Simulations of hot, dense iron plasma opacity at 89eV and comparison with experiment

Whittaker, D. S.; Edwards, M. H.; Tallents, G. J.

doi:10.1016/j.hedp.2007.03.003

Cited by 9 publications

(8 citation statements)

References 45 publications

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“…2a. Figure 2b shows the combined effect of the submodes, of the number of levels included in the calculation, and of the contributions of the dominant ions for iron at T = 25 eV and = 8 mg/cm 3 (conditions discussed in [5]). Dotted red curve corresponds to full CI mode, including n = 3 → n = 4("3L − 4L") transitions (Ni VII, 91,944 levels, NEGVEC = 159, 742, 731), (Ni VIII, 42,660 levels, NEGVEC = 28, 017, 451), (Ni IX, 39,274 levels, NEGVEC = 18, 325, 729), (Ni VIII, 28,906 levels, NEGVEC = 9, 629, 517).…”

Section: Configuration Interaction (Ci) Treatment In Hullac-v9mentioning

confidence: 99%

Influence of the number of atomic levels on the spectral opacity of low temperature nickel and iron in the spectral range 50–300 eV

Busquet¹,

Klapisch²,

Gilles

2013

EPJ Web of Conferences

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Abstract. Opacity is a fundamental ingredient for the secular evolution of stars. The calculation of the stellar plasma absorption coefficients is complex due to the composition of these plasmas, generally an H /He dominated mixture with a low concentration of partially ionized heavy ions (the iron group). The international collaboration OPAC recently presented extensive comparisons of spectral opacities of iron and nickel for temperatures between 15 and 40 eV and for densities of ∼ 3 mg/cm 3 , relevant to the stellar envelope conditions [1,2]. The role of Configuration Interaction (CI) and the influence of the number of atomic levels on the opacity using the recently improved version of HULLAC atomic code [3,4] are illustrated in this article. Comparisons with theoretical predictions already presented in [1] are discussed.

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Section: Configuration Interaction (Ci) Treatment In Hullac-v9mentioning

confidence: 99%

Influence of the number of atomic levels on the spectral opacity of low temperature nickel and iron in the spectral range 50–300 eV

Busquet¹,

Klapisch²,

Gilles

2013

EPJ Web of Conferences

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“…In a companion paper, definitions and illustrations of these calculations are given [7]. In this paper we compare also HULLAC-v9 predictions to two experimental conditions 1/ Da Silva et al (iron) [8,9] and 2/ LULI 2010 experiment (nickel) first analysis [2].…”

Section: Theoretical Opacity Spectra For Pulsating Stellar Envelope C...mentioning

confidence: 99%

“…3 Iron: comparison with transmission spectrum at 25eV and 8 mg/cm 3 The transmitted measurement of Da Silva et al [8,9] covers the spectral range from ≈ 50 to 120 eV where the opacity is dominated by contributions from Δn= 0, n= 3 iron transitions below 80 eV and n= 3 -> n= 4 transitions ("3L-4L") above 80 eV. This sub-keV spectral region is known to be dominant for the Rosseland mean opacity.…”

Section: Configuration Interaction (Ci) Treatments In Theoretical Cod...mentioning

confidence: 99%

Iron and Nickel spectral opacity calculations in conditions relevant for pulsating stellar envelopes and experiments

Gilles

Turck‐Chièze

Busquet³

et al. 2013

EPJ Web of Conferences

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Abstract. Seismology of stars is strongly developing. To address this question we have formed an international collaboration, OPAC, to perform specific experimental measurements, compare opacity calculations, and improve the opacity calculations in stellar codes [1]. We consider the following opacity codes: SCO, CASSANDRA, STA, OPAS, LEDCOP, OP, SCO-RCG. Their comparison has shown large differences for Fe and Ni in equivalent conditions of envelopes of type II supernova precursors, temperatures between 15 and 40 eV and densities of a few mg/cm 3 [2-4]. LEDCOP, OPAS, SCO-RCG structure codes and STA give similar results and differ from OP ones for the lower temperatures and for spectral interval values [3]. In this work we discuss the role of Configuration Interaction (CI) and the influence of the number of used configurations. We present and include in the opacity code comparisons new HULLAC-v9 calculations [5,6] that include full CI. To illustrate the importance of this effect we compare different CI approximations (modes) available in HULLAC-v9 [7]. These results are compared to previous predictions and to experimental data. Differences with OP results are discussed. THEORETICAL OPACITY SPECTRA FOR PULSATING STELLAR ENVELOPE CONDITIONSIn recent papers [2,3] we have compared a large number of opacity calculations for experimental conditions relevant for stellar envelope conditions of intermediate mass stars. The temperatures are between 15 and 40 eV and densities of a few mg/cm 3 . The codes are based on different approaches: statistical (SCO, STA), detailed (OPAS, OP, LEDCOP) or mixed (SCO-RCG) [2][3][4]. These comparisons show some differences in the frequency-dependent spectra among all codes but at low temperature and in the spectral range of our comparisons, indicate a clearly distinct behavior of the OP spectra with a

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“…Opacity contributions due to bound–bound, bound–free and free–free transitions are considered in our modelling. Details of the approach used for our opacity model can be found elsewhere (Whittaker et al 2007). Bound–free cross‐sections from a central potential model (Reilmann & Manson 1978) are used throughout the calculations.…”

Section: Modelling Approachmentioning

confidence: 99%

“…In both experiments, the plasma was created by indirect heating from quasi‐Planckian radiation fields. Edwards et al (2006) and Whittaker, Edwards & Tallents (2007) recently reported the measurement of iron plasma opacity at a single photon energy (89 eV) using an EUV laser as a probe. Bailey et al (2007) have recently measured the transmission of a backlighter created using a z‐pinch through hot iron plasma over a spectral range of 800–1800 eV, and there are many earlier reports of opacity measurements for photon energies greater than 1 keV (Davidson et al 1988, 1989; Bruneau et al 1991; Foster et al 1991; Perry et al 1991; Gary et al 1995; Perry et al 1995; Back et al 1997; Chenais‐Popovics et al 2000; Thais et al 2003; Hoarty et al 2006; Renaudin et al 2006).…”

Section: Introductionmentioning

confidence: 99%

Iron opacity predictions under solar interior conditions

Whittaker

Tallents

2009

Monthly Notices of the Royal Astronomical Society

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Iron opacity predictions over an extended spectral range are obtained with a model using Opacity Project atomic data for conditions within the solar convective zone. These predictions are compared with the published results of a laboratory experiment using a laser-plasma backlighter. The effect of differing line-broadening treatments on monochromatic and the Rosseland mean opacity is also investigated.

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Simulations of hot, dense iron plasma opacity at 89eV and comparison with experiment

Cited by 9 publications

References 45 publications

Influence of the number of atomic levels on the spectral opacity of low temperature nickel and iron in the spectral range 50–300 eV

Influence of the number of atomic levels on the spectral opacity of low temperature nickel and iron in the spectral range 50–300 eV

Iron and Nickel spectral opacity calculations in conditions relevant for pulsating stellar envelopes and experiments

Iron opacity predictions under solar interior conditions

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