Three-dimensional Kinetic Simulations of Magnetized Plasma Plumes with Particle-in-cell Method*

The study investigates the physics of magnetized and unmagnetized mesothermal plasma plumes using a fully kinetic particle-in-cell (PIC) code, CHAOS, a highly capable GPU-based solver that uses a MPI-CUDA parallelization strategy.  Recently, the electro-static version of the CHAOS code has been extended to simulate magnetized plasmas. An applied static divergent magnetic field with a topology created by a magnet of radius R_L = 2R₀, and a throat magnetic strength of B₀, where R₀ is the thruster radius, is mapped to the electric field-of trees octree grid to apply the Lorentz force on the charged particles.  The PIC simulations are being used to study electron cooling mechanisms and non-Maxwellian kinetic effects in quasi-neutral expanding plasma plumes with collocated ion and electron sources with initial ion and electron number densities on the order of 10¹⁴ to 10¹⁵ m^-3, and temperatures of 0.03 and 5 eV, respectively.  The evolution of the electron velocity distribution function (EVDF), plasma detachment, and anisotropic electron cooling processes are the primary focuses of the present study.  The talk will discuss the physics of magnetized plasma plumes and improve our understanding of how different collision mechanisms affect electron trapping and plasma detachment processes.