Particle acceleration in reconnecting current sheets in impulsive electron-rich solar flares

Electron and proton acceleration in reconnecting current sheets in electron -rich solar flares is considered. A significant three-dimensional magnetic field is assumed in the current sheet where the particles are accelerated b y the DC electric field. The tearing instability of a pre-flare current she et leads to the formation of multiple singular lines of magnetic held where the electric and magnetic fields are coaligned. Magnetized electrons are s hown to be accelerated to a few tens of MeV before they leave the vicinity of a singular line. The acceleration time is estimated to be less than 10(- 3) s. By contrast, much heavier protons are unmagnetized and their energy g ain is more modest. The model explains a high electron-to-proton ratio and the unusually intense gamma-ray continuum above 1 MeV observed in the elect ron-rich flares.