Full wave propagation modelling in view to integrated ICRH wave coupling/RF sheaths modelling

RF sheaths rectification can be the reason for operational limits for Ion Cyclotron Range of Frequencies (ICRF) heating systems via impurity production or excessive heat loads. To simulate this process in realistic geometry, the Self-consistent Sheaths and Waves for Ion Cyclotron Heating (SSWICH) code is a minimal set of coupled equations that computes self-consistently wave propagation and DC plasma biasing. The present version of its wave propagation module only deals with the Slow Wave assumed to be the source of RF sheath oscillations. However the ICRF power coupling to the plasma is due to the fast wave (FW). This paper proposes to replace this one wave equation module by a full wave module in either 2D or 3D as a first step towards integrated modelling of RF sheaths and wave coupling. Since the FW is propagative in the main plasma, Perfectly Matched Layers (PMLs) adapted for plasmas were implemented at the inner side of the simulation domain to absorb outgoing waves and tested numerically with tilted BD in Cartesian geometry, by either rotating the cold magnetized plasma dielectric tensors in 2D or rotating the coordinate vector basis in 3D. The PML was further formulated in cylindrical coordinates to account for for the toroidal curvature of the plasma. Toroidal curvature itself does not seem to change much the coupling. A detailed 3D geometrical description of Tore Supra and ASDEX Upgrade (AUG) antennas was included in the coupling code. The full antenna structure was introduced, since its toroidal symmetry with respect to the septum plane is broken (FS bars, toroidal phasing, non-symmetrical structure). Reliable convergence has been obtained with the density profile up to the leading edge of antenna limiters. Parallel electric field maps have been obtained as an input for the present version of SSWICH

ESPRESSO view on the cold and neutral gas in high-redshift galaxies

We present very recent ESPRESSO results on the studies of the neutral gas in damped Ly-alpha systems detected in spectra of high-redshift quasars. Due to unprecedented spectral resolution that available in ESPRESSO HR mode, we mostly focus on the species related to the cold H2-bearing phase of the interstellar medium of high redshift galaxies. Firstly, we discuss some improvements in long-standing problem of velocity decomposition of the line-profiles, obtained using R~140000 resolution spectrum. In particular, we show that FeI and CI absorption lines at resolution provided by ESPRESSO appears to separate on the several subcomponents. Secondly, we highlight some improvement of the constraints of isotopic ratios from the analysis of MgII and CI absorption lines. Finally, we discuss that ESPRESSO allows to deblend absorption lines from CO rotational levels, and hence accurately measure CO excitation diagram, that allows one to obtain tighter constraints on the CMB temperature at high redshifts, that was obtained before. The work is supported by RSF grant № 23-12-00166

Sequential modelling of ICRF wave near RF fields and asymptotic RF sheaths description for AUG ICRF antennas

A sequence of simulations is performed with RAPLICASOL and SSWICH to compare two AUG ICRF antennas. RAPLICASOL outputs have been used as input to SSWICH-SW for the AUG ICRF antennas. Using parallel electric field maps and the scattering matrix produced by RAPLICASOL, SSWICH-SW, reduced to its asymptotic part, is able to produce a 2D radial/poloidal map of the DC plasma potential accounting for the antenna input settings (total power, power balance, phasing). Two models of antennas are compared: 2-strap antenna vs 3-strap antenna. The 2D DC potential structures are correlated to structures of the parallel electric field map for different phasing and power balance. The overall DC plasma potential on the 3-strap antenna is lower due to better global RF currents compensation. Spatial proximity between regions of high RF electric field and regions where high DC plasma potentials are observed is an important factor for sheath rectification

Kompetenzen von Bibliothekar*innen im Auskunftsgespräch mit Grundschulkindern

Dieser Beitrag behandelt das bibliothekarische Auskunftsgespräch mit der Zielgruppe der Grundschulkinder sowie deren Besonderheiten in Bezug auf die Sprachentwicklung und die Lesekompetenz. Für ein erfolgreiches Auskunftsgespräch werden neben dem Medienbestand und der räumlichen Ausstattung auch verschiedene Kompetenzen von Bibliothekar*innen im Auskunftsdienst benötigt. Diese wurden mithilfe des KODE KompetenzAtlas ermittelt.This article deals with the reference interview with the target group of primary school children as well as their characteristics in respect to the language development and the reading competence. Besides the inventory and the endowment various competences of librarians are needed to successfully perform a reference interview. These were identified with the KODE KompetenzAtlas.Peer Reviewe