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The rising industrial demand for a high-quality power supply has resulted in a growing interest in superconducting magnetic energy storage (SMES). These devices have a storage capacity ranging from fractions of MWs up to about 1 MWh. The commercialized units are based on NbTi technology at liquid helium temperature. The development of mechanical cooling systems has been very active during the recent years. The cooling capacities of cryocoolers are well around 10 W at 10 K. Based on this fact, a conduction-cooled Nb3Sn SMES concept has been built and tested (uninterrupted power supply) application. The cryogenic interface of the coil also provides the protection scheme of the magnet which helps speed up the current decay during normality and thus diminishes the hot spot temperature in the winding. The test results are presented and discussed together with problems related to the cryointegration of the magnet. The magnet system has been demonstrated to compensate a short term loss of power.

Several parametric effects on the magnetic collection have been evaluated considering dimension, strength of external magnetic field, injected velocity and particle concentration in the working fluid. Besides, accidental environments, expected in the containment of nuclear power plants, have also been addressed for the capture efficiency. The capture efficiency is especially enhanced with magnetic particle size and magnetic field strength through increased magnetic force; the non-magnetic coating thickness and fluid velocity hinder the magnetic collection. Based on the assessment, the magnetic withdrawal system can effectively capture magnetic particles even under accidental environments. Withdrawal of multifunctional magnetic particles or filtering of magnetic impurities can be effectively realized through the system.

This paper deals with the development of a magnetic lead screw (MLS) for wave energy conversion. Initially, a brief state-of-the-art regarding linear PM generators and magnetic lead screws is given, leading to an introduction of the magnetic lead screw and a presentation of the results from a finite element analysis used to find the magnetic forces. Furthermore, the force per magnet surface area measure is presented as a better alternative to the force density measure, which is often used for linear magnetic devices. Based on this, the overall design of a 500 kN MLS is presented focusing on the bearing supports used to compensate for the magnetic attraction forces and the resulting deflection of the rotor. Also, in order to avoid some of the production related disadvantages of using surface mounted magnets, an embedded magnet topology is proposed. To demonstrate the technology a scaled 17 kN MLS is presented together with experimental results.

Inductance and energy of superconducting coils are calculated by (1) a long-solenoid approximation, (2) a finite-element model, and (3) working formulas and tables. The results of the finite-element model compare favorably with those of the working formulas. The long-solenoid approximation overpredicts the energy and inductance compared to the other two methods. The difference decreases with increasing length-to-diameter ratio. Energy stored in a coil with a ferromagnetic insert is calculated by using a long-solenoid approximation and a finite-element model. The analysis shows that the gain in energy ratio is equal to the relative permeability of the insert (which decreases with increasing current or current density). Even though large gains can be achieved at relatively low currents, the energy level itself is too low. The stored energy increases with current, but the gain decreases with increasing current because relative permeability decreases. If a coil with a diameter of 0.3 m and a length of 0.3 m is required to store 10 kJ of energy, the current density must equal 4000 A/cm2. The gain in energy ratio is equal to 2.55 when the insert is used.

This paper presents the design, fabrication and experimental power analysis of a novel double-stator magnetic geared permanent magnet (DSMGPM) machine which comprises of a double-stator permanent-magnet (PM) machine integrated a with triple rotor magnetic gear. The proposed machine can upscale the low-speed rotating magnetic field of the prime PMs on the prime rotor by using the modulation effect produced from the pole-pieces to high-speed rotating magnetic field from the field PMs. The low-speed prime rotor can also increase the speed of the field PM rotor and excite the coil windings to induce an electromotive force (EMF) resulting in electrical power. Thus, the machine is proposed for power generation in low-speed renewable energy applications such as wind turbines and tidal power generators. The proposed machine topology is presented and discussed while the performance power characteristics are evaluated experimentally. A prototype is fabricated and the measured results are in good agreement with the calculated results, therefore validating the proposed magnetic geared machine design.

The relationship between magnetism and catalysis has been an important topic since the mid-20th century. At present time, the scientific community is well aware that a full comprehension of this relationship is required to face modern challenges, such as the need for clean energy technology. The successful use of (para-)magnetic materials has already been corroborated in catalytic processes, such as hydrogenation, Fenton reaction and ammonia synthesis. These catalysts typically contain transition metals from the first to the third row and are affected by the presence of an external magnetic field. Nowadays, it appears that the most promising approach to reach the goal of a more sustainable future is via ferromagnetic conducting catalysts containing open-shell metals (i.e., Fe, Co and Ni) with extra stabilization coming from the presence of an external magnetic field. However, understanding how intrinsic and extrinsic magnetic features are related to catalysis is still a complex task, especially when catalytic performances are improved by these magnetic phenomena. In the present review, we introduce the relationship between magnetism and catalysis and outline its importance in the production of clean energy, by describing the representative case of 3d metal Pt-based alloys, which are extensively investigated and exploited in PEM fuel cells.

In early 2014 a design study started at CERN for a Future Circular Collider. A new tunnel with a circumference of about 100 km for the collider magnets is foreseen as well as new general-purpose particle detectors to probe electron-positron (e-e+), electron-hadron (eh), and hadron-hadron (hh) collisions, housed in large underground caverns. In the last four years baseline designs for the various detector magnets were developed. For the FCC-ee detector two magnet variants were defined: a 7.6-m bore and 7.9-m-long classical 2 T solenoid with 600 MJ stored energy, surrounding the calorimeters, and also a very challenging 4-m bore, 6-m-long, some 100-mm-thick ultrathin and radiation transparent 2 T solenoid with a stored energy of some 170 MJ, that surrounds only the inner tracker of the detectors. For the FCC-eh detector, the detector solenoid is combined with forward and backward dipole magnets required to guide the electron beam in and out of the collision point. This detector requires a 3.5 T solenoid, 2.6-m free bore and 9.2-m length with about 230 MJ of stored energy. Most demanding is the FCC-hh detector with a 14 GJ stored energy magnet system comprising three series connected solenoids, requiring 4 T in the main solenoid with 10-m free bore and a length of 20 m, in line with two 3.2 T forward solenoids with 5.1-m free bore and 4-m length. A quite challenging series of detector magnets is proposed, that needs to be further engineered in the coming years. The superconductor technology though is essentially the same in all the solenoids proposed: conductors comprising Rutherford type cables made of NbTi/Cu strands, stabilized by nickel doped pure aluminum and structurally reinforced with a high yield strength aluminum alloy. The cold masses are conduction cooled through helium cooling pipes welded to their outer support cylinder. The designs of the various baseline magnets as well as their engineering are presented.

Amorphous metal (AM), specifically amorphous ferromagnetic metal, is considered as a satisfactory magnetic material for exploring electromagnetic devices with high-efficiency and high-power density, such as electrical machines and transformers, benefits from its various advantages, such as reasonably low power loss and very high permeability in medium to high frequency. However, the characteristics of these materials have not been investigated comprehensively, which limits its application prospects to good-performance electrical machines that have the magnetic flux density with generally rotational and non-sinusoidal features. The appropriate characterization of AMs under different magnetizations is among the fundamentals for utilizing these materials in electrical machines. This paper aims to extensively overview AM property measurement techniques in the presence of various magnetization patterns, particularly rotational magnetizations, and AM property modeling methods for advanced electrical machine design and analysis. Possible future research tasks are also discussed for further improving AM applications.