Magnetic confinement of plasmas in laser-induced breakdown spectroscopy for improving sensitivity and accuracy

Effects of magnetic fields with different intensities on laser-induced plasmas were investigated. Plasmas were formed in air by KrF eximer laser ablation of graphite (C), copper (Cu) and lead targets (Pb). Transverse magnetic fields were applied to the plasmas using two permanent magnets. Optical signals from the plasmas were collected both by an ultrafast phototube and an optical multi-channel analyzer (OMA) system. The full width at half maximum (FWHM) of the signals captured by an oscilloscope connected to the phototube were taken as a measure of the plasmas lifetimes. Time-resolved spectra captured by the OMA system were analyzed to observe the decay of specific spectral lines of the ionic forms of C, Cu, and Pb. The results were analyzed to gain an understanding of the relationship between magnetic confinement of laser-induced plasmas and the atomic masses of the substrate materials.