Hybrid iterative approach for simulation of radio-frequency fields in plasma

A novel iterative approach for solving discretized linear wave equations in frequency domain, which combines time evolution with iterative relaxation schemes, is presented. In this hybrid approach each iteration cycle consists of evolution of the electromagnetic (EM) fields in time over specified number of field periods followed by several iterative relaxations. Provided that there is sufficient dissipation, both the time evolution and the iterative relaxations contribute to the convergence of the EM fields to the solution of the formulated full wave boundary value problem. Time evolution rapidly distributes EM fields, propagating with group velocity, over simulation domain, while the iterative relaxations smooth the fields reducing the numerical errors such that iteration cycles converge to a steady state solution approximating the solution of the formulated problem. This approach is intended for large scale simulations which are beyond the capabilities of direct solvers presently used for solving wave equations in frequency domain. Formulation of the hybrid iterative approach and its application to cold plasma modeling of RF beam in ECR frequency range for realistic tokamak parameters, will be presented.