SPACE AND TIME-RESOLVED LASER-INDUCED BREAKDOWN SPECTROSCOPY USING CHARGE-COUPLED-DEVICE DETECTION

Space and time-resolved studies of laser induced plasmas in air at atm ospheric pressure are presented. Photovoltaic solar cells have been us ed as samples. The second harmonic (532 nm) of a Nd:YAG laser at an ir radiance of 18 x 10(12) W/cm(2) has been used. The precise focus of th e beam allows a microanalysis at a 0.02 mm(2) surface area working in single-shot mode. The use of an intensified charge-coupled device (CCD ) detector has allowed time-resolved studies in both imaging or spectr oscopy modes. The two-dimensional capability of the CCD has enabled th e study of atomic and ionic species distribution along the plume. Most data have been recorded using single-laser shot experiments. Spectral lines have been assigned to transitions in atomic components of the m aterial under investigation in the neutral or ionic states of the corr esponding atoms. Effects of delay in improving spectral resolution and some examples of spectral characterization of species as a function o f its decay are shown.