Helium flow and temperature distribution in the CS1 module of the DEMO CS coil

Two alternative designs of the CS1 module for the DEMO Central Solenoid (CS) coil have recently been proposed by EPFL-SPC PSI Villigen and CEA Cadarache. According to the SPC design the CS1 module consists of 10 sub-coils, each of which includes 2 layers wound using the same kind of conductor. The two innermost sub-coils utilize Re-123 High Tc Superconductor (HTS), the next five sub-coils are made of R&W Nb3Sn conductors, and the three most outer sub-coils use NbTi. In the present work we study thermal-hydraulic phenomena which may occur in the CS1 coil (SPC design) at the normal operating conditions. Time evolution of the mass flow rate, temperature, pressure and Tcs profiles in each conductor during the whole current cycle are simulated using the THEA code from Cryosoft. We take into account time evolution of the magnetic field and AC losses heat load profiles in each conductor.