Standoff Detection of Geological Samples of Metal, Rock, and Soil at Low Pressures Using Laser-Induced Breakdown Spectroscopy

Abstract

Categorized certified reference materials simulating metal, rock, soils, or dusts are used to demonstrate the standoff detection capability of laser-induced breakdown spectroscopy (LIBS) at severely low pressure conditions. A Q-switched Nd:YAG laser operating at 1064 nm with 17.2-50 mJ energy per pulse was used to obtain sample signals from a distance of 5.5 m; the detection sensitivity at pressures down to 0.01 torr was also analyzed. The signal intensity response to pressure changes is explained by the ionization energy and electronegativity of elements, and from the estimated full width half-maximum (FWHM) and electron density, the decrease in both background noise and line broadening makes it suitable for low pressure detection using the current standoff LIBS configuration. The univariate analyses further showed high correlation coefficients for geological samples. Therefore, the present work has extended the current state-of-the-art of standoff LIBS aimed at harsh environment detection.

Shock wave plasma generation in low pressure ambient gas from powder sample using subtarget supported micro mesh as a sample holder and its potential applications for sensitive analysis of powder samples

“…More than one billion people, particularly children and pregnant women suffer from Zn deficiency related health problems in Asia [7,8]. These pulverized powder samples are commonly mixed with some binding materials such as an epoxy [9][10][11][12][13][14][15][16] and pressed into pellets for laser ablation in LIBS. However, this common technique of powder sample preparation is known to give rise to the problem of matrix effect which complicates the spectral analysis [17,18].…”

Rapid detection and identification of rocks and minerals by laser‐induced breakdown spectroscopy

“…Spectroscopy technique, such as quartz-enhanced photoacoustic spectroscopy (QEPAS), light-induced thermoelastic spectroscopy (LITES), and laser-induced breakdown spectroscopy (LIBS), has the advantages of high sensitivity, noncontact measurement, real-time in situ, and can be apply in the exploration in the outer space. [6][7][8][9][10][11][12][13] LIBS is a remote and real-time detection 7,10,[14][15][16] suitable for geological exploration both on earth and outside earth. In the process, laser pulses hit the sample surface, turning the material on the sample surface into a plasma.…”

Spectral filtering method for improvement of detection accuracy of Mg, Cu, Mn and Cr elements in aluminum alloys using femtosecond LIBS

“…Its advantage of enabling microdestructive testing and multi-element analysis have made it popular in recent decades. The elemental analysis technology of LIBS has been widely used for applications in food safety, 1,2 industrial testing, 3–5 geological correlation analysis, 6,7 environmental quality monitoring, 8–10 cultural heritage, 11,12 materials science, 13 biomedicine 14 and many other fields. Related basic research in LIBS has been continuously advancing.…”