X‐Ray Loop‐Top Source Generated by Processes in a Flare Collapsing Trap

Abstract

Using the two-dimensional MHD model of the magnetic reconnection, the cusp structure with the collapsing trap is simulated. Scaling these computational results into solar flare conditions, we study the electron acceleration in the collapsing trap. We use the test-particle technique with the guiding center approximation in which the collisional losses and scattering of accelerated electrons are included. We found that this "secondary" acceleration process essentially modifies the distribution function of electrons preaccelerated in the reconnection process. The collapsing trap consists of a structure with the return current, which influences the spatial structure of the loop-top X-ray source. The significance of the curvature drift of electrons in the electric field direction for the electron acceleration is confirmed. The acceleration is more efficient, and the X-ray loop-top source is more intense, but spatially more prolonged than the X-ray source computed in the model without this drift.