Spatially and Temporally Resolved Aluminum Laser-Induced Breakdown Spectroscopy Measurements

ORAL

Abstract

Laser-induced breakdown spectroscopy measurements of a laser ablated aluminum sample are analyzed to determine the temporal evolution of aluminum containing plasma from atomic and molecular emissions. These studies facilitate the understanding of key characteristics of plasma/metal interactions. Optical breakdown is initiated by tightly focusing 12 nanosecond pulsed laser radiation onto the surface of an aluminum alloy target. Spatially and temporally resolved emission spectra are recorded with an ICCD. Aluminum atomic emissions at 396.15 and 394.4 nm are used to infer the electron density of the plasma from 0.2 to 1 $\mu $s following optical breakdown. At corresponding time delays, the plasma temperature is determined from aluminum 308.24, 309.27, 394.4 and 396.15 nm emissions using Boltzmann plot methods. At later times, from 4 to 20 $\mu $s following breakdown, atomic hydrogen Balmer series H$_{\mathrm{\alpha }}$ and H$_{\mathrm{\beta }}$ emissions are used to evaluate the electron density. The plasma temperature is further compared with results from fitting to aluminum monoxide emissions superimposed with H$_{\mathrm{\beta}}$ spectra that are recorded for time delays longer than 10 $\mu $s after optical breakdown.

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Authors

  • David Surmick

    University of Tennessee Space Institute

  • Brad Cox

    North Carolnia State University, Vanderbilt University, University of South Carolina, University of Virginia, Francis Marion Univ, Oak Ridge National Laboratory, Massachusetts Institute of Technology, Florida International University, Georgia College, JINR, Tsinghua University, LBNL, GANIL, Austin Peay State University, Lehigh University, University of Pardubice, Universit\'e de Rennes, Austin Peay State University Department of Physics and Astronomy, Oak Ridge National Laboratory, Oak Ridge TN 37831, American Superconductor Corp., Westborough MA 01581, University of North Georgia, Dahlonega GA 30597, Florida State University, Ecole Polytechnique, Space Telescope Science Institute, Fermi National Accelerator Lab, National Optical Astronomy Observatory, Austin Peay State Univerity, North Carolna State University, Florida Intl Univ, University of North Georgia, Clemson University, Clemson Univ, Vanderbilt University/ORNL, Vanderbilt University/Univ. of Kentucky, College of William and Mary, Louisiana State University, Presbyterian College, North Carolina State Univ, Department of Physics, Virginia Tech, Mathematical Institute, University of Oxford, Virginia Tech University, Hollins University, University of Tennessee Space Institute, Davidson College, University of Tennessee, American Superconductor Corporation, University of South Alabama, North Carolina State University, James Madison University, Lousiana State University, Korea Electrotechnology Research Institute, Changwon Korea