Superconducting Cables Development for High Energy Physics and Power Grids

This doctoral thesis investigates the mechanical and structural development of advanced superconducting conductors through comprehensive finite element modeling (FEM), addressing the stringent requirements of next-generation particle accelerators and sustainable power grids. The research is structured into two primary thematic areas: the analysis of Nb3Sn strands for high-field magnets and the technical feasibility of the TRICHECO hybrid energy pipeline. The first part of the study focuses on Nb3Sn, the candidate material to succeed Nb-Ti in dipole magnets capable of exceeding 16 T. Nb3Sn magnets are fabricated using a "wind-and-react" technique, where Rutherford cables are wound from wires containing precursor materials. A critical challenge addressed in this work is the impact of mechanical stress at different stages of the magnet’s lifecycle. During cabling and winding, the unreacted wires undergo significant plastic deformations that can lead to a degradation of future transport properties. Following heat treatment, the resulting Nb3Sn phase becomes extremely brittle, making it highly sensitive to stresses arising from cooling, assembly, and Lorentz forces during activation. Through a collaboration between INFN-Genoa and CERN, this research develops 2D finite element models to simulate these behaviors. By comparing idealized geometries with real cross-sections derived from SEM images of MQXF quadrupole wires, the study quantifies internal strains and validates simulation results against experimental measurements, providing essential tools to assess the operational limits of high-field magnets. The second part of the thesis explores the TRICHECO project, which proposes a 30-km submarine link for the simultaneous transport of liquid hydrogen (LH2) and electrical power via MgB2 superconducting cables. The LH2 serves a dual role as a carbon-free energy carrier and a cryogenic coolant. The research employs FEM analysis to evaluate the structural integrity of the stainless-steel cryostat under extreme conditions and quantifies the critical thermal contraction of the cable. Collectively, this work demonstrates that numerical modeling is an indispensable tool for bridging the gap between fundamental material science and the engineering of large-scale superconducting infrastructures for high-energy physics and future energy systems.