Jesús García Rubiano

Universidad de Las Palmas de Gran Canaria | ULPGC · Department of Physics

The ninth International Symposium Monitoring of Mediterranean Coastal Areas: Problems and Measurements Techniques was organized by CNR-IBE in collaboration with Italian Society of Silviculture and Forest Ecology, and Natural History Museum of the Mediterranean and under the patronage of University of Florence, Accademia dei Lincei, Accademia dei Ge...

The modelization is based in a real model building in Saelices el Chico (Salamanca, Spain). This prototype was designed to study radon entries and mitigation techniques. It has been monitorized since 2006.

The aim of this study is to analyse the role of natural radionuclides ²²⁶Ra, ²²⁸Ra, ⁴⁰K and unsupported ²¹⁰Pb (²¹⁰Pbex), as erosion and accumulation process tracers. For this purpose, a complex system, including both the characteristic dynamics of a closed beach and those associated with a beach open to wave action, was studied. A 3-year study of m...

The recommendations of the European Atomic Energy Community (EURATOM) have recently been incorporated into Spanish regulations in the Basic Document of Health Standards of the Technical Building Code (CTE), section HS6, on protection against radon exposure. This further accentuates the need to delimit radon prone areas as a strategy to address meas...

Knowledge of coastal sedimentary dynamics is an essential tool in the sustainable management of high-value natural places, such as beaches, which play an important role in human life. With this aim, spatio-temporal variations of activity concentrations of the main natural radionuclides in intertidal sand samples were measured in order to analyse th...

The Basic Safety Standard (BSS) Directive 2013/59/EURATOM of the European Union (EU) has stated the need for member states to establish national action plans to mitigate their general population's long-term risks of exposure to radon gas. Maps of radon-prone areas provide a useful tool for the development of such plans. This paper presents the maps...

Nowadays, the use of wild and culture harvest seaweed in food industry is a booming productive sector. In this context, a radiological characterization of five globally common seaweed species that were collected in arrival on Gran Canaria coast was carried out. The studied algae species were Cymopolia barbata, Lobophora variegata, Sargassum vulgare...

The aim of this paper is to characterize two HPGe gamma-ray detectors used in two different laboratories for environmental radioactivity measurements, so as to perform efficiency calibrations by means of Monte Carlo Simulation. To achieve such an aim, methodologies developed in previous papers have been applied, based on the automatic optimization...

Numerical simulations of laboratory astrophysics experiments on plasma flows require plasma microscopic properties that are obtained by means of an atomic kinetic model. This fact implies a careful choice of the most suitable model for the experiment under analysis. Otherwise, the calculations could lead to inaccurate results and inappropriate conc...

In this work, we have developed a computational methodology for characterizing HPGe detectors by implementing in parallel a multi-objective evolutionary algorithm, together with a Monte Carlo simulation code. The evolutionary algorithm is used for searching the geometrical parameters of a model of detector by minimizing the differences between the...

The Canary Islands archipielago (Spain) comprises seven main volcanic islands and several islets that form a chain extending for around 500 km across the eastern Atlantic, between latitudes 27°N and 30°N, with its eastern edge only 100 km from the NW African coast. The administrative province of Las Palmas comprises the three eastern Canary Islands...

The determination in a sample of the activity concentration of a specific radionuclide by gamma spectrometry needs to know the full energy peak efficiency (FEPE) for the energy of interest. The difficulties related to the experimental calibration make it advisable to have alternative methods for FEPE determination, such as the simulation of the tra...

222Rn has been detected in 28 groundwater samples from the northeast of Gran Canaria (Canary Islands, Spain) utilizing a closed loop system consisting of an AlphaGUARD monitor that measures radon activity concentration in the air by means of an ionization chamber, and an AquaKIT set that transfers dissolved radon in the water samples to the air wit...

This work is divided into two parts. In the first one, a study of radiative properties (such as monochromatic and the Rosseland and Planck mean opacities, monochromatic emissivities, and radiative power loss) and of the average ionization and charge state distribution of xenon plasmas in a range of plasma conditions of interest in laboratory astrop...

A computational investigation based on collisional-radiative simulations of a supersonic and radiatively cooled aluminum plasma jet is presented. The jet, both in vacuum and in argon ambient gas, was produced on the MAGPIE (Mega Ampere Generator for Plasma Implosion Experiments) generator and is formed by ablation of an aluminum foil driven by a 1....

Radiative shock waves are ubiquitous throughout the universe and play a crucial role in the transport of energy into the interstellar medium. This fact has led to many efforts to scale the astrophysical phenomena to accessible conditions. In some laboratory experiments radiative blast waves are launched in clusters of gases by means of the direct d...

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...

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 o...

Concentrations of natural radionuclides 226Ra, 232Th, 40K and man-made 137Cs in most important tourist Gran Canaria beaches have been determined using a high-purity Germanium detector to analyse their radiological hazard. Average values of the activity concentrations of 226Ra, 232Th and 40K were 17.6±1.4, 21.3±1.8 and 480±22 Bq kg−1, respectively....

