Particle Acceleration During Collisionless Magnetic Reconnection

无碰撞磁重联期间的粒子加速

• 批准号: 1500460
• 负责人: James Drake
• 金额: $ 36万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1500460&HistoricalAwards=false
• 关键词: Particle; Acceleration; During; Collisionless; Magnetic

This project is focused on the understanding of particle acceleration during the process of magnetic reconnection. Magnetic reconnection is a fundamental process in which magnetic energy is converted into high-speed flows and energetic particles. It underlies important phenomena in nature, including solar flares, strong disturbances in the Earth's magnetic field, and disruptions in laboratory fusion experiments. Magnetic reconnection is also the driver of space weather, which can negatively impact satellite communications and threaten astronauts in space. Great progress has been made on understanding the mechanisms for the fast release of magnetic energy seen in nature and the laboratory during magnetic reconnection. Solar observations suggest that a large fraction of the magnetic energy released appears in the form of energetic particles. The mechanisms for particle acceleration are not understood and are the focus of this research project. The project will include active involvement of undergraduate students, the training of graduate students, including female graduate students, and thus further the broad educational goals of NSF.The technical goal of this research program is to understand electron and ion heating and acceleration during magnetic reconnection and to develop a model for particle acceleration that can be compared with observations. Particle-in-cell simulations and analytic approaches will be used to address four key issues related to electron and ion acceleration during magnetic reconnection: to identify and quantify the dominant mechanisms for electron acceleration; to establish the physics basis for the ubiquitous observations of power-law spectra of energetic particles; to establish the mechanism for ion acceleration and abundance enhancements in impulsive flares; and to develop a Fokker-Planck model of particle acceleration that can be used to predict the hazards associated with space weather. Collaborations will be continued with scientists working on laboratory experiments and with satellite data to benchmark the theoretical predictions with observations.

该项目的重点是了解磁重联过程中的粒子加速。 磁场重联是将磁能转化为高速流和高能粒子的基本过程。 它是自然界重要现象的基础，包括太阳耀斑、地球磁场的强烈扰动和实验室聚变实验的中断。磁场重联也是空间天气的驱动因素，可能对卫星通信产生负面影响，并威胁到太空中的宇航员。在自然界和实验室中，人们对磁场重联过程中磁能快速释放的机制的理解已经取得了很大的进展。 太阳观测表明，释放的大部分磁能以高能粒子的形式出现。 粒子加速的机制尚不清楚，这是本研究项目的重点。 该项目将包括本科生的积极参与，研究生的培训，包括女研究生，从而进一步的NSF的广泛的教育目标。该研究计划的技术目标是了解磁重联过程中的电子和离子加热和加速，并开发一个粒子加速模型，可以与观测进行比较。粒子模拟和分析方法将用于解决与磁重联期间电子和离子加速有关的四个关键问题：确定和量化电子加速的主要机制;为高能粒子幂律谱的普遍观测建立物理基础;建立脉冲耀斑中离子加速和丰度增加的机制;并开发一个粒子加速的福克-普朗克模型，用于预测与空间天气有关的危险。将继续与从事实验室实验的科学家和卫星数据进行合作，以便将理论预测与观测结果进行比较。