Mass quadrupole spectrometry for infrared laser-generated plasmas detection

A nanosecond pulsed Nd:YAG laser, operating at the fundamental wavelength of 1064 nm and at an intensity of about 10^10 W/cm^2, was employed to irradiate the Cu0.4W0.6 metallic alloy and the relative pure components (Cu and W) in vacuum to investigate about the ablation. Produced plasmas were characterized in terms of thermal and Coulomb interactions evaluating the equivalent temperatures and acceleration voltages developed in the non-equilibrium plasma core. The particles emission, produced along the normal to the target surface, was investigated by measuring, with the special electrostatic mass quadrupole spectrometer Hiden EQP 300, neutral and ion energy distributions and fitting experimental data with the “Coulomb-Boltzmann-shifted” function. Results indicated that the metal alloy stoichiometry, in a first approximation, is well transported to the ion and neutral stoichiometry of the plasma.