Particle acceleration and transport from the Sun to the outer heliosphere
Examining Particle Acceleration in an Analytical Model for Collapsing Magnetic Traps
Alexei Borissov
Thomas Neukirch (University of St Andrews), James Threlfall (University of St Andrews)
University of St Andrews
Collapsing magnetic traps (CMTs) are one proposed mechanism for generating non-thermal particle populations in solar flares. CMTs occur if an initially stretched loop-like magnetic field structure relaxes rapidly into a lower-energy configuration, which is believed to happen as a by-product of magnetic reconnection. A similar mechanism for energising particles has also been found to operate in Earth's magnetotail. One particular feature proposed to be of importance for particle acceleration in the magnetotail is that of a braking plasma jet, i.e. a localised region of strong flow encountering stronger magnetic field which causes the jet to slow down and stop. Such a feature has not been included in previously proposed analytical models of CMTs for solar flares. We propose a CMT model incorporating a braking plasma jet for the first time. Results of test particle calculations in this new model are presented. We demonstrate new types of particle behaviour caused by the magnetic structure of the jet braking region, which allows electrons to be trapped both in the braking jet region and in the loop legs. We compare and contrast the behaviour of particle orbits for various parameter regimes of the underlying trap by examining particle trajectories, energy gains and the frequency with which different types of particle orbit are found for each parameter regime.
09:00 - 10:30
EX - C3 (150)