RELATIVISTIC ACCELERATION OF PROTONS IN RECONNECTING CURRENT SHEETS OF SOLAR-FLARES

Acceleration of protons in a reconnecting current sheet (RCS), which f orms as a consequence of filament eruption in the corona, is considere d as a possible mechanism of generation of the relativistic particles during the late phase of solar flares. In order to explain the acceler ation of protons and heavier ions up to several GeV in a time of < 0.1 s, the transverse electric field outside the RCS must be taken into a ccount. Physically, this field is always present as a consequence of e lectric charge separation owing to the difference in the electron and proton masses. The new effect demonstrated in this paper is that the t ransverse electric field efficiently 'locks' nonthermal ions in the RC S, thus allowing their acceleration by the direct electric field in th e RCS. The mechanism considered may be useful in construction of a mod el for generation of relativistic ions in large gamma-ray/proton flare s.