Particle acceleration and radiation by single or multiple 3D reconnecting current sheets

A. Anastasiadis$^1$, C. Gontikakis$^2$, C. Efthymiopoulos$^2$

$^1$National Observatory of Athens, Institute for Space Applications and Remote Sensing, GR-15236 Penteli, Greece
$^2$Academy of Athens, Research Centre of Astronomy and Applied Mathematics, Soranou Efessiou 4, GR-11527 Athens, Greece

The acceleration of charged particles (electrons and protons) in a site of magnetic reconnection is analyzed by detailed numerical simulations. Single or multiple encounters of the particles with Harris-type reconnecting current sheets (RCS) are modelled as an overall stochastic process taking place within a solar active region. Our main goal is to investigate how the acceleration process changes the shape of the particles' kinetic energy distribution. In the case of consecutive encounters, we find that the kinetic distribution tends to converge to a practically invariant form after a relatively small number of encounters. Finally we compute the theoretical X-ray spectra that would be emitted by the simulated particles in a thick target model of radiation.