[en] High-precision lifetime measurements of the metastable 1s²2s²2p²P⁰_3/2 level in boronlike Ar XIV and the 3s²2p ²P⁰_3/2 level in aluminumlike Fe XIV were performed at the Heidelberg electron beam ion trap (HD-EBIT). The lifetimes were inferred by monitoring their optical decay curves resulting from the magnetic dipole (M1) transition 1s²2s²2p²P⁰_3/2-²P⁰_1/2 and 3s²3p ²P⁰_3/2-²P⁰_1/2 to the ground state configuration with transition wavelengths of 441.256 nm and 530.29 nm, respectively. Possible systematic error sources were investigated by studying the dependence of the decay times of the curves on various trapping conditions with high statistical significance. A new trapping scheme for lifetime measurements at an EBIT has been applied and allowed to reach an unprecedented precision in the realm of lifetime determinations on highly charged ions. The results of 9.573(4)(⁺¹²_-5) ms (stat)(syst) for Ar XIV and 16.726(10)(+17) ms (stat)(syst) for Fe XIV with a relative accuracy of 0.14% and 0.13%, respectively, make these measurements for the first time sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM). The results, improving the accuracy of previous measurements by factors of 10 and 6, respectively, show a clear discrepancy of about 3σ and 4σ to the trend of existing theoretical models, which in almost all cases predict a shorter lifetime, when adjusted for the EAMM. The obvious disagreement between experimental results and the predictions points at the incompleteness of the theoretical models used. (orig.)

[en] 70 women with an equivocal gynecological examination were examined by computer tomography (CT). All patients were submitted to surgery. A good correlation between operative and CT findings was found (87%). CT seems to be helpful in detecting pelvic masses, especially if they can not be located by palpation. Misinterpretations of CT-scans are due to non-existing density-differences and the anatomic variations of the female genital system. (orig.)

[en] The lifetime of the 3s²3p ²P₃ at _∼sol∼ at ₂^o first excited energy level of Fe XIV (Al like) was measured at the Heidelberg electron beam ion trap by monitoring its optical decay to the ground state by a magnetic dipole (M1) forbidden transition at λ=530.29 nm (green coronal line), a well-known line in stellar spectra. A new trapping scheme has been applied. Possible systematic effects were investigated by studying the dependence of the decay curves on various trapping conditions with high statistical significance. The result of 16.726_-0.010^+0.020 ms shows an unexplained discrepancy in the average value of existing theoretical predictions. The inclusion of the electron anomalous magnetic moment within the theoretical calculations increases this disagreement, thus pointing at other possible origins of this discrepancy

No abstract available

[en] With the intense and coherent x-ray pulses available from free-electron lasers, the possibility to transfer non-linear spectroscopic methods from the laser lab to the x-ray world arises. Advantages especially regarding selectivity and thus information content as well as an improvement of signal levels are expected. The use of coherences is especially fruitful and the example of coherent x-ray/optical sum-frequency generation is discussed. However, many non-linear x-ray methods still await discovery, partially due to the necessity for extremely adaptable and versatile instrumentation that can be brought to free-electron lasers for the analysis of the spectral content emitted from the sample into a continuous range of emission angles. Such an instrument (called MUSIX) is being developed and employed at FLASH, the free-electron laser in Hamburg and is described in this contribution together with first results. (paper)

[en] We report on two-level laser spectroscopy on the electron dipole-forbidden 1s²2s²2p ²P_3/2–²P_1/2 transition in boron-like Ar¹³⁺ ions stored in an electron beam ion trap. By monitoring the laser-induced fluorescence as a function of the laser frequency, the transition wavelength was determined to be 441.25575(17) nm. The accuracy achieved in this first investigation is equal to that of the best wavelength measurements in highly charged ions. (paper)

[en] The study investigates three points of main interest: (1) The clinical efficacy of MR imaging as a routine method, if possible to be assessed in comparison to comparable imaging methods, and referring to a broad spectrum of available types of equipment and modes of operation, to be expressed in terms of diagnostic value and indication of therapy. (2) Specific economic aspects, considering different sites of operation and application conditions. (3) Results of clinical application with regard to individual cases (patient careers), in order to establish a nationwide basis for economic cost-benefit assessment of this diagnostic tool. Another aspect taken into account whenever available data allow so, is substitutional or additional application of MR imaging. The survey is performed on the basis of data accumulated by more than 21.000 MR examinations, and of data describing the application environment, furnished by 25 users from university hospitals, general hospitals, or private practice. (orig./HP)

[en] The dielectronic recombination resonance (DRR) processes for highly charged krypton ions have been investigated through simultaneously observing the x-ray emission and the ions extracted at the Heidelberg EBIT while slowly scanning the electron beam energy. It was found that at their DR resonance electron energies, the yield of the He-like krypton ions was substantially reduced, whereas that of the Li-like krypton ions was correspondingly increased. At slightly higher electron energies similar features were observed for the Li- and Be-like krypton ions. From the observed ratios of the Li-like/He-like krypton ion currents, we have deduced the dielectronic recombination (DR) strength for the He-like ions, which was found to be in reasonable agreement with theoretical calculations. We have also concluded from the present experiments that the DRR processes can be used to modify the ion charge state distributions and to concentrate the extracted ion currents into particular charge states. This is particularly important for future charge breading experiments with short-lived radioactive isotopes

[en] We present a lifetime measurement of the 3s ²3p ⁵² P^o_1/2 first excited fine-structure level of the ground state configuration in chlorine-like Fe X, which relaxes to the ground state through a magnetic dipole (M1) transition (the so-called red coronal line) with a wavelength accurately determined to 637.454(1) nm. Moreover, the Zeeman splitting of line was observed. The lifetime of 14.2(2) ms is the most precise one measured in the red wavelength region and agrees well with advanced theoretical predictions and an empirically scaled interpolation based on experimental values from the same isoelectronic sequence.

[en] The scope of this work is to demonstrate the applicability of an eddy resolving turbulence model in a turbomachinery configuration. The model combines the Large Eddy Simulation (LES) and the Reynolds Averaged Navier Stokes (RANS) approach. The point of interest of the present investigation is the unsteady rotating stall phenomenon occurring at low part load conditions. Since RANS turbulence models often fail to predict separation correctly, a LES like model is expected to give superior results. In this investigation the scale-adaptive simulation (SAS) model is used. This model avoids the grid dependence appearing in the Detached Eddy Simulation (DES) modelling strategy. The simulations are validated with transient measurement data. The present results demonstrate, that both models are able to predict the major stall frequency at part load. Results are similar for URANS and SAS, with advantages in predicting minor stall frequencies for the turbulence resolving model.