Collaborative Research: Electron Heat Flux Regulation in the Solar Wind

合作研究：太阳风中的电子热通量调节

• 批准号: 2203319
• 负责人: Chadi Salem
• 金额: $ 28.73万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2203319&HistoricalAwards=false
• 关键词: Collaborative; Research; Electron; Heat; Flux

Understanding and characterizing fundamental processes that take place within the heliosphere and throughout the universe is important, and it could be vital for future human explorations of space, as well as for studying the space environmental impact on modern civilization. Solar wind is the medium through which harmful radiation travels. An accurate description of the solar wind is necessary to understand the propagation of these disturbances from the Sun to the Earth. This project studies solar wind physics. The work supports training of a graduate student and post-doctoral researcher.The research aims to address the compelling science question of "what regulates the solar wind heat flux?" The electrons in the solar wind efficiently conduct heat, thus carrying the heat flux along the anti-sunward direction. Among physical processes that regulate the heat flux, whistler heat-flux instabilities are suggested as being important in the collisionless heat flux regime, while in the collisional regime, the binary collisions are the classical regulation mechanism. Both processes compete against the radial expansion effects. The relative importance of these competing processes, that is, instabilities, collisions, and expansion, remains an outstanding and thus, together they constitute a compelling research topic. The project will use the self-consistent quasilinear theory and kinetic theory of collisions in magnetized plasma to model the evolution of the waves and electron heat flux in the radially-varying solar wind. The theory will be driven by inputs from, and tested against, the well-calibrated measurements of the solar wind electron distribution function from various spacecraft between 0.3 and 1 AU, as well as proton parameters, magnetic field and plasma wave data. Such an integrated and collaborative research on the nature of solar wind electrons and the heat flux they carry will greatly contribute toward improving our understanding of the fundamental processes that take place within the heliosphere.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.

理解和表征在Heliosphere内部和整个宇宙中发生的基本过程至关重要，对于未来的人类对空间的探索以及研究太空环境对现代文明的影响可能至关重要。太阳风是有害辐射传播的介质。对于理解这些干扰从太阳传播到地球的繁殖需要准确描述太阳风。该项目研究太阳能物理学。该工作支持研究生和博士后研究人员的培训。该研究旨在解决“是什么调节太阳风热通量？”的引人入胜的科学问题。太阳风中的电子有效地进行热量，从而沿着反肺方向携带热通量。在调节热通量的物理过程中，惠斯勒的热量升级不稳定性在无碰撞的热通量状态中很重要，而在碰撞状态中，二进制碰撞是经典的调节机制。这两个过程都与径向扩展效应竞争。这些竞争过程的相对重要性，即不稳定性，碰撞和扩展，仍然是一个杰出的，因此，它们共同构成了一个令人信服的研究主题。该项目将使用磁化等离子体中碰撞的自洽的准线性理论和动力学理论来对径向变化的太阳风中的波和电子热通量的演变进行建模。该理论将由来自0.3和1 AU之间的各种航天器的太阳风电子分布函数以及质子参数，磁场和等离子体波数据的太阳风电子分布函数的投入和测试驱动。关于太阳能电电子性质及其携带的热量的这种综合和协作研究将极大地有助于提高我们对Heliosphere内发生的基本过程的理解。该奖项反映了NSF的法定任务，并被视为值得的支持值得通过使用基金会的智力优点和更广泛影响的评论标准进行评估。