Design and Realisation of an Experimental Setup for the Determination of the NZPV and MQE of Aluminium-Stabilised REBCO Stack Cables

Abstract

With the growth of ambitions in space exploration, future spacecraft will require higher power while remaining strongly constrained by mass and thermal management. REBCO-coated conductors offer a promising solution because they can carry large currents with no DC resistance. Potential applications include high-power electric propulsion, magnetic shielding, and power-distribution systems. An interesting example is the proposed AMS-100 cosmic-ray observatory, whose design includes a large REBCO-based superconducting magnet operating at 50--60~K. However, their implementation remains limited by cryogenic requirements and quench behaviour, the latter being the focus of this work.

REBCO conductors have a low Normal Zone Propagation Velocity (NZPV), which generates highly localised normal zones and increases the risk of thermal damage. This is further enhanced in vacuum, where the lack of heat convection reduces heat removal. Increasing the stabiliser volume can improve the Minimum Quench Energy (MQE), but also affects heat diffusion, current redistribution, and quench propagation. The characterisation of MQE and NZPV is therefore critical for the safe use of REBCO systems in terrestrial and space applications.

This thesis presents the design, manufacture, assembly, and experimental validation of a cryogenic setup for the electrical and thermal characterisation of an Al-stabilised REBCO stack cable developed at CERN for future detector magnets. The setup operates under vacuum with cryocooler-based conduction cooling, conditions relevant to compact HTS magnet systems for space applications. Two cryogenic campaigns were performed to assess its vacuum, cooldown, and thermal performance. The Al-stabilised REBCO stack cable and the setup were successfully validated for future MQE and NZPV measurements, with relevance and application to both detector magnets and lightweight, cryogen-free space systems.