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.

SPIRAL 2¹ is a rare isotope accelerator dedicated to the production of high intensity beams (E = 40 MeV, I = 5 mA). The driver is a linear accelerator (LINAC) that uses bulk Niobium made quarter wave RF cavities. 19 cryomodules inclose one or two cavities respectively for the low and the high energy sections. To supply the 1300 W at 4.2 K required to cool down the LINAC, a cryogenic system has been set up. The heart of the latter is a 3 turbines geared HELIAL®LF (ALAT²) cold box that delivers both the liquid helium for the cavities and the 60 K Helium gaz for the thermal screens. 19 valve-boxes insure cryogenic fluid distribution and management. Key issues like cool down speed or cavity RF frequency stability are closely linked to the cryogenic system management. To overcome these issues, modelling and simulation efforts are being undertaken prior to the first cool down trials. In this paper, we present a status update of the Spiral 2 cryogenic system and the cool down strategy considered for its commissioning.

From simple physical systems to full production lines, numerical models could be used to minimize downtime and to optimize performances. In this article, the system of interest is the SPIRAL2 heavy ion accelerator cryogenic system. This article illustrates three different applications based on a SPIRAL2 cryostat model: optimal controller synthesis, virtual sensor synthesis, and anomaly detection. The two first applications have been deployed on the system. Experimental results are used to illustrate the benefits of such applications. The third application is a case study based on data generated from a thermodynamic twin model.