Electrostatic time-domain PIC simulations of RF density-modulated electron sources with MICHELLE
There is a significant level of effort by SAIC and BWR, funded by ONR & JTO, to enhance the three dimensional (3D) finite-element (FE) electrostatic time-domain (ESTD) particle-in-cell (PIC) code MICHELLE to provide modeling and simulation of the interaction of electron emission sources in the presence of electromagnetic cavity fields. These enhancements have direct importance to the free-electron laser (FEL) based high-energy laser community, providing the capability of modeling advanced photo-emission RF electron guns and the input cavity of high-power UHF inductive output tubes (IOT), both of which are needed for the FEL injector. We will discuss these code modifications, enhancements to our emission models, recent results of benchmarking against electromagnetic codes, as well as the limitations to the model.