A spectroscopic study of laser ablation plasma from Mo target

The goal of this contribution is to present time-resolved optical spectroscopy studies of laser ablation of the Mo target with similar to 3.5 ns, 0.4 J pulses delivered by the Nd-YAG laser system at 1.06 mu m. The sample was placed in a vacuum chamber under 5x10(-5) mbar pressure and irradiated, with power densities varied up to 22.7 GW cm(-2). The ion emission from the plasma plume was measured using an electrostatic ion energy analyzer (IEA) and ion collector, which allowed us to estimate the ion kinetic energy and charge independent of the applied power densities. The signal collected by the IEA indicated the presence of molybdenum ions up to eight-ion charge. Simultaneously after the ion emission, the optical spectra acquired within 2 mu s of exposure time were observed in the wavelength range from 200 to 1000 nm with a Mechelle 5000 spectrometer equipped with an iCCD (iStar) detector. The plasma electron temperature was estimated from a Boltzmann plot based on the registered spectra as well as from the ion measurements.