TIDM² x SC Magnets Lecture Series 2025

3 Jun 2025, 16:30 → 19 Jun 2025, 18:40 Europe/Zurich

Hugues Marie Alain Bajas (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE)), Marta Bajko (CERN)

The Lectures on Superconducting Magnet Test Stands, Magnet Protections and Diagnostics (TIDM² x SC Magnets) scheduled for 2025 are part of the SMTF Workshop (link) & IDSM Workshop. This event will be held for the second time, following its inaugural edition in 2023 (link).

For this series of 22 lectures, speakers from worldwide laboratories (ASIPP, CEA, CERN, CFS, EPFL, FNAL, IFJ PAN, IPP CAS, LBNL, ORNL, PSI, Pennsylvania State University, PSFC MIT, Tampere University ) will cover the main aspects of a superconducting magnet test stand (cryogenics systems, power supplies, current leads). A second part will then be dedicated to the design and use of magnet protection systems (high voltage electrical integrity checks, quench detection, energy extraction, strip heaters, CLIQ) with emphasis on specific instrumentations technics (quench antenna, strain gauges, fiber optic sensors). A session dedicated to HTS coil testing with cryocoolers is planned on the second part as well. The third part will introduce the problematics of testing large fusion superconducting coils with practical examples from ITER, ASIPP and CFS experience.

Tuesday 3 June

16:30 → 17:30 Superconducting magnet tests: Introduction to the series of lectures

About the lecture:

This introductory lecture will begin with a brief overview of the origins and objectives of the training program, as well as a few words about the small but dedicated team behind its organization. It will outline the structure and practical aspects of the course, including the final examination options and the type of feedback we hope to receive from you.

Following this, a short overview of the four thematic parts that make up the training sessions will be presented. The lecture will then conclude with a general introduction to the fundamentals of superconductivity, the underlying motivations for testing in this field, and a description of the major components of a test stand.

About the speaker:

Graduating from the Technical University of Budapest as a mechanical engineer in 1994, Marta joined a small research team at CEDEX (Spain), where she was first introduced to superconducting magnet design and testing. In 1996, she joined CERN, contributing to the design of corrector magnets for the LHC. From 1999, she was responsible for the final assembly steps of the LHC main dipoles and led the technology transfer from CERN to industrial partners. Following that, she oversaw the contractual follow-up of the superconducting dipoles produced in industry for the LHC machine.
After one year of hardware commissioning for the LHC, she assumed leadership of CERN’s Superconducting Magnet Test Facility (SM18), a role she held until 2020. She now leads the HL-LHC IT String — an integrated test facility dedicated to the High-Luminosity LHC project at CERN.

Speaker: Marta Bajko (CERN)

Introduction SMTF Lecture MBshort.pdf

Introduction SMTF Lecture MBshort.pptx

Modus Operandi of the training1.pdf

Modus Operandi of the training1.pptx

Recorded Lecture

17:30 → 17:40 Break

17:40 → 18:40 Expectation from magnet designer to magnet testing

About the lecture:

Superconducting magnets are at the heart of advanced scientific and industrial applications — their development presents great challenges. These are inherently complex, multiphysics systems in which many parameters remain uncertain or only partially understood. Achieving reliable, high-performance operation requires meticulous design and engineering across a wide range of disciplines. At the same time, cost constraints demand careful performance optimization: simply adding operational margin is often prohibitively expensive, making the search for the optimal design a critical part of the development process.
As one of the first lectures in this series focused on superconducting magnet test stands, this talk will provide an introduction to essential concepts such as training and quench, and will frame the critical role of testing in the broader magnet lifecycle. Drawing on my experience in magnet design and construction, I will outline the key information that designers and builders need from testing facilities in order to refine designs, ensure reliability, and ultimately enable the construction of affordable and effective superconducting systems.

About the speaker:

Susana joined the CERN magnet group in 2010 to work on the preparation activities for the Large Hadron Collider (LHC) First Long Shut down. In 2012 she started working in the Magnet Design and Technology Section, on the development of high field Nb3Sn accelerator magnets. Susana leads now the HL-LHC WP3 (link), in charge of the IR magnets for the upgrade in the LHC. She is also responsible for the Large Magnet Facility section at CERN, overseeing the construction of magnets and cold masses for the HL-LHC project.

