Accession Number:

ADA475564

Title:

Laboratory Evaluation of Laser-Induced Breakdown Spectroscopy (LIBS) as a New in situ Chemical Sensing Technique for the Deep Ocean

Descriptive Note:

Doctoral thesis

Corporate Author:

WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Personal Author(s):

Report Date:

2007-09-01

Pagination or Media Count:

176.0

Abstract:

Laser-induced breakdown spectroscopy LIBS possesses many of the characteristics required for in situ chemical sensing, and is a promising technique for field measurements in extreme environments. In this work, laboratory experiments validate the LIBS technique in a simulated deep ocean environment to pressures up to 2.76 x 10to the 7th power Pa. A key focus of this work is the validation that select elements important for understanding hydrothermal vent fluid chemistry Na, Ca, Mn, Mg, K, and Li are detectable using LIBS. A data processing scheme that accurately deals with the extreme nature of laser-induced plasma formation was developed that allows for statistically accurate comparisons of spectra. The use of both single and double pulse LIBS for high pressure bulk aqueous solutions is explored and the system parameters needed for the detection of the key analytes are optimized. Using both single and double pulse LIBS, the limits of detection were found to be higher than expected as a result of the spectrometer used in this experimentation. However, the results of this validation show that LIBS possesses the characteristics to be a viable chemical sensing method for in situ analyte detection in high pressure environments like the deep ocean.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE