Modeling lithium plasma formation by laser ionization based on resonance saturation (LIBORS) and implications for extreme-current ion sources

Summary form only given, as follows. Key issues for light ion beam fusion are decreased ion beam divergence with increased ion beam current density. A satisfactory ion source for these kA/cm/sup 2/ beams is essential, and we are studying active lithium sources where an independent energy source is used to pre-form a lithium plasma against the anode. We are developing a comprehensive computer code for investigating lithium plasma formation by laser ionization based on resonance saturation (LIBORS) in the presence of large density gradients. In our computer code, a system of time-dependent rate equations, which couples the detailed atomic model with the external radiation field (laser) is solved self-consistently to predict the rapidly-changing ionization characteristics of the lithium vapor. In particular, 1-D effects will be studied in detail, and time-dependent spectroscopy information will be provided so that the theoretical predictions can be compared with the results of spectroscopy measurement. Details of the physical model and the results will be reported.