Abstrait

Synthesis Temperature Effects on Ex - Situ Manufactured MgB2 Wires Useful For Power Applications

Gianmarco Bovone, Davide Matera, Cristina Bernini, Emilio Bellingeri, Antonio Sergio Siri, Andrea Malagoli, Maurizio Vignolo

Ex - situ powder in tube manufacturing process is based on the filling of a metal sheath with pre - synthesized MgB2 powders. It is necessary for MgB2 used in wire manufacturing to have the required p roperties of grain size and connectivity. Synthesis temperature for MgB2 is an important paramete r to improve the quality of powders and subsequently enhance performances of wire for large - scale applications. In this work we investigated the effect of synthesis temperature on morphology, and how this is reflected on superconducting properti es. A detai led study on the influence of MgB2 synthesis temperature on grain size has been given, evaluated through SEM images and magnetic measurement, by applying a model for average grain size distribution based on the penet ration of magnetic field in the supercon ductor, that was found to be in agreement with several other methodologies. Engineering current density has been evaluated from direct measurement using a four - probe configuration