accedaCRIShttps://accedacris.ulpgc.es/jspuiThe accedaCRIS digital repository system captures, stores, indexes, preserves, and distributes digital research material.Fri, 08 Dec 2023 22:51:26 GMT2023-12-08T22:51:26Z50221Calculation of radiative opacity of plasma mixtures using a relativistic screened hydrogenic modelhttp://hdl.handle.net/10553/45554Title: Calculation of radiative opacity of plasma mixtures using a relativistic screened hydrogenic model
Authors: Mendoza, M.A.; Rubiano, J. G.; Gil, J. M.; Rodriguez, R.; Florido, R.; Espinosa, G.; Martel, P.; Mínguez, Emilio
Abstract: We present the code ATMED based on an average atom model and conceived for fast computing the population distribution and radiative properties of hot and dense single and multicomponent plasmas under LTE conditions. A relativistic screened hydrogenic model (RSHM), built on a new set of universal constants considering j-splitting, is used to calculate the required atomic data. The opacity model includes radiative bound–bound, bound–free, free–free, and scattering processes. Bound–bound line-shape function has contributions from natural, Doppler and electron-impact broadenings. An additional dielectronic broadening to account for fluctuations in the average level populations has been included, which improves substantially the Rosseland mean opacity results. To illustrate the main features of the code and its capabilities, calculations of several fundamental quantities of one-component plasmas and mixtures are presented, and a comparison with previously published data is performed. Results are satisfactorily compared with those predicted by more elaborate codes.
Wed, 01 Jan 2014 00:00:00 GMThttp://hdl.handle.net/10553/455542014-01-01T00:00:00ZParametrization of the average ionization and radiative cooling rates of carbon plasmas in a wide range of density and temperaturehttp://hdl.handle.net/10553/45555Title: Parametrization of the average ionization and radiative cooling rates of carbon plasmas in a wide range of density and temperature
Authors: Gil, J. M.; Rodriguez, R.; Florido, R.; Rubiano, J. G.; Mendoza, Miguel A.; De La Nuez Cruz, Arabela; Espinosa, G.; Martel, P.; Mínguez, E.
Abstract: In this work we present an analysis of the influence of the thermodynamic regime on the monochromatic emissivity, the radiative power loss and the radiative cooling rate for optically thin carbon plasmas over a wide range of electron temperature and density assuming steady state situations. Furthermore, we propose analytical expressions depending on the electron density and temperature for the average ionization and cooling rate based on polynomial fittings which are valid for the whole range of plasma conditions considered in this work.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10553/455552013-01-01T00:00:00ZAnalysis of microscopic magnitudes of radiative blast waves launched in xenon clusters with collisional-radiative steady-state simulationshttp://hdl.handle.net/10553/45556Title: Analysis of microscopic magnitudes of radiative blast waves launched in xenon clusters with collisional-radiative steady-state simulations
Authors: Rodriguez, R.; Espinosa, G.; Gil, J. M.; Florido, R.; Rubiano, J. G.; Mendoza, M.; Martel, P.; Minguez, Emilio; Symes, Daniel R.; Hohenberger, Matthias; Smith, R. A.
Abstract: Radiative shock waves play a pivotal role in the transport energy into the stellar medium. This fact has led to many efforts to scale the astrophysical phenomena to accessible laboratory conditions and their study has been highlighted as an area requiring further experimental investigations. Low density material with high atomic mass is suitable to achieve radiative regime, and, therefore, low density xenon gas is commonly used for the medium in which the radiative shocks such as radiative blast waves propagate. In this work, by means of collisional-radiative steady-state calculations, a characterization and an analysis of microscopic magnitudes of laboratory blast waves launched in xenon clusters are made. Thus, for example, the average ionization, the charge state distribution, the cooling time or photon mean free paths are studied. Furthermore, for a particular experiment, the effects of the self-absorption and self-emission in the specific intensity emitted by the shock front and that is going through the radiative precursor are investigated. Finally, for that experiment, since the electron temperature is not measured experimentally, an estimation of this magnitude is made both for the shock shell and the radiative precursor.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10553/455562013-01-01T00:00:00ZAnalysis of the influence of the plasma thermodynamic regime in the spectrally resolved and mean radiative opacity calculations of carbon plasmas in a wide range of density and temperaturehttp://hdl.handle.net/10553/45559Title: Analysis of the influence of the plasma thermodynamic regime in the spectrally resolved and mean radiative opacity calculations of carbon plasmas in a wide range of density and temperature
Authors: Gil, J. M.; Rodriguez, R.; Martel, P.; Florido, R.; Rubiano, J. G.; Mendoza, M. A.; Minguez, E.
