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Related papers: R-matrix electron-impact excitation data for the O…

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We aim to present a comprehensive theoretical investigation of dielectronic recombination (DR) of the silicon-like isoelectronic sequence and provide DR and radiative recombination (RR) data that can be used within a generalized…

Atomic Physics · Physics 2018-03-14 Jagjit Kaur , T. W. Gorczyca , N. R. Badnell

We present extensive calculations of radiative transition rates and electron impact collision strengths for Fe II. The data sets involve 52 levels from the $3d\,^7$, $3d\,^64s$, and $3d\,^54s^2$ configurations. Computations of $A$-values…

A unified scheme using the R-matrix method has been developed for electron-ion recombination subsuming heretofore separate treatments of radiative and dielectronic recombination (RR and DR). The ab initio coupled channel approach unifies…

Astrophysics · Physics 2009-11-10 Sultana N. Nahar , Anil K. Pradhan

This work reports radiative transition rates and electron impact excitation rate coefficients for levels of the n= 3, 4, 5, 6, 7, 8 configurations of Ca II. The radiative data were computed using the Thomas-Fermi-Dirac central potential…

Astrophysics · Physics 2009-11-13 M. Melendez , M. A. Bautista , N. R. Badnell

Spectral modelling of kilonovae (KNe) require large amounts of collisional excitation and photoionization atomic data for lowly ionised (neutral, singly and doubly ionised) species of heavy elements. Much of the data currently used is…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Leo P. Mulholland , Catherine A. Ramsbottom , Connor P. Ballance , Albert Sneppen , Stuart A. Sim

The influence of the uncertainties in the rate coefficient data for electron-impact excitation and ionization on non-LTE Li line formation in cool stellar atmospheres is investigated. We examine the electron collision data used in previous…

Solar and Stellar Astrophysics · Physics 2015-05-27 Y. Osorio , P. S. Barklem , K. Lind , M. Asplund

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

Electron impact collision strengths among 560 levels of Si IX, 320 levels of Si X and 350 levels of Si XI have been calculated using the Flexible Atomic Code (FAC) of Gu (2003). Collision strengths $\Omega$ at ten scattered electron…

Atomic Physics · Physics 2015-06-26 Guiyun Liang , Gang Zhao , Jiaolong Zeng

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

The CHIANTI atomic database was first released in 1996 and has had a huge impact on the analysis and modeling of emissions from astrophysical plasmas. The database has continued to be updated, with version 8 released in 2015. Atomic data…

Solar and Stellar Astrophysics · Physics 2016-04-20 Peter R. Young , Ken P. Dere , Enrico Landi , Giulio Del Zanna , Helen Mason

Using the multiconfiguration Dirac-Hartree-Fock and the relativistic configuration interaction methods, a consistent set of transition energies and radiative transition data for the main states of the $2s^2 2p^4$, $2s 2p^5$, $2p^6$, $2s^2…

Atomic Physics · Physics 2021-04-14 C. X. Song , C. Y. Zhang , K. Wang , R. Si , M. Godefroid , P. Jönsson , D. Wei , X. H. Zhao , J. Yan , C. Y. Chen

We present electron collision strengths and their thermally averaged values for the forbidden lines of the astronomically abundant doubly-ionized oxygen ion, O^{2+}, in an intermediate coupling scheme using the Breit-Pauli relativistic…

Atomic Physics · Physics 2014-05-30 P. J. Storey , Taha Sochi , N. R. Badnell

In this work, we investigate the ionization of silicon by electron impacts in hot plasmas. Our calculations of the cross sections and rates rely on the Coulomb-Born-Exchange, Binary-Encounter-Dipole and Distorted-Wave methods implemented in…

Atomic Physics · Physics 2024-12-10 Jean-Christophe Pain , Djamel Benredjem

Modeling the spectral emission of low-charge iron group ions enables the diagnostic determination of the local physical conditions of many cool plasma environments such as those found in H II regions, planetary nebulae, active galactic…

Astrophysics of Galaxies · Physics 2015-06-18 N. R. Badnell , C. P. Ballance

We present R-matrix calculations of photoabsorption and photoionization cross sections across the K edge of the Li-like to Ca-like ions stages of Ni. Level-resolved, Breit-Pauli calculations were performed for the Li-like to Na-like stages.…

High Energy Astrophysical Phenomena · Physics 2015-05-28 M. C. Witthoeft , M. A. Bautista , J. Garcia , T. R. Kallman , C. Mendoza , P. Palmeri , P. Quinet

We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Kr XXXV. The GRASP (general-purpose relativistic atomic structure package) is adopted for…

Atomic Physics · Physics 2015-06-05 K. M. Aggarwal , F. P. Keenan

A general formulation is employed to study and quantitatively ascertain the effect of plasma broadening of {\it intrinsic} autoionizing (AI) resonances in photoionization cross sections. In particular, R-matrix data for iron ions described…

Solar and Stellar Astrophysics · Physics 2023-08-30 A. K. Pradhan

New X-ray observatories (Chandra and XMM-Newton) are providing a wealth of high-resolution X-ray spectra in which hydrogen- and helium-like ions are usually strong features. We present results from a new collisional-radiative plasma code,…

Astrophysics · Physics 2009-11-06 Randall K. Smith , Nancy S. Brickhouse , Duane A. Liedahl , John C. Raymond

Neutral tungsten is the primary candidate as a wall material in the divertor region of the International Thermonuclear Experimental Reactor (ITER). The efficient operation of ITER depends heavily on precise atomic physics calculations for…

Atomic Physics · Physics 2018-05-09 R. T. Smyth , C. P. Ballance , C. A. Ramsbottom , C. A. Johnson , D. A. Ennis , S. D. Loch

We describe the latest release of AtomDB, version 2.0.2, a database of atomic data and a plasma modeling code with a focus on X-ray astronomy. This release includes several major updates to the fundamental atomic structure and process data…

High Energy Astrophysical Phenomena · Physics 2015-06-05 A. R. Foster , L. Ji , R. K. Smith , N. S. Brickhouse