[en] All the available data on L₃ subshell fluorescence yields, ω, have been collected. Suitably chosen criteria were used to select a reliable data set and these were then fitted to a polynomial of the 7th degree. The fitted values are then compared with the other fitted, semi-empirical and theoretical values. (author)

[en] It is pointed out that different definitions of weak and strong diffusion of electrons in the magnetosphere do not necessarily agree with each other. If the concept of weak and strong diffusion introduced by Kennel and Petschek(1966) is used then the electron diffusion at L≤ 1.5 would be expected to be virtually always weak. (author). 7 refs

[en] The deviations of the experimental L-subshell ionization cross sections relative to the first order perturbation theories are discussed in terms of vacancy transfer between the L-subshells during the collisions, by means of a two-step model in the impact parameter formulation. (authors)

[en] The occurrence of a line at 2.1556 A in the L emission spectrum of cerium and two lines at 1.6679 and 1.8379 A in the L emission spectrum of samarium, reported many years ago, has remained a puzzle. These have now been identified as EXAFS minima occurring at the L absorption edges of the respective elements. (author)

No abstract available

[en] The L absorption spectra of γ- and α-Ce have been measured. The L₂ and L₃ spectra of both systems show white lines, but α-Ce exhibits an additional peak 9 eV above the white line. The white line and the EXAFS of α-Ce are correctly described by the single particle picture. We deduce that α-Ce is not valence fluctuating, and that it has the same valence (3⁺) as γ-Ce. We suggest that the α-peak arises from a process in which the 2p and the 4f electrons are simultaneously excited into empty 5d states. (orig.)

[en] We report measurements of the line polarization of Ne-like and F-like of iron n=3 to n=2 transitions in the x-ray region. We used the ''two-crystal technique'' developed in previous polarization measurements in our laboratory. Preliminary results from our measurements are presented together with the theoretical calculations using the Flexible Atomic Code (FAC). Our calculations show that contributions from cascades play an important role in the polarization calculations of most of the transitions. The uncertainties and difficulties of our experiments are also discussed

[en] The superconfiguration (SC) approach to collisional-radiative modeling can significantly decrease the computational demands of finding non-LTE level populations in complex systems. However, it has not yet been fully determined whether the statistical averaging of SC models leads to a significant loss of accuracy. The present work compares results from two independent models: a detailed-level accounting (DLA) model based on HULLAC data and the SC model MOST. The relatively simple level structures of the K- and L-shell ions of the neon test system ensure a tractable number of levels in the DLA model but challenge the statistical assumptions of the SC approach. Nonetheless, we find fair agreement between the two models for average ion charges, SC populations, and various effective temperatures

No abstract available

No abstract available