Properties of OV Spectral Lines in Ionizing and Recombining Plasmas

A collisional-radiative model for Be-like oxygen ions has been constructed for OV plasmaspectroscopy. The model takes into account recombination processes as well as collisional ionization, radiative transitions, and collisional excitation/deexcitation. Two sets of atomic data are used for comparison. We obtain OV line intensities as functions of electron temperature and density. The line intensity ratios of 2s3s 35 - 2s3p \u27Pr=o.r., are measured in LHD plasmas and are consistent with our models. The line intensity ratio of 2s2p 3P - 2p"P and 2s2 tS - 2s2p rP in recombining plasma is an increasing function of temperature and one measured in the LHD plasma indicates electron temperature less than 7eV. The ratios measured in steady-state phase are larger than I and difficult to explain with the current model

Cross Sections and Rate Coefficients for Excitation of delta n = 1 Transitions in Li-like Ions with 6 < Z < 42

Excitation cross sections and rate coefficients by electron impact were calculated for the I s^2 2s - I s2s2p, I s^2 2s - Is2s^2 and Is^2 2s - I s2p^2 transitions of the Li-like ions (CIV, NV, OVI, NeVIII, MgX, A1XI, SiXII, SXIV, ArXVI, CaXVIII, TiXX, FeXXIV, NiXXVI, ZnXXVIII, GeXXX, SeXXXII, KrXXXIIV and MoXXXX) in the Coulomb-Bom approximation with exchange including relativistic effects and configuration interaction. Level energies, mixing coefficients and transition wavelengths and probabilities were also computed. Calculations performed by the 1/Z perturbation theory and Coulomb-Born approximation are compared with the R- matrix method and the distorted-wave approximation were Z is the nuclear charge. Formulae obtained for the angular factors of n-electron atomic system allow one to generalize this method to an arbitrary system of highly charged ions

Relativistic Many-Body Calculations of Energies for n = 3 States in Aluminiumlike Ions

Energies of the 148 (3l3l'3l") states for aluminiumlike ions with Z=14-100 are evaluated to second order in relativistic many-body perturbation theory. Second-order Coulomb and Breit-Coulomb interactions are included. Corrections are made to lowest order for the frequency-dependent Breit interaction and for the Lamb shift. A detailed discussion of the various contributions to the energy levels is given for aluminiumlike germanium (Z=32). Comparisons of the calculated energy levels with available experimental data are made for the entire sequence

Dielectronic Recombination Rate Coefficients to Excited States of Be-like Oxygen

We have calculated energy levels, radiative transition probabilities, and autoionizatin rate for Be-like oxygen (O^{4+}) including 1s{^2} 2lnl' (n = 2 - 8, l /leq n - 1) and 1s^2 3l'nl (n = 3 - 6, l leq n - 1) states by multi configurational Hartree-Fock method (Cowan code) and perturbation theory Z-expansion method (MZ code). The state selective dielectronic recombination rate coefficients to excited states of Be-like O ions are obtained. Configuration mixing plays an important role for the principal quantum number n distribution of the dielectronic recombination rate coefficients for 2snl (n /leq 5) levels at low electron temperature. The orbital angular momentum quantum number l distribution of the rate coefficients shows a peak at l = 4. The total dielectronic recombination rate coefficient is derived as a function of electron temperature

Dielectronic Recombination Rate Coefficients to the Excited States of CI From CII

The dielectronic recombination rate coeflicients to the excited states for n=2-6 are calculated including Is^2 2l_1 21_2 21_3 nl (n=2-6, I leq (n-1)) states. The values for the excited states higher than n=6 are extrapolated and the total dielectronic recombination rate coefficients are derived. The rate coefficients to the excited states are fitted to an analytical formula and the fit parameters are given

Spectral Line Intensities of NeVII for Non-equilibrium Ionization Plasma Including Dielectronic Recombination Processes

