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Absorption and emission spectra of multicharged-ion plasmas contain a huge number of electron configurations and electric-dipolar lines, which can be handled by global methods. However, some transition arrays consist only of a small bunch…

Atomic Physics · Physics 2013-06-28 Jean-Christophe Pain , Franck Gilleron , Quentin Porcherot , Thomas Blenski

Absorption and emission spectra of plasmas with multicharged-ions contain transition arrays with a huge number of coalescent electric-dipole (E1) lines, which are well suited for treatment by the unresolved transition array and derivative…

Atomic Physics · Physics 2015-05-28 Quentin Porcherot , Jean-Christophe Pain , Franck Gilleron , Thomas Blenski

We present recent evolutions of the detailed opacity code SCO-RCG which combines statistical modelings of levels and lines with fine-structure calculations. The code now includes the Partially-Resolved-Transition-Array model, which allows…

Solar and Stellar Astrophysics · Physics 2021-03-10 Jean-Christophe Pain , Franck Gilleron , Thomas Blenski

The broadening of lines by Stark effect is an important tool for inferring electron density and temperature in plasmas. Stark-effect calculations often rely on atomic data (transition rates, energy levels,...) not always exhaustive and/or…

Atomic Physics · Physics 2016-06-22 Jean-Christophe Pain , Franck Gilleron , Dominique Gilles

The broadening of lines by Stark effect is widely used for inferring electron density and temperature in plasmas. Stark-effect calculations often rely on atomic data (transition rates, energy levels,...) not always exhaustive and/or valid…

Atomic Physics · Physics 2017-04-05 Jean-Christophe Pain , Franck Gilleron , Maxime Comet , Dominique Gilles

Calculating opacities for a wide range of plasma conditions (i.e. temperature, density, element) requires detailed knowledge of the plasma configuration space and electronic structure. For plasmas composed of heavier elements, relativistic…

Plasma Physics · Physics 2023-05-02 Nathanael Gill , Christopher Fontes , Charles Starrett

Radiative opacity is an important quantity in the modeling of stellar structure and evolution. In the present work we recall the role of opacity in the interpretation of pulsations of different kinds of stars. The detailed opacity code…

Solar and Stellar Astrophysics · Physics 2022-09-26 Jean-Christophe Pain , Franck Gilleron , Maxime Comet

Nowadays, several opacity codes are able to provide data for stellar structure models, but the computed opacities may show significant differences. In this work, we present state-of-the-art precise spectral opacity calculations, illustrated…

Solar and Stellar Astrophysics · Physics 2019-04-30 Jean-Christophe Pain , Franck Gilleron , Maxime Comet

Recently the sparse representation based classification (SRC) has been proposed for robust face recognition (FR). In SRC, the testing image is coded as a sparse linear combination of the training samples, and the representation fidelity is…

Computer Vision and Pattern Recognition · Computer Science 2015-06-04 Meng Yang , Lei Zhang , Jian Yang , David Zhang

Solving the continuum radiative transfer equation in high opacity media requires sophisticated numerical tools. In order to test the reliability of such tools, we present a benchmark of radiative transfer codes in a 2D disc configuration.…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Pinte , T. J. Harries , M. Min , A. M. Watson , C. P. Dullemond , P. Woitke , F. Menard , M. C. Duran-Rojas

A new opacity model based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of local thermodynamic equilibrium plasmas, was developed. The atomic code, named STAR (STA-Revised), is described and used…

Solar and Stellar Astrophysics · Physics 2016-04-20 M. Krief , A. Feigel , D. Gazit

Modelling the interaction between ionizing photons emitted from massive stars and their environment is essential to further our understanding of galactic ecosystems. We present a hybrid Radiation-Hydrodynamics (RHD) scheme that couples an…

Instrumentation and Methods for Astrophysics · Physics 2024-04-29 Cheryl S. C. Lau , Maya A. Petkova , Ian A. Bonnell

Accurate determination of opacity is critical for understanding radiation transport in both astrophysical and laboratory plasmas. We employ atomic data from R-Matrix calculations to investigate radiative properties in high-energy-density…

High Energy Astrophysical Phenomena · Physics 2025-10-24 Anil K. Pradhan , Sultana N. Nahar

Spatially-coupled (SC) codes, known for their threshold saturation phenomenon and low-latency windowed decoding algorithms, are ideal for streaming applications. They also find application in various data storage systems because of their…

Information Theory · Computer Science 2021-01-26 Siyi Yang , Ahmed Hareedy , Shyam Venkatasubramanian , Robert Calderbank , Lara Dolecek

In the Super-Transition-Array statistical method for the computation of radiative opacity of hot dense matter, the moments of the absorption or emission features involve partition functions with reduced degeneracies, occurring through the…

Atomic Physics · Physics 2024-05-14 Jean-Christophe Pain , Brian Wilson

High precision atomic data is indispensable for experiments involving studies of fundamental interactions, astrophysics, atomic clocks, plasma science, and others. We develop new parallel atomic structure codes and explore the difficulties…

Atomic Physics · Physics 2021-03-11 C. Cheung , M. S. Safronova , S. G. Porsev

We present a largely improved version of CRASH, a 3-D radiative transfer code that treats the effects of ionizing radiation propagating through a given inhomogeneous H/He cosmological density field, on the physical conditions of the gas.…

Astrophysics · Physics 2009-11-10 A. Maselli , A. Ferrara , B. Ciardi

This paper seeks to combine dictionary learning and hierarchical image representation in a principled way. To make dictionary atoms capturing additional information from extended receptive fields and attain improved descriptive capacity, we…

Computer Vision and Pattern Recognition · Computer Science 2019-11-11 Tong Zhang , Fatih Porikli

We combine a Monte Carlo radiative transfer code with an SPH code, so that -- assuming thermal equilibrium -- we can calculate dust-temperature fields, spectral energy distributions, and isophotal maps, for the individual time-frames…

Astrophysics · Physics 2009-11-11 Dimitris Stamatellos , Anthony Whitworth

An extended version of the R-matrix methodology is presented for calculation of radiative parameters for improved plasma opacities. Contrast and comparisons with existing methods primarily relying on the Distorted Wave (DW) approximation…

Solar and Stellar Astrophysics · Physics 2023-08-30 A. K. Pradhan , S. N. Nahar , W. Eissner
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