High-resolution spectroscopy of laser-produced L-shell molybdenum plasma.

Abstract

A wide variety of spectroscopic methods are used for the diagnostics of laser-produced plasma. One particularly powerful diagnostic is high-resolution emission line spectroscopy, in conjunction with atomic calculations and radiation hydrodynamic simulations. In this work, we present line-resolved spectra of L-shell molybdenum (Z=42) plasma produced by high-energy laser pulses of ∼200-400 J at a wavelength of 351 nm, with durations of 1-3 ns. The experiments were conducted at the National Laser Facility, Soreq, Israel. Time-integrated spectra were recorded in the range of 2 to 4.1 keV with a high-resolution crystal spectrometer (E/ΔE>400). Lines of Al-like Mo^{+29} to F-like Mo^{+33} were identified, although the spectrum is dominated by the intense Ne-like Mo^{+32} lines. Collisional-radiative calculations using the HULLAC and nomad codes are in good agreement with the experimental results, providing estimates of an electron density of n_{e}=0.6-3×10^{21}cm^{-3} and an electron temperature of kT_{e}=1.1-1.3keV originating from the coronal region of the plasma.