RAPID: Novel Experimental Quantification of Energetic Electron Properties During Ionospheric Modification

RAPID：电离层修改过程中高能电子特性的新颖实验量化

• 批准号: 1748578
• 负责人: Lara Waldrop
• 金额: $ 2.59万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1748578&HistoricalAwards=false
• 关键词: RAPID; Novel; Experimental; Quantification; Energetic

This one-year RAPID project is aimed at providing unprecedented empirical constraints on the energy distribution of electrons generated during high-power ionospheric modification as a means of advancing understanding of electron acceleration processes. High-power, high-frequency (HF) radio wave transmitters are an important tool for the experimental investigation of fundamental plasma physics in the terrestrial ionosphere. Three HF heating facilities (HAARP, EISCAT, and Arecibo Observatory) have demonstrated the ability to induce overhead plasma densities approaching those created by solar photoionization, thereby enabling empirical studies of energetic electron production, acceleration and transport. Despite numerous experiments over the past several decades, however, the physical mechanisms responsible for electron acceleration during ionospheric modification remain unsettled. In order to tackle this problem, this project adopts a novel approach that involves the combination of plasma-line and ion-line detection by the Arecibo Observatory incoherent scatter radar (ISR). This is the most sensitive instrument of its kind, together with passive measurement of optical airglow emitted by Oxygen atoms at 844.6 nm and 630.0 nm. The research campaign will utilize nearly all of the facility and the PI-owned optical instrumentation on site at the Arecibo Observatory and at the nearby Culebra island in an unprecedentedly coordinated effort. Unlike past investigations of electron acceleration during ionospheric modification, the research analysis during this project will incorporate coincident empirical estimates of thermospheric Oxygen density, which the PI will derive from calibrated measurements of the Oxygen 844.6 nm emission line brightness. This research effort will be led by an early-career, female PI. The research agenda of this RAPID project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research The results from the intended research effort to obtain unprecedented empirical constraints on energetic electron acceleration during ionospheric modification will have far-reaching impact on fundamental theories governing the physics of weakly magnetized plasmas. Future investigations of electron energy loss from pitch angle scattering in the plasmasphere, for example, will benefit from the results of this work. Although advancing ionospheric plasma physics is the primary focus of the effort, the careful experimental design by the PI will also yield crucial constraints on the rate of Oxygen 844.6 nm emission line excitation via O+ radiative recombination. Moreover, the intended implementation of astronomical calibration at this near-infrared wavelength as well as at the Oxygen 630.0 nm emission line will provide a long-awaited means of cross-calibrating the facility calibration sources for future campaigns. Finally, the new Oxygen 844.6 nm emission line photometer can easily be configured to conduct routine passive measurements for community use. Even in the absence of HF ionospheric heating, the calibrated Oxygen 844.6 nm emission line data provide a means for Thermospheric Oxygen sensing. This capability, which currently is not possible at any other ISR facility, enables crucial investigations of ion-neutral coupling which are needed to advance physics-based models of the upper atmosphere. .

这个为期一年的快速项目旨在为高功率电离层修饰过程中产生的电子的能量分布提供前所未有的经验约束，以此作为促进对电子加速过程的理解的一种手段。 高功率，高频（HF）无线电波发射器是对陆地电离层基本等离子体物理学实验研究的重要工具。 三个HF加热设施（HAARP，EISCAT和ARECIBO天文台）已经证明了诱导高架血浆密度接近太阳光电发电量产生的HF，从而实现了对能量电子产生，加速和运输的经验研究。 尽管在过去的几十年中进行了许多实验，但在电离层修饰过程中导致电子加速的物理机制仍然不稳定。 为了解决这个问题，该项目采用了一种新的方法，涉及arecibo天文台不一致的散射雷达（ISR）的等离子线和离子线检测的组合。 这是同类仪器中最敏感的仪器，再加上由844.6 nm和630.0 nm的氧原子发出的光学气流的被动测量。 该研究活动将在Arecibo天文台和附近的Culebra岛上使用几乎所有设施和PI拥有的光学仪器，以前所未有的协调努力。 与过去对电离层修饰过程中电子加速度的研究不同，该项目期间的研究分析将结合热圈氧密度的经验估计，PI将从氧气844.6 nm发射线的校准测量中得出。这项研究工作将由早期的女性PI领导。 该快速项目的研究议程支持AGS部门在发现，学习，多样性和跨学科研究中的战略目标，这些研究的结果来自预期的研究工作，以获得对电离层修饰期间能量电子加速的前所未有的经验约束，将对涉及弱量的MAGANESS PLASSMass的基础理论产生深远的影响。 例如，对等离子球中螺距角散射的电子能量损失的未来研究将受益于这项工作的结果。 尽管前进的电离层等离子体物理学是努力的主要重点，但PI仔细的实验​​设计还将对氧气844.6 nm发射线激发的速率产生至关重要的约束。 此外，在此近红外波长以及氧气630.0 nm排放线上的天文校准的预期实施将提供一种期待已久的跨校准设施校准源的方法，以供未来的运动。 最后，新的氧844.6 nm发射线光度计可以轻松地配置为进行常规的被动测量以供社区使用。 即使在没有HF电离层加热的情况下，校准的氧气844.6 nm发射线数据也为热层氧气传感提供了一种手段。 目前在任何其他ISR设施中都无法使用这种功能，可以对离子中性耦合进行关键研究，以推动基于物理大气的基于物理模型。 。