Extensive tabulations of Stark broadened hydrogen line profiles

Stehlé, C.; Hutcheon, R. J.

doi:10.1051/aas:1999118

Cited by 190 publications

(186 citation statements)

References 21 publications

(30 reference statements)

Supporting

Mentioning

182

Contrasting

Order By: Relevance

“…The electron density in the divertor volume, n e,V , is determined via a spectroscopic measurement of the Stark broadened D line. Synthetic Stark broadened line shapes, calculated and published by Stehlé [7] based on the model microfield method, are convoluted with the instrument function and the Doppler broadening of a fixed neutral temperature of T n = 5 eV. These shapes are fitted to the measured lines in a least square sense, in which n e,V is a fit parameter.…”

Section: Discharge and Diagnostic Setupmentioning

confidence: 99%

Characterization of the fluctuating detachment state in ASDEX Upgrade

Potzel

Wischmeier

Bernert

et al. 2013

Journal of Nuclear Materials

View full text Add to dashboard Cite

In this article we present experimental investigations of divertor detachment in ASDEX Upgrade. For this purpose we performed a series of ohmic and LMode density ramp discharges. The electron density in the divertor volume is determined with a spectroscopic measurement of the Stark broadened line shape of the D line. These measurements are combined with several other diagnostics, yielding a consistent picture of detachment. It will be shown that detachment in ASDEX Upgrade is not a continuously evolving process but can be divided into three different states. Within these states, the conditions in the inner and outer divertor are strongly coupled. Radiative fluctuations, measured with fast diode bolometers, combined with a region of high electron density appear at the X-point during one of these states. We show how N 2 seeding during this state alters the divertor conditions. Finally an unstable situation was found, where the divertor plasma oscillates between two detachment states.

show abstract

Section: Discharge and Diagnostic Setupmentioning

confidence: 99%

Characterization of the fluctuating detachment state in ASDEX Upgrade

Potzel

Wischmeier

Bernert

et al. 2013

Journal of Nuclear Materials

View full text Add to dashboard Cite

show abstract

“…The Hα profiles were computed using the ATLAS9 models and a modified version of the BALMER code 1 . The self-broadening of Hα was treated with the Barklem et al (2000b,a) theory, and for the Stark broadening the computations of Stehlé & Hutcheon (1999) were used. Adopted stellar parameters are listed in Table 2.…”

Section: Atmospheric Parametersmentioning

confidence: 99%

Three carbon-enhanced metal-poor dwarf stars from the SDSS

Behara

Bonifacio

Ludwig

et al. 2010

A&A

135

View full text Add to dashboard Cite

Context. The origin of carbon-enhanced metal-poor stars enriched with both s and r elements is highly debated. Detailed abundances of these types of stars are crucial to understand the nature of their progenitors. Aims. The aim of this investigation is to study in detail the abundances of SDSS J1349-0229, SDSS J0912+0216 and SDSS J1036+1212, three dwarf CEMP stars, selected from the Sloan Digital Sky Survey. Methods. Using high resolution VLT/UVES spectra (R ∼ 30 000) we determine abundances for Li, C, N, O, Na, Mg, Al, Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni and 21 neutron-capture elements. We made use of CO 5 BOLD 3D hydrodynamical model atmospheres in the analysis of the carbon, nitrogen and oxygen abundances. NLTE corrections for Ci and Oi lines were computed using the Kiel code. Results. We classify SDSS J1349-0229 and SDSS J0912+0216 as CEMP-r+s stars. SDSS J1036+1212 belongs to the class CEMPno/s, with enhanced Ba, but deficient Sr, of which it is the third member discovered to date. Radial-velocity variations have been observed in SDSS J1349-0229, providing evidence that it is a member of a binary system. Conclusions. The chemical composition of the three stars is generally compatible with mass transfer from an AGB companion. However, many details remain difficult to explain. Most notably of those are the abundance of Li at the level of the Spite plateau in SDSS J1036+1212 and the large over-abundance of the pure r-process element Eu in all three stars.

show abstract

“…P.S.B. independently determined the effective temperatures of both stars by applying the Stark broadening theory described in Stehlé & Hutcheon (1999) and the self-broadening theory of Barklem et al (2000), using MARCS model atmospheres, and adopting HERES surface gravities and metallicities. Synthetic profiles fits were performed for both Hα and Hβ, using an automated procedure (see Barklem et al 2002).…”

Section: Stellar Parametersmentioning

confidence: 99%

The Hamburg/ESO R-process enhanced star survey (HERES)

Hayek

Wiesendahl

Christlieb

et al. 2009

A&A

109

View full text Add to dashboard Cite

AstrophysicsThe Hamburg/ESO R-process enhanced star survey (HERES) The analysis is based on high-quality VLT/UVES spectra and MARCS model atmospheres. We detect lines of 15 heavy elements in the spectrum of CS 29491−069, and 18 in HE 1219−0312; in both cases including the Th II 4019 Å line. The heavy-element abundance patterns of these two stars are mostly well-matched to scaled solar residual abundances not formed by the s-process. We also compare the observed pattern with recent high-entropy wind (HEW) calculations, which assume core-collapse supernovae of massive stars as the astrophysical environment for the r-process, and find good agreement for most lanthanides. The abundance ratios of the lighter elements strontium, yttrium, and zirconium, which are presumably not formed by the main r-process, are reproduced well by the model. Radioactive dating for CS 29491−069 with the observed thorium and rare-earth element abundance pairs results in an average age of 9.5 Gyr, when based on solar r-process residuals, and 17.6 Gyr, when using HEW model predictions. Chronometry seems to fail in the case of HE 1219−0312, resulting in a negative age due to its high thorium abundance. HE 1219−0312 could therefore exhibit an overabundance of the heaviest elements, which is sometimes called an "actinide boost".IV

show abstract

Extensive tabulations of Stark broadened hydrogen line profiles

Cited by 190 publications

References 21 publications

Characterization of the fluctuating detachment state in ASDEX Upgrade

Characterization of the fluctuating detachment state in ASDEX Upgrade

Three carbon-enhanced metal-poor dwarf stars from the SDSS

The Hamburg/ESO R-process enhanced star survey (HERES)

Contact Info

Product

Resources

About