Spatial confinement of laser-induced silicon plasma spectroscopy with cylindrical cavity

摘要

In laser-induced breakdown spectroscopy (LIBS), a serious of cylindrical cavities are used to spatially confine the plasmas produced from silicon (Si) target by using a Nd:YAG laser in air. Time-resolved spectrum of Si plasma with different diameters of cylindrical spatial cavities is measured. Compared with the plasmas generated without the confined cavity, the spectral emission intensity of plasma generated with cylindrical cavity is enhanced at a certain delay time. As the diameter of cylindrical cavity increases, the spectral emission is enhanced later in time and the enhancement becomes weaker. The result shows that the presence of the confined cavity leads to an increase in the spectral emission of plasma which is attributed to compressed plasma by the reflected Shockwave.