<i>R</i>-matrix electron-impact excitation data for astrophysically abundant sulphur ions

Liang, G. Y.; Badnell, N. R.; Zhao, Gang; Zhong, Jiayong; Wang, F.L.

doi:10.1051/0004-6361/201117616

Cited by 19 publications

(18 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The number of energy levels of the target ion and the temperature range of the effective collision strength vary significantly. For instance, Tayal (2007) provided effective collision strengths for O ii between 47 energy levels over a temperature range of 10 3.3−5 K. Ramsbottom & Bell (1997) obtained effective collision strengths for Mg vi between 23 energy levels over a temperature range of 10 5.0−6.1 K. Liang et al (2011) provided effective collision strengths for S x between 84 energy levels over a temperature range of 10 4.3−8.3 K. Witthoeft et al (2007) calculated effective collision strengths for Fe xx between 302 energy levels over a temperature range of 10 2.0−8.3 K.…”

Section: Introductionmentioning

confidence: 99%

R-matrix electron-impact excitation data for the N-like iso-electronic sequence

Mao

Badnell

Zanna

2020

A&A

Self Cite

View full text Add to dashboard Cite

Context. Spectral lines from N-like ions can be used to measure the temperature and density of various types of astrophysical plasmas. The atomic databases of astrophysical plasma modelling codes still have room for improvement in their electron-impact excitation data sets for N-like ions, especially for R-matrix data. This is particularly relevant for future observatories (e.g. Arcus), which will host high-resolution spectrometers. Aims. We aim to obtain level-resolved effective collision strengths for all transitions up to nl = 5d over a wide range of temperatures for N-like ions from O II to Zn XXIV (i.e. O+ to Zn23+) and to assess the accuracy of the present work. We also examine the impact of our new data on plasma diagnostics by modelling solar observations with CHIANTI. Methods. We carried out systematic R-matrix calculations for N-like ions, which included 725 fine-structure target levels in both the configuration interaction target and close-coupling collision expansions. The R-matrix intermediate coupling frame transformation method was used to calculate the collision strengths, while the AUTOSTRUCTURE code was used for the atomic structures. Results. We compare the present results for selected ions with those in archival databases and the literature. The comparison covers energy levels, oscillator strengths, and effective collision strengths. We show examples of improved plasma diagnostics when compared to CHIANTI models, which use only distorted wave data as well as some using previous R-matrix data. The electron-impact excitation data are archived according to the Atomic Data and Analysis Structure (ADAS) data class adf04 and will be available in OPEN-ADAS. The data can be used to improve the atomic databases for astrophysical plasma diagnostics.

show abstract

Section: Introductionmentioning

confidence: 99%

R-matrix electron-impact excitation data for the N-like iso-electronic sequence

Mao

Badnell

Zanna

2020

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…Such analysis is worth performing only for highly accurate calculations. Many previous calculations were focused on providing collisional data and the atomic structure was evaluated with CI-based methods (Bhatia & Landi 2003a,b; Witthoeft et al 2007; Landi & Bathia 2008; Ludlow et al 2010; Liang et al 2010, 2011, 2012; Elabidi et al 2012). A large portion of such calculations has been collected in the CHIANTI v8 database (Dere et al 1997; Del Zanna et al 2015).…”

Section: Resultsmentioning

confidence: 99%

“…Multiple spectroscopic techniques have been used, including measurements with the beam-foil technique (Langenberg et al 1980; Yang et al 1980, 2009), lasers (Fawcett et al 1970; Fawcett & Hayes 1973, 1987; Faenov et al 1994), heavy-ion storage rings (Schippers et al 2012) and electron beam ion traps (EBIT) (Lepson & Beiersdorfer 2005; Beiersdorfer et al 2014; Hell et al 2016; Beiersdorfer et al 2017). On the theoretical/computational side, a large body of work has been performed, from systematic calculations of L-shell ions of S (Bhatia & Landi 2003a,b; Karpuškiene˙ et al 2005; Landi & Bathia 2008; Palmeri et al 2008; Luna et al 2009; Martins et al 2009; Fan et al 2009; Liang et al 2011; Pagan et al 2011; Elabidi et al 2012; Li et al 2013; Hell et al 2016) to isoelectronic sequence of various L-shell ions (Witthoeft et al 2007; Jönsson et al 2011; Liang et al 2012; Rynkunb et al 2012; Jönsson et al 2014; Rynkunb et al 2014; Nazé et al 2014; Wang et al 2014, 2015, 2017); see Fan et al (2009) and references therein for a short account of other calculations.…”

