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[en] We present high resolution measurements of dielectronic recombination (DR) of Fe XXII forming doubly excited Fe XXI. These measurements were performed at the Test Storage Ring (TSR) of the Max-Planck-Institute of Nuclear Physics (MPIK). Low-lying DR resonances allow precise energy determination of the doubly excited autoionising levels in Fe XXI and, with suitable future calculations of Rydberg binding energies (n ≥ 7), of 2s22p to 2s2p2 excitation energies of the boronlike Fe XXII core.
[en] Latent heat storage systems are an effective way of storing thermal energy. Recently, phase change materials were considered also in the thermal control of compact electronic devices. In the present work a numerical and experimental investigation is presented for a solid-liquid phase change process dominated by heat conduction. In the experimental arrangement a plane slab of PCM is heated from above with an on-off thermal power simulating the behaviour of an electronic device. A two-dimensional finite volume code is used for the solution of the corresponding mathematical model. The comparison between numerical predictions and experimental data shows a good agreement. Finally, in order to characterize this thermal energy storage system, the time distribution of latent and sensible heat is analyzed.
[en] We have observed a significant yield of (n + 2)P atoms after the excitation of nD Rydberg atoms in a Rb MOT, where 27 < n < 41, which can be attributed to binary collisions between Rydberg atoms. We have measured its dependence on principle quantum number as well as DC electric field. These results are compared to a model which uses the Landau-Zener method to calculate transition probabilities at avoided crossings in the two-atom potential energy curves, taking into account the effects of the DC Stark effect due to the background electric field.
[en] Ionization and successive evaporation of C_7_0"r"+ is studied as a function of the internal energy using collision induced dissociation under energy control. Multicharged ions C_7_0"r"+ are prepared in F"+ (3 keV) + C_7_0 → F"− + C_7_0"r"+ + ne collisions. Up to seven successive evaporation of C_2 are observed in an excitation energy range from 40 to 100eV. The dissociation energies of C_7_0_-_2_m"2"+ (m=1-7) are determined using a statistical cascade model to reproduce the excitation energy distribution of C_7_0"2"+ parent ions for each dissociation channel. Results are in good agreement with previous theoretical calculations
[en] A simple effective scheme to improve the self energy obtained by the dynamical mean field theory is proposed, in which a feedback of magnetic fluctuations is taken into account. We demonstrate effectiveness of the scheme for the two-dimensional periodic Anderson model by investigating the effect of the magnetic fluctuation in the formation of heavy quasiparticles. It is found that the spectral intensity near the Fermi level is strongly suppressed by the antiferromagnetic fluctuation slightly above the magnetic instability.
[en] The application of silicon photocells has been widely used in biological and energy field, how to improve the efficiency of silicon photocells has become the research hot spots. The light absorption efficiency is not ideal, only 10% to 20% of solar energy can be transformed into electricity, the paper embeds metal bow-tie antenna in the crystals of silicon, by the field enhancement of the surface plasma, it highly increase the absorptive capacity of light of the silicon photocells.
[en] LIQHYSMES, the recently proposed hybrid energy storage concept for variable renewable energies, combines the storage of LIQuid HYdrogen (LH2) with Superconducting Magnetic Energy Storage (SMES). LH2 as the bulk energy carrier is used for the large scale stationary longer-term energy storage, and the SMES cooled by the LH2 bath, provides highest power over shorter periods and at superior efficiencies. Both together contribute to the balancing of electric load or supply fluctuations from seconds to several hours, days or even weeks. Here different spectral power distributions of such imbalances between electricity supply and load reflecting different sources of fluctuations in the range between 1 sec and 15 minutes are considered. Some related implications for MgB2-based 100 MW-SMES operated at maximum fields of 2 T and 4 T, are considered for these buffering scenarios. Requirements as regards the storage capacity and correspondingly the minimum size of the LH2 storage tank are derived. The related loss contributions with a particular focus on the ramping losses are analysed.
[en] Continuum-scale equations of radiative transfer and corresponding boundary conditions are derived for a multi-component anisotropic medium consisting of components in the range of geometrical optics. The derivations are obtained by employing the volumeaveraging theory. This study generalizes the previous derivations obtained for multi-component isotropic media. (paper)
[en] In this work we report calculations of potential energy curves in the 1.2a.u. ≤ R ≤ 100a.u. range at the Multireference Configuration Interaction (MRCI) level for doubly excited states of the H_2 molecule. The molecular state which dissociates into two H(2s) atoms is clearly identified. The Generalized Oscillator Strength as a function of transferred momentum for three doubly excited states is also presented. (paper)
[en] In this work we want to assess the influence of nuclear dynamics on the features of the double corehole photoelectron and Auger spectra of small isolated molecules by performing wave packet propagation on precomputed ab initio potential energy surfaces. (paper)