We have calculated the dielectronic recombination rate coefficients from Li-like Ne (Ne^{7+}) ions to Be-like Ne (Ne^{6+}) ions for selected excited states of Ne^{6+} ions. A collisional-radiative model (CRM) for Ne^{6+} ions is constructed to calculate the population density of each excited state in non-equilibrium ionization plasmas, including recombining processes. NeVII spectral line intensities and the radiative power loss are calculated with the CRM. A density effect caused by collisional excitation from the metastable state 2s2p ^3P is found at an electron density of 10^5 - 10^{17} cm^{-3}. The collisional excitations between excited states become important at high electron temperature T_e >~ 100eV

E1, E2, M1, and M2 Transitions in the Neon Isoelectronic Sequence

A relativistic many-body method is developed to calculate energy and transition rates for multipole transitions in many-electron ions. This method is based on relativistic many-body perturbation theory (MBPT), agrees with MCDF calculations in lowest-order, includes all second-order correlation corrections, includes corrections from negative energy states, and is gauge independent. Reduced matrix elements, oscillator strengths, and transition rates are calculated for electric dipole (E1) and quadrupole (E2) transitions and magnetic dipole (M1) and quadrupole (M2) transitions in Ne-like ions with nuclear charges ranging from Z = 11 to 100. The calculations start from a 1s{^2}2s{^2}2p{^6} Dirac-Fock potential. First-order perturbation theory is used to obtain intermediate-coupling coefficients, and second-order MBPT is used to determine the matrix elements. The contributions from negative-energy states are included in the second-order E1, M1, E2 and M2 matrix elements. The resulting transition energies and transition rates are compared with experimental values and with results from other recent calculation

Dielectronic Recombination Rate Coefficients to the Excited States of CIII from CIV

Energy levels, radiative transition probabilities and autoionization rates for CIII including I s^2 2pnl' (n=2÷6. I' leq (n- l)) and I s^2 3lnl' (n=3÷6, I' leq(n- I )) states were calculated by using multi-configurational Hartree-Fock (Cowan code) method. Autoionizing levels above the Is^2 2s and I s^2 2p thresholds were considered and their contributions were computed. Branching ratios on the autoionization rate to the first threshold and intensity factor were calculated for satellite lines of CIII ion. The dielectronic recombination rate coefficients to the excited states for n=2-6 were calculated. The values for the excited states higher than n=6 were extrapolated and the total dielectronic recombination rate coefficients were also derived. The rate coefficients to the exited states were fitted to an analytical formula and the fitting parameters are given

Dielectronic Recombination Rate Coefficients to the Excited States of CII from CIII

Energy levels, radiative transition probabilities and autoionization rates for CII including Is^2 2l2l'nl" (n=2-6, l leq (n- l)) states were calculated by using multi-configurational Hartree-Fock (Cowan code) method. Autoionizing levels above three thresholds: Is^2 2s^2 (^lS), Is^2 2s2p(^3P), Is^22s2p(^1P) were considered. Branching ratios related to the first threshold and the intensity factor were calculated for satellite lines of CII ion. The dielectronic recombination rate coefficients to the excited states for n=2-6 are calculated with these atomic data. The rate coefficients are fitted to an analytical formula and the fit parameters are given. The values for higher excited states than n=6 are extrapolated and the total dielectronic recombination rate coefficients are derived. The effective recombination rate coefficient for different electron densities are also derived

Excitation Collision Strengths, Cross Sections and Rate Coefficients for OV, SiXI, FeXXIII, MoXXXIX by Electron Impact(1s22s2 -1s22s2p-1s22p2 Transitions)

Excitation collision strengths, cross sections and rate coefficients by electron impact are calculated for the transitions among the Is^22s^2, Is^22p^2, 1 s^22s2p levels of Be-like system of OV, SiXI, FeXXlll and MoXXXIX ions by Coulomb-Born approximation with exchange including relativistic effect and configuration interactions. The theoreticai method for calculation is described and the results are compared with the previous calculations. Numerical data and comparison are presented in Tables as well as in Figures. Two kinds of fitting formulae for cross sections and rate coefficients are discussed