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arXiv · 1004.1154

Electron Acceleration by Multi-Island Coalescence

M. Oka·T. -D. Phan·S. Krucker·M. Fujimoto·I. Shinohara
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Abstract

Energetic electrons of up to tens of MeV are created during explosive phenomena in the solar corona. While many theoretical models consider magnetic reconnection as a possible way of generating energetic electrons, the precise roles of magnetic reconnection during acceleration and heating of electrons still remain unclear. Here we show from 2D particle-in-cell simulations that coalescence of magnetic islands that naturally form as a consequence of tearing mode instability and associated magnetic reconnection leads to efficient energization of electrons. The key process is the secondary magnetic reconnection at the merging points, or the `anti-reconnection', which is, in a sense, driven by the converging outflows from the initial magnetic reconnection regions. By following the trajectories of the most energetic electrons, we found a variety of different acceleration mechanisms but the energization at the anti-reconnection is found to be the most important process. We discuss possible applications to the energetic electrons observed in the solar flares. We anticipate our results to be a starting point for more sophisticated models of particle acceleration during the explosive energy release phenomena.

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M. Oka, T. -D. Phan, S. Krucker, M. Fujimoto, I. Shinohara. 2010-04-07. Electron Acceleration by Multi-Island Coalescence. https://doi.org/10.1088/0004-637x%2F714%2F1%2F915

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