Hybrid Kinetic Method for Mixed-Collisional Plasma Flows with Sharp Gradients

We propose the development of an advanced software tool to model a broad spectrum of plasma ap-plications ranging from high energy density relativistic laser-matter interaction and pseudospark dis-charge to plasma plume expansion in vacuum. The Hybrid Kinetic method is a combination of Rela-tivistic Maxwell-Vlasov, Poisson-Boltzmann and Mixed-Collisional solvers. The core of the kinetic method is specifically designed to capture self-consistent evolution of strongly non-equilibrated gas and plasma flows with sharp gradients. Our approach combines unstructured adaptive grids for fine spatial resolution, a PIC-Vlasov hybrid for guaranteed velocity space coverage, a Boltzmann solver to treat various elastic and inelastic collisions, and a kinetic-fluid interface for mixed-collisional flows. The method has the following distinct features: adaptive high resolution mesh in space; adaptive time stepping; automatic tracking of discontinuities and regions of high spatial gradients; non-orthogonal adaptive elements to allow complex device geometry and large domains; low numerical noise and diffusion particle-mesh combination; high order finite-volume schemes for fields; non-Monte-Carlo procedures for accurate treatment of various collisions on the velocity grid; a unique interface con-necting non-equilibrated kinetic and equilibrated fluid regions; use of analytical solutions for trajecto-ries and collisions to assure stability and accuracy. The parallel hybrid code will be written with a transparent interface for easy porting with other codes, thus complementing non-kinetic techniques.