Abstract: In this work the spectrally resolved, multigroup and mean radiative opacities of carbon plasmas are calculated for a wide range of plasma conditions which cover situations where corona, local thermodynamic and non-local thermodynamic equilibrium regimes are found. An analysis of the influence of the thermodynamic regime on these magnitudes is also carried out by means of comparisons of the results obtained from collisional-radiative, corona or Saha–Boltzmann equations. All the calculations presented in this work were performed using ABAKO/RAPCAL code.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10553/455592013-01-01T00:00:00ZRelativistic screened hydrogenic radial integralshttp://hdl.handle.net/10553/45558Title: Relativistic screened hydrogenic radial integrals
Authors: Ruano, F. H.; Rubiano, J. G.; Mendoza, M.A.; Gil, J. M.; Rodriguez, R.; Florido, R.; Martel, P.; Mínguez, E.
Abstract: The computation of dipole matrix elements plays an important role in the study of absorption or emission of radiation by atoms in several fields such as astrophysics or inertial confinement fusion. In this work we obtain closed formulas for the dipole matrix elements of multielectron ions suitable for using in the framework of a Relativistic Screened Hydrogenic Model.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10553/455582013-01-01T00:00:00ZDevelopment of an analytical potential to include excited configurationshttp://hdl.handle.net/10553/46066Title: Development of an analytical potential to include excited configurations
Authors: Rodriguez, R; Rubiano, JG; Gil, JM; Martel, P.; Mínguez, E.; Florido, R
Abstract: Excited configurations are very important in dense plasma physics. In this work we propose a new analytical potential for excited configurations obtained from another one for ground configuration. With this potential several atomic magnitudes have been calculated for ions in excited configurations analyzing what kind of excited configurations introduce more influences in those magnitudes. Using this potential, atomic data generated are satisfactorily compared with those obtained using other analytical potential using sophisticated self-consistent codes, and with others available in the bibliography.
Tue, 01 Jan 2002 00:00:00 GMThttp://hdl.handle.net/10553/460662002-01-01T00:00:00ZA screened hydrogenic model using analytical potentialshttp://hdl.handle.net/10553/46068Title: A screened hydrogenic model using analytical potentials
Authors: Rubiano, JG; Rodriguez, R; Gil, JM; Ruano, F. H.; Martel, P.; Mínguez, E.
Abstract: The screened hydrogenic model and analytical potentials are tools widely used for atomic calculation of dense plasma physics. In this paper, we present a simple method to obtain screened hydrogenic energy levels and wave functions from analytical potentials for ions. Atomic data obtained using this model are compared satisfactorily with results of similar models and of more sophisticated self-consistent codes.
Tue, 01 Jan 2002 00:00:00 GMThttp://hdl.handle.net/10553/460682002-01-01T00:00:00ZRelativistic quantum mechanic calculation of photoionization cross-section of hydrogenic and non-hydrogenic states using analytical potentialshttp://hdl.handle.net/10553/46061Title: Relativistic quantum mechanic calculation of photoionization cross-section of hydrogenic and non-hydrogenic states using analytical potentials
Authors: Rodríguez, R.; Gil, J. M.; Rubiano, JG; Florido, R.; Martel, P.; Mínguez, E.
Abstract: Photoionization process is a subject of special importance in many areas of physics. Numerical methods must be used in order to obtain photoionization cross-sections for non-hydrogenic levels. The atomic data required to calculate them is huge so self-consistent calculations increase computing time considerably. Analytical potentials are a useful alternative because they avoid the iterative procedures typical in self-consistent models. In this work, we present a relativistic quantum calculation of photoionization cross-sections for isolated ions based on an analytical potential to obtain the required atomic data, which is valid both for hydrogenic and non-hydrogenic ions. Comparisons between our results and others obtained using either widely used analytical expressions for the cross-sections or more sophisticated calculations are done.
