[en] As part of the Dual Axis Radiography Hydrotest Facility, Phase II (DARHT II) multipulse Bremsstrahlung target, we have been performing an investigation of (1) the possible adverse effects of backstreaming ion emission from the Bremsstrahlung converter target and (2) maintaining sufficient target density to ensure dose in latter pulses. Theory predictions show that the first effect would primarily be manifested in the static focusing system as a rapidly varying x-ray spot. From experiments performed on ETA-II, we have shown that the first effect is not strongly present when the beam initially interacts with the target. Electron beam pulses delivered to the target after formation of a plasma are strongly affected, however. Secondly, we have performed studies of the effect of the time varying target density on dose and seek to demonstrate various techniques for maintaining that density. Measurements are presented of the target density as a function of time and are compared with our hydrodynamic models