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This work reports information about the temporal evolution of the excitation equilibrium departure in a high current pulsed arc. An argon plasma has been created in a linear lamp by discharging a capacitor bank on its electrodes. Spatially and temporally-resolved measurements have allowed us to determine electron density N e and excitation temperature T with great accuracy. Single-wavelength interferometry and H α -Stark broadening have been used to measure N e (0.2–0.98× 10 23 m -3 ). Excitation temperature has been obtained from Boltzmann-plot of ArII lines and ranges in this experiment from 13500 to 26500 K. By assuming this temperature is equal to kinetic electron temperature and by comparing the theoretically predicted and the experimental ArII/ArI intensities ratios at each instant of the plasma life, it is possible to measure the departure of the excitation processe from local them dynamic equilibrium (LTE) conditions and to show the ionizing characteristics of this close-to-LTE plasma. Different t...

Optical diagnostics is a known and powerful tool to obtain information concerning the processes involved inside and around plasma. In the case of helium plasmas, they are present in industrial applications, like welding or cutting processes and in scientific research, like the inertial confinement plasmas or astrophysical analysis. This work reports information on the pressure broadened profiles of the HEII Paschen-alpha (Pα), Paschen-beta (Pβ) and Paschen-gamma (Pγ) spectral lines measured in a pulsed discharge lamp. Information relative to the line shapes, full width at 1/2, 1/4 and 1/8 of the maximum intensity and the dip of the HEII 320.3 nm is provided. The electron density has been determined by two-wavelength interferometry and from the Stark width of the HEI 501.6 nm and ranges during the HeII emission from 0.54 to 0.64 1023 m-3 in the plasma. Temperature (1.7 - 2.4 eV) has been simultaneously determined from the Boltzmann-plot of HEI and from local thermodynamic equilibrium (LTE) assumptions. The final results have been compared with most of the previous existing data.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The purpose of this work is to show a suitable plasma source and experimental arrangement for high accuracy measurement of atomic parameters developed in the Optics Department of Valladolid University. It is important to remark the careful plasma diagnostics procedures followed, and as an example we present a NII emission experiment where a very extensive collection of 104 Stark widths and 47 shifts has been measured. Electron density and temperature range from 0.2 to 1.1×1023 m−3 and from 17000 to 29000 K, respectively. All the results have been very recently published [1].

RESEARCH LINES OF THE OPTICS DEPARTMENTpi UNWERSITY OF VALLADOLID.Santiago Mar, Fernando Munoz, Juan Gonzalez, Angel M. de Frutos, Marco A. Gigosos, M Inmaculada de laRosa, M Concepcion Perez, Carlos Baladron, Juan Antonio Aparicio, Juan Antonio del Vat, Manuel Angel Gonzalez,Luis M Fuentes, Victor Gonzalez, Andres Bustilo, Ana Belen Gonzalo, Raal Pastor, Maria C. Gonzalez, AlbertoBarbes, Raul GarcIa, Anabel Manchon, Ricardo Vergaz, Prudencio Herrero, MarIa J. Martin, Ramon Margarida,Alberto Beijon.Dpto. Optica y Fisica Aplicada. Facultad de Ciencias.Prado de la Magdalena s/n .

This work reports information about the temporal evolution of the equilibrium departure in a high current pulsed arc. An argon plasma has been created in a linear lamp by discharging a capacitor bank on its electrodes. Very careful diagnostics techniques have allowed us to determine electron density Ne (2.0 - 9.5 X 1022 m-3) and ArII excitation temperature which has been assumed to be equal to kinetic electron temperature T (13000 - 26000 K). By making ArII/ArI intensities ratio at each instant of the plasma life, it is possible to obtain a parameter which gives an idea of the departure of ionization-recombination processes from local thermodynamic equilibrium conditions.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We developed a model of corneal haze following photorefractive keratectomy (PRK) in Iber Braun hens and studied optical properties. The animals underwent PRK for -9.0 diopters of myopia and were divided into groups based on treatment with different wound-healing modulators. At different time points postoperatively, we evaluated haze by slit-lamp microscopy. An experimental device was developed to measure transmittance spatial maps and forward scattering of He-Ne laser light in the excised corneas. Subjective and objective haze measures were compared for each group at the different times. Keratocyte densities were determined by optical microscopy and keratocyte sizes by electron microscopy. The agreement between experimental results and a simple numerical model of scattering suggests that increases in stromal keratocyte density after PRK might explain the degree of corneal haze.