Canted Cosine Theta magnets are a very promising layout for applications in small accelerator systems, for example for the gantries needed at hadron therapy facilities. A 1-meter-long, straight and combined function magnet demonstrator with 80 mm aperture diameter, 4 T central field and 5 T/m quadrupole component is under development in the framework of the European-funded project IFAST. The main purpose of this demonstrator is to develop competencies and expertise about the CCT layout and explore the possibility of implementing a combined function CCT magnet. The design has been reported elsewhere. This paper includes details about the fabrication of this demonstrator, describing the techniques and tooling used in each step: machining, winding, wax impregnation and assembly. Special attention is paid to the splices since the cable is a twisted rope of six NbTi wires around a central copper wire.

In a report published in 2021 by the Bank of America Global Research entitled "To the Moonshots: Future Tech Primer", 14 technologies for the future were listed and analyzed. One item of this list is Oceantech, including harvesting the ocean energies to also produce electricity. The report forecasted that by 2030, the ocean global economy (obviously including much more aspects than solely energy production) will be equivalent to 2010 German GDP, existing a general consensus on the tremendous impact and activity that it may generate in ocean energy generation, including that required for activities associated to the blue economy.. The ocean electric power that can be converted from an ocean planar wave is proporcional to the wave period and to the square of the wave amplitude but, to extract the maximum available power from the wave, the system must be able to be tuned which means having the availability of producing high reactive forces (proportional to its displacement or to its acceleration) which can be even higher than the required active force for producing energy. Consequently, Power Take-Offs (PTO) have always been at the focus of the research, development and innovation in the wave energy sector and they have been one of the main priorities for wave energy during the last years. As a result, the European Commission has funded several projects in recent years addressing its development and optimization under the Horizon 2020 calls, such as OPERA, WaveBoost, WETFEET, IMAGINE and SEA TITAN. MARES is a recently granted Horizon Project proposing the development of a novel concept for a PTO able to produce the required big forces very efficiently and in a compact way (high energy density) and disregarding permanent magnets-based solutions requiring enormous quantities of rare.earth materials. The use of a simple generator topology (such as a cylindrical switched reluctance machine) and novel superconductors such as HTS or MgB2, make the proposal even more attractive not only for wave energy conversion but also for other applications where very high force density are required. This paper will first introduce the MARES Project to describe next the conceptual design of the superconducting generator prototype, a machine that will include both technologies of new superconductors and that will be also fabricated and tested by the MARES consortium. The project also includes the implementation analysis of this PTO into two real cases of Wave Energy Converters

The development of Power Take-Off (PTO) systems is crucial for the progress of wave energy technologies. Among the different PTO concepts, direct-drive systems based on linear electrical generators stand out due to their simplicity, robustness, and efficiency, as they minimize energy transformations. Despite their advantages, linear electrical generators face significant challenges, particularly in terms of force density and reactive power capability. These limitations are most evident at low operational speeds, where high currents are required to generate adequate forces, leading to significant Joule losses. Furthermore, the management of reactive power for implementing advanced control strategies, such as reactive or pseudo-optimal wave energy extraction, is hindered by constant energy dissipation. This is particularly problematic at null or low velocities, where Joule losses persist regardless of speed, limiting the use of reactive power Superconducting technology has emerged as a promising solution to these challenges by significantly improving force density while reducing Joule losses. However, the cryogenic systems required for maintaining superconducting conditions impose strict constraints, as all conductor losses, including AC losses associated with oscillating currents, must be minimized. In this context, the paper describes a novel concept for a linear generator based on switched reluctance and superconducting coils, protected under a patented design. To address the issue of AC losses in superconducting cables, we introduce an innovative control strategy for the electronic converter associated with the generator. This strategy is designed to minimize current ripple in the generator phases, reducing oscillation frequencies and, consequently, AC losses. The proposed approach employs a single-pulse switching strategy, where each phase of the converter is activated and deactivated without intermediate semiconductor switching. This eliminates additional ripple in the phase currents. To regulate the force amplitude, the voltage of the DC link connected to the converter is controlled, enabling precise force modulation. The paper provides a comprehensive description of the switching strategy and evaluates its performance under oscillatory motion conditions typical of wave energy converters (WECs). A detailed comparison with conventional strategies demonstrates the proposed approach's potential to enhance generator efficiency, reduce losses, and improve overall performance. This work highlights the feasibility of integrating superconducting direct-drive PTO systems into WECs, paving the way for more efficient and reliable wave energy technologies.

