• hybrid models
• landau fluid closure
• plasma physics
• simulations

Plasma waves and instabilities at ion and/or electron scales play a fundamental role in plasma dynamics. Alongside direct high-resolution measurements, numerical simulations play a key role in modeling these waves/instabilities so that the choice of an adequate plasma model is crucial. Since full kinetic models are computationally very demanding. reduced models, such as hybrid models, are needed. The project focus on the validation of the Hybrid-Vlasov-Landau Fluid (hereafter HVLM) model, in which the ions are fully kinetic and the electrons are treated as an anisotropic fluid on which equations a Landau-fluid closure is applied. The model has been developed in collaboration between the Laboratoire Lagrange (OCA, Nice, France) and University of Pisa (Pisa, Italy). Differently from the standard Hybrid models (also called Hybrid-Vlasov-Maxwell, hereafter HVM, where ions are full-kinetic and electron are modeled as a massless fluid with polytropic closure), the HVLF model allows one to observe electrons effects that are relevant at the ion scale, such us the electron Landau damping, and that would not be observed using a polytropic closure on electrons. Moreover, this model describes fluid and kinetic instabilities driven by electron temperature anisotropy. The HVLF model is validated through the study of three plasma waves/instability: (a) the Kinetic Alfven waves, (b) the firehose instability and (c) the mirror instability.