Current distributions in multi-filamentary HTS conductors

We have used scanning Hall probe microscopy to image in detail the current profile of two high-quality multi-filamentary Bi2223 tapes. In a tape with 37 twisted filaments, the derived current profile evolves smoothly across the width as the current is increased, whereas that of the untwisted 19-filament tape shows considerably more variation. In both cases, the central group of filaments carries most current at higher levels. The derived current distribution is well-described by the ellipsoidal solid conducting core model, rather than that of a thin flat conducting strip

Current distributions in multifilamentary conductors: the influence of intergrowths

The modelling of both critical and remanent states (i.e., the current density and field distributions) in periodic arrays of flat superconducting strips is important for calculating the AC losses in multifilamentary tapes made for power applications. We model the current and field profiles for such magnetically coupled conductors, and have measured these dependences for BSCCO-22223 tapes using a miniature scanning Hall probe technique. The results indicate that the filaments are also electrically connected to a significant extent, which must be caused by superconducting intergrowths between individual filaments

Untersuchungen des Verhaltens von Radioiod unter Stoerfallbedingungen in LWR in kleintechnischen Versuchsanlagen Abschlussbericht

Starting from safety considerations for WWER-type reactors main aspects of iodine chemistry are represented. By means of the use of application-oriented measuring techniques, existing equipment systems and their adaption to the requirements, investigations of the retention capacity of wet condensation systems for radioiodine were carried out. After analytical pre-tests (AAS, gaschromatography, laserspectrometry) - experiments were realized relating to both iodine absorption and iodine revolatilization. The absorption levels determined are between 92,5 and 99,9%, the iodine entrainment with revolatilization from the wet-condensation model is in the range between 0,003 and 0,0004%. (orig./HP)Ausgehend von Sicherheitsbetrachtungen fuer WWER-Reaktoren werden die Hauptaspekte der Iodchemie dargelegt. Durch Nutzung anwendungsorientierter Messtechniken, vorhandener Geraetesysteme und deren Anpassung an die Erfordernisse wurden Untersuchungen zum Rueckhaltevermoegne von Nasskondensationssystemen fuer Radioiod angestellt. Nach analytischen Vorversuchen (AAS, Gaschromatographie, Laserspektrometrie) wurden Experimente zur Iodabsorption zur Iodwiederfreisetzung durchgefuehrt. Die ermittelten Absorptionsgrade lagen zwischen 92,5 und 99,9%, der Iodaustrag bei der Wiederfreisetzung aus dem Nasskondensationsmodell bewegt sich im Bereich von 0,003 und 0,0004%. (orig./HP)SIGLEAvailable from TIB Hannover: F95B2102+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman