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X-ray spectra of H- and He-like ions (and satellites) from argon, calcium and chlorine have been measured in Alcator C-Mod tokamak plasmas using a high wavelength resolution imaging x-ray spectrometer system. For H-like charge states, the Lyα doublet intensity ratio is found to be slightly greater than 1/2 due to interaction with the 2S1/2 fine structure sub-level. Neighbouring satellites with spectator electrons occupying n = 2 through n = 7 have been modelled. The Lyα doublet ratio scalings with electron density and temperature are shown to be in good agreement with collisional–radiative modelling. For He-like ions, the n = 2 satellite intensities are in good agreement with calculations and can be used to determine the electron temperature. The high n Rydberg series has been resolved up to 1s2–1s14p, and satellites with spectator electrons up to the n = 12 level have been identified. [ABSTRACT FROM AUTHOR]

Relativistic many-body perturbation theory, including the Breit interaction, is used to evaluate energy levels, radiative matrix elements and autoionization rates for 1s2l2l' states of lithium-like Mo39 +, Pr56 +, W71 + and Hg77 +. Radiative and non-radiative data are combined to obtain branching ratios, intensities and effective emission rate coefficients of dielectronic satellite lines. Relative intensity factors are shown graphically for the 1s2l'2l''-1s22l radiative transitions in lithium-like ions with nuclear charges Z ranging from 6 to 100; however, our emphasis here is on dielectronic recombination rates in the four lithium-like ions listed above. Such data, for high-Z ions in particular, are relevant to spectroscopic diagnostics of very high-temperature plasmas including future experiments at the International Thermonuclear Experimental Reactor. [ABSTRACT FROM AUTHOR]

The Hartree-Fock relativistic method (Cowan code) and the relativistic many-body perturbation theory are used to perform a large-scale calculation of atomic parameters for dielectronic recombination (DR) of Pd-like Xe8+. The energy levels, radiative transition probabilities and autoionization rates are reported for 4d94fnl, 4d95l'nl, (n= 5-8) and 4d96lnl (n= 6-7) states in Ag-like Xe7+. The partial and total DR rate coefficients are calculated with account of high-n states, and contribution of different atomic configurations to DR is discussed. The branching ratios and intensity factors are calculated for dielectronic satellite lines. The obtained results can be used for modelling of various Xe plasmas including those used in lithography applications. [ABSTRACT FROM AUTHOR]