SM13A-4146:
Energy Conversion and Particle Acceleration during Magnetic Reconnection
Monday, 15 December 2014
Xiaocan Li1, Fan Guo2, William S Daughton3, Hui Li2, Shengtai Li2, Yi-Hsin Liu2 and Gang Li1, (1)University of Alabama in Huntsville, Huntsville, AL, United States, (2)Los Alamos National Lab, Los Alamos, NM, United States, (3)MS-F699, Plasma Theory and App, Los Alamos, NM, United States
Abstract:
We study energy conversion and particle acceleration during magnetic reconnection starting from a force-free current layer using two-dimensional particle-in-cell (PIC) simulations and high-Lundquist-number MHD simulations. In PIC simulations of collisionless magnetic reconnection, pressure anisotropy develops and is found to be stronger for particles with higher energies. When an external guide field is added, the pressure anisotropy is stronger with the magnitude of guide field. The energy conversion and particle acceleration through particle guiding center drifts, magnetization current, and parallel electric field are quantitatively evaluated and compared for a range of guide fields. The results are then explained using an electric current description associated with pressure anisotropy. This description is further used to study energy conversion during reconnection in high-Lundquist-number MHD simulations, where plasma pressure is assumed to be isotropic, and energy conversion is from compressional and Ohmic heating. These results demonstrate the importance of considering the influence of anisotropic velocity distributions on particle acceleration during magnetic reconnection.
