Hello,

I am simulating Wakefields/impedances of some accelerator components like taper transitions, cavity like structures and some others. I heard that indirect test beam method yields more accurate result than direct one. Is it true? If so, how can I simulate more accurately the wakefields produced by tapered structure? Can I add some PEC material at both ends to make cavity like structure?

The manual says if the cross sections at both ends are same we should be able to use indirect test beam method however in some cases, I could not use indirect test beam method though their cross section where the beam enters and leaves are same (see the following screen shot image).

Would you mind sharing your views based on your simulation experience about these issues? Thank you in advance for your answer.