KlyC expansion: Traveling wave module in Klystron simulation code

Since Klystron simulation code KlyC was released in 2017, it has been used for the design of series of high efficiency (HE) Klystron projects. Lots of new features such as coupling mode analysis, monotron diagnosis and complete small signal theory have been implemented into KlyC to facilitate sophisticated Klystron design. Nevertheless, Standing wave (SW) mode pattern is prerequisite condition in the beam-wave interaction analysis in well-established KlyC large signal simulations. In this report, the latest progress on upgrading KlyC by introducing Traveling-wave (TW) module is demonstrated for future analysis on TW or SW/TW hybrid device. It is proved that extended interaction Klystron (EIK) is still based on SW analysis so that for hybrid device development, pure Traveling wave (TW) module implementation is still necessary and essential. TW circuit model is then adopted in terms of the field excitation, based on which 2 types of exemplary TW tubes are simulated in updated KlyC. Benchmark results with CST PIC show that the accuracy could reach 5% level, taking advantage of KlyC's capability to precisely modeling the space charge effects, relativistic effects and radial stratification effects.