The Atomic Physics Group at the Institute of Nuclear Fusion (DENIM) in Spain has accumulated experience over the years in developing a collection of computational models and tools for determining some relevant microscopic properties of, mainly, ICF and laser-produced plasmas in a variety of conditions. In this work several applications of those mod...

Fundamental research and modelling in plasma atomic physics continue to be essential for providing basic understanding of many different topics relevant to high-energy-density plasmas. The Atomic Physics Group at the Institute of Nuclear Fusion has accumulated experience over the years in developing a collection of computational models and tools fo...

In this work several relevant parameters and properties for krypton and xenon plasmas are analyzed, such as, for example, the average ionization, the plasma thermodynamic regimes, the radiative power losses and the mean opacities. This analysis is performed in a range of density and temperature typically found in laboratory experiments to generate...

Xenon is a common element employed, for example, as impurity in magnetically confined plasmas or the medium in which radiative shocks propagate in laboratory astrophysics. In both situations, it is required the knowledge of plasma parameters such as the average ionization, the charge state distribution, the atomic level populations and the radiativ...

This article has been published in the Early View section of www.cpp-journal.org: 19 APR 2011 with the DOI number: 10.1002/ctpp.201000104 and is equal to the article: Determination and Analysis of the Thermodynamic Regimes of Xenon Plasmas (pages 863–876) R. Rodriguez, J.M. Gil, R. Florido, J.G. Rubiano, M.A. Mendoza, P. Martel, and E. Minguez publ...

A new Relativistic Screened Hydrogenic Model has been developed to calculate atomic data needed to compute the optical and thermodynamic properties of high energy density plasmas. The model is based on a new set of universal screening constants, including nlj-splitting that has been obtained by fitting to a large database of ionization potentials a...

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...

In this work we present a set of atomic models (called ABAKO/RAPCAL), and its validation with experiments and with other NLTE models. We consider that our code permits the diagnosis and the determination of opacity data. A review of calculations and simulations for the validation of this set is presented.As an interesting product of these calculati...

In this work we obtain analytical expressions for the radiative opacity of several low Z plasmas (He, Li, Be, and B) in a wide range of temperatures and densities. These formulas are obtained by fitting the proposed expression to mean opacities data calculated by using the code ABAKO/ RAPCAL. This code computes the radiative properties of plasmas,...

Non-local thermodynamic equilibrium (NLTE) conditions are universal in laboratory and astrophysical plasmas and, for this reason, the theory of NLTE plas-mas is nowadays a very active subject. The populations of atomic levels and radiative properties are essential magnitudes in the study of these plasmas and the calculation of those properties reli...

Radiative properties of hot dense plasmas remain a subject of current interest since they play an important role in inertial confinement fusion (ICF) research, as well as in studies on stellar physics. In particular, the understanding of ICF plasmas requires emissivities and opacities for both hydro-simulations and diagnostics. Nevertheless, the ac...

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 i...

In a simple previous analysis the ratio of local emission profiles of carbon impurities (C^4+ at 227.1 nm and C^5+ at 529.0 nm) measured from TJ-II plasmas was found to have a significant dependence of neutral density profile. Hence, the aim of this work is to have a better theoretical understanding of this system and finally validate or discard th...

We discuss the modeling of population kinetics of nonequilibrium steady-state plasmas using a collisional-radiative model and code based on analytical rates (ABAKO). ABAKO can be applied to low-to-high Z ions for a wide range of laboratory plasma conditions: coronal, local thermodynamic equilibrium or nonlocal thermodynamic equilibrium, and optical...

A code has been developed for calculating opacities of hot dense plasmas. This uses the average atom model and a new relativistic screened-hydrogenic model to calculate energy levels and occupation numbers in order to obtain opacities with contributions from bound-bound, bound-free, free-free and scattering processes under LTE conditions.

This work describes ABAKO∕RAPCAL, a flexible computational package for the study of population kinetics and radiative properties of non‐equilibrium plasmas in a wide range of physical conditions. The code was developed looking for an optimal compromise between accuracy and computational cost. ABAKO∕RAPCAL assembles a set of simple analytical models...

We present a first study of spectroscopic determination of electron temperature and density spatial profiles of aluminum K-shell line emission spectra from laser-shocked aluminum experiments performed at LULI. The radiation emitted by the aluminum plasma was dispersed with an ultra-high resolution spectrograph (lambda/Deltalambda~6000). From the re...

Radiative properties are fundamental for plasma diagnostics and hydro-simulations. For this reason, there is a high interest in their determination and they are a current topic of investigation both in astrophysics and inertial fusion confinement research. In this work a flexible computation package for calculating radiative properties for low and...

The purpose of this work is to calculate the multifrequential and mean opacity of optically thin carbon plasmas in a wide range of density and temperature, where corona equilibrium, local thermodynamic equilibrium and non-local thermodynamic equilibrium regimes are present.

