English
Related papers

Related papers: Self-Consistent R-matrix Approach To Photoionizati…

200 papers

Most astrophysical plasmas entail a balance between ionization and recombination. We present new results from the powerful R-matrix method which yields in an ab initio manner: (I) self-consistent photoionization and recombination cross…

Astrophysics · Physics 2007-05-23 Sultana N. Nahar

Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. An identical eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring…

Astrophysics · Physics 2007-05-23 Sultana N. Nahar

Ar XIII is found to be unique with new features in electron-ion recombination not seen in any other ion. The ion has been studied with the unified method which provides a theoretically self-consistent set of atomic parameters for the…

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

We investigate the effect of resonances in photoionization and recombination cross sections computed using the R-matrix method. Photoionization and recombination rates derived from high-resolution cross sections for oxygen ions are compared…

Astrophysics · Physics 2009-11-10 Franck Delahaye , Sultana N. Nahar , Anil K Pradhan , Hong Lin Zhang

The first complete set of unified cross sections and rate coefficients are calculated for photoionization and recombination of He- and Li-like ions using the relativistic Breit-Pauli R-matrix method. We present total, unified (e + ion)…

Astrophysics · Physics 2016-08-30 Sultana N. Nahar , Anil K. Pradhan , Hong Lin Zhang

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

The inverse processes of photoionization and electron-ion recombination of (hnu + Ni XXVI --> Ni XXVII + e and (hnu + Ni XXVII --> Ni XXVIII + e) are studied using the unified method for the total recombination. The method subsumes both the…

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

The theoretical approach developed here treats uniformly the direct and indirect mechanisms of dissociative recombination (DR) in a diatomic ion. The present theory is based on electron scattering calculations performed at several…

A theoretical investigation of photoabsorption and photoionization of Fe^{14+} extending beyond an earlier frame transformation R-matrix implementation is performed using a fully-correlated, Breit-Pauli R-matrix formulation including both…

Atomic Physics · Physics 2015-06-04 M. F. Hasoglu , T. W. Gorczyca , M. A. Bautista , Z. Felfli , S. T. Manson

Photoionization and recombination cross sections and rate coefficients are calculated for Li-like Fe XXIV and He-like Fe XXV using the Breit-Pauli R-matrix (BPRM) method. A complete set of total and level-specific parameters is obtained to…

Astrophysics · Physics 2009-10-31 Sultana N. Nahar , Anil K. Pradhan , Hong Lin Zhang

We present ground state photoionization cross sections of atoms and ions averaged over resonance structures for photoionization modeling of astrophysical sources. The detailed cross sections calculated in the close-coupling approximation…

Astrophysics · Physics 2009-10-30 M. A. Bautista , P. Romano , A. K. Pradhan

Relativistic and channel coupling effects in photoionization and unified electronic recombination of Fe XVII are demonstrated with an extensive 60-level close coupling calculation using the Breit-Pauli R-matrix method. Photoionization and…

Astrophysics · Physics 2009-11-06 Hong Lin Zhang , Sultana N. Nahar , Anil K. Pradhan

The R-matrix method has been used for theoretical calculation of electron collision with atoms and molecules for long years. The method was also formulated to treat photoionization process, however, its application has been mostly limited…

Chemical Physics · Physics 2010-04-08 Motomichi Tashiro

Latest developments in theoretical computations since the international Opacity Project (OP), under the new the Iron Project (IP) and extensions, are described for applications to a variety of objects such as stellar atmospheres, nebulae,…

Astrophysics · Physics 2016-08-30 Sultana N. Nahar

We present a theoretical investigation of dielectronic recombination (DR) of Ar-like ions that sheds new light on the behavior of the rate coefficient at low-temperatures where these ions form in photoionized plasmas. We provide results for…

Atomic Physics · Physics 2013-03-13 D. Nikolić , T. W. Gorczyca , K. T. Korista , N. R. Badnell

We have measured the resonance strengths and energies for dielectronic recombination (DR) of Fe XX forming Fe XIX via N=2 --> N'=2 (Delta_N=0) core excitations. We have also calculated the DR resonance strengths and energies using…

We present multi-configuration Breit-Pauli distorted-wave photoionization (PI) cross sections and radiative recombination (RR) and dielectronic recombination (DR) rate coefficients for the first six krypton ions. These were calculated with…

Solar and Stellar Astrophysics · Physics 2015-05-28 N. C. Sterling

Here we report new ${\it ab initio}$ calculations of the effective recombination coefficients for the \ion{N}{ii} recombination spectrum. We have taken into account the density dependence of the coefficients arising from the relative…

Solar and Stellar Astrophysics · Physics 2015-05-27 X. Fang , P. J. Storey , X. -W. Liu

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

Unified recombination cross sections and rates are computed for (e + Fe XVIII) --> Fe XVII including non-resonant and resonant (radiative and di-electronic recombination, RR and DR) processes in an ab initio manner with relativistic fine…

Astrophysics · Physics 2009-10-31 Anil K. Pradhan , Sultana N. Nahar , Hong Lin Zhang
‹ Prev 1 2 3 10 Next ›