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 ions for a wide range of laboratory plasma conditions: coronal, local thermodynamic equilibrium or nonlocal thermodynamic equilibrium, and optically thin or thick plasmas. ABAKO combines a set of analytical approximations to atomic rates, which yield substantial savings in computer running time, still comparing well with more elaborate codes and experimental data. A simple approximation to calculate the electron capture cross section in terms of the collisional excitation cross section has been adapted to work in a detailed-configuration-accounting approach, thus allowing autoionizing states to be explicitly included in the kinetics in a fast and efficient way. Radiation transport effects in the atomic kinetics due to line trapping in the plasma are taken into account via geometry-dependent escape factors. Since the kinetics problem often involves very large sparse matrices, an iterative method is used to perform the matrix inversion. In order to illustrate the capabilities of the model, we present a number of results which show that the ABAKO compares well with customized models and simulations of ion population distribution. The utility of ABAKO for plasma spectroscopic applications is also outlined.
1 January 2017 in Journal of Environmental Radioactivity
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 high Z optically thin and thick plasmas, both under local thermodynamic equilibrium and non-local thermodynamic equilibrium conditions, named RAPCAL is presented. This code has been developed with the aim of providing accurate radiative properties for low and medium Z plasmas within the context of detailed level accounting approach and for heavy elements under the detailed configuration accounting approach. In order to show the capabilities of the code, there are presented calculations of some radiative properties for carbon, aluminum, krypton and xenon plasmas under local thermodynamic and non-local thermodynamic equilibrium conditions.
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 within the circuit. Radon concentration in the water samples studied varies between 0.3 and 76.9 Bq/L. Spanish radiological protection regulations limit the concentration of 222Rn for drinking water to 100 Bq/L, therefore the values obtained for all the analyzed samples are below this threshold. The hydrogeological study reveals a significant correspondence between the radon activity concentration and the material characteristics of the aquifer. For a selected group of samples with high radon concentrations, gross alpha activity has been determined to have values higher than the prescriptive screening level (0.1 Bq/L).
1 October 1995 in Journal of Quantitative Spectroscopy and Radiative Transfer