First Wall and Vacuum Vessel Analysis for Compact Ignition Tokamaks

This paper describes the ongoing analysis efforts supporting the design of the first wall (FW) and vacuum vessel (VV) components for the Compact Ignition Tokamak (CIT). Thermal and stress analyses of FW graphite tiles have established a nominal tile thickness of 1.0 cm and a maximum allowable FW surface heat flux of 11.0 MW/m². Calculations have shown that for a cooldown time of one hour, the required tile to W thermal conductance is > 0.1 W/K. Estimates of worst-case electromagnetic loads and resulting stresses on the VV during plasma disruptions have shown the maximum stress levels to be below the allowable limits for the VV material. These results have demonstrated that the selected FW/VV concept is consistent with the design objectives.