Laser formation of lithium plasma ion sources for applied-B ion diodes on the PBFA-II accelerator

An active ion source, LEVIS (Laser Evaporation Ion Source), using a short pulsed Nd laser (1.06 m, 8ns) to form a thin Li vapor layer and a tuned dye laser (670.8nm, μsec) for ionization is being developed at Sandia. The LEVIS process has been developed and characterized in the laboratory. Initial experiments using these ion sources on PBFA-II produced ion beams with a low fraction of lithium ions and with low voltages. Recent experiments using improved distribution optics and anode cleaning techniques are described.