Sat, 01 Jan 2005 00:00:00 GMThttp://hdl.handle.net/10553/460612005-01-01T00:00:00ZLow Z opacities at high densitieshttp://hdl.handle.net/10553/46064Title: Low Z opacities at high densities
Authors: Schott, R.; Philippe, F.; Angelo, P.; Dufour, E.; Poquérusse, A.; Dalimier, E.; Sauvan, P.; Minguez, E.; Gil, J. M.; Rubiano, J. G.; Rodriguez, R.; Martel, P.; Mancini, R.
Abstract: We present an experimental study devoted to measuring the opacity of bound–bound transitions in ultra-dense, hot, low Z plasmas, which are at the extreme limit for conditions of both emission spectroscopy and absorption spectroscopy. In this work, we develop an absorption spectroscopy experiment specially adapted to high-density diagnostics, using newly designed structured targets and an ultra-high resolution spectrograph. An aluminum plasma is chosen as the first candidate and the opacity of the He-like 1s2–1s2p (Heβ) and 1s2–1s3p (Heγ) transitions are measured.
Wed, 01 Jan 2003 00:00:00 GMThttp://hdl.handle.net/10553/460642003-01-01T00:00:00ZAnalytical expressions for the n-order momenta of charge distribution for ionshttp://hdl.handle.net/10553/46073Title: Analytical expressions for the n-order momenta of charge distribution for ions
Authors: Martel, P.; Rubiano, JG; Gil, JM; Doreste, L.; Mínguez, E.
Abstract: In this work a family of four analytic expressions for the n-order momenta of the charge distribution for ions, 〈rn〉, depending on three, two, or one parameters will be presented. These expressions are derived through the use of electronic charge densities obtained from a family of four analytical potentials. The parameters in the expressions were obtained for ions in the ground state from helium to uranium isoelectronic sequences. The use of these parameters allows to find analytical expressions for the 〈rn〉 as functions of the nuclear charge, Z, only. Finally, the results obtained are compared with results computed by different methods.
Thu, 01 Jan 1998 00:00:00 GMThttp://hdl.handle.net/10553/460731998-01-01T00:00:00ZCalculation of the radiative opacity of laser-produced plasmas using a relativistic-screened hydrogenic modelhttp://hdl.handle.net/10553/46062Title: Calculation of the radiative opacity of laser-produced plasmas using a relativistic-screened hydrogenic model
Authors: Rubiano, JG; Florido, R; Rodriguez, R; Gil, JM; Martel, P.; Mínguez, E.
Abstract: n this work, we use a relativistic-screened hydrogenic model to compute the radiative opacity of laser-produced plasmas. The model is based on a set of screening charges which allow one to easily calculate atomic properties of isolated ions. These screened charges have been fitted to a fourth-order polynomial depending on the nuclear charge Z for ground and single excited states of ions belonging to the isoelectronic sequences comprised between He-like to U-like. In the opacity model used, ionic populations are obtained by solving the Saha equation including degeneracy corrections. Bound–bound transitions are determined using a Voigt profile for line shape, which includes natural, collisional, Doppler and UTA widths. Bound–free and free–free opacities are evaluated using the Kramer cross-sections with appropriate corrections. Scattering processes are computed through the use of the Thomson formula with corrections. The results are compared with other screened hydrogenic models and more sophisticated self-consistent codes.
Wed, 01 Jan 2003 00:00:00 GMThttp://hdl.handle.net/10553/460622003-01-01T00:00:00ZAn effective analytical potential including plasma effectshttp://hdl.handle.net/10553/46067Title: An effective analytical potential including plasma effects
Authors: Gil, J. M.; Martel, P.; Mínguez, E.; Rubiano, JG; Rodríguez, R.; Ruano, F. H.
Abstract: In this work, we have developed a method to build an effective analytical potential for ions in slightly nonideal plasmas. This proposed potential is obtained from an analytical isolated potential with one or two parameters depending on the total number of electrons of the ion. The plasma effects are included by means of the linearized Debye–Hückel approximation taking into account the reaction of the plasma-charge density to the optical electron. Due to the influence of the plasma over the atomic potential, this permits to obtain level energies and wave functions as a function of the inverse of Debye radius, the quantum numbers, the nuclear charge, the bound electron number and the ionization state of the ion. Also, we compare the analytical effective potential proposed in this paper with other ones very well known in the available literature.
