PIC simulations of extraction geometry B-diodes

Summary form only given, as follows. Experimental programs at Los Alamos for intense diagnostic neutral beams and for the thin-film deposition require efficient operation of extraction geometry B-ion diodes. Multidimensional particle-in-cell (PIC) calculations have been used to model beam formation and acceleration in the magnetically insulated diodes, as well as beam transport in the extraction section. Beam transport is facilitated by space-limited electron flow due to emission from the extractor walls. The emission is caused by ion beam self-fields. The effect of magnetic field strength and morphology on ion current and radial profiles has been studied. Divertor configurations to control electron sheath characteristics have also been investigated.