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Related papers: Photoionization and Recombination

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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

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

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

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

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 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

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

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 present the first detailed ab initio quantum mechanical calculations for total and state-specific recombination rate coefficients for e + Ni III --> Ni II. These rates are obtained using a unified treatment for total electron-ion…

Astrophysics · Physics 2009-11-06 Sultana N. Nahar , Manuel A. Bautista

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

Recent experimental work on the photorecombination and the photoionization of astrophysically relevant atomic ions employing the merged-beams technique at heavy-ion storage-rings and synchrotron-light sources, respectively, is summarized.…

Astrophysics · Physics 2011-01-06 Stefan Schippers

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

Highly excited eigenstates of atoms and ions with open f shell are chaotic superpositions of thousands, or even millions of Hartree-Fock determinant states. The interaction between dielectronic and multielectronic configurations leads to…

Atomic Physics · Physics 2015-06-17 V. A. Dzuba , V. V. Flambaum , G. F. Gribakin , C. Harabati , M. G. Kozlov

Absolute cross sections for the K-shell photoionization of ground-state Li-like carbon [C$^{3+}$(1s$^2$2s $^2$S)] ions were measured by employing the ion-photon merged-beams technique at the Advanced Light Source. The energy ranges…

Photoionization and its inverse, electron-ion recombination, are key processes that influence many astrophysical plasmas (and gasses), and the diagnostics that we use to analyse the plasmas. In this review we provide a brief overview of the…

Solar and Stellar Astrophysics · Physics 2023-03-21 D. John Hillier

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

Photoionization cross sections and recombination rate coefficients are presented for the L-shell ground state fine structure levels $2s^22p^4 \ ^3P_{2,0,1}$ of Fe~XIX. Several sets of calculations including relativistic effects are carried…

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

We report measured rate coefficients for electron-ion recombination for Si10+ forming Si9+ and for Si9+ forming Si8+, respectively. The measurements were performed using the electron-ion merged-beams technique at a heavy-ion storage ring.…

Rate coefficients for photorecombination (PR) and cross sections for electron-impact ionization (EII) of Fe$^{14+}$ forming Fe$^{13+}$ and Fe$^{15+}$, respectively, have been measured by employing the electron-ion merged-beams technique at…

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
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