In this work we present ABAKO, a new computational code based on analytical models and developed to study the population kinetics of steady-state plasmas. The tool ABAKO can be applied to low-to-high Z ions under a wide range of laboratory plasma conditions: coronal, LTE or NLTE, optically thin or thick plasmas. Autoionizing states are explicitly i...

The accurate computation of radiative opacities is basic in the ICF target physics analysis, in which the radiation is an important feature to determine in detail. For this reason, accurate analytical formulas for giving mean opacities versus temperature and density of the plasma seem to be a useful tool. In this work we analyse some analytical exp...

In this work it is accomplished a study of radiative properties of aluminium plasmas. It is analyzed the calculation of spectrally resolved and mean opacities both under NLTE and LTE approaches. Furthermore, the effect of the re-absorption of the radiation in these magnitudes is also examined. The calculations were performed into the detailed-level...

In this work is accomplished the determination of the corona, local and non-local thermodynamic equilibrium regimes for optically thin carbon plasmas in steady state, in terms of the plasma density and temperature using the ABAKO code. The determination is made through the analysis of the plasma average ionization and ion and level populations. The...

In this work we analyze the behavior of Pl anck and Rosseland mean opacites of carbon plasmas in a wide range of temperature and densities to propose si mple analytical expressions for these quantities. Carbon is one of the most interesting elem ents under investigation, since it is likely to be a major plasma-facing wall component in ITER, and it...

In several research fields of current interest such as astrophysics or inertial fusion confinement the knowledge of the interactions between the photons and the plasma particles, i.e. plasma radiative properties, result essential. Thus, for example, the understanding of these plasmas requires properties such as emissivities and opacities both for h...

We review the critical results of the 4th Non-LTE Code Comparison Workshop held in December 2005. To test the NLTE population kinetics codes, both steady-state and time-dependent cases for C, Ar, Fe, Sn, Xe, and Au plasmas were selected for detailed comparisons. Additional features such as the effects of non-Maxwellian free electrons, the influence...

As it is known, x-rays have special relevance as a major diagnostic tool of the plasma. Thus, x-ray emission is a primary process occurring during both the evolution and the expansion phases of the plasma and it is the main detectable process carrying information on the plasma during the stages of plasma production and heating, and, therefore, the...

We present a steady-state collisional-radiative (CR) model for the calculation of level populations in non-homogeneous plasmas with planar geometry. The line photon transport is taken into account following an angle- and frequency-averaged escape probability model. Several models where the same approach has been used can be found in the literature,...

We calculate different optical properties for carbon plasma in a wide range of temperatures and densities by using ATOM3R-OP code which has been recently developed. We have calculated average ionizations, level populations, opacities and emissivities and we focus our study on the identification with our code of Coronal Equilibrium, Non Local Thermo...

A flexible code developed to obtain optical properties for plasmas in a wide range of densities and temperatures named ATOM3R-OP is presented. It is structured in three modules devoted to the calculation of the atomic magnitudes, the ionic abundances and the optical properties, respectively, which are briefly described. Finally, some results and re...

In work a hydrogenic versions of the code ATOM3R-OP is presented. This flexible code has been developed to obtain optical properties for plasmas in a wide range of densities and temperatures named and the Hydrogenic versions is intended to couple with hydrodynamic codes. The code is structured in three modules devoted to the calculation of the atom...

We present a steady-state collisional-radiative (CR) model for the calculation of level populations in non-homogeneous plasmas with planar geometry. The line photon transport is taken into account following an angle- and frequency-averaged escape probability model. Several models where the same approach has been used can be found in the literature,...

In this work, we first presents a review of the work that research teams have developed in collaboration in order to determine the optical properties of plasmas during the recent years, and showing the achievements reached. The second part of this paper is devoted to one of these improvements, which is to include reabsorption of the radiation i...

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 a...

In this paper, we put forward a method to solve the Schrödinger equation with an arbitrary central or monodimensional potential. To check this method we apply it to find the approximate solution for the Schrödinger equation with a Debye potential. This solution is compared successfully with numerical calculation from the literature.

In 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...

Photoionization process is a subject of special importance in many areas of physics. Numerical methods must be used 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 alternativ...

In 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...

ANALOP is a opacity calculation code with uses analytical potentials for obtaining the atomic data required. In this work a brief review of ANALOP is done and its new improvements are detailed and commented. In a second part, an application of this code is presented to obtain average ionization and several lines of aluminium ions inmersed in plasma...

A target design for inertial confinement fusion (ICF), based on jet production was studied with ARWEN code. ARWEN is a 2D adaptive mesh refinement fluid dynamic and multigroup radiation transport. An experimental device to reproduce collisions of two shock waves, scaled to roughly represent cosmic supernova remnants was featured. It was found that...

Abstract In this work, two di9erent 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...

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...