Radiative Recombination

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M.b. Trzhaskovskaya - One of the best experts on this subject based on the ideXlab platform.

  • Radiative Recombination and Photoionization Data for Tungsten Ions. Electron Structure of Ions in Plasmas
    Atoms, 2015
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin
    Abstract:

    Theoretical studies of tungsten ions in plasmas are presented. New calculations of the Radiative Recombination and photoionization cross-sections, as well as Radiative Recombination and radiated power loss rate coefficients have been performed for 54 tungsten ions for the range W6+–W71+. The data are of importance for fusion investigations at the reactor ITER, as well as devices ASDEX Upgrade and EBIT. Calculations are fully relativistic. Electron wave functions are found by the Dirac–Fock method with proper consideration of the electron exchange. All significant multipoles of the Radiative field are taken into account. The Radiative Recombination rates and the radiated power loss rates are determined provided the continuum electron velocity is described by the relativistic Maxwell–Juttner distribution. The impact of the core electron polarization on the Radiative Recombination cross-section is estimated for the Ne-like iron ion and for highly-charged tungsten ions within an analytical approximation using the Dirac–Fock electron wave functions. The effect is shown to enhance the Radiative Recombination cross-sections by ≲20%. The enhancement depends on the photon energy, the principal quantum number of polarized shells and the ion charge. The influence of plasma temperature and density on the electron structure of ions in local thermodynamic equilibrium plasmas is investigated. Results for the iron and uranium ions in dense plasmas are in good agreement with previous calculations. New calculations were performed for the tungsten ion in dense plasmas on the basis of the average-atom model, as well as for the impurity tungsten ion in fusion plasmas using the non-linear self-consistent field screening model. The temperature and density dependence of the ion charge, level energies and populations are considered.

  • Radiative Recombination data for tungsten ions: I. W24+–W45+
    Atomic Data and Nuclear Data Tables, 2014
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin
    Abstract:

    Abstract We present new accurate data on Radiative Recombination and photoionization cross sections, Radiative Recombination rate coefficients, and radiated power loss rate coefficients for twenty tungsten impurity ions in plasmas that are of importance for the ASDEX Upgrade tokamak. Our calculations are based on the fully relativistic treatment of photoionization and Radiative Recombination. The Dirac–Fock method with proper consideration of the electron exchange interaction is used. All significant multipoles of the Radiative field are taken into account. The Radiative Recombination rates and the radiated power loss rates are found using the thermal average over relativistic cross sections provided the continuum electron velocity is described by the relativistic Maxwell–Juttner distribution. The photoionization and Radiative Recombination cross sections are given in the electron energy range from 1 eV to ∼80 keV. Partial cross sections for ground and excited states are approximated by a simple analytical expression involving five fit parameters. The Radiative Recombination and radiated power loss rates are determined in the temperature range 104–109 K. The total Radiative Recombination rates are fitted in this range by an another analytical expression with four fit parameters.

  • Multipole and relativistic effects in Radiative Recombination process in hot plasmas.
    Physical Review E, 2008
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin, R. E. H. Clark
    Abstract:

    On the basis of the fully relativistic Dirac-Fock treatment of photoionization and Radiative Recombination processes with regard to all multipoles of the Radiative field, we have assessed the influence of nondipole effects on the Radiative Recombination rate coefficients. A formula for the rate coefficient has been derived using the relativistic Maxwell-Boltzmann distribution of continuum electrons instead of the commonly used nonrelativistic distribution. This decreases the Recombination rate coefficient considerably in hot thermal plasmas.

  • Radiative Recombination and photoionization cross sections for heavy element impurities in plasmas
    Atomic Data and Nuclear Data Tables, 2008
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin, R. E. H. Clark
    Abstract:

    Abstract We have performed fully relativistic Dirac–Fock calculations of total cross sections for Radiative Recombination of heavy element impurities with electrons and subshell photoionization cross sections for 31 ions of Fe, Ni, Cu, Mo, and W, which are important elements in plasma studies. The electron kinetic energy range is 4 eV to 50 keV. To obtain the total Radiative Recombination cross section, subshell cross sections were calculated for ground and all excited electron states up to states with principal quantum number n  = 20. The total Radiative Recombination cross sections are presented in tabular and graphical forms. The subshell photoionization cross sections for excited states with n  ⩽ 12 and orbital momenta l ⩽ 6 were fitted by a simple analytical expression with five fit parameters. The fit parameters are tabulated.

V.k. Nikulin - One of the best experts on this subject based on the ideXlab platform.

