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Abstract
Laser-induced breakdown spectroscopy (LIBS) is a recent
Development in atomic emission spectroscopy (AES), in which a
high-powered laser is used as the excitation source . The
versatility and simplicity of the technique gives it advantages
over more conventional methods of AES, particularly
for field-based applications .
This thesis is a quantitative study of the analysis of iron
ore by LIBS. A computer-controlled spectrometer to measure the
LIBS spectra of ores was designed and constructed. The laser induced
plasmas were characterized in terms of their appearance,
spectra and electron temperature and density profiles . The
plasmas have lifetimes of several microseconds, and by using
temporally-resolved spectroscopy the line-to-background ratios of
the spectra were significantly improved. The optimum period in
the plasma lifetime for spectro-chemical analysis was determined .
Calibration curves were produced for calcium, silicon, magnesium,
aluminium and titanium in iron ore. The precision and detection
limits of the technique were calculated, and the effects of
experimental conditions on the calibration were determined.