Development and mechanical investigation of central solenoid structure for COMPASS-U tokamak

COMPASS-U will be the successor of the existing COMPASS tokamak which is the main experimental facility of the Tokamak Department at the Institute of Plasma Physics of the Czech Academy of Sciences. COMPASS-U tokamak will be a flexible high magnetic field device with an advantage for scaling towards ITER (International Thermonuclear Experimental Reactor) and DEMO (DEMOnstration Power Station). The ITER and DEMO are foreseen to produce more energy than needed to power them. Based on the results obtained from the COMPASS-U it will be possible to learn more about the tokamak device, which will give more knowledge to construct larger of this type devices in the future. COMPASS-U requires new design of the whole structure of the device. One of the most challenging issues is the design of the Central Solenoid (CS) coils and its support structure. This task requires evaluation of many different case studies which include inter alia geometrical, technological and material properties verifications. In this contribution we present development and mechanical investigation of the CS structure. Based on a previous work, which showed the need of further optimization of the CS structure, additional development was done. In this work preload structure was added to the whole system. This allows to include preload as an additional load step. Preload was added to include compression of the CS coils in axial direction. The influence of the impregnation conditions on the CS behavior was checked. Several ways of impregnation application were studied and their influence on the CS structure was examined. Mechanical analysis using Finite Element Method (FEM) includes 2D axisymmetric model of the CS structure. Results for CS structure are presented for one particular loading scenario which is the premagnetization of the coils without plasma.