Mechanical analysis of the European DEMO central solenoid pre-load structure and coils

The pre-conceptual design of the European DEMO fusion tokamak is currently being developed under the coordination of the EUROfusion Consortium. This paper reports the mechanical analysis of the Central Solenoid (CS), which comes right after the phase of definition of the winding pack proposed by the CEA. The first step consists in a draft-sizing of the tie-plates pre-compression structure. Then a global Finite element Analysis (FEA) of the CS, considering a sector-symmetry model and smeared winding pack properties is built-up in order to check this pre-load structure, and to identify the most critical loading scenario for the conductor. Finally, an axisymmetric local FEA of the CS winding pack is performed in order to study in detail the stress level in the conductor jacket and in the insulations layers. This pre-conceptual analysis procedure allowed to assess the acceptability of stress for the CEA winding pack proposal, and will be operated during the future magnetic system design iterations.