Accession Number : ADA321620

Title :   A Portable Laser Induced Breakdown Spectrometer for Toxic Metals. Phase 1.

Descriptive Note : Final rept. 24 May-23 Nov 96,

Corporate Author : J AND D SCIENTIFIC INC GAINESVILLE FL

Personal Author(s) : Smith, Benjamin W.

PDF Url : ADA321620

Report Date : 29 NOV 1996

Pagination or Media Count : 17

Abstract : A compact, portable laser induced breakdown spectroscopy (LIBS) system for the detection of lead in soils and paints has been designed and evaluated in the laboratory. Fundamental studies of the temporal, spatial and spectral evolution of the LIB plasma have resulted in an optimized instrument. The system consists of a compact Nd:YAG laser operating at 1 Hz with a 21 mJ output at 1064 nanometers. The laser produces a reliable, reproducible breakdown on all materials that were investigated (soils, painted surfaces, metals, and air). The design includes a CCD array spectrometer which was not available during phase I of the research; therefore, evaluations were conducted with an ungated portable spectrometer and a gated 0.5 m focal length laboratory spectrometer. The signal to noise ratio of the ungated, portable spectrometer is substantially degraded due to the intense background early in plasma formation. The laboratory spectrometer which is gated and has a resolution similar to the proposed portable spectrometer (0.08 nm) yields excellent results. A limit of detection of Pb in paint was 60 micro-g/g for a single shot.

Descriptors :   *PORTABLE EQUIPMENT, *METALS, *TOXICITY, *LASERS, *SPECTROMETERS, YAG LASERS, SPATIAL DISTRIBUTION, OPTIMIZATION, DETECTION, SPECTROSCOPY, PLASMAS(PHYSICS), SIGNAL TO NOISE RATIO, INTENSITY, ARRAYS, SURFACES, SPECTRA, SOILS, EVOLUTION(GENERAL), INSTRUMENTATION, PAINTS, NEODYMIUM, BREAKDOWN(ELECTRONIC THRESHOLD), LEAD(METAL).

Subject Categories : Physical Chemistry
      Inorganic Chemistry
      Lasers and Masers
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE