Experimental and theoretical investigations of 2-D vacuum power flow

Simulations of vacuum electron flow in a coaxial transmission line with and without ion emission are compared with each other and with experimental data from Gamble II. The simulation without ions shows large current losses just downstream of an impedance discontinuity. Simulations with ions show that the vacuum electron current past the impedance discontinuity is increased by the presence of ions. The losses are much more distributed than in the simulation without ions. The experimental data shows a more distributed current loss that is similar to the case where ion emission is allowed. This suggests that ions may be present and playing a role in the experiment.