TY - JOUR A1 - Scheuerlein, C. A1 - Ping, I. A1 - Senatore, C. A1 - Di Michiel, M. A1 - Thilly, L. A1 - Gerardin, A. A1 - Rehmer, Birgit A1 - Oberli, L. A1 - Willering, G. A1 - Bottura, L. T1 - Temperature induced degradation of Nb-Ti/Cu composite superconductors JF - Journal of physics / Conference series N2 - The degradation mechanisms of state-of-the-art Nb-Ti/Cu superconductors are described, based on in-situ synchrotron X-ray diffraction measurements during heat treatment. A quantitative description of the Nb-Ti/Cu degradation in terms of critical current density, Cu stabiliser resistivity and mechanical composite strength is presented. In an applied magnetic field a significant critical current degradation is already observed after a 5-minute 400 °C heat treatment, due to variations of –Ti precipitate size and distribution within the Nb-Ti alloy filaments. A strong degradation of the strand mechanical properties is observed after several minutes heating above 550 °C, which is also the temperature at which the formation of Cu-Ti intermetallic phases is detected. Several minutes heating at 250 °C are sufficient to increase the RRR of the strongly cold work strands inside a Rutherford type cable from about 80 to about 240. Heating for several minutes at 400 °C does not cause a significant conductor degradation in self-field and, thus, leaves enough temperature margin for the electrical interconnection of Nb-Ti/Cu conductors with common low temperature solders. KW - Supraleiter PY - 2010 DO - https://doi.org/10.1088/1742-6596/234/2/022031 SN - 1742-6588 SN - 1742-6596 VL - 234 IS - 2 SP - 022031-1 - 022031-5 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-22618 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -