Results 261 to 270 of about 197,703 (285)

Opacity measurements of a radiatively heated boron sample

Journal of Quantitative Spectroscopy and Radiative Transfer, 1997
Abstract A preliminary measurement of the opacity of a thin boron foil radiatively heated at moderate temperatures (5–20 eV) in conditions near local-thennodynamic-equilibrium (LTE) are reported. The opacity of a 0.37 μm thick boron sample has been measured in the K-shell range (40–60 A) using a 5000 l mm −1 transmission grating.
H. Merdji, T. Miβalla, F. Gilleron, C. Chenais-Popovics, J.C. Gauthier, P. Renaudin, S. Gary, J. Bruneau   +7 more
openaire   +1 more source

Radiative opacity due to the red system of CN

Journal of Quantitative Spectroscopy and Radiative Transfer, 1972
Abstract Recent observational and theoretical work has indicated that CN may play a major role in forming the spectrum and in fixing the thermal structure in a wide variety of cool stellar atmospheres. As the first step in investigating that role, we have calculated straight mean absorption coefficients over intervals of 100 cm -1 for the red system
Hollis R. Johnson, Irene R. Marenin, Stephan D. Price   +2 more
openaire   +1 more source

Scaling law of radiative opacities for ICF elements

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001
info:eu-repo/semantics ...
Mínguez, E., Ruíz Pablos, Rosa María, Martel, P., Gil, J.M., Rubiano, J.G., Rodríguez, R.   +5 more
openaire   +3 more sources

Calculation of the Radiative Opacity of a Hot Dense Plasma

Contributions to Plasma Physics, 1999
AbstractResults are presented for a theoretical model, known as the ion model (IM), recently elaborated to calculate the radiative opacity of a hot dense plasma. The model is based on the self‐consistent field method for subsystems obeying Gibbs statistics. The model is applied to compound chemical compositions.
openaire   +1 more source

Radiative opacities and photosphere models for soft gamma repeaters

AIP Conference Proceedings, 1996
We consider the radiative processes for conditions expected in photospheres of neutron stars (NSs) with magnetic fields B∼1014–1016 G. The radiative opacities are employed to construct model photospheres and to calculate the spectral flux and specific intensity emitted by these objects which are thought to be associated with Soft Gamma Repeaters (SGRs).
V. G. Bezchastnov, G. G. Pavlov, Yu. A. Shibanov, V. E. Zavlin   +3 more
openaire   +1 more source

Some estimates of the radiative Rosseland mean opacity

Journal of Quantitative Spectroscopy and Radiative Transfer, 1967
Abstract The effect of atomic number Z on the Rosseland mean opacity is presented in graphic form for a large range of temperatures and densities. This permits a rapid determination of the dominant process and, in many cases, greatly simplifies the calculation of a good approximation of the Rosseland mean opacity.
openaire   +1 more source

Analytical Models of Instantaneous Radiative Forcing Across Opacity Regimes

Journal of Climate
Radiative forcing by carbon dioxide depends on the difference between surface and stratospheric temperature scaled by the logarithm of its concentration (Wilson and Gea-Banacloche 2012; Jeevanjee et al. 2021). This relationship arises due to the cooling-to-space theory or the \(\tau=1\) law, where all emission of infrared radiation originates from ...
Paulina Czarnecki, Lorenzo Polvani, Robert Pincus   +2 more
openaire   +1 more source

Stochastic radiative transfer in random media. III. Effective opacity

Physical Review E
Homogenization of random media is a practical approach to efficiently simulate stochastic radiative transfer, which requires establishing a reliable effective opacity model. In this work, a new effective opacity model is developed by considering the two-point spatial correlations of the opacity fluctuation, which is further simplified by introducing ...
Cong-Zhang Gao, Jian-Wei Yin, Ying Cai, Zheng-Feng Fan, Pei Wang, Jian-Guo Wang   +5 more
openaire   +2 more sources

Development of radiative opacity code OPIND for high energy density plasma and its application in radiation hydrodynamics

Journal of Quantitative Spectroscopy and Radiative Transfer, 2021
Madhusmita Das, Chandrani Bhattacharya
exaly  

Theoretical isochrones from models with new radiative opacities

1994
In this paper we present large grids of theoretical isochrones for the initial chemical compositions [Z=0.0004, Y=0.23], [Z=0.004, Y=0.24], [Z=0.008, Y=0.25], [Z=0.02, Y=0.28], and [Z= 0.05, Y=0.352] and ages in the range 4 10(6) yr to 16 10(9) yr. These isochrones are derived from stellar models computed with the most recent radiative opacities by ...
Bertelli G., Bressan A., Chiosi, C., Fagottio, F., Nasi, E.   +4 more
openaire   +1 more source