| Presentation Title: | Evolution and effect of pre-existing non-thermal (PENT) particles in magnetic reconnection |
| Author(s): | Mitsuo Oka, Fan Guo, and Xiaocan Li |
Abstract:
Solar flares produce a significant number of high-energy, non-thermal particles. Earlier observations suggested that non-thermal electrons alone carry up to 50% of the released magnetic energy, and recent observations reported that nearly all electrons are accelerated to form a power-law. These observations may lead to the idea that particles, once accelerated, might replenish the acceleration region to receive further acceleration. However, it is not clear what happens to magnetic reconnection when it is replenished with non-thermal particles and if reconnection can sustain the energy conversion process. Here we show, using 2D particle-in-cell (PIC) simulations, that pre-existing non-thermal (PENT) particles do not experience significant re-acceleration by magnetic reconnection, and the reconnection process itself also does not receive substantial feedback from the PENT population, unless plasma beta is increased. While the result needs to be further tested in 3D, we anticipate that the problem of particle acceleration in solar flares remains challenging and requires breakthroughs in future observational studies.