Measured Stark widths of several spectral lines of Pb III

Abstract

Keywords:Laser-produced plasma Line profile Stark width Atomic data LeadThe Stark full widths at half of the maximal line intensity (FWHM, co) have been measured for 25 spectral lines of Pb III (15 measured for the first time) arising from the 5d 10 6s8s, 5d 10 6s7p, 5d 10 6s5f and 5d 10 6s5g electronic configurations, in a lead plasma produced by ablation with a Nd:YAG laser. The optical emission spectroscopy from a laser-induced plasma generated by a 10 640 Á radiation, with an irradiance of 2 x 10 10 W cm~ 2 on a lead target (99.99% purity) in an atmosphere of argon was analysed in the wavelength interval between 2000 and 7000 Á. The broadening parameters were obtained with the target placed in argon atmosphere at 6 Torr and 400 ns after each laser light pulse, which provides appropriate measurement conditions. A Boltzmann plot was used to obtain the plasma temperature (21,400 K) and published values of the Stark widths in Pb I, Pb II and Pb III to obtain the electron number density (7xl0 16 cm~3); with these values, the plasma composition was determined by means of the Saha equation. Local Thermodynamic Equilibrium (LTE) conditions and plasma homogeneity has been checked. Special attention was dedicated to the possible self-absorption of the different transitions. Comparison of the new results with recent available data is also presented.

Measurement of Laser-Induced Plasma: Stark Broadening Parameters of Pb(II) 2203.5 and 4386.5 Å Spectral Lines

“…When the density of plasma is > 10 15 cm −3 , Stark broadening is predominant, and Doppler effects, Van der Waals broadening, and resonance broadening can be neglected. 28,32,33 In this work, Stark broadening prevails, resulting from the perturbation of the excited levels of the radiating lead atoms due to collisions mainly with the plasma electrons, whereas other broadening mechanisms are negligible. The theoretical FWHM of a Stark broadened line can be used for the determination of Ne using the following equation: 32,33 where ωS(=Δλ12), in Angstrom units, is the FWHM of the transition considered and obtained at the density N e expressed in cm −3 .…”

“…The electron number density, N e (cm −3 ), of the plasmas investigated has been extracted by comparing the ωS(FWHM), in Å, of several lines Pb(I), Pb(II), and Pb(III), and line 4348.1 Å of Ar(II) obtained in this work with those ω exp values (at different temperatures and electron number densities) from other authors that are presented in Table II. 13,24,25,28,44 These electron densities have been estimated to an accuracy of 10–20%; error is essentially due to uncertainties of the used Stark broadening parameters. As already mentioned in obtaining the temperature, different spectral lines have been used in each time delay.…”

“…The experimental setup applied in this work is similar to the LIP system used in previous papers, see Colon and Alonso-Medina 13 and others, 22–29 so only a brief description with an emphasis on new features is given here. The schematic diagram of the experimental system is shown in Fig.…”

Laser-Induced Breakdown Spectroscopy for Determination of Spectral Fundamental Parameters

“…A. Alonso-Medina measured by LIBS the Stark widths of 34 spectral lines of Pb I in 2008 [73] and 25 emission lines of Pb III in 2011 [74]. Plasmas were produced by laser ablation with a Nd:YAG laser on a Sn-Pb alloy (with a Pb content of about 0.5%) and lead target (99.99% purity) in an argon atmosphere.…”

Experimental Determination of Electronic Density and Temperature in Water-Confined Plasmas Generated by Laser Shock Processing

“…This technique has been used in several scientific applications by the authors signing this work. In 2006, Colón and Alonso-Medina [16] measured Stark broadening of several Pb II spectral lines, and in 2011, Alonso-Medina [17] measured the broadening Stark of Pb III spectral lines. The LIBS technique also stands out as an analytical technique in different industrial applications (see, e.g., Noll et al [18]).…”