title: Characterization of laser-induced plasmas associated with energetic laser cleaning of metal particles on fused silica surfaces.
abstract: Time-resolved plasma emission spectroscopy was used to characterize the energy coupling and temperature rise associated with single, 10-ns pulsed laser ablation of metallic particles bound to transparent substrates. Plasma associated with Fe(I) emission lines originating from steel microspheres was observed to cool from >24,000 to ~15,000 K over ~220 ns as τ(-0.28), consistent with radiative losses and adiabatic gas expansion of a relatively free plasma. Simultaneous emission lines from Si(II) associated with the plasma etching of the SiO(2) substrate were observed yielding higher plasma temperatures, ~35,000 K, relative to the Fe(I) plasma. The difference in species temperatures is consistent with plasma confinement at the microsphere-substrate interface as the particle is ejected, and is directly visualized using pump-probe shadowgraphy as a function of pulsed laser energy.
authors.forename: Candace D
authors.initials: CD
authors.lastname: Harris
authors.forename: Nan
authors.initials: N
authors.lastname: Shen
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Rubenchik
authors.forename: Stavros G
authors.initials: SG
authors.lastname: Demos
authors.forename: Manyalibo J
authors.initials: MJ
authors.lastname: Matthews