Laser-driven hydrothermal process studied with excimer laser pulses

Journal Article · Mon Aug 21 00:00:00 EDT 2017 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4999306· OSTI ID:1458622

Mariella, Raymond ^[1]; Rubenchik, Alexander ^[1]; Fong, Erika ^[1]; Norton, Mary ^[1]; Hollingsworth, William ^[1]; Clarkson, James ^[2]; Johnsen, Howard ^[3]; Osborn, David L. ^[3]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2. Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Engineering
3. Sandia National Lab. (SNL-CA), Livermore, CA (United States)

Previously, we discovered [Mariella et al., J. Appl. Phys. 114, 014904 (2013)] that modest-fluence/modest-intensity 351-nm laser pulses, with insufficient fluence/intensity to ablate rock, mineral, or concrete samples via surface vaporization, still removed the surface material from water-submerged target samples with confinement of the removed material, and then dispersed at least some of the removed material into the water as a long-lived suspension of nanoparticles. We called this new process, which appears to include the generation of larger colorless particles, “laser-driven hydrothermal processing” (LDHP) [Mariella et al., J. Appl. Phys. 114, 014904 (2013)]. Now, we report that we have studied this process using 248-nm and 193-nm laser light on submerged concrete, quartzite, and obsidian, and, even though light at these wavelengths is more strongly absorbed than at 351 nm, we found that the overall efficiency of LDHP, in terms of the mass of the target removed per Joule of laser-pulse energy, is lower with 248-nm and 193-nm laser pulses than with 351-nm laser pulses. Given that stronger absorption creates higher peak surface temperatures for comparable laser fluence and intensity, it was surprising to observe reduced efficiencies for material removal. We also measured the nascent particle-size distributions that LDHP creates in the submerging water and found that they do not display the long tail towards larger particle sizes that we had observed when there had been a multi-week delay between experiments and the date of measuring the size distributions. This is consistent with transient dissolution of the solid surface, followed by diffusion-limited kinetics of nucleation and growth of particles from the resulting thin layer of supersaturated solution at the sample surface.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
• Sponsoring Organization: USDOD Defense Threat Reduction Agency (DTRA); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Contributing Organization: U.S. Geological Survey, Menlo Park, CA (United States)
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 1458622
• Report Number(s): LLNL-JRNL--698703; 829464
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 122; ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
chemical analysis
chemical compounds
gemstones
lasers
metalloids
metamorphic petrology
solid surfaces
thermodynamic processes