Speaker: Susana Izquierdo Bermudez (CERN)

2505_SusanaIzquierdo_ExpectationFromMagnetDesignerToMagnetTesting.pdf

2505_SusanaIzquierdo_ExpectationFromMagnetDesignerToMagnetTesting.pptx

Recorded Lecture

Wednesday 4 June

16:30 → 17:30 Cryogenic cooling systems for LTS and HTS devices

About the lecture:

This lecture provides an introduction to the various cryogenic cooling methods used to operate superconducting systems, whether small or large, HTS or LTS, from the smallest pick-up coils for medical applications to the largest magnets or detectors for high-energy physics. The lecture is aimed at physicists and engineers working in the fields of applied superconductivity and interested in the principles of cryogenic heat and mass transfer associated with the cooling technology used for superconducting magnets and other systems. For each cooling method and technology, the course will present the concept, the reasons for its use and the implementation strategy in the superconducting applications considered. For each case, one or two examples will be detailed. The course will cover the various methods of cooling superconducting systems, such as conduction, bath, forced flow, circulation loops and heat pipes with a cryogen or cryocooler as the cold source.

About the speaker:

Bertrand Baudouy has been working in the field of cryogenics for 30 years, mainly on experimental heat and mass transfer associated with cooling techniques for superconducting magnets or other cryomagnetic systems. He is involved in the study of helium heat transfer under reduced gravity and in the development of heat pipe technology for cooling superconducting magnets, cavities and space applications.

Speaker: Dr Bertrand Baudouy (CEA Paris-Saclay)

2025_TIDM²xSC Magnet.pdf

Recorded Lecture

17:30 → 17:40 Break

17:40 → 18:40 Current Leads and superconducting transmission

About the lecture:

Electrical transfer from a room temperature power source to a superconducting system can be done via conventional or superconducting current leads and superconducting buses or links. The principles of optimization of these devices are presented, with emphasis on the cryogenic, electrical, and superconductor related aspects that drive choices for a system.

About the speaker:

Senior scientist at CERN, the European Organization for Nuclear Research, Amalia Ballarino was responsible for the several thousand current leads that today power the superconducting magnets of the Large Hadron Collider (LHC). For the development of High Temperature Superconducting (HTS) current leads, which has been the first large-scale commercial application of HTS materials, she received the award of “Superconductor Industry Person of the Year 2006”. After having participated in the commissioning of the Large Hadron Collider, she proposed and worked on the development of novel superconducting electrical transmission systems, based on MgB2 technology, which are today part of the HL-LHC upgrade. Her field of expertise covers low temperature (Nb-Ti, Nb3Sn and MgB2) and high-temperature (BSCCO and REBCO) superconducting materials and systems. In 2021, she received the “IEEE Dr. James Wong Award” for Continuing and Significant Contributions to Applied Superconductor Materials Technology (IEEE Dr. James Wong Award for Continuing and Significant Contributions to Applied Superconductor Materials Technology | IEEE Council on Superconductivity (ieeecsc.org)). She serves the community as lecturer, supervisor of PhD students, co-chair and organizer of international workshops, member of international committees (2023 Particle Physics Project Prioritization Panel (P5), Technical Advisory Committee (TAC) of the USA Magnet Development Program, Electron Ion Collider Magnet Steering Group, IEC/TC90 committee), member of program committees of international conferences, and technical editor and reviewer of papers for scientific journals.

Speaker: Dr Amalia Ballarino (CERN)

Ballarino.pdf

Ballarino.pptx

Recorded Lecture

Thursday 5 June

16:30 → 17:30 Power Converters

About the lecture:

Power converters play a central role in particle accelerators where both their performances are directly linked. As accelerator complexes develop towards higher beam energies and more towards a more sustainable nature, in response to the needs of physics research and of reducing the environmental impact, power converters are required to be on the forefront of technology. They have proliferated into accelerator complexes where thousands of them are used in modern complexes as at CERN. They must, therefore, achieve high reliability and in many cases cutting-edge precision. Hence, powering superconducting magnets for accelerators and test benches is a driving force for the development of high-performance power converters.

This lecture intends to introduce the requirements of power converters for superconducting magnets used in particle accelerators and magnet test benches. After showing the power conversion principles, it describes the role of power converters, the challenges and constraints when powering superconducting magnets. The principles of redundancy and modularity are discussed in this lecture in addition to the power converter control and high precision definition. More sustainable installations would need a better management of electromagnetic energies used in accelerator complexes. This lecture shows, therefore, the latest tendencies in terms of energy storage for power converters. Finally, it lists the key circuit parameters to be taken into consideration to properly specify a power converter for superconducting magnets.

