The Acceleration of Ions in Solar Flares During Magnetic Reconnection
  The acceleration of solar flare ions during magnetic reconnection is explored via particle-in-cell simulations that self-consistently follow the motions of both protons and $\alpha$ particles. We demonstrate that the dominant ion heating during reconnection with a guide field (a magnetic component perpendicular to the reconnection plane) results from pickup behavior during the entry into reconnection exhausts. In contrast with anti-parallel reconnection, the temperature increment is dominantly transverse, rather than parallel, to the local magnetic field. The comparison of protons and alphas reveals a mass-to-charge ($M/Q$) threshold in pickup behavior that favors heating of high $M/Q$ ions over protons, which is consistent with impulsive flare observations. 
Kalman Knizhnik, Marc Swisdak, James F. Drake
astro-ph.SR physics.plasm-ph physics.space-ph