To get your head around what I am getting at here, the structure is a vertical column and I'm doing multiple simulations stacked on an ever growing inductive column. Because the loop gain goes up and phase changes as you climb the structure then or two things happen. You either get part of it oscillating (the top bit) Or if it has strong feedback then more cells lower down kick off as well but at a slightly higher frequency. So you get a chaotic chorus of electrons? Is this feasible? I don't really do particle physics so I run out of road at this point... But my guess is you can't treat this oscillation condition the same as regular amplification. I think there will be multiple events within parts of the structure spread over several MHz generating high RF voltages if the phases all combine at the common anode cap.