About the speaker:

Samer Yammine has obtained his master’s and PhD in electrical engineering from ENSEEIHT, Toulouse. He has joined the Electrical Power Converter group at CERN working on various projects related to the powering of the LHC accelerator complex and its HL-LHC upgrade and is now responsible for the HL-LHC IT String experimental test program.

Speaker: Samer Yammine (CERN)

2025-06-05_Powering_Insfrastructures_SY.pdf

2025-06-05_Powering_Insfrastructures_SY.pptx

Recorded Lecture

Friday 6 June

16:30 → 17:30 Magnet Protection

In the design and use of superconducting magnets one must always ensure safe dissipation of the stored magnetic energy after a quench. External energy extraction with a dump resistor is relatively simple to implement, and it has the advantage of dissipating the energy outside of the cryostat. However, it’s capacity is limited by the maximum allowed voltage across the magnet terminals, which limits the dump resistor size. When external energy extraction is not enough, a common method is to apply electrical strip heaters on coil surfaces. After quench detection these heaters are activated, and they will bring the superconducting coils to normal state thus increasing the coil resistance, increasing the magnet current decay rate and limiting the peak temperature. In this lecture, we will discuss practical guidelines for estimating the magnet quench protection requirements. These include estimating the magnet peak temperature adiabatically based on the so-called MIITs-concept, voltage based quench detection, and how to design and use dump resistors and/or strip heaters for magnet quench protection.

About the speaker:
Tiina Salmi is an Academy Research Fellow at Tampere University. She defended her PhD thesis at Tampere University in 2025. She has worked for quench protection analyses for various accelerator magnets, including HiLumi LHC, FCC h-h, and Muon Collider dipoles and quadrupoles.

Speaker: Dr Tiina Salmi (Tampere University)

17:30 → 17:40 Break

17:40 → 18:40 Other magnet protection devices

About the lecture:

Coupling-Loss Induced Quench (CLIQ) is a quench protection method for superconducting magnets developed at CERN, which relies on a capacitive discharge unit introducing an oscillation of the transport current in the superconducting cable of the coil. The resulting fast change of the local magnetic field introduces a high coupling-current loss, which, in turn, causes a fast quench of a large fraction of the coil due to enhanced temperature.

The External coil CLIQ (E-CLIQ) relies on a capacitive discharge through a resistive coil magnetically coupled with the solenoid but external to it. Various versions of this method (with other naming) were proposed in research institutes, and also at CERN.

This training will introduce the working principles of the CLIQ and E-CLIQ methods, evaluate their advantages and disadvantages, and highlight the key parameters affecting their performances. Furthermore, a selection of past applications will be presented to identify different CLIQ configurations and electrical circuits. Finally, practical recommendations will be provided to magnet test engineers preparing a test facility including CLIQ and testing magnets with a CLIQ unit.

About the speaker:

Emmanuele Ravaioli defended his PhD in applied physics at the University of Twente in 2015. He has worked on superconducting magnet quench protection, multi-physics modeling, and circuit design since 2009, at CERN and at the Lawrence Berkeley National Laboratory. He is currently co-owner of the STEAM project.

Speaker: Dr Emmanuele Ravaioli (CERN)

Saturday 7 June

16:30 → 18:40 No Lectures

Sunday 8 June

16:30 → 18:40 No Lectures

Monday 9 June

16:30 → 18:30 No Lectures

Tuesday 10 June

16:30 → 17:30 Electrical integrity tests and electrical failure diagnostics in superconducting circuits

About the lecture:

Electrical failures in superconducting circuits can cause severe damage to the equipment and even lead to personal injury due to high operating currents. Often a significant energy stored in the magnetic field generated by the superconducting magnets becomes an additional risk factor.

The lecture will cover various topics related to electrical integrity tests and electrical failure diagnostics, using examples gathered by Electrical Quality Assurance Team during 20 years of experience in electrical testing and nonconformity investigations of the Large Hadron Collider superconducting circuits.

Participants will learn about commonly used types of electrical tests, selection of test parameters, proper management of measurement data, how to troubleshoot electrical failures, and develop a comprehensive plan for electrical testing and diagnosis.

This lecture is designed for people working with superconducting circuits, as well as those involved in the design, manufacture, and maintenance of equipment that utilizes superconducting magnets and bus bars.

