Inclusion of non-ideal effects in 3-D PIC simulations of ion diodes

Summary form only given. The 3-D particle-in-cell code QUICKSILVER has been used extensively to simulate ion diodes. These simulations use an idealized setup; perfectly azimuthally-symmetric geometric and applied magnetic field, electrons incident on the anode are simply removed from the system, and the entire anode emission region emits only a single ion species directly from the physical surface throughout the simulation. Results from SABRE experiments exhibit significant differences with such "ideal" simulations. First, the beam has a time-dependent composition; early in time it is mostly the desired Li/sup +/ ions, but these are rapidly replaced by protons and C/sup +n/ (the "parasitic load"). Second, the diode impedance drops rapidly after peak lithium beam power. Third, there are substantial current losses in the diode (i.e. current not carried by the ion beam).