BOLVAPS/LIBORS lithium source experiments on PBFA-II

Summary form only given. BOLVAPS/LIBORS experiments have as a goal the development of a preformed lithium anode plasma layer from which a focusing ion beam can be generated immediately upon arrival of the generator power pulse. Lithium plasmas with average electron densities of >2×10¹⁶ cm^-3 and 2-mm thickness have been made using BOLVAPS/LIBORS on small-scale films on polished alumina substrates. To scale up this Li source to PBFA-II parameters, techniques were developed to manufacture thin films onto the 15-cm-radius anode (1000 cm²) used in the PBFA-II applied Bz diode. New applied B coils were built and a new diagnostics package designed. Open-shutter photographs taken during offline tests indicate uniform heating of the anode surface from the 20-ms preheat pulse. Initial PBFA-II machine tests using the new coils and diagnostics package, but with a proton-producing anode instead of the LiAg surface, have produced good ion beam performance (7 MV, 3 MA, 700 kJ coupled to diode)