Quantitative analysis of vacuum-ultraviolet radiation from nanosecond laser-zinc interaction

Abstract The paper reports measurements of the vacuum-ultraviolet spectral irradiances of a flat zinc target over a wavelength region of 124–164 nm generated by 10 and 60 ns duration low-intensities, 5 × 10 9 - 3 × 10 10  W cm −2 , 1.06 μm wavelength laser pulses. Maximum radiation conversion efficiencies of 2.5%/2 π sr and 0.8%/2 π sr were measured for 60 and 10 ns laser pulses at the intensities of 5 × 10 9 and 1.4 × 10 10  W cm −2 , respectively. Atomic structure calculations using a relativistic configuration-interaction, flexible atomic code and a developed non-local thermodynamic equilibrium population kinetics model in comparison to the experimental spectra detected by the Seya-Namioka type monochromator reveal the strong broadband experimental emission originates mainly from 3d 9 4p-3d 9 4s, 3d 9 4d-3d 9 4p and 3d 8 4p-3d 8 4s, 3d 8 4d-3d 8 4p unresolved-transition arrays of double and triple ionized zinc, respectively. Two-dimensional radiation-hydrodynamics code is used to investigate time-space plasma evolution and spectral radiation of a 10 ns full-width-at-half-maximum Gaussian laser pulse-zinc interaction.