Superconducting machines are promising candidates for direct-drive multimegawatt offshore wind turbines. Here, we designed a 20-MW fully superconducting synchronous wind turbine generator using magnesium diboride (MgB ₂ ) superconductors for both rotor and stator windings. MgB ² tapes operating at 10 K are used for the rotor windings in order to improve the packing factor. A Rutherford cable made of 91-filament MgB ₂ wires operating at 20 K is used for the stator windings in order to limit the ac losses. Two separate cryostats are considered for the stator and the rotor to increase the system reliability. Besides, to reduce the machine's weight and to simplify the cryogenic system, a toothless magnetic circuit is adopted. The goal of the two-dimensional finite element method based optimization was to minimize the levelized cost of energy (LCOE). Numerical results show that the adopted topology is lightweight enabling to reduce the cost of the nacelle, tower, and foundation, and therefore, the LCOE in comparison to a conventional generator. But the ac losses are significant, requiring at this stage of the study an impractical number of cryocoolers.

The Iseult project is a French-German initiative focused on very high magnetic-field molecular imaging. The project includes a Whole Body 11.7 T MRI magnet installed at Neurospin, a neuroscience research center operating at CEA Saclay since November 2006. After 7 years of fabrication at Belfort by GE Power (Ex Alstom), the Iseult magnet was delivered to CEA in June 2017, its connection with the cryoplant and all the ancillary equipment was completed in October 2018. After 4 months of cooldown and another 4 months of tests, the Iseult magnet reached its nominal field of 11.72T without any quench for the first time, on July 18th. This paper deals with the magnet connection at Neurospin with the cryoplant and with the electrical and control systems. Finally, the paper will present the magnet commissioning data, from the cooling phase to the step-by-step energization up to the nominal current.

The Grenoble Hybrid magnet is a modular platform using resistive and superconducting technologies to produce various DC high magnetic field and flux configurations for the scientific community. They range from 43 T in 34 mm diameter with 24 MW electrical power to 9 T in 800 mm diameter when the superconducting coil is used alone. Thanks to the ongoing upgrade of the electrical power installation at LNCMI-Grenoble to 30 MW, and possibly to 36 MW, the opportunity to increase the total field well above 45 T in the near future is anticipated and studied in detail. The key design parameters will be recalled comprising the specifically developed Nb-Ti/Cu conductor, the large-bore outsert superconducting coil, the magnet cryostat with its structure including the eddy-current shield, the cryogenic line for the interconnection with the cryogenic satellite and the dedicated 150 l/h He liquefaction plant. All components of the superconducting part of the hybrid magnet platform have been built, tested and delivered to LNCMI-Grenoble, where integration and final assembly are continuing. The status of the project will be presented with the main problems encountered and solved. It includes the recent commissioning tests of the cryogenic satellite producing the pressurized superfluid He at 1.8 K as well as the successful powering tests of the specially developed current leads at ultimate current and under fully degraded cooling conditions simulating the worst-case accidental scenario.

One of the frontier of particle physics beyond the Standard Model is the research of axion-like particles, to explain the absence of CP violation in the strong interaction and to provide dark matter candidates. In the MADMAX (MAgnetized Disk and Mirror AXion) experiment, the principle of axions detection relies on the predicted emission of an electric field, picked up using dielectric disks. The electric field intensity is proportional to the square of the local magnetic field, thus the MADMAX experiment would be set up in a 9 T NbTi dipole magnet, 6.9 m in length with a bore diameter of 1.35 m. The dipole produces a Figure of Merit over the surface of the disks of 100 T $^2$ m $^2$ along 2 meters, enough to detect axions with masses in the range of 100 μeV. This paper reports the 2D and 3D conceptual magnetic design of the MADMAX dipole. Starting from the experimental principles, it introduces the design parameters, constraints, and the methodology employed, aiming at minimizing the magnet cost minimizing the cost of the conductor. Then, the 2D and 3D designs are described, focusing in particular on the cross-section resulting from the 2D optimization and the heads optimization in 3D with and without iron, made by coupling a dedicated analytical approach to genetic algorithms.

In the framework of the project on development of an integrated system for the production of PET tracers based on a dry NbTi supraconducting cyclotron called Lotus, the CEA and SigmaPhi examine the possibility of replacing the NbTi by MgB ₂ . The aim of this work is to develop design tools and technologies for dry MgB ₂ magnet winding by the react-and-wind process. To validate this work, two dry prototype magnets have been developed: a solenoid of 1 T and a double pancake. To test these prototypes in conditions close to the Lotus cyclotron, a dry test facility, previously developed, will be used up to 3 T. This paper presents the double pancake design, fabrication, instrumentation, and the first test. The critical current and the n-value of the double pancake have been measured and compared with the sample measurement.

In the framework of the NEWGAIN project, which aims to build a second injector with a mass to charge-state ratio A/q=7 for the SPIRAL2 linear accelerator at GANIL, CEA is developing in collaboration with LPSC and GANIL a new superconducting 28 GHz ECR Ion Source Magnet named ASTERICS. The magnetic design is based on an advanced concept of the VENUS ECR ion source operating at Berkeley and the FRIB source under commisionning at MSU. The ion source superconducting magnet consists of a sextupole inside three solenoids to confine the plasma and a shell-based support structure to apply a preload to the sextupole coils. The confinement coils will be made in Nb-Ti and will be operated at 4.2 K. The cryogenic environment will be ensured by liquid helium thermosiphon closed loop thanks to six in-situ cryocoolers. Specific HTS current leads are being designed to power the magnet. A cold integrated He buffer will also allow He almost-lossless quenches. The preliminary design choices of the ASTERICS superconducting magnet are presented here from the magnetic, mechanical and protection design to the cryogenic definition emphasizing the global approach used to obtain the final magnet configuration.