Particle Acceleration During Collisionless Magnetic Reconnection

无碰撞磁重联期间的粒子加速

• 批准号: 1805829
• 负责人: James Drake
• 金额: $ 37.5万
• 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: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1805829&HistoricalAwards=false
• 关键词: Particle; Acceleration; During; Collisionless; Magnetic

This research project will focus on the origins of particle acceleration in magnetized astrophysical plasmas. The sun and other stars, many planetary systems and other astronomical objects produce magnetic fields. Observations reveal that when magnetic fields pointing in opposite directions come together in these systems, they can annihilate each other and explosively release magnetic energy. These explosions are revealed in solar and stellar flares, flares in astrophysical objects, storms in Earth's space environment and disruptions in laboratory fusion experiments. Magnetic energy release is also the driver of space weather, which can negatively impact satellite communications and threaten astronauts in space. Magnetic reconnection is the fundamental process that describes how magnetic fields annihilate. Great progress has been made on understanding the mechanisms for the fast release of magnetic energy seen in nature and the laboratory. The mechanisms for particle acceleration are not well understood and are the focus of this research grant. The active involvement of undergraduate students and the training of graduate students, including female graduate students, furthers the broad educational goals of NSF.The 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 coupled with an analytic effort will be used to address two key issues related to electron and ion acceleration during magnetic reconnection: (1) the mechanism for ion acceleration with application to abundance enhancements in impulsive flares, and (2) the physics basis for the ubiquitous observations of powerlaw spectra of energetic electrons and ions. A novel computational model will be implemented to explore particle acceleration in macro-scale systems that can be used to predict the spectra and photon and radio signatures of energetic particles in astrophysical plasmas. Collaborations will be continued and expanded with scientists working on laboratory experiments, satellite data and ground-based data to benchmark the theoretical predictions with observations.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.

这项研究项目将集中在磁化天体物理等离子体中粒子加速的起源。太阳和其他恒星、许多行星系统和其他天文物体都会产生磁场。观测显示，当指向相反方向的磁场在这些系统中聚集在一起时，它们可以相互湮灭并爆炸性地释放磁能。这些爆炸在太阳和恒星耀斑、天体物理物体的耀斑、地球空间环境中的风暴和实验室聚变实验中被发现。磁能释放也是空间天气的驱动因素，这可能会对卫星通信产生负面影响，并威胁到太空中的宇航员。磁重联是描述磁场如何湮灭的基本过程。在理解自然界和实验室中看到的磁能快速释放的机制方面，已经取得了很大的进展。粒子加速的机制还不是很清楚，这是这项研究拨款的重点。本科生的积极参与和包括女研究生在内的研究生的培训，进一步推动了国家自然科学基金会的广泛教育目标。该研究计划的目标是了解磁重联过程中电子和离子的加热和加速，并开发一个可以与观测相比较的粒子加速模型。粒子模拟和分析工作将被用来解决与磁重联过程中的电子和离子加速有关的两个关键问题：(1)离子加速的机制，并应用于脉冲耀斑中的丰度增强；(2)无处不在的高能电子和离子的幂定律谱的观测的物理基础。将实施一种新的计算模型来探索宏观尺度系统中的粒子加速，该模型可用于预测天体物理等离子体中高能粒子的光谱、光子和射电特征。将继续并扩大与从事实验室实验、卫星数据和地面数据工作的科学家的合作，以将理论预测与观测进行基准比较。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Reconnection With Magnetic Flux Pileup at the Interface of Converging Jets at the Magnetopause

• DOI: 10.1029/2018gl080994
• 发表时间: 2019-02
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: M. Øieroset;T. Phan;J. Drake;J. Eastwood;S. Fuselier;R. Strangeway;C. Haggerty;M. Shay;M. Oka;Sheng-Hsiang Wang;L. Chen;I. Kacem;B. Lavraud;V. Angelopoulos;J. Burch;R. Torbert;R. Ergun;Y. Khotyaintsev;P. Lindqvist;D. Gershman;B. Giles;C. Pollock;T. Moore;C. Russell;Y. Saito;L. Avanov;W. Paterson

Turbulence and Transport During Guide Field Reconnection at the Magnetopause

• DOI: 10.1029/2019ja027498
• 发表时间: 2020-04-01
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
• 影响因子: 2.8
• 作者: Price, L.;Swisdak, M.;Graham, D. B.
• 通讯作者: Graham, D. B.

Sunward-propagating Whistler Waves Collocated with Localized Magnetic Field Holes in the Solar Wind: Parker Solar Probe Observations at 35.7 R ⊙ Radii

向日传播的惠斯勒波与太阳风中的局域磁场空洞相结合：帕克太阳探测器在 35.7 R 半径处的观测

• DOI: 10.3847/2041-8213/ab799c
• 发表时间: 2020
• 期刊: The Astrophysical Journal
• 作者: Agapitov, O. V.;Wit, T. Dudok;Mozer, F. S.;Bonnell, J. W.;Drake, J. F.;Malaspina, D.;Krasnoselskikh, V.;Bale, S.;Whittlesey, P. L.;Case, A. W.
• 通讯作者: Case, A. W.

Switchbacks as signatures of magnetic flux ropes generated by interchange reconnection in the corona

• DOI: 10.1051/0004-6361/202039432
• 发表时间: 2021-06-02
• 期刊: ASTRONOMY & ASTROPHYSICS
• 影响因子: 6.5
• 作者: Drake, J. F.;Agapitov, O.;Velli, M.
• 通讯作者: Velli, M.

Decomposition of plasma kinetic entropy into position and velocity space and the use of kinetic entropy in particle-in-cell simulations

• DOI: 10.1063/1.5098888
• 发表时间: 2019-08-01
• 期刊: PHYSICS OF PLASMAS
• 影响因子: 2.2
• 作者: Liang, Haoming;Cassak, Paul A.;Delzanno, Gian Luca
• 通讯作者: Delzanno, Gian Luca