Magnetic refrigeration, a well-established technique employed to attain temperatures below the Kelvin scale, is currently gaining prominence for its application at temperatures corresponding to liquid helium and liquid hydrogen. This surge in interest is attributable to the elevated Carnot efficiency associated with magnetic refrigeration in such temperature ranges. A test stand has been developed for evaluating heat transfer coefficients of magnetocaloric materials. The system involves a hermetic helium gas circuit cooled to cryogenic temperatures, flowing through a packed bed of magnetocaloric material. A three-fluid heat exchanger is used to cool down the helium gas flowing through the magnetocaloric packed bed. This paper presents the test setup, experimental performance results and the analysis of the three-fluid heat exchanger in the 4.2 K–290 K temperature range. The recorded measurements are juxtaposed against numerical predictions across various mass flow rates and fluid stream pressures. Under nominal operational conditions with helium gas, an outlet temperature of less than 6K is attained, accompanied by a combined pressure drop of merely 2.5 mbar. Furthermore, recommendations for enhancing the design are proposed based on the findings.

The development of high-temperature superconductors (HTS) has highlighted the need for advanced cryocooling technologies capable of achieving high efficiency at extremely low temperatures. Among the various cooling techniques, magnetic refrigeration has emerged as a promising method due to its potential for high Carnot efficiency at temperatures corresponding to liquid helium and liquid hydrogen. A test stand has been developed to evaluate the heat transfer dynamics and the magnetocaloric effect of packed beds of magnetocaloric materials. This article presents the results and analysis of the testing of two magnetocaloric materials, Erbium Aluminum II (ErAl2) and Gadolinium Gallium Garnet (GGG), in the range of 4.2–20 K. The recorded temperatures measurements are compared with numerical predictions for different fluid mass flow rates, temperatures, and magnetic field values. Insights gained from the testing will be used to develop a scaled magnetic refrigerator based on both materials.

The shift from fossil fuel to electric based propulsion in the waterborne transport sector has been sped up by recent policies aiming to reduce the sector emissions. This trend creates highly electrified vessels, with needs for energy storage systems (ESS) to satisfy the power demand affordably and to increase the on-board grid reliability and efficiency. Initial industry efforts have been put in the study and integration of high energy density ESS solutions, mainly electrochemical batteries. However, other innovative ESS, with different capabilities, have not been yet fully addressed. It is the case of Fast Response Energy Storage Systems (FRESS), such as Supercapacitors, Flywheels, or Superconducting Magnetic Energy Storage (SMES) devices. The EU granted project, POwer StoragE IN D OceaN (POSEIDON) will undertake the necessary activities for the marinization of the three mentioned FRESS. This study presents the design process followed in the POSEIDON project for the definition of an SMES suitable for maritime operation. First, the boundary conditions imposed by the marine environment, and the potential on-board applications of the SMES will be established. Next, the technological options: superconducting material, cooling system, coil fabrication and magnet topology which have been selected for this specific system will be presented.

The AMIT cyclotron was developed as a collaboration led by CIEMAT to produce a compact and efficient superconducting cyclotron for radioisotope production. The magnet and its closed loop cryogenic system, based on Helium cooled by means of just one remotely located cryocooler, was manufactured. During the commissioning there was an accident at the first ramp up and the magnet supporting system was damaged. The alignment system of the coils was not able to properly position the coils inside the iron yoke, so finally it was decided to dismantle the whole cryostat to check the actual state of the inner parts. This paper describes the issues found during the commissioning of the AMIT cyclotron magnet and its cryogenic system, the partial solutions implemented and the final aperture of the cryostat. The conclusions are focused on the lessons learnt for manufacturing such a compact and low thermal losses superconducting magnet for radioisotope production and the recommendations for an improved and more reliable version.

