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Related papers: R-Matrix calculations for opacities: I. Methodolog…

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Aimed at ionization balance and spectral analysis of UV and X-ray sources, we present self-consistent sets of photoionization cross sections, recombination cross sections, and rate coefficients for Li-like O VI and He-like O VII.…

Astrophysics · Physics 2009-11-07 Sultana N. Nahar , Anil K. Pradhan

We consider three recent large-scale calculations for the radiative and electron-impact excitation data of N IV, carried out with different methods and codes. The scattering calculations employed the relativistic Dirac $R$-matrix (DARC)…

Solar and Stellar Astrophysics · Physics 2019-02-20 G. Del Zanna , L. Fernandez-Menchero , N. R. Badnell

Techniques for producing cold and ultracold molecules are enabling the study of chemical reactions and scattering at the quantum scattering limit, with only a few partial waves contributing to the incident channel, leading to the…

Chemical Physics · Physics 2016-09-21 Jonathan Tennyson , Laura K. McKemmish , Tom Rivlin

An alternative method is introduced to solve a simple two-dimensional models describing vibrational excitation and dissociation processes during the electron-molecule collisions. The model works with one electronic and one nuclear degree of…

Chemical Physics · Physics 2018-12-19 Roman Čurík , Dávid Hvizdoš , Chris H. Greene

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

Electron-atom collisions in warm dense plasmas are crucial for astrophysics and controlled fusion research, where calculating short-range scattering matrices under screening plasma potentials is essential. While electron-neutral atom…

Atomic Physics · Physics 2026-01-28 Chao Wu , Wen Hao Xia , Yong Wu , Jun Yan , Ming Li , Jian Guo Wang , Xiang Gao

Petaflop architectures are currently being utilized efficiently to perform large scale computations in Atomic, Molecular and Optical Collisions. We solve the Schr\"odinger or Dirac equation for the appropriate collision problem using the…

Atomic Physics · Physics 2015-01-15 Brendan M. McLaughlin , Connor P. Ballance , Michael S. Pindzola , Alfred Müller

For the reliable analysis and modelling of astrophysical, laser-produced and fusion plasmas, atomic data are required for a number of parameters, including energy levels, radiative rates and electron impact excitation rates. Such data are…

Instrumentation and Methods for Astrophysics · Physics 2013-01-15 Km Aggarwal , Fp Keenan

The present study presents a comprehensive theoretical investigation of atom and asymmetric top molecule inelastic scattering based on the R-matrix formalism. The proposed methodology establishes a rigorous framework for treating inelastic…

The increased sensitivity of future radio telescopes will result in requirements for higher dynamic range within the image as well as better resolution and immunity to interference. In this paper we propose a new matrix formulation of the…

Astrophysics · Physics 2014-11-18 Chen Ben-David , Amir Leshem

Petaflop architectures are currently being utilized efficiently to perform large scale computations in Atomic, Molecular and Optical Collisions. We solve the Schroedinger or Dirac equation for the appropriate collision problem using the…

Distributed, Parallel, and Cluster Computing · Computer Science 2014-08-18 Brendan M. McLaughlin , Connor P. Ballance

For crucial tests between theory and experiment, ab initio close coupling calculations are carried out for photoionization of O II, O III, O IV, O V. The relativistic fine structure and resonance effects are studied using the R-matrix and…

Astrophysics · Physics 2009-11-10 Sultana N. Nahar

Relativistic and resonance effects in the photoionization of Mg-like Fe~XV are investigated using the Breit-Pauli R-matrix Method (BPRM) at near-threshold and intermediate energies, complemented by the Relativistic Random Phase…

Astrophysics · Physics 2009-10-31 Nasreen Haque , Anil K. Pradhan

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

We present a comprehensive description of the theory and practice of opacity calculations from the infrared to the ultraviolet needed to generate models of the atmospheres of brown dwarfs and extrasolar giant planets. Methods for using…

Astrophysics · Physics 2009-11-11 Christopher M. Sharp , Adam Burrows

Calculations of the opacity of hot, dense matter require models for plasma line broadening. However, the most general theories are too complex to calculate directly and some approximation is inevitably required. The most widely-used…

Plasma Physics · Physics 2020-10-05 R. A. Baggott , S. J. Rose , S. P. D. Mangles

We formulate a computationally efficient time-independent method based on the multi-electron molecular R-matrix formalism. This method is used to calculate transition matrix elements for the multi-photon ionization of atoms and molecules…

Atomic Physics · Physics 2022-05-10 Jakub Benda , Zdeněk Mašín

A matrix balanced version of the Recursive Centered T Matrix Algorithm (RCTMA) applicable to systems possessing resonant inter-particle couplings is presented. Possible domains of application include systems containing interacting localized…

Optics · Physics 2009-05-21 Brian Stout , Jean-Claude Auger , Alexis Devilez

Material ejected during (or immediately following) the merger of two neutron stars may assemble into heavy elements by the r-process. The subsequent radioactive decay of the nuclei can power electromagnetic emission similar to, but…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Daniel Kasen , N. R. Badnell , Jennifer Barnes

We present new calculations of Rosseland and Planck gaseous mean opacities relevant to the atmospheres of giant planets and ultracool dwarfs. Such calculations are used in modeling the atmospheres, interiors, formation, and evolution of…

Earth and Planetary Astrophysics · Physics 2021-06-28 Richard S. Freedman , Jacob Lustig-Yaeger , Jonathan J. Fortney , Roxana E. Lupu , Mark S. Marley , Katharina Lodders