Speaker
Description
Magnetic reconnection is an ubiquitous phenomenon observed in laboratory, fusion and space plasmas. It is usually accompanied by the energy conversion between electromagnetic fields and plasmas [1]. Recently, a new regime called “electron-only magnetic reconnection” (e-rec hereafter) was observed and studied in the Earth’s magnetosheath [2] and in laboratory plasmas [3]. The novelty of e-rec lies in that its temporal and spatial scales are so small that only electrons are involved in this process and ion outflow jets existing in standard ion-coupled reconnection are absent in this new regime. It has been discovered in numerical simulations that electronscale reconnection is an integral part of plasma turbulence and may play a role in the energy cascade and dissipation. The energy conversion and particle heating in standard ion-coupled reconnection has been extensively investigated in both experiments and simulations. However, the energy transfer in e-rec is poorly investigated, especially in the presence of intense guide fields. In our work, we analyze the energy conversion and electron heating of electron-only reconnection in the presence of intense guide fields through 2.5D Particle-in-Cell (PIC) simulations. We initialize our setup with a force-free equilibrium and study different cases by adjusting the strength of the out-of-plane guide field Bg (with values of Bg up to 20 times the reconnecting in-plane magnetic field). The electron heating is anisotropic and primarily concentrated along the reconnection separatrices. The width of the heating region on the separatrices is influenced by the strength of the guide field. Non-Maxwellian electron velocity distribution functions are also observed in multiple regions.
References
[1] Biskamp, D. Magnetic Reconnection in Plasmas. Vol. 3. Cambridge University Press, 2000.
[2] Phan, T. D., et al. "Electron magnetic reconnection without ion coupling in Earth’s turbulent magnetosheath." Nature 557.7704 (2018): 202-206.
[3] Shi, Peiyun, et al. "Electron-only reconnection and associated electron heating and acceleration in PHASMA." Physics of Plasmas 29.3 (2022).
