Bridging hybrid- and full-kinetic models with Landau-fluid electrons: magnetic reconnection

Francesco Finelli

Magnetic reconnection (MR) plays a fundamental role in plasma dynamics under many different conditions. Alongside direct measurements, numerical simulations play a key role in investigating this process. Thus, the choice of an adequate plasma model is crucial. We consider a new hybrid plasma model that includes a refined electron response. To test its capabilities, we perform 2D simulations of MR with moderate guide field using three models: a hybrid model with isotropic and isothermal electrons, a hybrid model with anisotropic electrons equipped with a Landau-fluid closure, and a full-kinetic one. The second (new) model effectively reproduces the main features of MR, including several aspects of the electron micro-physics. Anisotropy driven instabilities play a relevant role in regulating electrons anisotropy. As expected, the new model captures all these features, except for the electron-cyclotron instability. Ongoing research is about how the new model performs with 3D MR.

Related paper: https://arxiv.org/abs/2101.00040