Ionization equilibrium and radiative energy loss rates for C, N, and O ions in low-density plasmas

Experimental O VI dielectronic recombination rate coefficient and its enhancement by external electric fields

“…a) The thick grey curve results from our measured rate coefficient without the  extrapolation (see text). Also shown is the theoretical DR rate coefficient of Nussbaumer & Storey (1983) (dotted line) and the recommended DR rate coefficient of Arnaud & Rothenflug (1985) (dashed line) who combined the calculations of Nussbaumer & Storey (1983) for low energies and calculations of Jacobs et al (1978) as fitted by Shull & van Steenberg (1982) factor of 0.8 has been applied to the calculated DR cross section such that the theoretical DR spectrum matches the experimental one in the energy range of 2-11 eV. At higher energies where the experimental result is influenced by field ionization of high Rydberg states, it is simply substituted by the scaled  calculation.…”

“…2b) are only valid for temperatures above ≈26 500 K. The Burgess (1965) general formula (GFI) overestimates the rate coefficient by ≈60%. The data of Shull & van Steenberg (1982) is based on results of Jacobs et al (1978) and is within the experimental uncertainty above ≈10 5 K. McLaughlin & Hahn (1984) calculated the DR rate coefficient for temperatures above 6.5 × 10 5 K. At 4 × 10 6 K it underestimates the experimentally derived rate coefficient by ≈35%. The results of Aldrovandi & Péquignot (1973) have been calculated using the GFI including ∆n 0 DR which is the reason for the additional difference between theory and experiment above 2 × 10 5 K. Relativistic intermediate coupling calculations have been carried out by Chen (1991) for temperatures beyond 10 5 K. The result is shown in Fig.…”

Dielectronic recombination data for dynamic finite-density plasmas

“…LS-coupling results were first presented for the C, N, O, Ne, Mg, Si, S, Ca, Fe, and Ni isonuclear ions by Jacobs et al (1977Jacobs et al ( , 1978Jacobs et al ( , 1979Jacobs et al ( , 1980. They used a simplified model where the autoionization rates are obtained from the threshold values of the partial-wave electron-impact excitation cross sections for the corresponding ions, and radiative decay of autoionizing states was approximated as the ionic core radiative decay rate.…”

Analysis of a Series of Solar Flare X-Ray Spectra.

“…In addition to the collision strengths discussed above, we used ionization equilibrium calculations by Jacobs et al (1977Jacobs et al ( , 1978 Figure 4 illustrates the uncertainty in c(T) for one of the spectra.…”