Particle generation by laser ablation during surface decontamination

Abstract

Laser ablation allows significant number of particles to be generated from the surfaces of cement, chromiumembedded cement, stainless steel, or alumina. The number concentrations and size distributions of the particles were experimentally investigated with respect to applied laser fluence (mJ cm −2 ) and wavelength. Based on the measurements, 266-nm laser ablation generates particles most efficiently. Of the three materials tested, cement was the most favorable for material removal, stainless steel was the next, and alumina was the least. The removal of particles from chromium-embedded cement by 532-and 1064-nm-wavelength lasers was less effective than from stainless steel, but more effective than from alumina. For ablation with a 266-nm laser, chromium enhanced the removal above 20 J cm −2 . Comparisons of other characteristics such as the size and removal rate of these particles are also discussed in this paper. ᭧

Particle Generation by Ultraviolet-Laser Ablation during Surface Decontamination

“…[11][12][13]16 Laser ablation can be applied, for example, for decontamination and decommissioning (D&D) of nuclear facilities at U.S. Department of Energy (DOE) complexes across the United States. For D&D applications, previous results 17 showed that laser ablation with an ultraviolet (UV) wavelength (266-nm) pulsed laser was most effective in particle generation compared with that with lasers of other (1064-or 532-nm) wavelengths. In this paper, the authors report, in detail, the production and transformation of particles when the UV laser was used on selected surrogate surfaces: Portland cement (cement) with or without a toxic heavy metal, chromium (Cr), prepared under laboratory conditions, stainless steel 316, and pure alumina (Al 2 O 3 ).…”

Testing Nonthermal Plasma for Decontamination of Sensitive Weapons Platforms and Systems

“…This second source was based on the design of Lin and Cheng (2002), Cheng (2004a and2004b), and Cheng et al (2006) using a laser--induced breakdown instead of pulsed electrical breakdown to generate transition plasma. Note that laser--induced plasma contains higher number (~ 10 19 ) of electrons and ions than that of electrical plasma by one to two orders of magnitude; thus, theoretically, we could provide a more effective plasma source than the electrical power.…”

Generation of metal nanoparticles by laser ablation

“…However, characteristics of particles generated by laser ablation are not fully known. Therefore, the studies of particle concentration and their size distribution are hot topics in current laser ablation investigations recently [1][2][3][4][5][6][7][8][9]. Nanoparticle generation by laser ablation is used for a variety of applications such as biotechnology, electronic industry, etc.…”

“…Nanoparticle generation by laser ablation is used for a variety of applications such as biotechnology, electronic industry, etc. The laser ablation is also an intensive source of submicron particle generation and their possible leakage into ambient air, therefore investigations of the particle formation kinetics in ambient air during laser processing are essential for the evaluation of potential generation of particle emission and their impact on human health [7]. For example, during laser processing particles formed of metals (e. g. iron, aluminium), especially toxic (e. g. manganese, zinc) or carcinogenic substances (e. g. chromium (VI) compounds, nickel), might penetrate into a human organism and cause health concerns [8,9].…”

“…Both the particle concentration and size distribution depend on laser operating parameters such as wavelength, pulse duration, energy, and repetition rate, beam scanning speed [3,7,10,11]. Studies show that experimental conditions during laser ablation could be established in order to control the particle size and distribution [1,3].…”