REGULAR AND CHAOTIC ACCELERATION OF ELECT RONS IN RECONNECTING CURRENT SHEETS ON THE SUN

The motion of charged particles in reconnecting current sheets can be either chaotic or regular depending on the magnetic field structure wi thin the current sheet, namely, relative transversal and longitudinal components of the magnetic field. The nonzero transversal magnetic fie ld is responsible for chaotic trajectories, whereas the appreciable lo ngitudinal component suppresses the chaos. In high-temperature current sheets typical for the solar atmosphere the threshold longitudinal co mponent is by an order of magnitude lower than the principal (reconnec ting) component. Variations of the longitudinal component may be respo nsible for the existence of various regimes of electron acceleration o bserved in solar flares.