Alternative cryogenic refrigeration methods are needed to improve the low efficiency of traditional gas cycles cryocoolers. Magnetic refrigeration is an old known technique used to reach below Kelvin temperatures, though there is rising interest in using this method at liquid helium and liquid hydrogen temperatures due to its high Carnot efficiency. However, further experimentation is needed to fully understand the heat transfer dynamics of magnetocaloric materials at cryogenic temperatures. A test stand has been designed to evaluate the heat transfer coefficients of these materials using the single-blow transient test technique. The system consists of a hermetic helium gas circuit, which is cooled down to cryogenic temperatures and is forced to flow through a packed bed of magnetocaloric material. In order to test the heat transfer properties of the magnetocaloric materials at different magnetic fields the test stand has a superconducting solenoid capable of providing up to 4 T. The design and validation of the test stand for the characterization of magnetocaloric materials is described in the present paper.

The use of Canted Cosine Theta (CCT) magnets for accelerator applications has gained popularity due to their ease of manufacturing and assembly. In the context of two EU-Horizon2020-funded projects, HITRIplus and IFAST, the development of two 80 mm free bore and 4 T central field CCT dipoles for use in ion therapy (hadron therapy) is underway. In IFAST, a straight dipole CCT features a superimposed quadrupole component (combined function winding), while in HITRIplus a curved CCT (bending radius of 1.65 m) is wound as pure dipole. Both projects are based on a Cu/Nb-Ti multistrand rope as conductor. The article presents advancements in the engineering design of the magnets. A number of validation tests have been made to validate the choices made during the conceptual design. Characterization tests of the low losses rope, winding tests, splice tests, and impregnation tests will be described. The explored alternatives for the fabrication of the curved formers and the support structure are also discussed.

The electrification of transport has been no exception for waterborne vessels. The reduction of emissions, especially during port maneuvering and operation, has accelerated the transition from fossil fuel to electric propulsion. Moreover, military vessels, with specialized electric weapon systems, or civil vessels, like offshore wind tug boats, have high power systems that additionally contribute to a higher electrification of the ship grid. Energy storage systems are essential to meet the power load economically and to improve the system`s reliability and efficiency. Therefore, the use of high energy density storage systems, as chemical batteries, or hydrogen fuel cells, has experienced a significant increase in demand. However, during high frequency load fluctuations, high energy density storage systems are not capable to actuate, since the discharge rate of these systems is physically limited, which may provoke: deterioration and reduction of the lifetime of the storage systems, voltage and frequency fluctuation of the ship grid. To overcome this limitation, this paper studies the use of a Superconducting Magnetic Energy Storage (SMES) as a supporting energy storage device for the ship grid. The guidelines for dimensioning, in power and energy, the SMES are stablished. Furthermore, an optimization method is developed in order to compare different superconducting materials, and operating temperatures.

The common coil geometry provides an alternate design to the conventional cosine theta dipoles. It allows a wider range of conductor and magnet technologies. It also facilitates a low-cost, rapid-turn-around design and R&D program. Recent studies carried out as a part of the US Magnet Development Program revealed that at high fields (20 T with 15% operating margin or more), the common coil design also uses significantly less conductor (particularly much less HTS), as compared to that in the other designs.

