I have a problem, something that I should know but slipped through the cracks. I have posted this in another thread but I will re-post it here in truncate. the other thread is https://www.physicsforums.com/showthread.php?t=185203 (I hope I referenced this right.) anyway I do not intend to duplicate the same questions but I have questions more appropriate to ask in an engineering forum. Here is the question: If a particle is accelerated within a field it will have the energy imparted on it to the proportion of the potential of the field. This field (of which I see as static) is removed before the particle reaches the plate accelerating it. It then passes through a hole in the plate. How is the energy in the field dissipated? By what method does current flow from the cathode to the anode thus completing the circuit and allowing energy to be consumed? Like I said it seems to be static to me and thus no energy is used to accelerate the particle. I could just assume that the field will be damped and go on with life but I can no longer take it! My second question is also to satisfy my curiosity:(edit) but it was a retarded question.