Experimental study of unresolved transition arrays in laser-produced plasmas: Application to plasma diagnosis

The spectra of multicharged ions produced by laser irradiation of high-Z materials have been obtained for a large number of elements at the LULI laser facility using 0.53 µm laser wavelength and 10¹³-10¹⁵ W/cm² laser intensities. Measurements of the electron density and temperature have been performed in laser-irradiated gold targets using Stark broadening and relative intensities of H-like and He-like lines of aluminum mixed in gold with various dilutions. Gold transition array intensities were found in good agreement with the results of a detailed collisional-radiative model of Ni-like ion emission. A study of the position and intensity of the emission regions of He-like and H-like (Al) and Ni-like (Au) ions with increasing gold percentage show a steepening of the electron temperature gradient in agreement with 1D hydrocode calculations including radiation transport physics.