New Version of “PaWaIC” Helix-TWT Particle-Wave Interaction Code Based on Pseudospectral Analytical Time-Domain Technique With Collocated Space and Time-Marching Scheme: “PaWaIC-PSATD-CSaT”

Pseudospectral solvers (i.e., demonstrating equations in spatial Fourier domain) have extraordinary accuracy that makes them attractive in numerical modeling research. In this paper, we introduce a new and efficient version of recently introduced code “PaWaIC” based on pseudospectral analytical time-domain implementation named “PaWaIC-PSATD-CSaT. ” This new code is validated by a traveling wave tube product measurement results and the previous version code “PaWaIC-PSAOFDTD” (with pseudospectral arbitrary-order accurate temporal and spatial derivatives finite-difference time-domain technique). We show that for a unique grid cell size and time step length, the new code PaWaIC-PSATD-CSaT realizes the phase velocity of the tube better than the earlier version PaWaIC-PSAOFDTD while still has a fast simulation time. As well, we demonstrate the ability of the new code for pulse amplification response of wideband tubes by a single-run simulation.