  • Radiative Recombination and Photoionization Data for Tungsten Ions. Electron Structure of Ions in Plasmas
    Atoms, 2015
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin
    Abstract:

    Theoretical studies of tungsten ions in plasmas are presented. New calculations of the Radiative Recombination and photoionization cross-sections, as well as Radiative Recombination and radiated power loss rate coefficients have been performed for 54 tungsten ions for the range W6+–W71+. The data are of importance for fusion investigations at the reactor ITER, as well as devices ASDEX Upgrade and EBIT. Calculations are fully relativistic. Electron wave functions are found by the Dirac–Fock method with proper consideration of the electron exchange. All significant multipoles of the Radiative field are taken into account. The Radiative Recombination rates and the radiated power loss rates are determined provided the continuum electron velocity is described by the relativistic Maxwell–Juttner distribution. The impact of the core electron polarization on the Radiative Recombination cross-section is estimated for the Ne-like iron ion and for highly-charged tungsten ions within an analytical approximation using the Dirac–Fock electron wave functions. The effect is shown to enhance the Radiative Recombination cross-sections by ≲20%. The enhancement depends on the photon energy, the principal quantum number of polarized shells and the ion charge. The influence of plasma temperature and density on the electron structure of ions in local thermodynamic equilibrium plasmas is investigated. Results for the iron and uranium ions in dense plasmas are in good agreement with previous calculations. New calculations were performed for the tungsten ion in dense plasmas on the basis of the average-atom model, as well as for the impurity tungsten ion in fusion plasmas using the non-linear self-consistent field screening model. The temperature and density dependence of the ion charge, level energies and populations are considered.

  • Radiative Recombination data for tungsten ions: I. W24+–W45+
    Atomic Data and Nuclear Data Tables, 2014
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin
    Abstract:

    Abstract We present new accurate data on Radiative Recombination and photoionization cross sections, Radiative Recombination rate coefficients, and radiated power loss rate coefficients for twenty tungsten impurity ions in plasmas that are of importance for the ASDEX Upgrade tokamak. Our calculations are based on the fully relativistic treatment of photoionization and Radiative Recombination. The Dirac–Fock method with proper consideration of the electron exchange interaction is used. All significant multipoles of the Radiative field are taken into account. The Radiative Recombination rates and the radiated power loss rates are found using the thermal average over relativistic cross sections provided the continuum electron velocity is described by the relativistic Maxwell–Juttner distribution. The photoionization and Radiative Recombination cross sections are given in the electron energy range from 1 eV to ∼80 keV. Partial cross sections for ground and excited states are approximated by a simple analytical expression involving five fit parameters. The Radiative Recombination and radiated power loss rates are determined in the temperature range 104–109 K. The total Radiative Recombination rates are fitted in this range by an another analytical expression with four fit parameters.

  • Multipole and relativistic effects in Radiative Recombination process in hot plasmas.
    Physical Review E, 2008
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin, R. E. H. Clark
    Abstract:

    On the basis of the fully relativistic Dirac-Fock treatment of photoionization and Radiative Recombination processes with regard to all multipoles of the Radiative field, we have assessed the influence of nondipole effects on the Radiative Recombination rate coefficients. A formula for the rate coefficient has been derived using the relativistic Maxwell-Boltzmann distribution of continuum electrons instead of the commonly used nonrelativistic distribution. This decreases the Recombination rate coefficient considerably in hot thermal plasmas.

  • Radiative Recombination and photoionization cross sections for heavy element impurities in plasmas
    Atomic Data and Nuclear Data Tables, 2008
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin, R. E. H. Clark
    Abstract:

    Abstract We have performed fully relativistic Dirac–Fock calculations of total cross sections for Radiative Recombination of heavy element impurities with electrons and subshell photoionization cross sections for 31 ions of Fe, Ni, Cu, Mo, and W, which are important elements in plasma studies. The electron kinetic energy range is 4 eV to 50 keV. To obtain the total Radiative Recombination cross section, subshell cross sections were calculated for ground and all excited electron states up to states with principal quantum number n  = 20. The total Radiative Recombination cross sections are presented in tabular and graphical forms. The subshell photoionization cross sections for excited states with n  ⩽ 12 and orbital momenta l ⩽ 6 were fitted by a simple analytical expression with five fit parameters. The fit parameters are tabulated.

Jean-paul Kleider - One of the best experts on this subject based on the ideXlab platform.

