B-field interactions and electrode optimization in the plasma electrode Pockels cell

We use a 32 cm plasma electrode Pockels cell (PEPC) prototype at Lawrence Livermore National Laboratory to determine switching performance in the presence of external magnetic fields. The interaction with external magnetic fields is important because of the B-fields generated by the high current flow through amplifier flashlamp arrays, and their proximity to the PEPC. We have experimentally determined what is the maximum allowable magnetic induction for good PEPC operation, and then we calculate the magnetic induction generated by a flashlamp array to determine the minimum PEPC to amplifier spacing. We have also experimentally determined the effect of a tandem PEPC placement. We consider several cathode designs. We revisit the hollow cathode design and we investigate the tradeoffs between the hollow cathode and planar magnetron. The recent development of a metallic body for the future 1 X 2 PEPC has led us to do experiments with a biased boundary in the PEPC. Experimental results of various biasing potentials and dielectric coating materials for the PEPC body are discussed.