Charged Particle Acceleration in Solar Eruptive Events

Understanding the mechanisms for the generation of the large number of non-thermal accelerated particles observed in solar flares is currently one of the most interesting unsolved problems in solar physics. The energy for powering solar eruptive events fundamentally comes from the coronal magnetic field and its release involves magnetic reconnection. A variety of particle acceleration mechanisms have been associated with the process of magnetic reconnection. While the parallel electric field generated during magnetic reconnection is an obvious potential mechanism for particle acceleration, there is some doubt whether it can account for the number of high-energy particles observed due to the very limited size of the non-ideal reconnection regions. Mechanisms linked to the reconnection outflow region have been studied for a couple of decades, so far with somewhat inconclusive results for acceleration on macroscopic scales, but have recently have gained more attention for operating on smaller scales.
In this PhD project various previously unstudied aspects of particle acceleration mechanisms in reconnection outflow regions will be explored. In particular, it is planned that the project will focus on the differences between 2D and 3D models. The project will mainly use test particle calculations as a tool. The project is mainly theoretical in nature, but where possible comparison with observations will be made.