Collision Strengths for Electron Impact Excitation of Fine‐Structure Levels in Fe<scp>xiii</scp>

Gupta, Govind P.; Tayal, S. S.

doi:10.1086/306235

Cited by 21 publications

(69 citation statements)

References 21 publications

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“…absolute differences between theory and experiment is 0.038 Ryd for Gupta & Tayal (1998), 0.209 Ryd for Aggarwal & Keenan (2004), 0.039 Ryd for our target calculation and 0.035 Ryd for our 72CF calculation. On this measure there is little difference in quality between the present target calculation and that of Gupta & Tayal (1998) while the Aggarwal & Keenan (2004) results are significantly less good.…”

Section: The Scattering Targetmentioning

confidence: 54%

“…On this measure there is little difference in quality between the present target calculation and that of Gupta & Tayal (1998) while the Aggarwal & Keenan (2004) results are significantly less good. Aggarwal & Keenan (2004) explored the significance of increased configuration interaction and showed that a thirteen configuration GRASP calculation gave much better calculated energies than the six configuration calculation that they finally adopted due to computational constraints.…”

Section: The Scattering Targetmentioning

confidence: 68%

“…We now compare the results of our 72CF and target calculations with those from the two most recently published Fe 12+ scattering calculations described by Gupta & Tayal (1998) and Aggarwal & Keenan (2004). Table 5 shows the experimental and calculated level energies for the 27 levels of the three energetically lowest configurations.…”

Section: The Scattering Targetmentioning

confidence: 90%

“…In Table 5 we also give energies obtained after applying the socalled term energy corrections or TEC, (Zeippen et al 1977;Nussbaumer & Storey 1978) which introduce empirical corrections to the LS Hamiltonian matrix to bring the final level energies in to better agreement with experiment. Gupta & Tayal (1998) used the CIV3 code described by Hibbert (1975) while Aggarwal & Keenan (2004) used the relativistic GRASP code of Dyall et al (1989). The mean of the Notes.…”

Section: The Scattering Targetmentioning

confidence: 99%

“…The early calculations employing the distorted wave approximation could only approximate the effects of resonances. The most recent work (Tayal 1995;Gupta & Tayal 1998;Tayal 2000;Aggarwal & Keenan 2004, 2005) and the present work employ the close-coupling approximation to delineate resonance structures in detail. The calculations described in the first three of these papers, and the present one, also account for relativistic effects through the use of the Breit-Pauli Hamiltonian, while Aggarwal & Keenan (2004, 2005) use a fully relativistic treatment.…”

Section: Introductionmentioning

confidence: 99%

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Atomic data from the IRON project

Storey¹,

Zeippen

2010

A&A

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A new R-matrix calculation of rate coefficients for electron collisional excitation of Fe xiii is presented and compared to recent calculations of comparable complexity. At temperatures at which Fe 12+ is typically found in the solar corona, the present results, which use the intermediate coupling frame transformation method, show significant differences compared to some earlier work. We use a large configuration interaction calculation with extensive correlation to assess the accuracy of our and earlier workers' scattering targets.

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Section: The Scattering Targetmentioning

confidence: 54%

Section: The Scattering Targetmentioning

confidence: 68%

Section: The Scattering Targetmentioning

confidence: 90%

Section: The Scattering Targetmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Atomic data from the IRON project

Storey¹,

Zeippen

2010

A&A

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Synthetic Spectra of the Fe VIII – Fe XVI Emission Lines for Electron Non-Thermal Distributions

Dzifčáková

Tothova

2007

Sol Phys

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A certain class of non-thermal electron distributions can exhibit more monoenergetic shape and a higher peak than the Maxwellian distribution. This type of electron distribution can be observed mainly in flaring plasmas. We have studied the influence of this kind of electron energy distribution on the excitation equilibrium of Fe VIIIFe XVI in the solar corona. The changes in synthetic spectra of the emission lines belonging to these ions due to this non-thermal distribution are shown. The possibilities of finding the shape of the energy distribution function of electrons from the Fe line ratios are also discussed. The results can be used for diagnostics of coronal plasmas where the deviations of particle energy distributions from the Maxwellian one can be significant.

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Solar UV and X-ray spectral diagnostics

Zanna

Mason

2018

Living Rev Sol Phys

194

139

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X-ray and ultraviolet (UV) observations of the outer solar atmosphere have been used for many decades to measure the fundamental parameters of the solar plasma. This review focuses on the optically thin emission from the solar atmosphere, mostly found at UV and X-ray (XUV) wavelengths, and discusses some of the diagnostic methods that have been used to measure electron densities, electron temperatures, differential emission measure (DEM), and relative chemical abundances. We mainly focus on methods and results obtained from high-resolution spectroscopy, rather than broad-band imaging. However, we note that the best results are often obtained by combining imaging and spectroscopic observations. We also mainly focus the review on measurements of electron densities and temperatures obtained from single ion diagnostics, to avoid issues related to the ionisation state of the plasma. We start the review with a short historical introduction on the main XUV high-resolution spectrometers, then review the basics of optically thin emission and the main processes that affect the formation of a spectral line. We mainly discuss plasma in equilibrium, but briefly mention non-equilibrium ionisation and non-thermal electron distributions. We also summarise the status of atomic data, which are an essential part of the diagnostic process. We then review the methods used to measure electron densities, electron temperatures, the DEM, and relative chemical abundances, and the results obtained for the lower solar atmosphere (within a fraction of the solar radii), for coronal holes, the quiet Sun, active regions and flares.

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Collision Strengths for Electron Impact Excitation of Fine‐Structure Levels in Fexiii

Cited by 21 publications

References 21 publications

Atomic data from the IRON project

Atomic data from the IRON project

Synthetic Spectra of the Fe VIII – Fe XVI Emission Lines for Electron Non-Thermal Distributions

Solar UV and X-ray spectral diagnostics

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