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Related papers: Opacity of Shock-Heated Boron Plasmas

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We present a detailed comparison of two self-consistent equation-of-state models which differ from their electronic contribution: the atom in a spherical cell and the atom in a jellium of charges. It is shown that both models are well…

Plasma Physics · Physics 2009-11-13 Jean-Christophe Pain

Superflares on the solar type stars observed by \textit{Kepler} demonstrate the contrast in the optical continuum of the order 0.1--1 per cent. The mechanism of formation of this radiation is not firmly established. We consider a model…

Solar and Stellar Astrophysics · Physics 2020-04-09 B. A. Nizamov

A photoionized gas in thermal equilibrium can display a thermal instability, with 3 or more solutions in the multi-branch region of the S-shape curve giving the temperature versus the radiation-to-gas-pressure ratio. Many studies have been…

Astrophysics · Physics 2009-11-11 A. C. Goncalves , S. Collin , A. -M. Dumont , L. Chevallier

Path integral Monte Carlo simulations have been used to study deuterium at high pressure and temperature. The equation of state has been derived in the temperature and density region of 10000 < T < 1000000 K and 0.6 < rho < 2.5 gcm-3. A…

Statistical Mechanics · Physics 2017-03-22 Burkhard Militzer

A systematic study of the Hugoniot equation of state, phase transition, and the other thermodynamic properties including the Hugoniot temperature, the electronic and ionic heat capacities, and the Gr\"{u}neisen parameter for…

Materials Science · Physics 2007-05-23 Qili Zhang , Ping Zhang , Haifeng Song , Haifeng Liu

We develop a phenomenological statistical model for dilute star matter at finite temperature, in which free nucleons are treated within a mean-field approximation and nuclei are considered to form a loosely interacting cluster gas. Its…

Nuclear Theory · Physics 2010-12-24 Ad. R. Raduta , F. Gulminelli

Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions, in particular to better constrain the solar abundance problem [S. Basu and H.M. Antia, Physics Reports 457, 217 (2008)].…

Solar and Stellar Astrophysics · Physics 2014-05-19 T. Nagayama , J. E. Bailey , G. Loisel , S. B. Hansen , G. A. Rochau , R. C. Mancini , J. J. MacFarlane , I. Golovkin

We examine the spectrum of diffuse emission detected in the 17' by 17' field around Sgr A* during 625 ks of Chandra observations. The spectrum exhibits He-like and H-like lines from Si, S, Ar, Ca, and Fe, that are consistent with…

We present He-like line ratios (resonance, intercombination and forbidden lines) for totally and partially photoionized media. For solar plasmas, these line ratios are already widely used for density and temperature diagnostics of coronal…

Astrophysics · Physics 2009-10-31 Delphine Porquet , Jacques Dubau

The relationships between the effective surface (T_e) and internal temperatures of neutron stars (NSs) with and without accreted envelopes are calculated for T_e > 5\times10^4 K using new data on the equation of state and opacities in the…

Astrophysics · Physics 2008-02-03 A. Y. Potekhin , G. Chabrier , D. G. Yakovlev

Within the framework of the second order of the non-relativistic quantum perturbation theory, the analytical structure and absolute values of the generalized cross-sections of the two-photon resonant single ionization of the K-shell of…

Atomic Physics · Physics 2025-09-30 Hopersky A. N. , Nadolinsky A. M. , Novikov S. A. , Koneev R.

Quantum molecular dynamic simulations are introduced to study the shock compressed oxygen. The principal Hugoniot points derived from the equation of state agree well with the available experimental data. With the increase of pressure,…

Materials Science · Physics 2015-05-14 Cong Wang , Ping Zhang

Ultracold neutral plasmas are formed by photoionizing laser-cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral…

A scheme for analyzing Thomson scattering of x-rays by warm dense matter, based on the average-atom model, is developed. Emphasis is given to x-ray scattering by bound electrons. Contributions to the scattered x-ray spectrum from elastic…

Plasma Physics · Physics 2012-11-02 W. R. Johnson , J. Nilsen , K. T. Cheng

Opacity determines radiation transport through material media. In a plasma source the primary contributors to atomic opacity are bound-bound line transitions and bound-free photoionization into the continuum. We review the theoretical…

Solar and Stellar Astrophysics · Physics 2023-03-08 Anil Pradhan

The equation of state (EOS) of materials at warm dense conditions poses significant challenges to both theory and experiment. We report a combined computational, modeling, and experimental investigation leveraging new theoretical and…

We present computational results and tables of the equation-of-state, thermodynamic properties, and shock Hugoniot for hot dense fluid deuterium. The present results are generated using a recently developed chemical model that takes into…

Plasma Physics · Physics 2015-11-26 Mofreh R. Zaghloul

We used FUSE to observe ultraviolet emission from diffuse O VI in the hot gas in the Galactic halo. By comparing our result with another, nearby observation blocked by an opaque cloud at a distance of 230 pc, we could subtract off the…

Astrophysics · Physics 2011-02-11 Robin L. Shelton , Shauna M. Sallmen , Edward B. Jenkins

We study the response functions (chromo-electric susceptibilities) for an interacting quark-gluon plasma. The interaction effects have been encoded in the effective fugacities for quasi-partons which are extracted self-consistently from the…

Nuclear Theory · Physics 2014-11-18 Vinod Chandra , Akhilesh Ranjan , V. Ravishankar

In a previous article, with a new code designed for a photoionized thick hot medium using a full transfer treatment of both lines and continuum, we have studied the He-like emission of a medium photoionized by an X-ray source. We considered…

Astrophysics · Physics 2009-11-10 Olivier Godet , Suzy Collin , Anne-Marie Dumont