Tue, 01 Jan 2002 00:00:00 GMThttp://hdl.handle.net/10553/460672002-01-01T00:00:00ZA comparison of two atomic models for the radiative properties of dense hot low Z plasmashttp://hdl.handle.net/10553/46065Title: A comparison of two atomic models for the radiative properties of dense hot low Z plasmas
Authors: Mínguez, E.; Sauvan, P.; Gil, J. M.; Rodríguez, R.; Rubiano, JG; Florido, R.; Martel, P.; Angelo, P.; Schott, R.; Philippe, F.; Leboucher-Dalimier, E.; Mancini, R.
Abstract: In this work, two different atomic models (ANALOP based on parametric potentials and IDEFIX based on the dicenter model) are used to calculate the opacities for bound–bound transitions in hot dense, low Z plasmas, and the results are compared to each other. In addition, the ANALOP code has been used to compute free–bound cross sections for hydrogen-like ions.
Wed, 01 Jan 2003 00:00:00 GMThttp://hdl.handle.net/10553/460652003-01-01T00:00:00ZInfluence of the atomic description and configuration interaction effects on collisional-radiative calculations of low ionized carbon plasmashttp://hdl.handle.net/10553/46051Title: Influence of the atomic description and configuration interaction effects on collisional-radiative calculations of low ionized carbon plasmas
Authors: Rodriguez, R.; Florido, R.; Gil, J. M.; Rubiano, J. G.; Martel, P.; Minguez, E.
Abstract: An analysis of the influence of the atomic description and the configuration interaction effects in the calculation of plasma average ionization and relevant plasma radiative properties such as the spectrally resolved emissivities and opacities, radiative power losses and mean opacities, is performed. Since the larger effects of the configuration interaction are due to the lower ionization stages, i.e. CI and CII ions, the low temperature regime is analysed. However, a wide range of plasma densities is considered, covering this way different plasma thermodynamic regimes.
Thu, 01 Jan 2009 00:00:00 GMThttp://hdl.handle.net/10553/460512009-01-01T00:00:00ZSurface monitoring based on light scattering by metal nanosensorshttp://hdl.handle.net/10553/42727Title: Surface monitoring based on light scattering by metal nanosensors
Authors: Albella, Pablo; María Saiz, Jose; González, Francisco; Moreno, Fernando
Sat, 01 Jan 2011 00:00:00 GMThttp://hdl.handle.net/10553/427272011-01-01T00:00:00ZA method to obtain approximate solutions to the Schrodinger equationhttp://hdl.handle.net/10553/72840Title: A method to obtain approximate solutions to the Schrodinger equation
Authors: Ruano, FH; García Rubiano, Jesús
Abstract: In this paper, we put forward a method to solve the Schrodinger equation with an arbitrary central or monodimensional potential. To check this method we apply it to find the approximate solution for the Schrodinger equation with a Debye potential. This solution is compared successfully with numerical calculation from the literature.
Thu, 01 Jan 2004 00:00:00 GMThttp://hdl.handle.net/10553/728402004-01-01T00:00:00ZA parametric potential for ions from helium to iron isoelectronic sequenceshttp://hdl.handle.net/10553/53962Title: A parametric potential for ions from helium to iron isoelectronic sequences
Authors: Martel, P.; Doreste, L.; Mínguez, E.; Gil, J. M.
Abstract: It is shown that a new family of analytical potentials with one, two or three parameters produces similar results to those obtained with more complex models. The parameters of the potential are obtained by an iterative procedure with a selfconsistent relativistic potential that has corrections at large distances, and considers the exchange and correlation energy by means of the local density approximation. The analysis of the results obtained with the family of analytical potentials (eigenvalues, eigenfunctions and atomic energies) allowed us to propose a parametric potential with one or two parameters that depends on the electron number of ion. These parameters were fitted to power series in Z for intermediate and highly ionized atoms from helium to iron isoelectronic sequences. Finally, using this analytic potential, we obtained oscillator strengths for lithium and soduim like gold, which are compared with other models.
Sun, 01 Jan 1995 00:00:00 GMThttp://hdl.handle.net/10553/539621995-01-01T00:00:00ZPhotoionization cross section of non-hydrogenic levels for weakly coupled plasmashttp://hdl.handle.net/10553/47293Title: Photoionization cross section of non-hydrogenic levels for weakly coupled plasmas
Authors: Rodríguez, R.; Gil, J. M.; Florido, R.