Common Coil Dipole for High Field Magnet Design and R&D March 16, 2022 Ramesh Gupta, Kathleen Amm, Julien Avronsart, Michael Anerella, Anis Ben Yahia, John Cozzolino, Piyush Joshi, Mithlesh Kumar, Febin Kurian, Chris Runyan, William Sampson, Jesse Schmalzle, Brookhaven National Laboratory, Upton, NY 11973, USA Stephan Kahn, Ronald Scanlan, Robert Weggel, Erich Willen, Particle Beam Lasers, Inc., 8800 Melissa Court, Waxahachie, TX 75167-7279, USA Qingjin Xu, Institute of High Energy Physics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China Javier Munilla, Fernando Toral, Centro de Investigaciones Energéticas, Medioambientalesy Tecnológicas (CIEMAT), Avda. Complutense, 22, E-28040 Madrid, Spain Paolo Ferracin, Steve Gourlay, GianLuca Sabbi, Xiaorong Wang, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA Danko van der Laan, Jeremy Weiss, Advanced Conductor Technologies LLC, 2200 Central Avenue, Suite A/B, Boulder, CO 80301, USA

Normal and aberrant cognitive functions are the result of the dynamic interplay between large-scale neural circuits. Describing the nature of these interactions has been a challenging task yet important for neurodegenerative disease evolution. Graph theory has been the standard tool to provide biomarkers in imaging connectomics showing the Alzheimer’s disease (AD). We propose a novel concept - graph signal processing - to analyze the evolution of disease graphs leading from mild cognitive impairment (MCI) to AD and derive frequency-based biomarkers representative for this disease. We show that high oscillations derived from the graph Fourier decomposition can provide important discriminatory information. To quantify the qualitative intuition of high oscillations, we use two concepts from signal theory: (1) zero crossings and (2) total variations. We apply these concepts on functional and structural brain connectivity networks for control (CN), mild cognitive impairment (MCI) and Alzheimer’s disease (AD) subjects. Our results applied to functional brain networks suggest that graph signal processing can accurately describe the frequencies of brain networks, and explain how AD is associated with low frequency and localized averaging confirmed by clinical results.

Next generation ion therapy magnets both for gantry and for accelerator (synchrotron) are under investigation in a recently launched European collaboration that, in the frame of the European H2020 HITRI plus and I.FAST programmes, has obtained some funding for work packages on superconducting magnets. Design and technology of superconducting magnets will be developed for ion therapy synchrotron and -especially- gantry, taking as reference beams of 430 MeV/nucleon ions (C-ions) with 10 10 ions/pulse. The magnets are about 60–90 mm diameter, 4 to 5 T peak field with a field change of about 0.3 T/s and good field quality. The paper will illustrate the organization of the collaboration and the technical program. Various superconductor options (LTS, MgB 2 or HTS) and different magnet shapes, like classical CosTheta or innovative Canted CosTheta (CCT), with curved multifunction (dipole and quadrupole), are under evaluation, CCT being the baseline. These studies should provide design inputs for a new superconducting gantry design for existing facilities and, on a longer time scale, for a brand-new hadron therapy centre to be placed in the South East Europe (SEEIIST project).

The role of the Power Take-Off (PTO) as part of modern Wave Energy Converters is becoming more and more relevant and many efforts have been done or are ongoing to improve its performance especially in terms of force density and efficiency. Electric Linear PTOs are inherently the most efficient category, since they are really direct drives with no intermediate stages of energy conversion. Nevertheless, conventional electric machines are usually limited in force while their efficiency is better than other type of drives but still does not allow an intense energy capture in a broad band of wave periods. In this regard, superconductivity may become a very helpful alternative that allows improving both: efficiency and force density in spite of the technological difficulties that are introduced in the Wave Energy Converter. This paper, after justifying the need for better PTO performances, presents a new concept of superconducting PTO in which both, the stator and the translator work at cold temperature, performing a reciprocating displacement inside a flexible cryostat. The concept is later applied to a Cylindrical Switched Reluctance machine whose global design is also presented in the paper. This activity has been performed as one of the work packages of the EU H2020 Sea Titan Project in which also a resistive PTO with a novel configuration has been developed.

