Modeling of multistage depressed collectors using a 3D conformal finite-difference time-domain particle-in-cell code

Summary form only given. The feasibility of modeling a multistage depressed collector using a conformal finite-difference time-domain particle-incell code has been studied. A feedback mechanism is implemented to provide stable time-dependent voltages for each stage of the depressed collector. An arbitrary space-time dependent spent beam distribution can be given in our time domain simulations. We demonstrate the design of a five stage depressed collector recovering a triangular spent beam distribution achieving an energy recovery efficiency of 70%. Detail modeling and code capabilities will be presented.