NUMERICAL STUDY OF THE ELASTIC-PLASTIC CYCLIC DEFORMATION OF THE GLOBUS-M COMPACT TOKAMAK CENTRAL SOLENOID

The ''GLOBUS-M'' is a compact resistive tokamak with a central solenoi d (CS) wound around the inner portion of the toroidal field coils, The magnetic field at the solenoid axis amounts to 8.3 T. The CS incorpor ates two layers of conductor (CuCr copper alloy) baked into insulation , The solenoid is designed to sustain 80 000 energizing. During each l oading cycle the solenoid is subjected to the radial forces accompanie d with the vertical compression. The most loaded region has been consi dered and modeled with the use of 2D axisymmetric finite element (FE) model. The model includes two conductor turns baked into insulation co mpound, copper cooling tubes and solder, The stress analysis shows tha t there is some plastic deformation in the topper tube and solder duri ng loading and there is some hath plastic deformation in the solder du ring unloading. The reloading does not cause any change in the solenoi d stress-strain state in comparison with the ease of lending. Tie numb er of cycles to failure has been simulated for all metallic components of the solenoid.