About the speaker:

Jaromir Ludwin is an electrical engineer with background in physics. He’s working in the Institute of Nuclear Physics in Krakow, Poland. He’s a member of the Electrical Quality Assurance Team at CERN since 2006.

Speaker: Jaromir Ludwin (Polish Academy of Sciences (PL))

17:30 → 17:40 Break

17:40 → 18:40 Mechanical strain measurement

Speaker: Michael Guinchard (CERN)

Wednesday 11 June

16:30 → 17:30 Quench antennas for quench localization

Quench localization is a diagnostic technique used to support the development and testing of superconducting accelerator magnets. The accurate identification of the quench origin, when combined with other diagnostic methods, helps determine the possible causes of performance limitations and contributes to improving magnet design and development. Quench antennas are advanced magnetic sensors designed to detect the magnetic field perturbations caused by a quench. They typically consist of arrays of pickup coils distributed along the magnet, capable of capturing the fast and tiny magnetic transients that occur at quench onset. The resulting signals can be used to reconstruct the quench initiation position with high temporal and spatial resolution. The sensitivity design of the sensors determines the accuracy and robustness against noise. This lesson presents the basic design principles of quench antenna sensors, along with examples of their application in real cases.

Lucio Fiscarelli is an electronics engineer at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland. He holds a PhD in Information Engineering with a focus on magnetic measurements from the University of Sannio. He is member of the Magnets, Superconductors, and Cryostats (MSC) group within CERN’s Technology Department (TE), where he works on magnetic measurements and instrumentation for the test and characterization of magnets used in particle accelerators. His activities include the design and implementation of advanced magnetic measurement systems, such as rotating coils and quench antennas, in support of several projects, including the High-Luminosity LHC (HL-LHC) upgrade and the High Field Magnets (HFM) program.

Speaker: Lucio Fiscarelli (CERN)

17:30 → 17:40 Break

17:40 → 18:40 Fiber Optic Sensor for superconductor

Speaker: Federico Scurti (The Pennsylvania State University)

Thursday 12 June

16:30 → 17:30 Cryocoolers technologies

About the lecture:

The course will give a brief introduction to the cryocooler principles and its main components, which is required to understand the interaction of the cooling source with the cooling object in question. The first part will cover a recap of the cryocooler principle for JT, Stirling, GM and Pulse tube. Cryocooler components and their performance influence will be covered, as well as cooling power vs. interface temperatures and staging. A comparison of application fields to cryocooler cooling technologies will be illustrated with application examples from 80 K down to 1.5 K. Limitations of cryocooler applications (mechanical vibrations, temperature oscillation electromagnetic interaction and instabilities) will conclude this part. The second part will be dedicated to novel concepts of cooling links, covering free fluid circulation loops (gravity assisted), and He forced flow circuits. Components like high-effectiveness counter-flow HEXs, and circulators will be illustrated. Ways of boosting the cooling power of cryocoolers vs. physical separation to the cooling interface will be explained. An overall comparison between He refrigerators and cryocoolers will conclude this course, completed with general advice and references.

About the speaker:

Torsten Koettig is an engineer and applied physicist, specialized in low temperature research and development for more than 21 years with experience in European and American research laboratories. Stages of his professional career as research scientist/engineer were at Lawrence Berkely National Laboratory US and at ESS Sweden before joining CERN as responsible scientist for the CERN Cryolab in 2013. Novel cooling strategies for SC cavities and magnets are the focus of his work.

Speaker: Dr Torsten Koettig (CERN)

17:30 → 17:40 Break

17:40 → 18:40 High Temperature Superconductor coil testing

About the lecture:

Testing superconducting coils is always a challenge and of inestimable value to the magnet designer and manufacturer. It is also the last step in magnet production process, and the most exciting one!
In this lecture, I will provide an introduction to testing superconducting materials, focusing on various samples and HTS coils. Different types of test setups will be presented, from a simple LN2 bath to cryogen-free test stand. Topics such as instrumentation, data acquisition system and quench detection will be discussed. Finally, real-world examples of various scenarios will be presented and failure cases explained. If you want to start the adventure of testing superconducting materials this lecture is for you!

