Laser-induced fluorescence imaging of laser-ablated barium

Abstract
We have applied laser-induced fluorescence diagnostics to expanding recombining barium plasmas produced by laser ablation. For relatively modest ablation laser energy fluences (∼102–103 W cm−2), we have measured neutral barium leading edge density gradients of 1012–0.5×1013 cm−3 cm−1 and cloud expansion velocities of ∼106 cm s−1, consistent with recent results of ablation studies in copper [R. J. von Gutfeld and D. W. Dreyfus, Appl. Phys. Lett. 54, 1212 (1989)].