Results 1 to 10 of about 162 (82)
Adaptive Algorithm for the Generation of Superconfigurations in Hot-Plasma Opacity Calculations [PDF]
Plasma, 2022 In hot plasmas, such as the ones encountered in astrophysics or laser-fusion studies, the number of ionic excited states may become huge, and the relevant electron configurations cannot always be handled individually.
Jean-Christophe Pain
doaj +4 more sources
Optimized recursion relation for the computation of partition functions in the superconfiguration approach [PDF]
High Energy Density Physics, 2020 Partition functions of a canonical ensemble of non-interacting bound electrons are a key ingredient of the super-transition-array approach to the computation of radiative opacity. A few years ago, we published a robust and stable recursion relation for the calculation of such partition functions.
Pain, Jean-Christophe +2 more
arxiv +10 more sources
A comparison of detailed level and superconfiguration models of neon [PDF]
Journal of Quantitative Spectroscopy and Radiative Transfer, 2006 The superconfiguration (SC) approach to collisional-radiative modeling can significantly decrease the computational demands of finding non-LTE level populations in complex systems. However, it has not yet been fully determined whether the statistical averaging of SC models leads to a significant loss of accuracy.
Hansen, S B +4 more
openaire +4 more sources
Checking the reliability of opacity databases [PDF]
, 2023 Mathematical inequalities, combined with atomic-physics sum rules, enable one to derive lower and upper bounds for the Rosseland and/or Planck mean opacities. The resulting constraints must be satisfied, either for pure elements or mixtures. The intriguing law of anomalous numbers, also named Benford's law, is of great interest to detect errors in line-
Croset, Patricia, Pain, Jean-Christophe
arxiv +3 more sources
A superconfiguration approach to multi-electron ionization of Xe under strong x-ray irradiation [PDF]
Journal of Physics B: Atomic, Molecular and Optical Physics, 2013 The production of highly ionized states in xenon under intense x-ray irradiation, is discussed with the help of specific calculations. The approach, which retains only one-photon absorption processes (photoionization and photoexcitation) as well as Auger and radiative relaxations, makes use of properly defined superconfigurations as a global ensemble ...
Peyrusse, O., Deschaud, B., Rolles, D.
openaire +5 more sources
Simulations of collisional effects in an inner-shell solid-density Mg X-ray laser [PDF]
Philos Trans A Math Phys Eng Sci, 2023 Inner-shell K$\alpha$ x-ray lasers have been created by pumping gaseous, solid, and liquid targets with the intense x-ray output of free-electron-lasers (FELs). For gaseous targets lasing relies on the creation of K-shell core-holes on a time-scale short
Ren S, Vinko S, Wark J.
europepmc +1 more source
Resistivity in warm dense plasmas beyond the average-atom model [PDF]
, 2009 The exploration of atomic properties of strongly coupled partially degenerate plasmas, also referred to as warm dense matter, is important in astrophysics, since this thermodynamic regime is encountered for instance in Jovian planets' interior. One of the most important issues is the need for accurate equations of state and transport coefficients.
Benage +18 more
arxiv +3 more sources
A new Gaussian MCTDH program: implementation and validation on the levels of the water and glycine molecules. [PDF]
J Chem Phys, 2014 We report the main features of a new general implementation of the Gaussian Multi-Configuration Time-Dependent Hartree model. The code allows effective computations of time-dependent phenomena, including calculation of vibronic spectra (in one or more ...
Skouteris D, Barone V.
europepmc +3 more sources
New approach to dense plasma thermodynamics in the superconfiguration approximation
Laser and Particle Beams, 2002 We propose a new approach to the calculation of ion populations in the LTE dense plasmas in the superconfiguration approximation. The screening of plasma ions is obtained using the same free-electron chemical potential for each ion charge. This chemical potential is determined by iteration keeping the total density constant and varying the volume ...
Thomas Blenski, J.-Ch. Pain
openaire +3 more sources
Journal of Physics B: Atomic, Molecular and Optical Physics, 2023 Abstract One of the challenges in calculating the opacity of dense plasmas is the difficulty in consistently modeling electrons bound to nuclei and those that exist within the continuum of free states in electronic structure models. We address this issue by adapting the green’s function approach, originally developed for use in average ...
N M Gill, C J Fontes, C E Starrett
openaire +3 more sources