A Novel Dispersive Time-Domain Interaction Code for Helix TWT by Collocated Space and Staggered Time Scheme Pseudospectral Analytical Time-Domain Method

Remarkable advantages are achieved by pseudospectral techniques such as pseudospectral analytical time-domain (PSATD) method in numerical simulations. Examples are, but not limited to discretization effects reduction (e.g., numerical dispersion error) and geometrical dispersion consideration. In this paper, a novel well-organized version [a newly presented particle-wave interaction code (PaWaIC)], employing collocated space and staggered time scheme PSATD method is introduced: PaWaIC-PSATD-CSST. Validity of the new code is investigated. It is shown that a more accurate phase velocity is realized by PaWaIC-PSATD-CSST in comparison with PaWaIC-pseudospectral arbitrary order finite-difference time-domain (PaWaIC-PSAOFDTD) code for an identical time step and grid size. The fast single-run capability of this novel code for simulating pulse response of wideband tubes is also presented.