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A new method, 'Configurationally-Resolved-Super-Transition-Arrays', for calculation of the spectral absorption coefficient in hot plasmas is presented. In the new method, the spectrum of each Super-Transition-Array is evaluated as the…

Atomic Physics · Physics 2015-06-04 G. Hazak , Y. Kurzweill

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

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

Partition functions of a canonical ensemble of non-interacting bound electrons are a key ingredient of the super-transition-array approach to the computation of radiative opacity. A few years ago, we published a robust and stable recursion…

Statistical Mechanics · Physics 2020-10-28 Jean-Christophe Pain , Franck Gilleron , Brian G. Wilson

The synthetic emission spectra and opacity of high-density, high-temperature germanium (Z=32) plasma from super-transition-array (STA) calculations are presented. The viability of the STA model, which is based on a statistical…

The partition function by means of the static path approximation (SPA) plus the random-phase approximation (RPA) treatment can be written as a contour integral form without solving the RPA equations for a separable interaction. This method…

Nuclear Theory · Physics 2009-11-11 K. Kaneko , M. Hasegawa

A new formalism and computer code, ASTRA (AttoSecond TRAnsitions), has been developed to treat the interactions of short, intense radiation with molecules. The formalism makes extensive use of transition density matrices, computed using a…

G.~Hazak and J.~Kurzweil discovered a method of configurational resolution of transition arrays for the Super Transition Arrays approach to the bound-bound opacity calculation. Their method is based on the representation of the…

Plasma Physics · Physics 2025-11-04 Evgeniya Arapova , Yulia Koryakina , Mikhail Vronskiy

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

A theoretical model based on the method of super transition arrays (STA) is used to compute the emissivities, opacities and average ionization states of carbon (C) and polystyrene (CH) plasmas in the warm-dense matter regime in which the…

Plasma Physics · Physics 2018-11-20 Teck-Ghee Lee , M. Busquet , M. Klapisch , J. W. Bates , A. J. Schmitt , S. X. Hu , J. Giuliani

Compressed sensing has shown great potentials in accelerating magnetic resonance imaging. Fast image reconstruction and high image quality are two main issues faced by this new technology. It has been shown that, redundant image…

Medical Physics · Physics 2016-01-27 Yunsong Liu , Zhifang Zhan , Jian-Feng Cai , Di Guo , Zhong Chen , Xiaobo Qu

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

Robust high-dimensional data processing has witnessed an exciting development in recent years, as theoretical results have shown that it is possible using convex programming to optimize data fit to a low-rank component plus a sparse outlier…

Computer Vision and Pattern Recognition · Computer Science 2015-04-21 Jun He , Dejiao Zhang , Laura Balzano , Tao Tao

We present the hybrid opacity code SCO-RCG which combines statistical approaches with fine-structure calculations. Radial integrals needed for the computation of detailed transition arrays are calculated by the code SCO (Super-configuration…

Atomic Physics · Physics 2019-04-30 Jean-Christophe Pain , Franck Gilleron , Quentin Porcherot , Thomas Blenski

In this paper, we propose an efficient numerical scheme for solving some large scale ill-posed linear inverse problems arising from image restoration. In order to accelerate the computation, two different hidden structures are exploited.…

Numerical Analysis · Mathematics 2024-12-20 Zixuan Chen , James Nagy , Yuanzhe Xi , Bo Yu

In this paper, a new method is proposed for sparse PCA based on the recursive divide-and-conquer methodology. The main idea is to separate the original sparse PCA problem into a series of much simpler sub-problems, each having a closed-form…

Computer Vision and Pattern Recognition · Computer Science 2012-12-03 Qian Zhao , Deyu Meng , Zongben Xu

Coherent X-ray Diffraction Imaging (CXDI) technique offers unique insights into the nanoscale world, enabling the reconstruction of 3D structures with a nanoscale resolution achieved through computational phase reconstruction from measured…

Computational Physics · Physics 2024-03-26 Fangzhou Ai , Oleg Shpyrko , Vitaliy Lomakin

Rare transitions in stochastic processes can often be rigorously described via an underlying large deviation principle. Recent breakthroughs in the classification of reversible stochastic processes as gradient flows have led to a connection…

Statistical Mechanics · Physics 2019-05-22 Tobias Grafke

In this article, we address the issue of recovering latent transparent layers from superimposition images. Here, we assume we have the estimated transformations and extracted gradients of latent layers. To rapidly recover high-quality image…

Computer Vision and Pattern Recognition · Computer Science 2012-11-20 Han Li , Kun Gai , Pinghua Gong , Changshui Zhang

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
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