JOHN BROWN UNIVERSITY
Grant: $74,521 - National Science Foundation - Jul. 23, 2009
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Award Description: Localized bipolar electric field pulses have been observed by many satellite missions throughout Earth's plasma environment including the auroral ionosphere, regions of the magnetosphere (e.g., the cusp, the magnetosheath, and the magnetotail), and in the solar wind. These bipolar pulses are the electric fi?eld signature of holes in particle phase space. A less frequently observed localized electric ?field structure that has been observed directly by spacecraft in the Earth's plasma environment is double layers. The double layers in the auroral region often contain a signifi?cant potential drop and have been shown to be responsible for the particle acceleration necessary to form the often observed ion and electron holes. The research eff?ort proposed here will address the structure and evolution of ion holes, double layers, and ion acoustic solitons in plasma conditions relevant to the auroral upward current region. Using a multidimensional particle-in-cell code, The PI will address some long-standing questions regarding the stability of oblique double layers in a magnetic ?field in multiple phase space dimensions, including an investigation of how perpendicular ion heating aff?ects the evolution of the double layer and whether a 2D double layer is quasi-stable for a long enough time to account for observations of persistent ion beams in the upward current region. The stability of U-shaped potential structures inferred from spacecraft observations will also be investigated. Finally, the evolution of ion holes and ion acoustic solitons will be studied in relation to the double layer evolution.
Project Description: See Award Description
Jobs Summary: A researcher to write a computer code to investigate the evolution of double layers in the space environment. (Total jobs reported: 0)
Project Status: Less Than 50% Completed
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