Thermal analysis of the TPX TF coil case for eddy-current and neutron heating

A finite element, thermal analysis of the Tokamak Physics eXperiment´s (TPX) toroidal field (TF) coil case is presented. The analysis models the 316LN coil case as a 3-D shell with imposed thermal loads dominated by neutron and eddy current heating. Heat sinks which simulate the flow of supercritical helium in the coil case cooling system and adjacent conductor conduits are used to extract the steady-state heat load. The model is used to estimate the heat leak rate into the winding pack as input for heat removal and conductor temperature margin calculations. The proposed cooling scheme flows 5 K helium at 5 atmospheres to the TF coil winding packs. The effluent is directed into the case cooling channels. Results indicate that the case cooling system and ground wrap insulation are effective means of thermally isolating the superconductor from the heat deposited in the coil case; 92% of the 8.07 kW deposited in the cell cases by eddy currents and neutrons are extracted by the helium flowing in the case cooling channels while only 0.65 kW are transmitted into the adjacent conductors of the winding packs.<>