Particle Acceleration During Collisionless Magnetic Reconnection

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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.