Speaker
Description
SupraFusion is a French research program aiming to boost HTS (High-Temperature Superconductors) technologies towards large-scale societal applications and particularly compact fusion machines. In the framework of this program, a large-scale HTS magnet demonstrator is presently under design. This large-scale magnet aims to demonstrate our capability to reach safely a peak field of about 20 T and 100 MJ of magnetic stored energy under nominal conditions of current and temperature. One important point of this demonstrator design is that it is planned to be fully insulated. These operating conditions and performances pose significant risks for the protection of the magnet and its conductors in case of quench. Indeed, due to their slow normal zone propagation velocities, quench in HTS coils are hard to detect and can totally damage a magnet by the high joule power locally deposited. To address these challenges, several protection strategies are being explored, aiming to optimize critical parameters such as hotspot temperature, current density, and voltage.
To assist in this process, multiple numerical models have been developed simulating the REBCO-based conductor of the demonstrator. These models allow for the analysis of thermal stability, quench propagation, and hotspot behavior under transient conditions. Additionally, parametric studies have been conducted to determine the optimal design of the conductor and the electrical characteristics of the protection circuit, ensuring that the detection and protection criteria for the demonstrator are met. This paper will present the main protection strategies explored for the demonstrator and the related thermal and electrical transient computation results.