  • Temperature dependence of the Radiative Recombination coefficient in crystalline silicon by spectral and modulated photoluminescence
    physica status solidi (RRL) - Rapid Research Letters, 2017
    Co-Authors: Rudolf Brüggemann, José Alvarez, Mohamed Boutchich, Jean-paul Kleider
    Abstract:

    Phone: þ33 (0)169851645, Fax: þ33 (0)169418318 By the combination of temperature-dependent spectral photo-luminescence with modulated photoluminescence measurements the band-to-band Radiative Recombination coefficient is determined for crystalline silicon without the requirement to model the temperature dependence of the intrinsic carrier density, thus eliminating a source of error. By application of this approach we reproduce the variation of the Radiative Recombination coefficient in crystalline silicon with temperature reported in the literature for temperatures !77 K. Above all, we extend the measured range for the Radiative Recombination coefficient to a temperature of 20 K. In this extended temperature range between 20 and 70 K the Recombination coefficient increases with decreasing temperature by about three orders of magnitude.

  • Temperature dependence of the Radiative Recombination coefficient in crystalline silicon by spectral and modulated photoluminescence
    physica status solidi (RRL) - Rapid Research Letters, 2017
    Co-Authors: Rudolf Brüggemann, José Alvarez, Mohamed Boutchich, Jean-paul Kleider
    Abstract:

    By the combination of temperature-dependent spectral photoluminescence with modulated photoluminescence measurements the band-to-band Radiative Recombination coefficient is determined for crystalline silicon without the requirement to model the temperature dependence of the intrinsic carrier density, thus eliminating a source of error. By application of this approach we reproduce the variation of the Radiative Recombination coefficient in crystalline silicon with temperature reported in the literature for temperatures ≥77 K. Above all, we extend the measured range for the Radiative Recombination coefficient to a temperature of 20 K. In this extended temperature range between 20 and 70 K the Recombination coefficient increases with decreasing temperature by about three orders of magnitude.

R. E. H. Clark - One of the best experts on this subject based on the ideXlab platform.

  • Multipole and relativistic effects in Radiative Recombination process in hot plasmas.
    Physical Review E, 2008
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin, R. E. H. Clark
    Abstract:

    On the basis of the fully relativistic Dirac-Fock treatment of photoionization and Radiative Recombination processes with regard to all multipoles of the Radiative field, we have assessed the influence of nondipole effects on the Radiative Recombination rate coefficients. A formula for the rate coefficient has been derived using the relativistic Maxwell-Boltzmann distribution of continuum electrons instead of the commonly used nonrelativistic distribution. This decreases the Recombination rate coefficient considerably in hot thermal plasmas.

  • Radiative Recombination and photoionization cross sections for heavy element impurities in plasmas
    Atomic Data and Nuclear Data Tables, 2008
    Co-Authors: M.b. Trzhaskovskaya, V.k. Nikulin, R. E. H. Clark
    Abstract:

    Abstract We have performed fully relativistic Dirac–Fock calculations of total cross sections for Radiative Recombination of heavy element impurities with electrons and subshell photoionization cross sections for 31 ions of Fe, Ni, Cu, Mo, and W, which are important elements in plasma studies. The electron kinetic energy range is 4 eV to 50 keV. To obtain the total Radiative Recombination cross section, subshell cross sections were calculated for ground and all excited electron states up to states with principal quantum number n  = 20. The total Radiative Recombination cross sections are presented in tabular and graphical forms. The subshell photoionization cross sections for excited states with n  ⩽ 12 and orbital momenta l ⩽ 6 were fitted by a simple analytical expression with five fit parameters. The fit parameters are tabulated.

Toshihide Takagahara - One of the best experts on this subject based on the ideXlab platform.

  • Radiative Recombination lifetime of excitons in thin quantum boxes
    Journal of Applied Physics, 1997
    Co-Authors: Hideki Gotoh, H. Ando, Toshihide Takagahara
    Abstract:

    Exciton Radiative Recombination lifetime in a thin quantum box in the intermediate spatial dimension between the two-dimension and the zero-dimension is investigated by a theoretical analysis which rigorously treats the electron-hole Coulomb interaction. The higher exciton states as well as the ground exciton state are explicitly taken into account to estimate the temperature dependence of exciton Recombination lifetime. We clarify how the temperature dependence of the Recombination lifetime varies with a change in the quantum confinement dimension which can be controlled by the lateral width of a thin quantum box. We also discuss the effect of the exciton localization due to structural imperfection on the Radiative Recombination lifetime.