Progress with DIMOHA for fast time-domain simulations of traveling-wave tubes

Abstract

We presented at previous IVEC conferences a new model for traveling-wave tubes (TWTs). Since then, we used this model to build the DIMOHA algorithm as an alternative to current particle-in-cell (PIC) and frequency domain codes. Its validity is assessed against these codes and against measurements from several TWTs. We present simulations for an 80 watts TWT in Q band presently in development. An industrial version of DI-MOHA is under construction for the design and characterization of TWTs.

Time-Domain non-linear simulations of a 3 meter long traveling wave tube

“…This symplectic algorithm [11] is written in modern Fortran and parallelized with the Message Passing Interface (MPI) libraries. DIMOHA bears several advantages, including a its grand versatility, as it supports any periodic slow wave structure and as it has been tested and validated for a large range of industrial TWTs of different geometries and types [12,13], and a relatively small computing cost as well as a small number of input parameters requirement. It is the discrete method used in our model that enables DI-MOHA to be much faster than PIC codes : electromagnetic fields are decomposed on space cells of the size of the helix pitch (more generally, the length of the periodic structure cell).…”