The Influence of Anode/Target Ion Species on the Magnetically Immersed Diode

The magnetically immersed (B_z) diode [1] is being investigated as a source for pulsed-power driven flash radiography. Experiments fielding this diode have revealed a limit on its achievable current density on target. Either a small spot produces a low dose, or a high dose is achieved with a large spot. It has been proposed that this limit is due to non-protonic ions liberated from the anode surface and subsequently ionizing to higher states [2,3]. The three-dimensional particle-in-cell code LSP [4] is used to investigate this proposal. Data from the recent immersed diode experiments conducted on the RITS-3 accelerator are compared to LSP models of the experimental configuration, including the B_z field map. We report on how the non-protonic and protonic ion models compare to data, and proposals for future investigation.