顾了磁层产生极光弧的理论，并确定了用于辨别驱动极光弧的机制的关键磁层测量。此外，研究了实验的等离子体物理，包括航天器充电缓解、光束稳定性、光束散射、和电子轨道理论。列举了关于电子束能量的权衡（keV 与 MeV）。