Radiative opacities and configuration interaction effects of hot iron plasma using a detailed term accounting model

Forty Years of the Applications of Stark Broadening Data Determined with the Modified Semiempirical Method

The aim of this paper is to analyze the various uses of Stark broadening data for non-hydrogenic lines emitted from plasma, obtained with the modified semiempirical method formulated 40 years ago (1980), which are continuously implemented in the STARK-B database. In such a way one can identify research fields where they are applied and better see the needs of users in order to better plan future work. This is done by analysis of citations of the modified semiempirical method and the corresponding data in international scientific journals, excluding cases when they are used for comparison with other experimental or theoretical Stark broadening data or for development of the theory of Stark broadening. On the basis of our analysis, one can conclude that the principal applications of such data are in astronomy (white dwarfs, A and B stars, and opacity), investigations of laser produced plasmas, laser design and optimization and their applications in industry and technology (ablation, laser melting, deposition, plasma during electrolytic oxidation, laser micro sintering), as well as for the determination of radiative properties of various plasmas, plasma diagnostics, and investigations of regularities and systematic trends of Stark broadening parameters.

Opacity of iron, nickel, and copper plasmas in the x-ray wavelength range: theoretical interpretation of 2p-3d absorption spectra

This paper deals with theoretical studies on the 2p-3d absorption in iron, nickel, and copper plasmas related to LULI2000 (Laboratoire pour l'Utilisation des Lasers Intenses, 2000J facility) measurements in which target temperatures were of the order of 20 eV and plasma densities were in the range 0.004-0.01 g/cm(3). The radiatively heated targets were close to local thermodynamic equilibrium (LTE). The structure of 2p-3d transitions has been studied with the help of the statistical superconfiguration opacity code SCO and with the fine-structure atomic physics codes HULLAC and FAC. A new mixed version of the sco code allowing one to treat part of the configurations by detailed calculation based on the Cowan's code RCG has been also used in these comparisons. Special attention was paid to comparisons between theory and experiment concerning the term features which cannot be reproduced by SCO. The differences in the spin-orbit splitting and the statistical (thermal) broadening of the 2p-3d transitions have been investigated as a function of the atomic number Z. It appears that at the conditions of the experiment the role of the term and configuration broadening was different in the three analyzed elements, this broadening being sensitive to the atomic number. Some effects of the temperature gradients and possible non-LTE effects have been studied with the help of the radiative-collisional code SCRIC. The sensitivity of the 2p-3d structures with respect to temperature and density in medium-Z plasmas may be helpful for diagnostics of LTE plasmas especially in future experiments on the Δn=0 absorption in medium-Z plasmas for astrophysical applications.

Spectrally resolved and Rosseland and Planck mean opacities of iron plasmas at temperatures above 100 eV: a systematic study

The radiative opacity of iron plasmas at high temperatures is very important in astrophysics. The spectrally resolved radiative opacity and Rosseland and Planck means were investigated by using the detailed-level-accounting (DLA) model for iron plasmas at high temperatures and a variety of density. The accuracy of atomic data such as energy levels and transition probabilities is checked by comparison with data from the National Institute of Standards and Technology. The transmission of iron plasma at a temperature of 156 eV and an electron density of 6.9 x 10(21) cm(-3) is studied in detail and compared with results of a recent experiment [Bailey et al., Phys. Rev. Lett. 99, 265002 (2007)] and other theoretical results. General good agreement is found between our DLA transmission and the experimental and other theoretical results. By using our developed DLA model, we can deduce valuable information on the physical condition of the plasma created in the experiment. The information includes the fractional distribution of different ion stages and whether the plasma is in local thermodynamic equilibrium or not. Illustrative results are given for three isothermal sequences of 100, 150, and 200 eV with different mass densities and for three isodensity sequences of 0.1, 0.05, and 0.01 g/cm3 with different temperatures. The Rosseland and Planck mean opacities are compared with other theoretical results obtained by the Los Alamos light element detailed configuration opacity code.

Detailed diagnostics for a hot bromine plasma by the open M-shell opacity

The experimental transmission spectrum of a hot bromine plasma [J. E. Bailey, J. Quant. Spectrosc. Radiat. Transf. 81, 31 (2003)] has been simulated by using a detailed level accounting model (DLA). With assumption of the local thermodynamic equilibrium, the major absorption lines of the experimental spectrum are well reproduced by the present DLA calculation, and the details of the absorption line shapes are used to determine the temperature of the plasma. In contrast to the results of two former statistical models, where the temperature was determined via a global fitting to the experimental data, the present DLA diagnoses the plasma temperature by the line ratios of different charge states in the 2p-->3d transition groups resulting in a temperature of 37 eV . It is shown that a change of 1 eV in temperature could cause perceptible changes in the simulated spectrum. It is also shown that the 2 p1/2 -->3 d3/2 absorptions have been overestimated by the statistical models.