7 research outputs found

    Measured Stark widths of several spectral lines of Pb III

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    The Stark full widths at half of the maximal line intensity (FWHM, ω) have been measured for 25 spectrallines of PbIII (15 measured for the first time) arising from the 5d106s8s, 5d106s7p, 5d106s5f and 5d106s5g 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 Å radiation, with an irradiance of 2 × 1010 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 Å. 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 Starkwidths in Pb I, Pb II and PbIII to obtain the electron number density (7 × 1016 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

    Transition probabilities of 30 Pb II lines of spectrum obtained by emission of a laser-produced plasma

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    Transition probabilities have been determined for 30 lines of Pb II by measuring the intensities of the emission lines of a laser-produced plasma (LPP) of Pb in an atmosphere of Ar. The plasma has been seen to contain local thermodynamic equilibrium (LTE) and homogeneity; the plasma studied has a temperature of 11 500 K and an electron density of 1016 cm−3. The experimental results obtained during this study have been compared with the experimental and theoretical values given by other authors

    A spectroscopic study of the plasma generated in a thallium arc. Transition probabilities for several lines of Tl I

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    The optical emission spectra (2000–15 000) A of a plasma produced an a Tl arc lamp have been recorded and analysed; using the series nd 2D3/2`5/2 → 6p 2P Q3/2 and ns 2SL/2 → 6p 2P Q3/2 we have obtained that the electron density is of the order of 10L4 cm−3 and the excitation temperature is (2880 ± 50) K. Relative transition probabilities for 26 lines from excited levels near the ionization limit of Tl I have been determined from line intensities

    A Spectroscopic study of laser-induced Tin-Lead plasma: transition probabilities for spectral lines of Sn I

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    In this paper, we present transition probabilities for 97 spectral lines of Sn I, corresponding to transitions n(n = 6,7,8)s → 5p2, n(n = 5,6,7)d → 5p2, 5p3 → 5p2, n(n = 7)p → 6s, determined by measuring the intensities of the emission lines of a Laser-induced breakdown (emission) spectrometry (LIBS). The optical emission spectroscopy from a laser-induced plasma generated by a 10 640 Å radiation, with an irradiance of 1.4 × 1010 Wcm− 2 on an Sn–Pb alloy (an Sn content of approximately 20%), in vacuum, was recorded at 0.8 µs, and analysed between 1900 and 7000 Å. The population-level distribution and corresponding temperature were obtained using Boltzmann plots. The electron density of the plasma was determined using well-known Stark broadening parameters of spectral lines. The plasma under study had an electron temperature of 13,200 K and an electron number density of 2 × 1016 cm− 3. The experimental relative transition probabilities were put on an absolute scale using the branching ratio method to calculate Sn I multiplet transition probabilities from available radiative lifetime data of their upper states and plotting the Sn I emission spectrum lines on a Boltzmann plot assuming local thermodynamic equilibrium (LTE) to be valid and following Boltzmann's law. The LTE conditions and plasma homogeneity have been checked. Special attention was paid to the possible self-absorption of the different transitions. The experimental results obtained have been compared with the experimental values given by other authors
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