Abstract: Photoionization process is a subject of special importance in many areas of physics. Numerical methods must be used in order to obtain photoionization cross-sections for non-hydrogenic levels. The atomic data required to calculate them is huge and self-consistent calculations increase computing time considerably, overall when we are studying plasmas where it is found million of ion levels. Analytical potentials are a useful alternative because they avoid the iterative procedures typical in self-consistent models. In this work, we present a relativistic quantum-mechanic calculation of photoionization cross-sections for non-hydrogenic ions immersed in weakly coupled plasmas. Both the energy levels and bound and free wave functions are determined by means of the Dirac equation. It is employed as effective potential an analytical one developed to model non-isolated many-electron ions making use of the Debye–Hückel approach but including the reaction of the plasma-charge density to the optical electron. The effect of the plasma screening in the photoionization cross-section and in the threshold energy is analyzed as a function of the photon energy, the Debye radius, the ionization and the mono-electronic bound level involved in the transition. Some comparisons between our results and others are also made.
Mon, 01 Jan 2007 00:00:00 GMThttp://hdl.handle.net/10553/472932007-01-01T00:00:00ZAnalysis of radiative opacities for optically thin and thick astrophysical plasmashttp://hdl.handle.net/10553/57432Title: Analysis of radiative opacities for optically thin and thick astrophysical plasmas
Authors: Espinosa Vivas, Guadalupe; Rodríguez Pérez, Rafael; Gil, Juan Miguel
Abstract: The resolution of the radiative transfer equation in radiation-hydrodynamic simulations of astrophysical plasmas require radiative opacities. In this work, an analysis of the monochromatic and multigroup opacities of an astrophysical plasma mixture has been carried out. The study has been made in ranges of electron temperatures and densities of 1−1000 eV and 1011−1020 cm−3, respectively, a wide range of plasma conditions that can be found in several astrophysical scenarios where local and non-local thermodynamic regimes are attained. Collisional-radiative calculations were performed to obtain the plasma level populations and the monochromatic opacities in that range of plasma conditions, covering both thermodynamic regimes. Since the astrophysical mixture includes chemical elements from hydrogen to iron, their contribution to the total opacity will depend on the plasma conditions and we have made a characterization of their contribution as a function of the electron density and temperature and also of the photon frequency. Multigroup and gray approaches are commonly used in the radiative transfer equation in radiation-hydrodynamic calculations. We have analyzed the influence of the number of the groups in the accuracy of the multigroup opacities and we have showed that, for a given plasma condition, the opacity of the multicomponent plasma in the gray approach may be considerably influenced by only some of the contributing elements, due to the influence of the weighting function in the mean, which can lead to great differences with respect to the monochromatic opacity. Finally, since there are situations in which the self-absorption of the plasma radiation becomes relevant due to the dimensions of the plasma, we have performed an analysis of the influence of the radiation trapping in the monochromatic and multigroup opacities in terms of the plasma conditions and the width of the plasma slab, assuming the plasma with planar geometry and we have also studied the departures of the local thermodynamic regime.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10553/574322019-01-01T00:00:00ZInfluence of the substrate optical properties on the backscattering of contaminated microstructureshttp://hdl.handle.net/10553/42739Title: Influence of the substrate optical properties on the backscattering of contaminated microstructures
Authors: Albella, P.; Moreno, F.; Saiz, J. M.; González, F.
Tue, 01 Jan 2008 00:00:00 GMThttp://hdl.handle.net/10553/427392008-01-01T00:00:00ZApplication of the polar decomposition to light scattering particle systemshttp://hdl.handle.net/10553/42736Title: Application of the polar decomposition to light scattering particle systems
Authors: Sanz, J. M.; Albella, P.; Moreno, F.; Saiz, J. M.; González, F.
Thu, 01 Jan 2009 00:00:00 GMThttp://hdl.handle.net/10553/427362009-01-01T00:00:00Z2D double interaction method for modeling small particles contaminating microstructures located on substrateshttp://hdl.handle.net/10553/42740Title: 2D double interaction method for modeling small particles contaminating microstructures located on substrates
Authors: Albella, P.; Moreno, F.; Saiz, J. M.; González, F.
Mon, 01 Jan 2007 00:00:00 GMThttp://hdl.handle.net/10553/427402007-01-01T00:00:00Z