About the speaker:

Michal Duda received his PhD in solid state physics from the AGH University of Science and Technology in Krakow in 2010. Since then, he worked at DESY in Hamburg performing magnetic measurements of superconducting magnets for Europen XFEL. In 2017, he joined the CERN SM18 team testing prototypes of superconducting magnets for the HL-LHC project. Since 2020, he has been in charge of the superconducting magnets test lab at PSI.

Speaker: Dr Michal Duda (Paul Scherrer Institute)

Friday 13 June

16:30 → 17:30 Machine learning in a test bench

Speaker: Maira Khan (Fermi National Accelerator Laboratory)

17:30 → 17:40 Break

17:40 → 18:40 Magnet test: A practical example with FAIR sFRS magnet

About the lecture:

This lecture walks through the complete testing workflow for FAIR Super-FRS superconducting magnets, highlighting the reasons behind each step and the technical challenges encountered. From mechanical installation to cryogenic connection, leak detection, cooldown, high-voltage verification, and magnetic qualification, each phase serves to confirm the magnet’s readiness for accelerator integration under realistic conditions.
Particular focus is given to protection systems, quench behavior, and the importance of thermal and electrical integrity. The lecture also serves as a synthesis, reinforcing concepts covered in other talks—from cryogenics and power converters to instrumentation and quality control—by demonstrating how they come together in a real, full-scale magnet test campaign.

About the speaker:

Hugo Bajas have done is PhD with ITER and CEA on the mechanical optimization of Nb3Sn cable-in-conduit conductor for the ITER reactor based on numerical simulation. His design is now used for the ITER Central Solenoid conductor.
He then worked at CERN as fellow then staff during 11 years on HL-LHC magnet testing in the Test Facility Section, where among others, he was greatly involved in the design and commissioning of new test facilities of accelerator magnets.
He later joined the Swiss Plasma Center at EPFL and worked on fusion conductor design and testing. He was also in charge of the fiber optic sensor development for quench detection for fusion conductor.
He is now member of GSI in the SuperConducting Magnet Group where he is in charge of the FAIR SuperFRS magnets testing at the dedicated test facility based at CERN.

Speaker: Hugo Bajas (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

Saturday 14 June

16:30 → 18:40 No Lectures

Sunday 15 June

16:30 → 18:40 No Lectures

Monday 16 June

16:30 → 17:30 Superconducting cable for fusion testing

Speaker: Kamil Sedlak (EPFL Lausanne)

17:30 → 17:40 Break

17:40 → 18:40 ITER magnet testing

About the lecture:

The presentation shares experience gained from magnets testing, especially ITER, starting from the ITER EDA (Engineering Design Activities), then during construction phase of ITER to the latest tests of the CS modules that will go into ITER machine. Rational and justification for tests, things that only testing of the large magnets can reveal are discussed. Correlation between the test results of the components and predictions for performance of the assembly is important part of the analyses.
Necessary equipment in the test facilities, essential features and lessons learned are discussed. Special attention is paid to the quench detection and quench protection in the large test facilities.

About the author:

Started in the field of Applied superconductivity in 1977 as an analyst of stability, thermo-hydraulic, mechanical and magnetic and electrical field analyses, also carried out analyses of the test data from superconducting conductors and magnets. Have been working on fusion magnets since 1977 and on ITER since the beginning of the project in 1985. Among R&D, conductor development, design, fabrication, commissioning and other activities I was involved in testing of about 20 large magnets and in most campaigns as a Testing Group Chairman, but also as a test program leader, instrumentation and analyses responsible engineer and a Test Reports compiler and editor. Participated in construction and operation of two large Test facilities at LLNL and GA.

Speaker: Nicolai Martovetsky (ORNL)

ITER Magnet Testing.pdf

ITER Magnet Testing.pptx

Tuesday 17 June

16:30 → 17:30 Fusion coil testing at ASIPP

Speaker: Zichuan Guo (institute of plasma pgysics chinese academy of sciences)

17:30 → 17:40 Break

17:40 → 18:40 Fusion coil testing at MIT/CFS

Speaker: Dr Theodore Golfinopoulos (Massachusetts Institute of Technology)

Wednesday 18 June

16:30 → 17:30 ITER TF coil testing

Speaker: Christine Hoa (ITER)

17:30 → 17:40 breal

17:40 → 18:40 HTS fusion coil testing

Speaker: Erica Salazar (Commonwealth Fusion Systems Massachusetts Institute of Technology)

Thursday 19 June

16:30 → 17:30 Cryostat design

Speaker: Vittorio Parma (CERN)