Atomic transitions for the doubly ionized argon spectrum, Ar III

We present new experimental atomic transition values for the atomic emission spectrum of doubly ionized argon, Ar III. In this work we studied 3s23p4 — 3s23p33d, 3s23p4 — 3s23p34s , 3s23p4 — 3s23p34d, 3s23p4 — 3s23p35s, 3s23p33d — 3s23p34p, and 3s23p34s — 3s23p34p transition arrays and 196 lines were identified as new atomic transitions between levels of these configurations. The experimental data were obtained from a capillary-discharge tube. The identifications are supported by multiconfiguration Hartree-Fock relativistic calculations.Centro de Investigaciones ÓpticasFacultad de Ciencias Astronómicas y Geofísica

Atomic transitions for the doubly ionized argon spectrum, Ar III

We present new experimental atomic transition values for the atomic emission spectrum of doubly ionized argon, Ar III. In this work we studied 3s23p4 — 3s23p33d, 3s23p4 — 3s23p34s , 3s23p4 — 3s23p34d, 3s23p4 — 3s23p35s, 3s23p33d — 3s23p34p, and 3s23p34s — 3s23p34p transition arrays and 196 lines were identified as new atomic transitions between levels of these configurations. The experimental data were obtained from a capillary-discharge tube. The identifications are supported by multiconfiguration Hartree-Fock relativistic calculations.Centro de Investigaciones ÓpticasFacultad de Ciencias Astronómicas y Geofísica

Atomic transitions for the doubly ionized argon spectrum, Ar III

We present new experimental atomic transition values for the atomic emission spectrum of doubly ionized argon, Ar III. In this work we studied 3s23p4 — 3s23p33d, 3s23p4 — 3s23p34s , 3s23p4 — 3s23p34d, 3s23p4 — 3s23p35s, 3s23p33d — 3s23p34p, and 3s23p34s — 3s23p34p transition arrays and 196 lines were identified as new atomic transitions between levels of these configurations. The experimental data were obtained from a capillary-discharge tube. The identifications are supported by multiconfiguration Hartree-Fock relativistic calculations.Centro de Investigaciones ÓpticasFacultad de Ciencias Astronómicas y Geofísica

Evaluation of self-absorption of manganese emission lines in Laser Induced Breakdown Spectroscopy measurements

This paper is part of a more general study aimed to the determination of the best experimental procedures for reliable quantitative measurements of Fe-Mn alloys by LIBS. In this work, attention is pointed on the self-absorption processes, whose effect deeply influences the LIBS measurements, reflecting in non-linear calibration curves. The effect of self-absorption on the line intensity can be quantified by defining a self absorption coefficient, that measures the deviation of the line intensity from the linear extrapolation of the curve of growth in the optically thin regime. The authors demonstrated in a previous paper that self absorption coefficients could be calculated once the electron density of the plasma is known and the Stark coefficients of the lines are available. However, when the Stark coefficients of the lines of interest are not known, a different approach is needed. In this work a new method for evaluation of self absorption coefficients in LIBS measurements is presented, which does not require the knowledge of Stark coefficients. In order to understand the basic principles and setting out the theoretical tools that will be used for the analysis o f the alloys, a preliminary study was done on pure Mn; LIBS spectra were acquired in different experimental conditions, at different laser energies and different delays after the laser irradiation o f the sample. Moreover, collinear double pulse measurements were also performed. Analytical relations were derived and experimental procedures devised for evaluation o f the self absorption coefficients of several Mn lines, which are important for characterization and control of the experimental conditions in which the analysis is performed

Evaluation of self-absorption of manganese emission lines in laser induced breakdown spectroscopy measurements

This paper is part o f a more general study aimed to the determination o f the best experimental procedures for reliable quantitative measurements o f F e-M n alloys by LIBS. In this work, attention is pointed on the self-absorption processes, whose effect deeply influences the LIBS measurements, reflecting in non-linear calibration curves. The effect o f self-absorption on the line intensity can be quantified by defining a self absorption coefficient, that measures the deviation o f the line intensity from the linear extrapolation o f the curve o f growth in the optically thin regime. The authors demonstrated in a previous paper that self absorption coefficients could be calculated once the electron density o f the plasma is known and the Stark coefficients o f the lines are available. However, when the Stark coefficients o f the lines o f interest are not known, a different approach is needed. In this work a new method for evaluation o f self absorption coefficients in LIBS measurements is presented, which does not require the knowledge o f Stark coefficients. In order to understand the basic principles and setting out the theoretical tools that w ill be used for the analysis o f the alloys, a preliminary study was done on pure Mn; LIBS spectra were acquired in different experimental conditions, at different laser energies and different delays after the laser irradiation o f the sample. Moreover, collinear double pulse measurements were also performed. Analytical relations were derived and experimental procedures devised for evaluation o f the self absorption coefficients o f several Mn lines, which are important for characterization and control o f the experimental conditions in which the analysis is performed.Facultad de Ingenierí

Evaluation of self-absorption of manganese emission lines in laser induced breakdown spectroscopy measurements

This paper is part o f a more general study aimed to the determination o f the best experimental procedures for reliable quantitative measurements o f F e-M n alloys by LIBS. In this work, attention is pointed on the self-absorption processes, whose effect deeply influences the LIBS measurements, reflecting in non-linear calibration curves. The effect o f self-absorption on the line intensity can be quantified by defining a self absorption coefficient, that measures the deviation o f the line intensity from the linear extrapolation o f the curve o f growth in the optically thin regime. The authors demonstrated in a previous paper that self absorption coefficients could be calculated once the electron density o f the plasma is known and the Stark coefficients o f the lines are available. However, when the Stark coefficients o f the lines o f interest are not known, a different approach is needed. In this work a new method for evaluation o f self absorption coefficients in LIBS measurements is presented, which does not require the knowledge o f Stark coefficients. In order to understand the basic principles and setting out the theoretical tools that w ill be used for the analysis o f the alloys, a preliminary study was done on pure Mn; LIBS spectra were acquired in different experimental conditions, at different laser energies and different delays after the laser irradiation o f the sample. Moreover, collinear double pulse measurements were also performed. Analytical relations were derived and experimental procedures devised for evaluation o f the self absorption coefficients o f several Mn lines, which are important for characterization and control o f the experimental conditions in which the analysis is performed.Facultad de Ingenierí

Weighted oscillator strengths and lifetimes for the ArIII spectrum

The weighted oscillator strengths (gf) and the lifetimes for Ar III presented in this work were carried out in a multiconfiguration Hartree-Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observations and lifetimes values that are closer to the experimental ones. In this work we presented all the experimentally known electric dipole Ar III spectral lines. (C) 2001 Published by Elsevier Science Ltd.69217118