ELECTRON ACCELERATION BY MULTI-ISLAND COALESCENCE
By Mitsuo Oka, T. Phan, S. Krucker, Masaki Fujimoto, Iku Shinohara. 2010
218 citations recorded by the source corpus.
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 two-dimensional 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.
Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/f886766acd7135bfc5fcea8007ac245518db25ce
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Citations in the corpus
- RELATIVISTIC RECONNECTION: AN EFFICIENT SOURCE OF NON-THERMAL PARTICLES (2014, background): “1a, the particles experience a variety of other acceleration processes (Drake et al. 2006; Oka et al. 2010), yet the power-law index does not appreciably change.”
- PARTICLE ACCELERATION AND PLASMA DYNAMICS DURING MAGNETIC RECONNECTION IN THE MAGNETICALLY DOMINATED REGIME (2015, background): “The fast acceleration is distinct from that of nonrelativistic magnetic reconnection, where particles are at most accelerated to mildly relativistic energy (e.g., Fu et al. 2006; Drake et al. 2006; Pritchett 2006; Oka et al. 2010).”
- ACCELERATION OF PARTICLES AT THE TERMINATION SHOCK OF A RELATIVISTIC STRIPED WIND (2011, background): “During the coalescence of magnetic islands, particles may be accelerated by the antireconnection electric field at the X-point located in between the two merging islands (Jaroschek et al. 2004; Oka et al. 2010).”
- Modelling Quasi-Periodic Pulsations in Solar and Stellar Flares (2018, background): “Since the particle acceleration is expected during the coalescence (Tajima et al. 1982; Oka et al. 2010; Karlický and Bárta 2011), QPPs seen in emissions originated from non-thermal, high-energy particles could be caused by the oscillations associated with the coalescence instability (an observation”
- Particle Acceleration in the Magnetotail and Aurora (2012, methodology): “…order to understand the particle acceleration in reconnection, the nonlinear time evolution of a thin current sheet has been studied by many different research groups (e.g., Hoshino et al. 2001; Drake et al. 2003; Pritchett 2008; Oka et al. 2010) using particle-in-cell (PIC) simulations.”