Hello, I am a newbie to Comsol. I am going throught the ion funnel example. I have a few things which I did not understant quite well: 1) In Explicit1, what is the purpose of choosing boundary # 144? 2) why it is "Explicit"? why not union? May be I did not understant well the purpose of "Explicit". 3) The DC voltage is chosen under Electrostatics (es), while the RF is chosen under Electric current (ec) in Terminal1 and Terminal 2. Why not RF also defined under Electrostatics? Is it because RF is time dependent? 4) Again, related to question 3. Why Terminal 1 and Terminal 2 (Physics >Boundaries > Terminal) instead of Electric potential (Physics>Boundaries>Electric potential)? I would like to know the difference between Boundaries Potential and Boundaries Terminal.
Thank you very much.