M. A. Gigosos

New plasma diagnosis tables of hydrogen Stark broadening including ion dynamics

A set of tables of the Stark width of the first three lines of Lyman and Balmer series of hydrogen, useful for plasma diagnosis purposes, is presented in this work. These tables have been obtained by means of a fully recognized computer simulation technique. Computer experiments have been carried out for density values between and . Simulation temperatures range from 2245 K to 224 856 K. Ion dynamics effects are taken into account in a natural way and the most significative gas mixtures have been covered in the simulations, carried out at the reduced mass of the emitter - perturber pair , 0.6, 0.8, 0.9, 1.0, 1.25, 1.5, 1.75 and 2.0. A detailed discussion of the influence of the relevant plasma parameters on the characteristics of the profiles is also included. The results show an excellent agreement with up-to-date experimental results and confirm these kind of profile calculation techniques as now the most accurate.

Stark broadening models for plasma diagnostics

A review of the models used for the calculation of the Stark broadening spectrum for plasmas is presented. The aim is to provide an overview of the related theories using a simple formalism, useful for an introduction to the study of this phenomenon, which is encountered in plasma diagnostics. A historical development is followed and some of the problems that are currently under investigation are mentioned.

A program for the evaluation of electron number density from experimental hydrogen balmer beta line profiles

Abstract A program for the determination of plasma electron number density, 1020≤(Ne)≤1023 m−3, from the comparison of experimental and theoretical hydrogen Balmer beta (Hβ) line profiles is described in detail. Three theoretical data sets (one set is calculated within the framework of this paper) are included with the program and may be selected as a users choice. Apart from Ne determination from the comparison of the whole experimental and theoretical profiles, this program offers a fast estimation of Ne from the halfwidth of the experimental line shape. If necessary, certain parts of the experimental profile may be neglected in the procedure of comparison with theory. This possibility enables the use of noisy line shape recordings for Ne determination. The Hβ asymmetry study may be carried out by generating the difference between experimental and best-fitted theoretical line profiles.

Measurement of Stark broadening and shift of singly ionized Ar lines

A very extensive compilation of Stark widths and shifts for more than 125 Ar II visible spectral lines is presented in this work. These atomic parameters have been measured in a pulsed discharge lamp by using different mixtures of pure argon or argon and helium. The electron density, which typically ranges from 0.2 to has been determined interferometrically and, in the case of pure argon plasmas, also spectroscopically from -Stark broadening. The Ar II excitation temperature (15 000-31 000 K) has been determined by Boltzmann-plot techniques from the intensity of Ar II lines. A detailed description of all the relevant points in this kind of measurement is given. Comparisons with most of the data published about this topic for Ar II are also included.

Study of some electrokinetic phenomena in charged microcapillary porous membranes

Abstract A detailed study of some transport properties of charged capillary membranes (concentration potential and solute permeability) is presented. The used transport model is based upon the Nernst-Planck and Poisson-Boltzmann equations. It is solved by an original numerical method which gives the degree of convergence. An experimental verification of the model is carried out for some small pore size microporous capillary membranes (Nuclepore).

Measurement of Stark broadening and shift parameters of several Ar I lines

This work reports Stark shifts and widths of 15 Ar I lines measured in a pulsed arc. Plasma parameters, electron density and temperature, range in this experiment from 0.25 to and from 13 500 to 26 500 K, respectively. The former has been measured interferometrically at a single wavelength and spectroscopically from the -Stark broadening. The latter has been measured from the Boltzmann plot of Ar II lines and from the ratio of Ar II and Ar I line intensities. Comparisons with most of the data published to date about this topic in Ar I are also included.

Molecular dynamics simulation for modelling plasma spectroscopy

The ion-electron coupling properties for an ion impurity in an electron gas and for a two-component plasma are carried out on the basis of a regularized electron-ion potential removing the short-range Coulomb divergence. This work is largely motivated by the study of radiator dipole relaxation in plasmas which makes a real link between models and experiments. Current radiative property models for plasmas include single electron collisions neglecting charge-charge correlations within the classical quasi-particle approach commonly used in this field. The dipole relaxation simulation based on electron-ion molecular dynamics proposed here will provide a means to benchmark and improve model developments. Benefiting from a detailed study of a single ion embedded in an electron plasma, the challenging two-component ion-electron molecular dynamics simulations are proved accurate. They open new possibilities of obtaining reference lineshape data.

Calibration of the Stark-broadening parameters of two He I lines with forbidden components

Measurements of the Stark-broadening parameters of two \HeI lines with forbidden components, have been done in a pulsed arc plasma. Electron density, ranging from 1.50×1022 to 1.45×1023 m-3, is obtained by the interferometry of two wavelengths. Plasma temperature, determinated by Boltzmann plots of several \HeIlines, lies in the interval 16 000–25 000 K. A set of four geometrical profile parameters are obtained and compared with previous experimental and theoretical results. The empirical formulae proposed in this paper can be used in plasma diagnostics.

Transition probability measurement in an Ar II plasma

This work reports a collection of 200 Ar II transition probabilities of lines in the spectral region 360 - 750 nm for 16 lifetime values, all of them measured in an emission experiment. Relative intensity measurements have been made on a pulsed discharge lamp and the absolute values have been obtained by using data taken from the literature. The electron density, which ranges from 0.2 to in the plasma, has been determined simultaneously by interferometry and from -Stark broadening. The Ar II excitation temperature (15 000 - 27 000 K) has been calculated by a new method which also provides transition probabilities and plasma composition. The high number of measurements has allowed us to properly discuss the plasma equilibrium model. Comparisons have been made with the most recent experimental and theoretical data collections.

Charge-charge coupling effects on dipole emitter relaxation within a classical electron-ion plasma description

Studies of charge-charge (ion-ion, ion-electron, and electron-electron) coupling properties for ion impurities in an electron gas are carried out on the basis of a regularized electron-ion potential without short-range Coulomb divergence. This work is motivated, in part, by questions arising from recent spectroscopic measurements revealing discrepancies with present-day theoretical descriptions. Many of the current radiative property models for plasmas include only single electron-emitter collisions and neglect some or all charge-charge interactions. A molecular-dynamics simulation of dipole relaxation is proposed here to allow proper account of many electron-emitter interactions and all charge-charge couplings. As illustrations, molecular-dynamics simulations are reported for the cases of a single ion embedded in an electron plasma and for a two-component ion-electron plasma. Charge-charge coupling effects are discussed for hydrogen-like Balmer alpha lines at weak coupling conditions.