A laser-produced lithium ion source for pulsed-power inertial confinement fusion

We are investigating direct laser-produced plasmas as an ion source for the PBFA II pulsed power accelerator. Laser-generated plasmas have several potential advantages for this application, including the ability to generate a pre-formed anode plasma, simplicity, and flexibility. Previous experiments have shown that a high-density lithium plasma can be produced by direct laser irradiation of a solid lithium surface with a pulsed dye laser tuned to the Li 1s-2p resonance line at 670.8 nm (Laser Ionization Based On Resonant Saturation - LIBORS). We are also investigating a two-step approach, which uses a short-pulse Nd:YAG laser to efficiently vaporize the lithium-bearing source material, followed by LIBORS ionization of the evolving vapor to produce plasmas of mid-10¹⁶/cm³ densities.