The overcritical current regime of commercial REBCO tapes: a Strategy toward Resilience

Thursday 1 Apr 2021, 10:30 → 12:00 Europe/Zurich

ZOOM

Nicolo' Riva (EPFL - EPF Lausanne)

Abstract:

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High-Temperature Superconductors (HTS) materials hold immense potential for future applications such as medical and power applications, especially REBCO commercial tapes. It is important to develop accurate numerical methods for modeling the electro-magneto-thermal behavior of such applications. Specifically, when modeling REBCO tapes for devices working near or above the critical current value (I>Ic), the resistivity models of the superconductor in such regime remain very empirical and it is typically described by a power-law model. The lack of good knowledge in the overcritical current regime is a major issue in developing quality simulation tools for optimizing the design of superconducting devices working near and above the critical current. The challenges in retrieving such properties lie in both the experimental characterization and the data-analysis. 

During my Ph.D., I investigated the overcritical current regime of commercial tapes. To address these challenges and better understand the overcritical current regime, I combined ultra-fast pulsed current measurements performed on HTS REBCO based coated conductors, with Finite Element Modeling based data-analysis. 

The major result is a resistivity relationship, an alternative to the commonly used resistivity models, describing the overcritical current regime and to be used in numerical simulations of REBCO tapes. This work can help optimize the use of superconducting material as well as the amount of stabilizer. More interestingly, it opens the study of the overcritical current regime, a new exciting aspect of REBCO commercial tapes.