PROMPT HIGH-ENERGY PARTICLE-ACCELERATION DURING 2-CURRENT-LOOP COLLISIONS

We present a model of prompt high-energy particle acceleration during two-current-loop collisions. By investigating test proton and test electron motions in the electromagnetic field derived from the MHD equations, we found that high-energy particle acceleration occurs only in the case of Y-type, loop-loop collisions. The results depend strongly on the plasma beta and initial position of the test particle. When the plasma beta increases, the particle acceleration rate decreases. The particles near the edge of the collision region can be accelerated to higher energy than the ones inside it. It has been shown that both protons and electrons can be accelerated to approximately 10 GeV within 0.001 s and approximately MeV within 10(-6) s, respectively. In the case of Y-type loop-loop collisions, one may expect that high-energy gamma-ray and neutrons will be generated from interaction between high-energy particles and the low atmospheric plasma.