Partially-ionized gases in heavy-ion fusion accelerators

Summary form only given. The role of partially-ionized gas in heavy-ion fusion accelerators is an active topic of research. Of particular concern is the desorption and ionization of neutrals from the walls of the pipe, resulting from stray beam ions in a halo population. We present recent numerical simulation results of partially-ionized gases in heavy-ion fusion devices. We discuss ideas for how models of neutral gas desorption and secondary electron yield needs to change at highly-grazing incidence due to effects such as ion backscattering and varying energy loss rates. Finally, we compare the simulation results with recent experimental results from the High Current Experiment at Lawrence Berkley National Laboratory and Lawrence Livermore National Laboratory.