arXiv subjects

Harold S. Ruiz

Publications and source records attributed to Harold S. Ruiz.

3 recordsLinked to original sources

arXiv2026

A Cloud-Accessible Open-Source Framework for the Electromagnetic Modelling of Applied Superconductors

We present the H-cloud formalism, a cloud-accessible and open-source finite-element framework for electromagnetic modelling of applied superconductors. The proposed method expresses the nonlinear electromagnetic response of type-II superconductors in a curl-conforming discretisation based on Nédélec finite elements, where the tangential applied-field boundary condition, nonlinear E-J power law, and fully implicit time-discrete residual are stated explicitly at the variational level, all within a scripted Python finite-element workflow. The weak form is used as the basis for forward simulation and for extension to adjoint differentiation and PDE-constrained optimisation, while keeping the governing assumptions, boundary conditions, and solver structure fully visible to the user. The implementation is realised in Firedrake with UFL and PETSc-backed nonlinear solvers, allowing the identical script to run on local machines and in browser-accessible environments such as Google Colab without reformulating the problem. The method is verified on the canonical magnetisation benchmark of a cylindrical superconductor under Bean-like penetration conditions and then benchmarked against an independently constructed COMSOL model for a practical high temperature superconducting Bi2212 wire. Across matched mesh studies, the open-source workflow reproduces the commercial-reference magnetisation loops to within approximately \(1\%\) , with relative peak errors below 1.5%, while cloud execution preserves the same numerical solution at rather modest additional runtime considering the use of (freely available) reduced hardware resources. The proposed framework provides a rigorous, reproducible, and portable route for superconducting simulation, benchmarking, and future optimisation-led modelling of applied and functional superconductors, shareable and executable into open cloud environments.

cond-mat.supr-con↗

arXiv2026

Massive Mitigation of Transport AC Losses in Superconducting Hybrid CORC-TSTC Cables

High-current superconducting cables are emerging as key enablers for next-generation power transmission systems; however, their deployment is often limited by transport AC losses. Hybrid superconducting cables combining Conductor-on-Round-Core (CORC) and Twisted Stacked-Tape Conductor (TSTC) architectures have recently been proposed as a promising route toward cables with high current capacity and compact form factors. However, their electrodynamic response under transport current operation remains poorly understood, particularly regarding how current injection conditions govern internal current redistribution. Here, we employ a fully-3D electromagnetic model, previously validated against magnetisation experiments in equivalent cables, to investigate the influence of current injection strategy on the electrodynamics of hybrid CORC-TSTC cables under self-field conditions. By comparing configurations in which the total current is either injected through a common connection between the CORC and TSTC conductors (non-insulated feeding) or supplied independently to each conductor (insulated feeding), we show that electrical coupling in non-insulated designs leads to strong current redistribution, pronounced waveform distortion and elevated AC losses once the CORC layers approach magnetic saturation. In contrast, independent current feeding suppresses inter-conductor current exchange, stabilises the current waveforms, and exhibits an outstanding reduction in transport AC losses of up to 90% at practical operating currents, compared with conventional feeding schemes. These findings reveal the central role of the current injection strategy in governing the internal electrodynamics and energy dissipation of hybrid superconducting cables, and identify the electrical decoupling of the constituent conductors at the feeding point as a simple and scalable route toward ultra-efficient power cables.

cond-mat.supr-con↗

arXiv2025

An Open and Collaborative Database of Properties of Materials for High-Temperature Superconducting-Based Devices

The successful integration of high-temperature superconductors (HTS) into modern technologies requires consistent, accessible, and comprehensive material data, a need that is currently unmet due to the fragmented and incomplete nature of existing resources. This paper introduces a new collaborative, open-access database specifically designed to address this gap by providing standardized data on HTS materials and crucial auxiliary components for HTS applications. The database encompasses extensive data on structural, cryogenic, electrical, magnetic, and superconducting materials, supporting diverse requirements from HTS modelling to magnet design. Developed through collaborative efforts and organized using an ontology-driven data model, this platform is dynamically adaptable, ensuring that it can grow as new materials and data emerge. Key features include user-driven contributions, peer-reviewed data validation, and advanced filtering capabilities for efficient data retrieval. This innovative database, to the knowledge of the authors, being the largest publicly available for material properties of HTS technologies is positioned as a valuable tool for the HTS community, promoting more efficient research and development processes, accelerating the practical application of HTS, and fostering a collaborative approach to knowledge sharing within the field. The database is available at https://sc.hi-scale.grisenergia.pt/app.

cond-mat.supr-con↗