CEA Broad Studies on EU DEMO CS and PF Magnet Systems

In the framework of EU design activities for dimensioning the future fusion DEMOnstration reactor (DEMO), extensive analyses were conducted in EUROfusion context, aiming at ultimately defining the design of the DEMO magnet system. In this objective CEA proposes designs for all cryomagnetic systems: Toroidal Field (TF) coils, Central Solenoid (CS) and Poloidal Field (PF) coils. In the previous DEMO reactor baselines, designs for CS and PF systems were investigated with pre-dimensioning macroscopic CEA tools, resulting in possible design options. Broad parametric investigations, conducted on the CS and PF systems will be presented. With considerations of constraints imposed by the new DEMO 2018 baseline important inputs (scenario current settings, flux at plasma center...) the PF and CS design features will be quantified, with considerations on design strategy. On PF system a parametric exploration will be led impacting on PFs aspect ratio and a tentative design proposal will be issued. On CS system conductor current range choice is investigated, (DEMO 2018 CS design proposal will be issued under those guidelines) and parametric studies on breakdown regime will be conducted on two CS designs. The outcomes of both exhaustive explorations will be exposed and discussion will be led with tentative recommendations.