Unconditionally Stable CFS-PML Based on CNAD-BOR-FDTD for Truncating Unmagnetized Plasma

The unconditionally stable complex frequency-shifted perfectly matched layer (CFS-PML) based on Crank-Nicolson approximate decoupling is introduced to the body of revolution finite-difference time-domain for truncating unmagnetized plasma. The proposed algorithm not only removes the Courant-Friedrichs-Lewy stable constraint, but also saves much CPU time. Its implementation takes advantage of the auxiliary differential equation method for the CFS-PML and the trapezoidal recursive convolution method for unmagnetized plasma. A numerical test is provided to confirm the effectiveness of the proposed algorithm in the two-dimensional cylindrical grids. The results show that the proposed PML for truncating plasma is efficient in attenuating the low-frequency evanescent waves and reducing the late-time reflections.