Collaborative Research: Causes and Consequences of Relativistic Electron Precipitation as Revealed by the CubeSat Mission ELFIN’s Pitch-Angle Resolved Loss Cone Measurements

联合资助的NSF/NASA ELFIN任务由两个相同的立方体卫星组成，在极地（~ 93度倾角），近圆形，低地球轨道上。ELFIN于2018年9月15日发射，目前在地球空间环境中运行。这笔资金将用于分析ELFIN目前收集的数据的主要任务目标，以推进对波粒相互作用及其对外部辐射带中相对论电子的影响的理解。两名本科生、一名研究生和三名早期职业科学家将获得资助。ELFIN数据产品被整合到加州大学洛杉矶分校的课程和洛杉矶地区的公共推广活动中。该项目将利用ELFIN，连同它与其他赤道太阳物理任务的结合，来解决EMIC波降水的有效性，以及在观测到的相对论性电子散射（100 keV到几MeV能量）中，EMIC波、哨子波和动力学alfvn波的相对贡献。具体的科学目标是：(1)主位波是否负责0.5-2MeV的电子沉淀？(2)除了位源波（主要是齐声波和动力学alfvsamn波（kaw））之外的波是否也对显著的相对论性电子散射负责？(3)不同波型的典型降水率随地磁条件的变化有哪些？该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The jointly funded NSF/NASA ELFIN mission consists of two identical CubeSats on a polar (~ 93 degree inclination), nearly circular, low-Earth orbit. ELFIN was launched on September 15, 2018 and is currently operating within the geospace environment. This funding will address the prime mission objective of analyzing the data currently being collected by ELFIN to advance understanding of wave-particle interactions and their effect on relativistic electrons in the outer radiation belt. Two undergraduate students, a graduate student, and three early career scientists will be supported. ELFIN data products are integrated into courses at UCLA and in public outreach events in the Los Angeles area.The project will utilize ELFIN, together with its conjunctions with other, equatorial Heliophysics missions to address the efficacy of EMIC wave precipitation, and the relative contribution of EMIC, whistlers and kinetic Alfvén waves in the observed relativistic electron scattering (100s of keV to a few MeV energy). The specific science objectives are: (1) Are EMIC waves responsible for 0.5-2MeV electron precipitation?(2) Are waves other than EMIC waves (principally chorus waves and kinetic Alfvén waves (KAWs)), also responsible for significant relativistic electron scattering? (3) What are the typical precipitation rates associated with various wave types as function of geomagnetic conditions?This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.