Double-pulse laser-induced breakdown spectroscopy with liquid jets of different thicknesses.

Double-pulse laser-induced breakdown spectroscopy of magnesium in water has been performed with different jet thicknesses. A Meinhard nebulizer has been used to create a jet of 0.3-mm diameter, whereas a homemade liquid jet injector produced a thicker jet of 1.0-mm diameter. The relationship of line intensity to delay time between the two laser pulses for these two jets is compared and discussed. The limits of detection in these two jets are also determined and compared. The line intensity observed from the double-pulse measurement is correlated with the measured electron density calculated with the Halpha line. Also, the behavior of plasma density relative to time delay between the lasers is described.