EAGER: High Speed Tomographic Imaging Facility for Studies of Auroral Fine Structure

研究人员将开发一种高帧率层析成像设备，以及一种基于物理的反演方法，以便在最精细的尺度上量化极光的三维运动。虽然已经提出了几种理论来解释这些尺度上的结构，但确定哪种模型是正确的以及在哪种情况下需要了解两个参数，而不是通过单个成像系统直接观察到的：1)极光形式相对于对流参照系的横向运动或传播；2)主要粒子光谱的平均能量变化，表现在极光形式的明显垂直变形中。前者解决了能量在磁力线上的分散，而后者解决了电磁和动能之间耦合的变化。新方法使用粒子穿透的物理模型，以使难以观测到的场对准维度正则化。除了使问题规范化之外，这种方法还提供了对感兴趣的物理量的访问：初级电子能谱中的时空可变性。这项研究利用了最近在商业和国防领域开发的技术（例如，电子倍增CCD相机，固态驱动器，毫秒GPS同步）。如果成功，这项研究将提供新的观测证据，以解决空间物理学中一个尚未解决的基本问题。这些结果将有助于理解整个宇宙中发生的普遍等离子体过程。该项目支持一名早期职业空间科学家、一名工程研究生和几名本科生研究助理。

The investigators will develop a high frame-rate tomographic imaging facility, and a physics-based inversion methodology, in order to quantify three-dimensional motions of the aurora at its finest scales. Although several theories have been suggested to account for structuring at these scales, determining which model is correct and under which circumstance requires knowledge of two parameters not directly observed by a single imaging system: 1) the transverse motion or spreading) of auroral forms with respect to the convecting frame of reference, and 2) the change in average energy of the primary particle spectrum, manifested in the apparent vertical deformation of auroral forms. The former addresses the dispersion of energy across magnetic lines of force, while the latter addresses changes in coupling between electromagnetic and kinetic energy. The new approach uses a physical model of particle penetration in order to regularize the poorly observed field-aligned dimension. In addition to regularizing the problem, this approach provides access to the physical quantity of interest: the space-time variability in the primary electron spectrum. The research leverages technologies recently developed in the commercial and defense sectors (e.g., Electron Multiplying CCD cameras, solid state drives, millisecond GPS synchronization). If successful, the research will provide new observational evidence needed to address a fundamental unresolved question space physics. The results will contribute to the understanding of universal plasma processes occurring throughout the cosmos. The project supports an early career space scientist, a graduate student in engineering, and several undergraduate research assistants.