Emission signal enhancement and plasma diagnostics using collinear double pulse for laser-induced breakdown spectroscopy of aluminum alloys

A time and spatially resolved technique was used for the investigation of emission signal enhancement in collinear double- pulse LIBS. Two Q-switched Nd:YAG lasers at 1064 nm wavelength have been employed to produce laser-induced plasmas on aluminum-based alloys by single- (SP) and double-pulse (DP) LIBS. Time and spatial evolution of the plasma temperature and electron number density was investigated in these two experimental schemes. The enhancement of the emission line intensities was investigated, and a relation between the increases in intensity and excitation energy level was established. The results shows that the production of the second plasma by second laser pulse was important in DP experiment in collinear geometry.