Section: Introductionmentioning

confidence: 99%

Relativistic MR-MP Energy Levels for L-shell Ions of Sulfur and Argon

Santana

Lopez-Dauphin

Butler

et al. 2018

ApJS

View full text Add to dashboard Cite

Calculated level energies for valence and K-vacancy states are provided for the ion series S VII - S XIV and Ar IX - Ar XVI. The calculations were performed with the relativistic Multi-Reference Mxller-Plesset Perturbation Theory method (MR-MP). The data set includes all the level energies with configurations 1s22(s, p)q, 1s22(s, p)q−1nl, 1s12(s, p)q+1, 1s12(s, p)qnl, 2(s, p)q+2 and 2(s, p)q+1nl, where 1 ≤ q ≤ 8, n ≤ 5 and l ≤ 3. We have compared our results with data from the National Institute of Standards and Technology (NIST) on-line database and with previous calculations. The average deviation of valence level energies ranges from 0.16 eV in Ne-like ions to 0.01 eV in Li-like ions, showing that the present MR-MP valence level energies are highly accurate. In the case of K-vacancy states, the deviation is generally below 0.3 eV for Li-like S XIV and Ar XVI. The deviation for K-vacancy energies in other L-shell ions (Be-, B-, C-, N- and O-like Ar ions) is higher but likely because the NIST-recommended values have a higher uncertainty. The data set includes many n = 4 and n = 5 valence and K-vacancy levels in L-shell ions of S and Ar not previously reported. The data can be used for line identification and modeling of L-shell ions of S and Ar in astrophysical and laboratory-generated plasmas, and as energy references in the absence of more accurate laboratory measurements.

show abstract

“…In recent years, a large amount of data collected by space-based observatories, such as XMM-Newton, Chandra X-ray observatory and Hubble space telescope, highlighted the need of accurate atomic data for the investigation and classification of the spectra from astrophysical plasma [1][2][3] and laboratory plasmas [4]. In light of the high cosmic abundance of sulfur [5][6][7], many researchers have earlier investigated transition data and spectral lines from sulfur ions experimentally [8][9][10][11][12][13][14][15][16][17][18][19][20] and theoretically [21][22][23][24][25][26][27][28][29][30][31]. In laboratory measurements, most of the earlier published work on the spectra of low-lying multi-excited states in sulfur ions was obtained by beam-foil spectroscopic technique [8][9][10][11][12] and laser spectroscopy technique [13][14].…”

Section: Introductionmentioning

confidence: 99%

“…The theoretical studies include the configuration interaction (CI) method of Ho and Henry [21] and Tayal [22], who used the CIV3 code; and the work of Galavís et al [23] and Elabidi et al [24], who employed the SUPERSTRUCTURE code. Liang et al [25][26] calculated the electron impact excitation data for highly-charged sulfur ions [25] for Na + to Kr 26+ including S 6+ and [26] for S 8+ to S 11+ , using the intermediate coupling frame transformation R-matrix approach. Chen et al [27][28] calculated the K-shell Auger transition energies, transition probabilities, and Kα x-ray from the sulfur ions by the multiconfiguration Dirac-Fock (MCDF) method.…”

Section: Introductionmentioning

confidence: 99%

Energy levels and radiative transitions of the K-shell excited sextet states in boron-like sulfur ion

Sun

Sang

et al. 2016

Can. J. Phys.

View full text Add to dashboard Cite

Theoretical calculations are reported for energy levels and transition probabilities of the K-shell excited sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) for the astrophysically important element sulfur. Energy levels, fine structure splittings, and transition parameters of the high-lying sextet series 6Se,o(m) and 6Po,e(m) (m = 1–7) in boron-like sulfur ion are calculated with the multi-configuration Rayleigh–Ritz variation method. To obtain the accurate energy level, the relativistic corrections and mass polarization effect are included by using the first-order perturbation theory. Configuration structures of these sextet series are assigned according to the energies, percentage contributions of basis states to the eigenvector, relativistic effect corrections, and verification of fine structure splittings. The oscillator strengths, transition probabilities, and wavelengths of electric-dipole transitions between 6So,e(m) and 6Pe,o(m) (m = 1–7) states are also systematically calculated and discussed.

show abstract

R-matrix electron-impact excitation data for astrophysically abundant sulphur ions

Cited by 19 publications

References 29 publications

R-matrix electron-impact excitation data for the N-like iso-electronic sequence

R-matrix electron-impact excitation data for the N-like iso-electronic sequence

Relativistic MR-MP Energy Levels for L-shell Ions of Sulfur and Argon

Energy levels and radiative transitions of the K-shell excited sextet states in boron-like sulfur ion

Contact Info

Product

Resources

About