5th International Workshop on Cooling Systems for HTS Applications
Keynote Speakers
Tabea Arndt
Karlsruhe Institute of Technology
BIOGRAPHY
Tabea Arndt received her Diploma in Physics in 1992 and PhD in 1995 from the University of Karlsruhe, now KIT. After an academia-industry R&D grant at Vacuumschmelze, she worked in magnetic materials and LTS and HTS superconductor production, supporting applications including MRI, NMR, high-energy physics magnets, transformers, cables, motors, generators, fault-current limiters and current leads. In 2008, she joined Siemens Corporate Technology and became Head of the Superconducting Applications research group. In 2019, she was appointed full professor and co-director at KIT’s Institute for Technical Physics, where she works on superconducting magnets, high-current components, liquid-hydrogen applications and electric machines. She received the IEEE Council on Superconductivity Award in 2023 for continuing and significant contributions to applied superconductivity.
Cooling and operating stationary and rotating superconducting arrangements: concepts of the past, special requirements, and recent developments
ABSTRACT
Historically and even today for selected applications, superconducting coils have been cooled by liquid helium pool cooling. The technical viability and business case in magnets and power applications has been widely influenced by the operating conditions and the available cooling devices. HTS have simplified cryogenic measures and considerably extended the devices’ suitable power range. For stationary and rotating applications, specific requirements pose additional challenges for cooling concepts. However, current trends in magnets and rotating machines may enable new concepts. This presentation will give an overview of the historical basis, special aspects, the changes, and new prospects.
Taketsune Nakamura
Kyoto University
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BIOGRAPHY
Prof. Taketsune Nakamura completed the doctoral programme at Kyushu University in 1998 and became an assistant professor at Kyoto University in the same year. He is currently a program-specific professor at Kyoto University. His research includes first-principles studies of electromechanical energy conversion, engineering applications of nonlinear electromagnetic phenomena and dissipative structures, fundamental research on conventional and superconducting rotating machines, and the development of applications for automotive systems, aircraft, liquefied-hydrogen pumps and related technologies.
Current Status and Prospects of Liquid-Hydrogen-Cooled High-Temperature Superconducting Rotating Machines
ABSTRACT
Liquid hydrogen serves as an excellent medium for transporting hydrogen, a clean energy source for the next generation. Its atmospheric boiling point of 20 K is well-suited to the operating environment of high-temperature superconducting equipment. The synergistic effect between liquid hydrogen—acting as both an energy source and a coolant—and superconducting equipment enables highly efficient systems. This presentation provides an overview of liquid-hydrogen-cooled HTS rotating machines, covering their fundamental concepts, applications in aircraft and liquid-hydrogen pumps, and future prospects.
Mariusz Wozniak
CERN
BIOGRAPHY
Mariusz Wozniak holds a PhD in Materials Science from the University of Cambridge, where he worked on MgB2 wires and joints for MRI magnets. From 2012 to 2020, he worked at Siemens Magnet Technology in Oxford on quench protection and AC losses in cryogen-free MRI magnets. Since 2021, he has been an applied physicist at CERN and leads the Quench Detection and Protection work package for LTS and HTS accelerator magnets within the High Field Magnet programme. He owns and co-develops STEAM, CERN’s open-source framework for simulating transient effects in superconducting magnets and circuits, and has authored around 90 peer-reviewed publications.
Protection of HTS CC Magnets: Strategies, Challenges, and the Role of Numerical Modelling
ABSTRACT
High-temperature superconducting coated-conductor magnets can reach high fields for accelerators, fusion devices and user magnets, but protection against quench-induced damage remains a central obstacle. This talk reviews strategies for distributing or extracting stored magnetic energy through conductors, coupled coils, structures and power sources. It compares energy extraction, quench heaters, CLIQ, Energy Shift with Coupling, and the intrinsic current sharing of no-insulation and metal-insulation windings. A central theme is the need for coupled magneto-thermal-mechanical modelling, including the STEAM framework, to support HTS-specific protection and cryogenic design.
Markus Mueller
University of Edinburgh
BIOGRAPHY
Markus Mueller earned a BSc in Electrical and Electronic Engineering from Imperial College London in 1988 and a PhD in Electrical Engineering from the University of Cambridge in 1991. After research and industrial positions, he joined the University of Edinburgh in 2004 and was appointed Professor of Electrical Generation Systems in 2012. In 2023, he received a Royal Academy of Engineering Chair in Emerging Technologies, providing ten years of support to develop novel HTS machines for energy and transport. His research on direct-drive modular permanent-magnet generators is being commercialised by the spin-out CGEN Engineering Ltd.
SuperMachine – a platform modular electrical machine for energy and transport applications
ABSTRACT
Electrification of energy, aviation and shipping requires lightweight, highly efficient electrical machines. Conventional permanent-magnet machines are difficult to scale to multi-megawatt wind systems while maintaining low mass, or to the power densities required for transport. The SuperMachine concept aligns the machine structure with the benefits of HTS materials and provides a highly modular architecture. This presentation covers experimental validation, modular cooling options and design studies for wind, aerospace and marine applications.
Herman ten Kate
University of Twente
Advances in High-Temperature Superconductors and their Application: Promises, Problems and Prospects
ABSTRACT
For over four decades, we have specialised in high-temperature superconductor (HTS) technology. The current-carrying capacity, manufacturability and practical performance of the conductors has increased significantly.
A variety of materials were considered for use as practical conductors. However, the current focus of R&D and industrial efforts is primarily, although not exclusively, on ReBCO tape conductors for the fabrication of cables and coils. These include high-field magnet facilities, magnets for fusion devices, power transmission, electric motors, magnetic levitation and medical technologies.
While current tape technology may be adequate for low-energy stationary devices, more development is necessary for larger-scale high-energy devices and varying field magnets, which require cables and large coils. It is essential that this technology evolves to ensure stable and reliable operation, initially in demonstrator models and subsequently in commercial devices.
There are still several challenges to be addressed, including manufacturing costs, material brittleness, electrical and mechanical anisotropy, AC loss, quench protection, and cooling requirements at 20 - 40 K level.
The promises, problems and prospects of HTS technology in terms of achieving a more efficient and sustainable future are addressed.