A4 Tesla superconducting magnet has been developed by CIEMAT for a compact cyclotron for radioisotope production in the framework of AMIT project (Advanced Molecular Imaging Techniques) in collaboration with other Spanish companies. First power tests were performed using liquid helium transferred from dewars. An autonomous cooling system has been developed in collaboration with CERN, where the system was characterized with a dummy load. Some improvements have been implemented to reduce the cooling time before connecting the cyclotron magnet. A new low-thermal-loss transfer line has been developed to overcome the problems detected in the first cooling tests connecting the magnet.

The second prototype of the MCBXFB nested orbit corrector for the upgrade of the LHC has been manufactured at CIEMAT and assembled at CERN, in the framework of the HL-LHC project. This paper describes the changes introduced with respect to the first prototype in order to test some design improvements intended for the series magnets. The preload of the coils has been carefully studied, aiming to improve the performance in combined operation. A power test campaign has been carried out for this second prototype at CERN. Both dipoles reached ultimate current without any quench when individually powered. However, the results in combined operation did not improve those of the first prototype. Further analysis and studies are ongoing.

The European XFEL is a hard X-ray free-electron laser (FEL) based on a high-electron-energy superconducting linear accelerator. The superconducting technology allows for the acceleration of many electron bunches within one radio-frequency pulse of the accelerating voltage and, in turn, for the generation of a large number of hard X-ray pulses. We report on the performance of the European XFEL accelerator with up to 5,000 electron bunches per second and demonstrating a full energy of 17.5 GeV. Feedback mechanisms enable stabilization of the electron beam delivery at the FEL undulator in space and time. The measured FEL gain curve at 9.3 keV is in good agreement with predictions for saturated FEL radiation. Hard X-ray lasing was achieved between 7 keV and 14 keV with pulse energies of up to 2.0 mJ. Using the high repetition rate, an FEL beam with 6 W average power was created. The first operation of the European X-ray free-electron laser facility accelerator based on superconducting technology is reported. The maximum electron energy is 17.5 GeV. A laser average power of 6 W is achieved at a photon energy of 9.3 keV.

The first prototype of the short orbit corrector for the upgrade of the LHC has been fabricated at CIEMAT, in collaboration with CERN, in the framework of the HL-LHC project. It consists of two nested dipoles, with an aperture of 150 mm and physical length of 1.5 m. A first power test was performed without the outer dipole coils, which were replaced by a support structure to align the iron yoke with the collared inner dipole. This test was aimed to validate the coil fabrication techniques, which are innovative for a NbTi Rutherford cable. In the power test of the full assembled magnet, individual training of both dipoles was fine to ultimate current. However, the magnet was not able to reach nominal torque in combined operation. Several power tests and re-assemblies were necessary to be able to power both dipoles till nominal current. This paper describes the test results and analysis of the measurements. The magnet is heavily instrumented with voltage taps, collars with strain gauges and bullet gauges at the axial pushers.

Part of the Future Circular Collider (FCC-hh) study is dedicated to the development of the 16 Tesla Nb 3 Sn superconducting dipole magnets. The design of the magnets was enabled by a cooperative effort of national research institutes, universities, and CERN. These actors tackled the problem from different sides, namely, the electromagnetic design, the mechanical design, the design of the quench protection systems, and the circuit design. The article deals with the design of the quench protection systems and provides solid motivations for the selection of the coupling-loss-induced quench (CLIQ) device as the baseline protection system for the FCC-hh main dipole magnets. The article shows that the design domains mentioned above are tightly interconnected and, therefore, the simulation of a quench event involves a complex multiphysics problem. The STEAM cosimulation framework, recently developed at CERN, is applied to address the complexity. The STEAM-SIGMA models are employed to simulate the CLIQ quench protection system applied to the FCC-hh dipole magnets. Dedicated CLIQ configurations are identified to protect the magnets in case of a quench. In addition, the possible implications of the CLIQ protection system on the mechanical design of the magnets are discussed. To this end, the article employs the co-simulation of different software platforms to calculate the mechanical stress during a quench. The results show that CLIQ does not produce additional stress.