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

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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

Time dependent numerical simulations of the K ALPHA complex of Fe XXV are carried out as a function of temperature/density/radiation field variations in high-temperature astrophysical and laboratory plasmas. In addition to several well…

Astrophysics · Physics 2008-11-26 Justin Oelgoetz , Anil K. Pradhan

New theoretical results from large-scale relativistic close coupling calculations reveal the precise effect of resonances in collisional excitation of x-ray lines of Ne-like Fe XVII. Employing the Breit-Pauli R-matrix method and a 89-level…

Astrophysics · Physics 2008-11-26 Guo-Xin Chen , Anil K. Pradhan

We present He-like line ratios (resonance, intercombination and forbidden lines) for totally and partially photoionized media. For solar plasmas, these line ratios are already widely used for density and temperature diagnostics of coronal…

Astrophysics · Physics 2009-10-31 Delphine Porquet , Jacques Dubau

The calculations of the ratios of the Helium-like ion X-ray lines from C V to Si XIII are revisited in order to apply the results to density, temperature and ionization process diagnostics of data from high-resolution spectroscopy of the…

Astrophysics · Physics 2007-05-23 D. Porquet , R. Mewe , J. S. Kaastra , J. Dubau , A. J. J. Raassen

Aims: To calculate transition rates from ground and excited states in neutral oxygen atoms due to electron collisions for non-LTE modelling of oxygen in late-type stellar atmospheres, thus enabling reliable interpretation of oxygen lines in…

Astrophysics · Physics 2009-11-11 P. S. Barklem

The intensity of the \oiv~2s$^{2}$ 2p $^{2}$P-2s2p$^{2}$ $^{4}$P and \siv~3 s$^{2}$ 3p $^{2}$P- 3s 3p$^{2}$ $^{4}$ P intercombination lines around 1400~\AA~observed with the \textit{Interface Region Imaging Spectrograph} (IRIS) provide a…

Solar and Stellar Astrophysics · Physics 2016-10-19 V. Polito , G. Del Zanna , J. Dudík , H. E. Mason , A. Giunta , K. K. Reeves

The introduction of gases like nitrogen or neon for cooling the edge region of magnetically confined fusion plasmas has triggered a renewed interest in state selective cross sections necessary for plasma diagnostics by means of charge…

The effects of radiation on the structure of shocks in a fully-ionized plasma are investigated by solving the steady-state fluid equations for ions, electrons, and radiation. The electrons and ions are assumed to have the same bulk velocity…

High Energy Astrophysical Phenomena · Physics 2016-03-28 Bryan M. Johnson , Richard I. Klein

The ion production in an ECRIS is modelled using a particle-in-cell Monte-Carlo collision code in a three-dimensional geometry. Only the heavy particles (ions and atoms) are tracked, with the electron density determined from the requirement…

Atomic Physics · Physics 2009-07-29 V. Mironov , J. P. M. Beijers

Radiative atomic data and electron impact excitation cross sections for the $2s-2p$ transitions in O VI for transitions among the fine structure levels belonging to the $1s^{2}nl$ ($2\leq n\leq5$) configurations have been calculated. We…

Atomic Physics · Physics 2018-03-14 Haykel Elabidi , Sylvie Sahal-Bréchot , Nébil Ben Nessib

A complete model of helium-like line and continuum emission has been incorporated into the plasma simulation code Cloudy. All elements between He and Zn are treated, any number of levels can be considered, and radiative and collisional…

Astrophysics · Physics 2019-08-19 R. L. Porter , G. J. Ferland

A programme is outlined for the assembly of a comprehensive dielectronic recombination database within the generalized collisional--radiative (GCR) framework. It is valid for modelling ions of elements in dynamic finite-density plasmas such…

The R ratio is a useful diagnostic of the X-ray emitting astrophysical plasmas defined as the intensity ratio of the forbidden over the inter-combination lines in the K$\alpha$ line complex of He-like ions. The value is altered by…

The spectra of singly ionised Strontium and Yttrium (Sr {\sc ii} and Y {\sc ii}) have been proposed as identifications of certain spectral features in the AT2017gfo spectrum. With the growing demand for NLTE simulations of Kilonovae, there…

High Energy Astrophysical Phenomena · Physics 2024-07-02 Leo Mulholland , Niall McElroy , Fiona McNeill , Stuart Sim , Connor Ballance , Catherine Ramsbottom

Recent R-matrix calculations claim to produce a significant enhancement in the opacity of Fe XVII due to atomic core excitations [S. N. Nahar & A.K. Pradhan, Phys. Rev. Letters 116, 235003 (2016), arXiv:1606.02731] and assert that this…

Electronic excitations and ionisations produced by electron impact are key processes in the radiation-induced damage mechanisms in materials of biological relevance, underlying important medical and technological applications, including…

Chemical Physics · Physics 2021-08-04 Pablo de Vera , Isabel Abril , Rafael Garcia-Molina

Energy levels, radiative rates and lifetimes are calculated among the lowest 98 levels of the n <= 4 configurations of Be-like Al X. The GRASP (General-purpose Relativistic Atomic Structure Package) is adopted and data are provided for all…

Solar and Stellar Astrophysics · Physics 2015-06-18 K. M. Aggarwal , F. P. Keenan

The paper discusses some 3D simulations to compute the ionizing radiation dose during laser-plasma experiments leading to the generation of accelerated protons and electrons. Also, we suggest a new method to increase the measurement…

Instrumentation and Detectors · Physics 2019-10-02 M. Ganciu , A. Chirosca , A. Groza , E. Stancu , O. Stoican , D. B. Dreghici , B. Butoi , C. Ticos , B. Mihalcea , B. Cramariuc

The hydroxyl radical, OH, is an important component of many natural and technological plasmas but there is little available information on processes involving its collisions with low-energy electrons. Low-energy electron collisions with OH…

Atomic Physics · Physics 2019-09-04 Kalyan Chakrabarti , Vincenzo Laporta , Jonathan Tennyson
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