Method for measurement of transition probabilities by laser-induced breakdown spectroscopy based on CSigma graphs. Application to Ca II spectral lines

We propose a method for determination of transition probabilities by laser-induced breakdown spectroscopy that avoids the error due to self-absorption. The method relies on CSigma graphs, a generalization of curves of growth which allows including several lines of various elements in the same ionization state. CSigma graphs are constructed including reference lines of an emitting species with well-known transition probabilities, together with the lines of interest, both in the same ionization state. The samples are fused glass disks prepared from small concentrations of compounds. When the method is applied, the concentration of the element of interest in the sample must be controlled to avoid the failure of the homogeneous plasma model. To test the method, the transition probabilities of 9 Ca II lines arising from the 4d, 5s, 5d and 6s configurations are measured using Fe II reference lines. The data for 5 of the studied lines, mainly from the 5d and 6s configurations, had not been measured previously.This work has been supported by the project FIS2011-29521 of the Spanish Ministerio de Economía y Competitividad

Experimental Stark widths and shifts of V II spectral lines

We have measured the Stark widths and shifts of V II spectral lines in the wavelength range 2000-4200 Å belonging to 75 multiplets. The spectra are emitted by laser-induced plasmas generated from fused glass discs prepared by borate fusion. The electron density and temperature are in the ranges (0.72-6.5) × 1017 cm-3 and (11 000-14 900) K, respectively. To avoid self-absorption, we have used seven samples with vanadium concentrations selected by the CSigma graph methodology. This has allowed to include strong and weak lines in the study, including resonance and forbidden lines. The experimental widths and shifts are compared with theoretical values available in the literature.Fil: Manrique Rosel, Javier. Universidad CEU San Pablo; EspañaFil: Diaz Pace, Diego Martin. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; ArgentinaFil: Aragón, Concepción. Universidad Publica de Navarra. Departamento de Ciencias.; EspañaFil: Aguilera Andoaga, Jose antonio. Universidad Publica de Navarra. Departamento de Ciencias.; Españ